betadex and Hemolysis

Polymer-based nanomaterials have exhibited promising alternative avenues to combat the globe challenge of multidrug-resistant bacterial infection. However, most of the reported polymeric nanomaterials have facially linear amphiphilic structures with positive net charges, which may lead to nonspecific binding, high hemolysis, and uncontrollable self-organization, limiting their practical applications. In this contribution, we report a one-dimensional glyconanorod (GNR) through self-assembly of well-defined β-cyclodextrin-based glycoconjugates (RMan) featuring hydrophobic carbon-based chains and amide rhodamines with an adenosine triphosphate (ATP)-recognition site and targeted and hydrophilic mannoses and positively net-charged ethylene amine groups. The GNRs show superior targeting sensing and killing for Gram-negative

Topics: Anti-Bacterial Agents; Bacteria; beta-Cyclodextrins; Escherichia coli; Glycoconjugates; Hemolysis; Humans

In this study, we report that host defense protein-derived ten amino acid long disulfide-linked peptides self-assemble in the form of β-sheets and β-turns, and exhibit concentration-dependent self-assembly in the form of nanospheres, termed as disulfide linked nanospheres (DSNs). As expected, bare DSNs are prone to aggregation in ionic solutions and in the presence of serum proteins. To yield physiologically stable self-assembled peptide-based materials, DSNs are stabilized in the form of supramolecular assemblies using β-cyclodextrins (β-CD) and fucoidan, as delivery carriers. The inclusion complexes of DSNs with β-CD (β-CD-DSN) and electrostatic complexation of fucoidan with DSNs (FC-DSN) stabilizes the secondary structure of DSNs. Comparison of β-CD-DSNs with FC-DSNs reveals that inclusion complexes of DSNs formed in the presence of β-CD are highly stable under physiological conditions, show high cellular uptake, exhibit bacterial flocculation, and enhance antibacterial efficacies of DSNs in a range of Gram-positive and Gram-negative bacteria.

Topics: Animals; Anti-Bacterial Agents; beta-Cyclodextrins; Caco-2 Cells; Chickens; Disulfides; Escherichia coli; Hemolysis; Humans; Microbial Sensitivity Tests; Nanospheres; Particle Size; Peptides; Salmonella enterica; Staphylococcus aureus; Surface Properties

Osteoporosis is a skeletal disorder characterized by a low bone mass and density. Alendronate (Alen), a second-generation bisphosphonate drug, was indicated as the first-line regimen for the treatment of osteoporosis. However, the use of Alen has been limited due to its low bioavailability and gastrointestinal side effects. Herein, Alen-decorated nanoparticles were prepared through ionic cross-linking between poly (lactic-co-glycolic acid), β-cyclodextrin-modified chitosan (PLGA-CS-CD), and Alen-modified alginate (ALG-Alen) for Alen loading and bone-targeted delivery. Alen was selected as a therapeutic drug and a bone-targeting ligand. The nanoparticles have negatively charged surfaces, and sustained release of Alen from the nanoparticles can be observed. Cytotoxicity detected using cell counting kit-8 (CCK-8) assay and lactate dehydrogenase release test on MC3T3 cells showed that the nanoparticles had good cytocompatibility. A hemolysis test showed that the hemolysis ratios of nanoparticles were <5%, indicating that the nanoparticles had no significant hemolysis effect. Moreover, the Alen-decorated nanoparticles exhibited enhanced binding affinity to the hydroxyapatite (HAp) disks compared with that of nanoparticles without Alen modification. Thus, the Alen-decorated nanoparticles might be developed as promising bone-targeted carriers for the treatment of osteoporosis.

Topics: Alendronate; Alginates; Animals; beta-Cyclodextrins; Bone and Bones; Bone Density Conservation Agents; Cell Line; Cell Survival; Delayed-Action Preparations; Drug Carriers; Drug Liberation; Durapatite; Erythrocytes; Goats; Hemolysis; Mice; Nanoparticles; Osteoporosis; Polylactic Acid-Polyglycolic Acid Copolymer

With the use of engineered nano-materials (ENM) becoming more prevalent, it is essential to determine potential human health impacts. Specifically, the effects on biological lipid membranes will be important for determining molecular events that may contribute to both toxicity and suitable biomedical applications. To better understand the mechanisms of ENM-induced hemolysis and membrane permeability, fluorescence lifetime imaging microscopy (FLIM) was performed on human red blood cells (RBC) exposed to titanium dioxide ENM, zinc oxide ENM, or micron-sized crystalline silica. In the FLIM images, changes in the intensity-weighted fluorescence lifetime of the lipophilic fluorescence probe Di-4-ANEPPDHQ were used to identify localized changes to membrane. Time-resolved fluorescence anisotropy and FLIM of RBC treated with methyl-

Topics: beta-Cyclodextrins; Erythrocyte Membrane; Fluorescence Polarization; Fluorescent Dyes; Hemolysis; Humans; Microscopy, Fluorescence; Nanostructures; Particle Size; Pyridinium Compounds; Silicon Dioxide; Titanium; Zinc Oxide

Cholesterol suppresses the hemolysis and the detachment of cytoskeletal proteins from bilayer in the human erythrocyte membrane under stress conditions. However, there is little information on how cholesterol functions. So, examining the role of a short side chain of cholesterol, we used the plant sterols such as β-sitosterol and stigmasterol. Incorporation of sterols into the membrane using a sterol/methyl-β-cyclodextrin complex was confirmed by the mass spectrometry. Hemolysis of human erythrocytes under high hydrostatic pressure (200 MPa) or hypotonic conditions was suppressed by cholesterol, but not by β-sitosterol and stigmasterol. Moreover, the bilayer-cytoskeleton interaction was also strengthened by cholesterol, but not by β-sitosterol and stigmasterol. Taken together, we suggest that the short side chain of cholesterol plays an important role in the membrane stability of human erythrocytes.

Topics: beta-Cyclodextrins; Cell Membrane; Cells, Cultured; Cholesterol; Cytoskeletal Proteins; Cytoskeleton; Erythrocytes; Hemolysis; Humans; Sitosterols; Stigmasterol

Fabrication of a smart drug delivery system that could dramatically increase the efficiency of chemotherapeutic drugs and reduce the side effects is still a challenge for pharmaceutical researchers. By the emergence of nanotechnology, a huge window was opened towards this goal, and a wide type of nanocarriers were introduced for delivering the chemotherapeutic to the cancer cells, among them are cyclodextrins with the ability to host different types of hydrophobic bioactive molecules through inclusion complexation process.. The aim of this study is to design and fabricate a pH-responsive theranostic nanocapsule based on cyclodextrin supramolecular nano-structure.. This nanostructure contains iron oxide nanoparticles in the core surrounded with three polymeric layers including polymeric β-cyclodextrin, polyacrylic acid conjugated to sulfadiazine, and polyethylenimine functionalized with β-cyclodextrin. Sulfadiazine is a pH-responsive hydrophobic component capable of making inclusion complex with β-cyclodextrin available in the first and third layers. Doxorubicin, as an anti-cancer drug model, was chosen and the drug loading and release pattern were determined at normal and acidic pH. Moreover, the biocompatibility of the nanocapsule (with/without drug component) was examined using different techniques such as MTT assay, complement activation, coagulation assay, and hemolysis.. The results revealed the successful preparation of a spherical nanocapsule with mean size 43±1.5 nm and negatively charge of -43 mV that show 160% loading efficacy. Moreover, the nanocapsule has an on/off switching release pattern in response to pH that leads to drug released in low acidic pH. The results of the biocompatibility tests indicated that this nano drug delivery system had no effect on blood and immune components while it could affect cancer cells even at very low concentrations (0.3 μg mL. The obtained results suggest that this is a "switchable" theranostic nanocapsule with potential application as an ideal delivery system for simultaneous cancer diagnosis and therapy.

Topics: Animals; beta-Cyclodextrins; Doxorubicin; Drug Delivery Systems; Drug Liberation; Ferric Compounds; Hemolysis; Humans; Hydrogen-Ion Concentration; MCF-7 Cells; Mice; Nanocapsules; Partial Thromboplastin Time; Polyethyleneimine; Prothrombin Time; Static Electricity; Sulfhydryl Compounds; Theranostic Nanomedicine; X-Ray Diffraction

Cancer is one of the major world public health problems and the currently available treatments are nonspecific and ineffective. This reality highlights the importance of developing novel therapeutic approaches. In this field, multifunctional nanomedicines have the potential to revolutionize the currently available treatments. These unique nanodevices can simultaneously act as therapeutic and imaging agents allowing the real-time monitoring of the nanoparticles biodistribution and the treatment outcome. Among the different nanoparticles, the gold-core silica shell (AuMSS) nanoparticles advantageous physicochemical and biological properties make them promising nanoplatforms for cancer therapy. Nevertheless, their successful application as an effective cancer nanomedicine is limited by the unfavorable pharmacokinetics and uncontrolled release of the therapeutic payloads. Herein, a new polymeric coating for AuMSS nanospheres was developed by combining different ratios (25/75, 50/50 and 75/25) of two materials, Poly-2-ethyl-2-oxazoline (PEOZ) and β-cyclodextrin (β-CD). The surface functionalization of AuMSS nanospheres led to a size increase and to the neutralization of the surface charge. On the other side, the nanoparticles biological performance was improved. The coated AuMSS nanospheres showed an increased cytocompatibility and internalization rate by the HeLa cancer cells. Overall, the obtained data confirm the successful modification of the AuMSS nanospheres with PEOZ and β-CD as well as their promising properties for being applied in cancer therapy.

Topics: Animals; beta-Cyclodextrins; Cell Movement; Fibroblasts; Gold; HeLa Cells; Hemolysis; Humans; Mice; Nanoparticles; Nanospheres; Neoplasms; Polyamines; Silicon Dioxide

A novel glutathione-responsive (GSH-responsive) star-like amphiphilic polymer (C

Topics: Animals; Antineoplastic Agents; beta-Cyclodextrins; Cell Death; Cell Line, Tumor; Cell Survival; Doxorubicin; Drug Carriers; Drug Delivery Systems; Drug Liberation; Goats; HEK293 Cells; Hemolysis; Humans; Mice, Nude; Nanoparticles; Polyethylene Glycols; Spectroscopy, Fourier Transform Infrared; Tissue Distribution

Indoxyl sulfate (IS) is a uremic toxin related to the progression of chronic kidney diseases. Removal of IS from the plasma would reduce the risk of cardiovascular disease. In this study, crosslinked poly-β-cyclodextrins (PCDs) were used as a water-soluble adsorbent agent for IS in dialysis for the first time. The molecular weight of PCDs was found to be proportional to the crosslinking time between β-cyclodextrin monomers and epichlorohydrin, yet the proportion of β-cyclodextrin that reacted with epichlorohydrin decreased. It was observed that PCD after 2 h crosslinking yielded the best IS-binding capability in PBS, while reaching the binding equilibrium within 30 min and yielding a maximum binding capability of 45 mg g

Topics: beta-Cyclodextrins; Cross-Linking Reagents; Erythrocytes; Hemolysis; Humans; Indican; Renal Dialysis; Solubility; Temperature; Water

Cooperation between researchers in the areas of medical, pharmaceutical and materials science has facilitated the development of pharmaceutical dosage forms that elicit therapeutic effects and protective action with a single product. In addition to optimizing pharmacologic action, such dosage forms provide greater patient comfort and increase success and treatment compliance. In the present work, we prepared semipermeable bioactive electrospun fibers for use as wound dressings containing silver sulfadiazine complexed with β-cyclodextrin in a poly(Ɛ-caprolactone) nanofiber matrix aiming to reduce the direct contact between silver and skin and to modulate the drug release. Wound dressings were prepared by electrospinning, and were subjected to ATR-FT-IR and TG/DTG assays to evaluate drug stability. The hydrophilicity of the fibrous nanostructure in water and PBS buffer was studied by goniometry. Electrospun fibers permeability and swelling capacity were assessed, and a dissolution test was performed. In vitro biological tests were realized to investigate the biological compatibility and antimicrobial activity. We obtained flexible matrices that were each approximately 1.0 g in weight. The electrospun fibers were shown to be semipermeable, with water vapor transmission and swelling indexes compatible with the proposed objective. The hydrophilicity was moderate. Matrices containing pure drug modulated drug release adequately during 24 h but presented a high hemolytic index. Complexation promoted a decrease in the hemolytic index and in the drug release but did not negatively impact antimicrobial activity. The drug was released predominantly by diffusion. These results indicate that electrospun PCL matrices containing β-cyclodextrin/silver sulfadiazine inclusion complexes are a promising pharmaceutical dosage form for wound healing.

Topics: Bandages; beta-Cyclodextrins; Blood Cells; Chemical Phenomena; Dosage Forms; Drug Carriers; Drug Liberation; Drug Stability; Electroplating; Hemolysis; Humans; Materials Testing; Microbial Sensitivity Tests; Nanofibers; Polyesters; Silver Sulfadiazine; Thermogravimetry; Wound Healing

OSW-1 is a structurally unique steroidal saponin isolated from the bulbs of Ornithogalum saundersiae, and has exhibited highly potent and selective cytotoxicity in tumor cell lines. This study aimed to investigate the molecular mechanism for the membrane-permeabilizing activity of OSW-1 in comparison with those of other saponins by using various spectroscopic approaches. The membrane effects and hemolytic activity of OSW-1 were markedly enhanced in the presence of membrane cholesterol. Binding affinity measurements using fluorescent cholestatrienol and solid-state NMR spectroscopy of a 3-d-cholesterol probe suggested that OSW-1 interacts with membrane cholesterol without forming large aggregates while 3-O-glycosyl saponin, digitonin, forms cholesterol-containing aggregates. The results suggest that OSW-1/cholesterol interaction is likely to cause membrane permeabilization and pore formation without destroying the whole membrane integrity, which could partly be responsible for its highly potent cell toxicity.

Topics: Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Biological Transport; Cholestenones; Cholesterol; Digitonin; Dimyristoylphosphatidylcholine; Erythrocyte Membrane; Fluoresceins; Glycyrrhizic Acid; Hemolysis; Humans; Membrane Lipids; Oleanolic Acid; Ornithogalum; Phosphatidylcholines; Saponins; Unilamellar Liposomes

The development of biocompatible vector for hydrophobic drug delivery remains a longstanding issue in cancer therapy. We design and synthesis a drug delivery system based on HPG modified β-CD (β-CD-HPG) by conjugating HPG branches onto β-CD core and its structure was confirmed by NMR, FTIR, GPC and solubility. In vitro biocompatibility tests showed that HPG modification significantly improved red blood cells morphology alteration and hemolysis cause by β-CD and β-CD-HPG displayed cell safety apparently in a wide range of 0.01-1mg/mL. An anti-cancer drug, docetaxel, was effectively encapsulated into β-CD-HPG which was confirmed by DSC analysis. This copolymer could form nanoparticles with small size (<200nm) and exhibited better DTX loading capacity and controlled release kinetics without initial burst release behavior compared with β-CD. Furthermore, antitumor assay in vitro show that β-CD-HPG/DTX effectively inhibited proliferation of human breast adenocarcinoma cells. Therefore, β-CD-HPG/DTX exhibit great potential for cancer chemotherapy.

Topics: Adenocarcinoma; beta-Cyclodextrins; Breast Neoplasms; Cell Line; Delayed-Action Preparations; Docetaxel; Drug Screening Assays, Antitumor; Erythrocytes; Female; Glycerol; Hemolysis; Humans; Polymers; Taxoids

A novel drug carrier based on hydroxypropyl-β-cyclodextrin (HP-β-CD) modified carboxylated graphene oxide (GO-COOH) was designed to incorporate anti-cancer drug paclitaxel (PTX). The formulated nanomedicines were characterized by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Results showed that PTX can be incorporated into GO-COO-HP-β-CD nanospheres successfully, with an average diameter of about 100 nm. The solubility and stability of PTX-loaded GO-COO-HP-β-CD nanospheres in aqueous media were greatly enhanced compared with the untreated PTX. The results of hemolysis test demonstrated that the drug-loaded nanospheres were qualified with good blood compatibility for intravenous use. In vitro anti-tumor activity was measured and results demonstrated that the incorporation of PTX into the newly developed GO-COO-HP-β-CD carrier could confer significantly improved cytotoxicity to the nanosystem against tumor cells than single application of PTX. GO-COO-HP-β-CD nanospheres may represent a promising formulation platform for a broad range of therapeutic agent, especially those with poor solubility.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Cell Survival; Drug Carriers; Erythrocytes; Graphite; Hemolysis; Humans; Hydrogen-Ion Concentration; Microscopy, Atomic Force; Oxides; Paclitaxel; Solubility; Spectroscopy, Fourier Transform Infrared

In this study, a series of star-shaped polycarbonates are synthesized by metal-free organocatalytic ring-opening polymerization of benzyl chloride (BnCl) and mannose-functionalized cyclic carbonate monomers (MTC-BnCl and MTC-ipman) with heptakis-(2,3-di-O-acetyl)-β-cyclodextrin (DA-β-CD) as macroinitiator. The distributions and compositions of pendent benzyl chloride and protected mannose group (ipman) units are facilely modulated by varying the polymerization sequence and feed ratio of the monomers, allowing precise control over the molecular composition, and the resulting polymers have narrow molecular weight distribution. After deprotection of ipman groups and quaternization with various N,N-dimethylalkylamines, these star polymers with optimized compositions of cationic and mannose groups in block and random forms exhibit strong bactericidal activity and low hemolysis. Furthermore, the optimal mannose-functionalized polymer demonstrates mannose receptor-mediated intracellular bactericidal activity against BCG mycobacteria without inducing cytotoxicity on mammalian cells at the effective dose. Taken together, the materials designed in this study have potential use as antimicrobial agents against diseases such as tuberculosis, which is caused by intracellular bacteria.

Topics: Animals; Anti-Infective Agents; Bacteria; beta-Cyclodextrins; Cations; Hemolysis; Mammals; Mannose; Polycarboxylate Cement; Polymerization; Polymers

Herein, we report the synthesis of a novel tri-component nanocomposite system incorporating β-cyclodextrin (β-CD) with nano-hydroxyapatite (n-HA) and chitosan (CS), (n-HA/β-CD/CS) at three different temperatures via co-precipitation method. The chemical interactions and surface morphology have been evaluated by TEM, SEM and AFM techniques revealing the agglomerated nanoparticles in CS/n-HA-HA binary system whereas the ternary systems produced needle shaped nanoparticles dispersed homogeneously at low temperature with more porous and rougher surface. The addition of β-CD in CS/n-HA at low temperature decreased the particle size and raised the thermal stability as compared to CS/n-HA. The comparative hemolytic, protein adsorption and platelet adhesion studies confirmed the better hemocompatibility of n-HA/β-CD/CS-(RT,HT,LT) nanocomposites relative to CS/n-HA. The cell viability has been evaluated in vitro using MG-63 cell line which revealed superior non toxicity of n-HA/β-CD/CS-LT nanocomposite in comparison to n-HA/β-CD/CS-(RT,HT) and CS/n-HA nanocomposites. Thus it may be concluded that the orchestrated organic/inorganic n-HA/β-CD/CS-(RT,HT,LT) nanocomposites exhibited relatively higher cell viability of human osteoblast cells, stimulated greater osteogenesis, controlled biodegradation, enhanced antibacterial activity with excellent in-vitro biomineralization and remarkable mechanical parameters as compared to CS/n-HA nanocomposite and thus may provide opportunities for potential use as an alternative biomaterial for Bone tissue engineering applications.

Topics: Alkaline Phosphatase; Anti-Bacterial Agents; beta-Cyclodextrins; Biocompatible Materials; Bone and Bones; Cell Line; Chitosan; Compressive Strength; Durapatite; Hardness; Hemolysis; Humans; Nanocomposites; Tissue Engineering; Tissue Scaffolds

The present communication deals with preparation of β-cyclodextrin (βCD) grafted hydroxypropylmethylcellulose (HPMC) hydrogel films using citric acid as crosslinking agent with the aim of improving the loading and achieving controlled release of hydrophobic weak base (ketoconazole). The hydrogel films were characterized by attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy, solid state

Topics: Antifungal Agents; beta-Cyclodextrins; Citric Acid; Cross-Linking Reagents; Drug Evaluation, Preclinical; Drug Liberation; Hemolysis; Humans; Hydrogels; Hydrophobic and Hydrophilic Interactions; Hypromellose Derivatives; Ketoconazole

Hydroxypropyl-β-cyclodextrin (HP-β-CD) has been widely used as an effective solubilizing agent in pharmaceutical industry for many years. However, the effect of degree of substitution (D.S.) of HP-β-CD on solubilizing capacity and toxicity has not been concerned. In this study, solubilizing capacity of HP-β-CDs with three different D.S. (4.55, 6.16 and 7.76) for 16 drugs were measured and their toxicities were compared by a 7-day i.v. administration (q.d.) study in rats. Generally, HP-β-CD with high D.S. (7.76) showed weaker solubilizing capacity for steroids and BCS class II drugs, but lower hemolytic activity, compared with that of HP-β-CD with low (4.55) or medium (6.16) D.S. HP-β-CD with low D.S. resulted in more changes in hematological and biochemical parameters, but the effects were reversible after a 7-day recovery. Moreover, HP-β-CD with medium D.S. may have slightly greater nephrotoxicity than the other two HP-β-CDs. HP-β-CDs with different D.S. had similar urine excretion percentage after i.v. administration and none of them was found to affect glomerular filtration function of rats. The results suggest that HP-β-CD with low D.S. would be a better choice considering both the solubilizing capacity and toxicity. However, comparison in toxicity of HP-β-CDs with different D.S. should be carried out in human in view of its species-dependence property.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; beta-Cyclodextrins; Erythrocytes; Excipients; Female; Glomerular Filtration Rate; Hemolysis; Male; Pharmaceutical Preparations; Rabbits; Rats, Sprague-Dawley; Solubility

Primary effusion lymphoma (PEL) is a subtype of aggressive and chemotherapy-resistant non-Hodgkin lymphoma that occurs predominantly in patients with advanced AIDS. In this study, we examined the antitumor activity of methyl-β-cyclodextrin (M-β-CyD) in vitro and in vivo. M-β-CyD quickly induced caspase-dependent apoptosis in PEL cells via cholesterol depletion from the plasma membrane. In a PEL xenograft mouse model, M-β-CyD significantly inhibited the growth and invasion of PEL cells without apparent adverse effects. These results strongly suggest that M-β-CyD has the potential to be an effective antitumor agent against PEL.

Topics: Animals; Antineoplastic Agents; Apoptosis; beta-Cyclodextrins; Cell Survival; Cholesterol; Culture Media; Female; Hemolysis; L-Lactate Dehydrogenase; Lymphoma, Primary Effusion; Membrane Microdomains; Mice; Mice, Inbred NOD; Mice, SCID; Neoplasm Transplantation; Xenograft Model Antitumor Assays

The use of antimicrobial peptides (AMPs) as therapeutic agents for periodontal infections has great advantages, such as broad spectrum of action, low toxicity, and limited bacterial resistance. However, their practical use is limited because of the large amount of peptide required to exercise the microbicidal function.. LyeTxI, LL37f, and KR12 cationic peptides were prepared with β-cyclodextrin (βCD) at 1:1 molar ratios. The susceptibility of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum were assessed in anaerobic conditions. Cytotoxicity assays were performed using osteoblast and Caco-2 epithelial cells, and hemolytic activity was assessed on rabbit erythrocytes at an absorbance of 414 nm. Parameters of surface roughness and electrical charge were established by atomic force microscopy and zeta (ζ) potential, respectively.. AMP/βCDs drastically decreased the peptide concentration required for activity against the bacteria tested. Moreover, AMPs associated with βCD were able to modify cell-surface parameters, such as roughness and ζ potential. On the other hand, AMP/βCD did not alter the degree of hemolysis induced by the pure AMPs. The effective concentration at half-maximum values of the peptides and compounds on osteoblasts were greater than the concentrations required to achieve inhibition of bacterial growth in all the species tested. AMP/βCDs inhibited the proliferation of Caco-2 epithelial cells in a more efficient manner than AMPs alone.. AMP/βCD compounds more effectively inhibit periodontopathogenic bacteria than AMPs alone, with the additional ability of inhibiting the proliferation of epithelial cells at concentrations that are non-cytotoxic for osteoblasts and erythrocytes.

Topics: Aggregatibacter actinomycetemcomitans; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Antimitotic Agents; beta-Cyclodextrins; Caco-2 Cells; Cathelicidins; Cell Proliferation; Electrochemistry; Epithelial Cells; Erythrocytes; Fusobacterium nucleatum; Hemolysis; Humans; Microscopy, Atomic Force; Osteoblasts; Peptide Fragments; Porphyromonas gingivalis; Rabbits; Sequestering Agents

To obtain a tumor cell-selectivity of methyl-β-cyclodextrin (M-β-CyD), we newly synthesized folate-appended M-β-CyD (FA-M-β-CyD), and evaluated the potential of FA-M-β-CyD as a novel anticancer agent in vitro and in vivo. Potent antitumor activity and cellular association of FA-M-β-CyD were higher than those of M-β-CyD in KB cells, folate receptor (FR)-positive cells. FA-M-β-CyD drastically inhibited the tumor growth after intratumoral or intravenous injection to FR-positive Colon-26 cells-bearing mice. The antitumor activity of FA-M-β-CyD was comparable and superior to that of doxorubicin after both intratumoral and intravenous administrations, respectively, at the same dose, in the tumor-bearing mice. All of the tumor-bearing mice after an intravenous injection of FA-M-β-CyD survived for at least more than 140 days. Importantly, an intravenous administration of FA-M-β-CyD to tumor-bearing mice did not show any significant change in blood chemistry values. These results strongly suggest that FA-M-β-CyD has the potential as a novel anticancer agent.

Topics: Animals; Antineoplastic Agents; beta-Cyclodextrins; Caspase 3; Caspase 7; Cell Line, Tumor; Cholesterol; Colonic Neoplasms; Doxorubicin; Folic Acid; Hemolysis; Humans; KB Cells; Male; Mice; Mice, Inbred BALB C; Rabbits; Xenograft Model Antitumor Assays

Many natural broad-spectrum cationic antimicrobial peptides (AMPs) possess a general mode of action that is dependent on lipophilicity and charge. Modulating the lipophilicity of AMPs by the addition of a fatty acid has been an effective strategy to increase the lytic activity and can further broaden the spectrum of AMPs. However, lipophilic modifications that narrow the spectrum of activity and exclusively direct peptides to fungi are less common. Here, we show that short peptide sequences can be targeted to fungi with structured lipophilic biomolecules, such as vitamin E and cholesterol. The conjugates were active against Aspergillus fumigatus, Cryptococcus neoformans, and Candida albicans but not against bacteria and were observed to cause membrane perturbation by transmission electron microscopy and in membrane permeability studies. However, for C. albicans, selected compounds were effective without the perturbation of the cell membrane, and synergism was seen with a vitamin E conjugate and amphotericin B. Moreover, in combination with β-cyclodextrin, antibacterial activity emerged in selected compounds. Biocompatibility for selected active compounds was tested in vitro and in vivo using toxicity assays on erythrocytes, macrophages, and mice. In vitro cytotoxicity experiments led to selective toxicity ratios (50% lethal concentration/MIC) of up to 64 for highly active antifungal compounds, and no in vivo murine toxicity was seen. Taken together, these results highlight the importance of the conjugated lipophilic structure and suggest that the modulation of other biologically relevant peptides with hydrophobic moieties, such as cholesterol and vitamin E, generate compounds with unique bioactivity.

Topics: Amphotericin B; Animals; Antimicrobial Cationic Peptides; Aspergillus fumigatus; Bacteria; beta-Cyclodextrins; Candida albicans; Cell Membrane; Cell Membrane Permeability; Cholesterol; Cryptococcus neoformans; Drug Synergism; Erythrocytes; Hemolysis; Hydrophobic and Hydrophilic Interactions; Macrophages; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Microscopy, Electron, Transmission; Mycoses; Species Specificity; Static Electricity; Vitamin E

Bromhexine hydrochloride (bromhexine) is a mucolytic agent with very low aqueous solubility. However, with addition of cyclodextrins (CD) to the formulation, this disadvantage may be limited and therapeutic doses of bromhexine in solution can be achieved. The interaction of bromhexine with α-, β-, γ- and sulfobutylether (SBE)-β-CD, respectively, was elucidated by means of phase solubility diagrams and calorimetric analysis. The complexes were further characterized by size, and the effect of the CD concentrations used was evaluated in a viability assay. From phase solubility diagrams with α-, β-, γ- and SBE-β-CD and bromhexine, it was determined that the solubility of bromhexine significantly increased with addition of CDs, showing an A(L) type solubility curve for bromhexine/α- and β-CD, and an A(N) type for bromhexine/γ- and SBE-β-CD. The highest soluble concentrations of bromhexine were achieved with α- and SBE-β-CD, i.e. when using a 100mM α- or SBE-β-CD solution, 4 and 5.5 times more bromhexine was solubilized, respectively, compared to pure aqueous solubilization of bromhexine. The apparent association constants determined from the phase solubility studies showed very low values of 34, 17, 8 and 156 M(-1) for bromhexine/α-, β-, γ- and SBE-β-CD, respectively, as compared to the association constants determined by ITC which exhibited values of 89, 307 and 1680 M(-1) for bromhexine/α-, β- and SBE-β-CD, respectively. The formation of aggregates aided solubilization of bromhexine in the phase solubility studies explaining the difference in the association constants between the two methods. Due to very low signal to noise ratio, no information was extracted for bromhexine/γ-CD solutions from the ITC measurements. The effect on cellular viability of the CDs ranked β->α->SBE-β->γ-CD. In conclusion, the results altogether demonstrated that SBE-β-CD is the most suitable CD for future drug delivery systems from the aspect of high amounts of solubilized bromhexine and high safety of the SBE-β-CD.

Topics: alpha-Cyclodextrins; Animals; beta-Cyclodextrins; Biocompatible Materials; Bromhexine; Calorimetry; Cell Survival; Chemistry, Pharmaceutical; Cyclodextrins; Dose-Response Relationship, Drug; Drug Carriers; Drug Compounding; Excipients; Expectorants; gamma-Cyclodextrins; HeLa Cells; Hemolysis; Horses; Humans; Particle Size; Solubility; Technology, Pharmaceutical

Polyester vascular prostheses (PVPs) coated with a polymer of hydroxypropyl-β-cyclodextrin (HPβCD) have been designed to provide an in situ reservoir for the sustained delivery of one or more bioactive molecules. The goal of this study was to assess the efficacy, the safety and the healing properties of these prostheses.. Collagen-sealed PVPs were coated with the HPβCD-based-polymer (PVP-CD) using the pad-dry-cure textile finishing method and loaded with one or two antibiotics. Appropriate control and PVP-CD samples were tested in several in vitro and animal model conditions. The study end points included haemolysis, platelet aggregation, antibacterial efficacy, polymer biodegradation, acute toxicity and chronic tolerance.. PVP-CD proved to be compatible with human blood, since it did not induce haemolysis nor influenced ADP-mediated platelet aggregation. Sustained antimicrobial efficacy was achieved up to 7 days against susceptible bacteria when PVP-CDs were loaded with the appropriate drugs. Analysis of harvested PVP-CD from the animal model revealed that the HPβCD-based coating was still present at 1 month but had completely disappeared 6 months after implantation. All grafts were patent, well encapsulated without healing abnormalities. Clinical data, blood-sample analysis and histological examination did not evidence any signs of acute or chronic, local or systemic toxicity in the animal models.. PVP-CD was proved safe and demonstrated excellent biocompatibility, healing and degradation properties. Effective antimicrobial activity was achieved with PVP-CD in conditions consistent with a sustained-release mechanism.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; Anti-Bacterial Agents; beta-Cyclodextrins; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Ciprofloxacin; Coated Materials, Biocompatible; Dogs; Drug Therapy, Combination; Drug-Eluting Stents; Female; Hemolysis; Humans; In Vitro Techniques; Methicillin-Resistant Staphylococcus aureus; Mice; Platelet Aggregation; Prosthesis-Related Infections; Rifampin; Toxicity Tests; Treatment Outcome; Vancomycin; Wound Healing

The activity of antivirals can be enhanced by their incorporation in nanoparticulate delivery systems. Peculiar polymeric nanoparticles, based on a β-cyclodextrin-poly(4-acryloylmorpholine) monoconjugate (β-CD-PACM), are proposed as acyclovir carriers. The experimental procedure necessary to obtain the acyclovir-loaded nanoparticles using the solvent displacement preparation method will be described in this chapter. Fluorescent labeled nanoparticles are prepared using the same method for cellular trafficking studies. The biocompatibility assays necessary to obtain safe nanoparticles are reported. Section 4 of this chapter describes the assessment of the antiviral activity of the acyclovir-loaded nanoparticles.

Topics: Acrylic Resins; Acyclovir; Animals; Antiviral Agents; beta-Cyclodextrins; Cell Survival; Chlorocebus aethiops; Complement Activation; Hemolysis; Herpesvirus 1, Human; Humans; Materials Testing; Nanocapsules; Particle Size; Reactive Oxygen Species; Skin; Surface Properties; Tissue Culture Techniques; Vero Cells; Viral Load; Viral Plaque Assay

The physicochemical and biological properties of the new branched cyclomaltooligosaccharides (cyclodextrins; CDs), 2-O-α-D-galactosyl-cyclomaltohexaose (2-O-α-D-galactosyl-α-cyclodextrin, 2-Gal-αCD) and 2-O-α-D-galactosyl-cyclomaltoheptaose (2-O-α-D-galactosyl-β-cyclodextrin, 2-Gal-βCD), were investigated. The formation of inclusion complexes of 2-Gal-CDs with various kinds of guest compounds (clofibrate, cholesterol, cholecalciferol, digitoxin, digitoxigenin, and prostaglandin A(1)) was examined by a solubility method, and the results were compared with those of non-branched CDs and other 6-O-glycosyl-CDs such as 6-O-α-D-galactosyl-CDs, 6-O-α-D-glucosyl-CDs, and 6-O-α-maltosyl-CDs. The inclusion abilities of 2-Gal-αCD for clofibrate and prostaglandin A(1), and 2-Gal-βCD for clofibrate, cholecalciferol, cholesterol, and digitoxigenin were markedly weaker than those of non-branched CD and other 6-O-glycosyl-CDs in each series, probably because of a steric hindrance caused by the α-(1→2)-galactoside linkage. The hemolytic activities of 2-Gal-CDs on human erythrocytes were the lowest among each CD series, and the compounds showed negligible cytotoxicity towards Caco-2 cells up to at least 100mM.

Topics: alpha-Cyclodextrins; beta-Cyclodextrins; Caco-2 Cells; Chemical Phenomena; Dose-Response Relationship, Drug; Erythrocytes; Hemolysis; Humans; Magnetic Resonance Spectroscopy; Solubility

2-Hydroxybutyl-β-cyclodextrins (HB-β-CyDs) with different degrees of substitution (D.S.) were prepared and their physicochemical and biological properties and solubilizing abilities were studied and compared with those of 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD). The surface activity of HB-β-CyD was higher than that of HP-β-CyD (D.S. 5.6) and increased with its concentration and D.S. The moisture sorption of HB-β-CyD (D.S. 5.5) was less than that of HP-β-CyD (D.S. 5.6), because of the introduction of hydrophobic hydroxybutyl groups in a molecule. The hemolytic activity (rabbit erythrocytes) decreased in the order of 2,6-di-O-methyl-β-cyclodextrin (DM-β-CyD)>methyl-β-cyclodextrin (M-β-CyD)>HB-β-CyD (D.S. 5.5)>β-CyD>HP-β-CyD (D.S. 5.6). The hemolytic activity of HB-β-CyD increased with D.S. and HB-β-CyD induced echinocyte (or crenation), as well as DM-β-CyD does. It was suggested from the solubility study of membrane components that HB-β-CyD interacted predominantly with cholesterol in erythrocytes, resulting in the hemolysis. The inclusion ability of HB-β-CyD was higher than that of HP-β-CyD (D.S. 5.6), especially for poorly water-soluble drugs with long linear structures such as biphenylylacetic acid and flurbiprofen (FP). For example, HB-β-CyD formed the inclusion complex with FP in a molar ratio of 1:1, by including the biphenyl moiety in the host cavity. The dissolution rate of FP/HB-β-CyD (D.S. 5.5) complex was faster than that of HP-β-CyD (D.S. 5.6) complex. The results suggested that HB-β-CyDs have considerable pharmaceutical potential and can work as a fast-dissolving carrier for poorly water-soluble drugs.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; beta-Cyclodextrins; Drug Carriers; Excipients; Flurbiprofen; Hemolysis; Hydrophobic and Hydrophilic Interactions; Male; Phenylacetates; Rabbits; Solubility; Structure-Activity Relationship

Staphylococcus aureus pneumonia is a common, potentially life-threatening infection caused by this human pathogen. The only therapies available to treat S. aureus pneumonia are antibiotics, a modality that is jeopardized by the organism's remarkable ability to acquire antimicrobial resistance. S. aureus alpha-hemolysin is a pore-forming cytotoxin that is essential for the pathogenesis of pneumonia. Strains lacking this cytotoxin are avirulent in a murine model of pneumonia; likewise, vaccine-based strategies that antagonize the toxin afford protection against lethal disease. Disruption of the function of this toxin therefore provides a potent mechanism to prevent and/or treat S. aureus pneumonia. beta-Cyclodextrin derivatives are small molecules with a sevenfold symmetry that mirrors the heptameric alpha-hemolysin. These compounds block the assembled alpha-hemolysin pore, compromising toxin function. We report that a modified beta-cyclodextrin compound, IB201, prevents alpha-hemolysin-induced lysis of human alveolar epithelial cells. This protective effect does not result from the ability of the beta-cyclodextrin to impair formation of the oligomeric alpha-hemolysin on the cell surface, supporting a role for this molecule in blockade of the lytic pore. An examination of IB201 in murine S. aureus pneumonia demonstrated that administration of this compound prevents and treats disease, protecting against mortality. Consistent with the vital importance of alpha-hemolysin in pneumonia caused by methicillin-sensitive and highly virulent methicillin-resistant S. aureus strains, IB201 protects against lethal challenge with both types of isolates. These observations, coupled with a favorable safety profile of beta-cyclodextrin compounds, provide a novel strategy that may be developed to combat S. aureus pneumonia.

Topics: Animals; beta-Cyclodextrins; Cell Line; Cell Survival; Erythrocytes; Hemolysin Proteins; Hemolysis; Lung; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Pneumonia, Staphylococcal; Rabbits; Staphylococcus aureus

Several beta-cyclodextrin (beta-CD) derivatives have been synthesized recently to improve the physicochemical properties and inclusion capacities of the parent molecule, however, there is limited information available about their cytotoxic effects. In this study we investigated the cytotoxic and hemolytic properties of various beta-CDs in correlation with their cholesterol-solubilizing capacities to expose the mechanism of toxicity. MTT cell viability test, performed on Caco-2 cells showed significant differences between the cytotoxicity of beta-CD derivatives. Cell toxicity of methylated-beta-CDs was the highest, while ionic derivatives proved to be less toxic than methylated ones. Most of the second generation beta-CD derivatives, having both ionic and methyl substituents showed less cytotoxicity than the parent compounds both on Caco-2 cells and human erythrocytes. Inclusion of cholesterol into the ring of randomly methylated-beta-CD and heptakis(2,6-di-O-methyl)-beta-CD abolished the cell toxicity indicating the role of cholesterol extraction in cytotoxicity. These data demonstrate the correlation between the cytotoxic effect, hemolytic activity and the cholesterol complexation attributes of beta-CD derivatives and we propose that cholesterol-solubilizing properties can be a predictive factor for beta-CD cell toxicity.

Topics: beta-Cyclodextrins; Caco-2 Cells; Cell Survival; Cholesterol; Erythrocytes; Excipients; Hemolysis; Hemolytic Agents; Humans; Inhibitory Concentration 50; Methylation; Solubility; Structure-Activity Relationship

alpha-Toxin mediates extreme corneal damage during Staphylococcus aureus keratitis. Chemical inhibition of this toxin was sought to provide relief from toxin-mediated pathology.. Inhibition of alpha-toxin by phosphate-buffered saline (PBS), 0.1% methyl-beta-cyclodextrin (CD), or CD plus cholesterol (0.1%, CD-cholesterol) was assayed by hemolysis of rabbit erythrocytes. Pathologic changes in rabbit corneas injected with 12 hemolytic units of alpha-toxin suspended in PBS, 1% CD, or 1% CD-cholesterol were compared over time. Rabbit corneas injected with 10(2) colony forming units (CFU) of S. aureus were treated from 7 to 13 hours postinfection (PI) with a total of 15 drops of CD-cholesterol, CD, or PBS. Slit lamp examination (SLE) and measurement of erosions were performed at 13 hours PI and bacteria were quantified at 14 hours PI.. Toxin-mediated lysis of erythrocytes was inhibited up to 16,000-fold in the presence of CD-cholesterol compared with CD or PBS. Eyes injected with alpha-toxin mixed with CD-cholesterol had, at 7 hours postinjection, significantly smaller erosions than eyes injected with alpha-toxin in PBS or alpha-toxin mixed with CD (P = 0.0090 and P = 0.0035, respectively). Eyes infected with S. aureus and treated with CD-cholesterol had significantly lower SLE scores than eyes treated with CD or PBS (P or= 0.0648).. CD-cholesterol is a potent inhibitor of alpha-toxin activity in vitro and an effective means to arrest corneal damage during S. aureus keratitis.

Topics: Animals; Bacterial Toxins; beta-Cyclodextrins; Cholesterol; Cornea; Corneal Ulcer; Disease Models, Animal; Drug Therapy, Combination; Erythrocytes; Exotoxins; Eye Infections, Bacterial; Hemolysin Proteins; Hemolysis; Rabbits; Sodium Chloride; Staphylococcal Infections; Staphylococcal Toxoid; Staphylococcus aureus; Virulence; Virulence Factors

Three positional isomers of 6(1),6(n)-di-O-(alpha-L-fucopyranosyl)-beta-cyclodextrin [6(1),6(n)-di-O-(alpha-L-Fuc)-betaCD, n=2-4] were chemically synthesized by using the corresponding authentic compounds, 6(1),6(n)-di-O-(tert-butyldimethylsilyl)-betaCD (n=2-4) as fucosyl acceptors and 2,3,4-tri-O-benzyl-L-fucopyranosyl trichloroacetimidate as a fucosyl donor. Their structures were analyzed by HPLC, MS and NMR spectroscopy. The hemolytic activities of the alpha-L-Fuc-betaCDs were lower than that of betaCD, while the water solubility of these branched betaCDs was much higher than that of betaCD. The molecular interaction between these compounds and the fucose-binding lectin, Aleuria aurantia lectin (AAL), was investigated by using an optical biosensor based on the surface plasmon resonance (SPR) technique. The order of binding affinity, as a function of the fucose-binding position, was 6(1),6(4)- > 6(1),6(3)- > 6(1),6(2)-di-O-(alpha-L-Fuc)-betaCD > 6-O-(alpha-L-Fuc)-betaCD.

Topics: beta-Cyclodextrins; Erythrocytes; Fucose; Hemolysis; Humans; Isomerism; Lectins; Solubility; Surface Plasmon Resonance; Water

Lipid rafts on cell membranes have heterogeneity such as cholesterol-rich microdomains and sphingolipids-rich microdomains. We previously reported that beta-cyclodextrin (beta-CyD) induced morphological changes of red blood cells (RBC) from discocyte to stomatocyte, possibly due to extraction of cholesterol from cholesterol-rich lipid rafts of RBC membranes. In this study, the effects of methyl-beta-cyclodextrin (M-beta-CyD) and 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-CyD) on lipid rafts and morphological changes in rabbit RBC (RRBC) were examined, compared to those of beta-CyD. In sharp contrast to beta-CyD, M-beta-CyD and DM-beta-CyD induced morphological changes of RRBC from discocyte to echinocyte. At pre-hemolytic concentrations of beta-CyDs, M-beta-CyD and DM-beta-CyD strongly released cholesterol from cholesterol-rich lipid rafts, compared to beta-CyD. Meanwhile, the lowering effects of DM-beta-CyD on fluorescent sphingomyelin analogue in sphingolipids-rich lipid rafts were more potent than those of beta-CyD and M-beta-CyD. The magnitude of the abilities of M-beta-CyD and DM-beta-CyD to extract membrane constituents was higher than that of beta-CyD, consistent with that of hemolytic activity. Furthermore, DM-beta-CyD and M-beta-CyD, not beta-CyD, lowered the amount of proteins in cholesterol-rich lipid rafts of RRBC. These results suggest that higher hemolytic activity and morphological changes from discocyte to echinocyte in RRBC induced by M-beta-CyD and DM-beta-CyD may be due to the extraction of both cholesterol and proteins from cholesterol-rich lipid rafts of RRBC, although DM-beta-CyD may interact with sphingolipids-rich lipid rafts on RRBC membranes only slightly.

Topics: Animals; beta-Cyclodextrins; Blood Proteins; Cholesterol; Erythrocytes; Flow Cytometry; Hemolysis; In Vitro Techniques; Membrane Microdomains; Microscopy, Electron, Scanning; Phospholipids; Rabbits; Sphingomyelins

The aim of this work was to study the complexation capability of new sulfobutyl ether-alkyl ether (SBE-AE-CD) mixed beta- and gamma-cyclodextrin derivatives with a series of structurally related steroids (6alpha-methylprednisolone, prednisolone, triamcinolone, D(-) norgestrel and hydrocortisone) and a number of dihydropyridine calcium channel blockers (nimodipine, nitrendipine, nifedipine) that traditionally interact poorly with other cyclodextrins (CDs). The effect of the total degree of substitution (TDS) and of the length of the alkyl side chain on binding capacity of these new modified CDs was evaluated as was their ability to induce red blood cell hemolysis. An attempt was made to correlate hemolysis to surface activity. Binding constants between the SBE-AE-CDs and selected molecules were determined by spectroscopic studies, and only in few cases by solubility studies. Hemolysis percentage was determined using citrated rabbit blood and citrated human blood with UV analysis. The surface activity was measured with a tensiometer. A significant improvement in the binding capacity between various substrates and the new SBE-AE-CDs was observed when compared to the SBE-CDs. The length of the alkyl chain and total degree of alkylation affected the binding with the relationship being complex. For most compounds, an intermediate degree of substitution appeared to be advantageous. The hemolysis studies showed that some of the derivatives may induce hemolysis and this correlated with higher surface activity for some but not all of the derivatives.

Topics: Algorithms; Animals; beta-Cyclodextrins; Calcium Channel Blockers; Cyclodextrins; Dihydropyridines; Erythrocytes; Ethers; Hemolysis; Rabbits; Solubility; Spectrophotometry, Ultraviolet; Steroids; Surface Tension

A few membrane-intercalating amphipaths have been observed to stimulate the interaction of cholesterol with cholesterol oxidase, saponin and cyclodextrin, presumably by displacing cholesterol laterally from its phospholipid complexes. We now report that this effect, referred to as cholesterol activation, occurs with dozens of other amphipaths, including alkanols, saturated and cis- and trans-unsaturated fatty acids, fatty acid methyl esters, sphingosine derivatives, terpenes, alkyl ethers, ketones, aromatics and cyclic alkyl derivatives. The apparent potency of the agents tested ranged from 3 microM to 7 mM and generally paralleled their octanol/water partition coefficients, except that relative potency declined for compounds with >10 carbons. Some small amphipaths activated cholesterol at a membrane concentration of approximately 3 mol per 100 mol of bilayer lipids, about equimolar with the cholesterol they displaced. Lysophosphatidylserine countered the effects of all these agents, consistent with its ability to reduce the pool of active membrane cholesterol. Various amphipaths stabilized red cells against the hemolysis elicited by cholesterol depletion, presumably by substituting for the extracted sterol. The number and location of cis and trans fatty acid unsaturations and the absolute stereochemistry of enantiomer pairs had only small effects on amphipath potency. Nevertheless, potency varied approximately 7-fold within a group of diverse agents with similar partition coefficients. We infer that a wide variety of amphipaths can displace membrane cholesterol by competing stoichiometrically but with only limited specificity for weak association with phospholipids. Any number of other drugs and experimental agents might do the same.

Topics: beta-Cyclodextrins; Cells, Cultured; Cholesterol; Cholesterol Oxidase; Erythrocyte Membrane; Hemolysis; Humans; Hydrophobic and Hydrophilic Interactions; Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; Intercalating Agents; Phospholipids

Paclitaxel is a potent anticancer agent with limited bioavailability due to side-effects associated with solubilizer used in its commercial formulation and the tendency of the drug to precipitate in aqueous media. In this study, paclitaxel was encapsulated in amphiphilic cyclodextrin nanoparticles. Safety of blank nanoparticles was compared against commercial vehicle cremophor:ethanol (50:50 v/v) by hemolysis and cytotoxicity experiments. Data revealed that nanoparticles caused significantly less hemolysis. Results were confirmed with SEM imaging of erythrocytes treated with nanospheres, nanocapsules or commercial vehicle. Cytotoxicity of the blank carriers was evaluated against L929 cells. A vast difference between the cytotoxicity of nanoparticles and cremophor:ethanol mixture was observed. Physical stability of paclitaxel in nanoparticles was assessed for 1 month with repeated particle size and zeta potential measurements and AFM imaging. Recrystallization of paclitaxel, very typical in diluted aqueous solutions of the drug, did not take place when the drug is bound to cyclodextrin nanoparticles. Anticancer efficacy of paclitaxel-loaded nanoparticles was evaluated in comparison to paclitaxel in cremophor vehicle against MCF-7 cells. Cyclodextrin nanoparticle caused a slightly higher anticancer effect than cremophor:ethanol vehicle. Thus, amphiphilic cyclodextrin nanoparticles emerged as promising alternative formulations for injectable paclitaxel administration with low toxicity and equivalent efficacy.

Topics: Animals; Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Caproates; Cell Line; Cell Line, Tumor; Cell Survival; Drug Delivery Systems; Erythrocytes; Fibroblasts; Hemolysis; Humans; Mice; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Nanoparticles; Paclitaxel; Particle Size; Static Electricity; Surface Properties

Ropivacaine (RVC) is an enantiomerically pure local anesthetic (LA) largely used in surgical procedures, which presents physico-chemical and therapeutic properties similar to those of bupivacaine (BPV), but associated to less systemic toxicity. This study focuses on the development and pharmacological evaluation of a RVC in 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) inclusion complex. Phase-solubility diagrams allowed the determination of the association constant between RVC and HP-beta-CD (9.46 M(-1)) and showed an increase on RVC solubility upon complexation. Release kinetics revealed a decrease on RVC release rate and reduced hemolytic effects after complexation (onset at 3.7 mM and 11.2mM for RVC and RVC HP-beta-CD, respectively) were observed. Differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray analysis (X-ray) showed the formation and the morphology of the complex. Nuclear magnetic resonance (NMR) and job-plot experiments afforded data regarding inclusion complex stoichiometry (1:1) and topology. Sciatic nerve blockade studies showed that RVC HP-beta-CD was able to reduce the latency without increasing the duration of motor blockade, but prolonging the duration and intensity of the sensory blockade (p<0.001) induced by the LA in mice. These results identify the RVC HP-beta-CD complex as an effective novel approach to enhance the pharmacological effects of RVC, presenting it as a promising new anesthetic formulation.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Amides; Anesthetics, Local; Animals; beta-Cyclodextrins; Calorimetry, Differential Scanning; Dose-Response Relationship, Drug; Drug Compounding; Hemolysis; Hot Temperature; Humans; Kinetics; Magnetic Resonance Spectroscopy; Male; Mice; Microscopy, Electron, Scanning; Molecular Structure; Nerve Block; Pain Threshold; Ropivacaine; Sciatic Nerve; Solubility; Stereoisomerism; Time Factors; X-Ray Diffraction

The aim of this study was to develop an aqueous parenteral formulation containing itraconazole (ITZ) using an o/w microemulsion system. A mixture of benzyl alcohol and medium chain triglyceride (3/1) was chosen as the oil phase. Pseudoternary phase diagrams of the microemulsion formations were constructed in order to determine the optimum ratio of oils, the concentration range of surfactant and cosurfactant and the optimum ratio between them. Consequently, the suitability of the chosen microemulsion system as a parenteral formulation was evaluated using droplet size analysis and hemolysis tests. Among the surfactants and cosurfactants screened, a mixture of polyoxyethylene (50) hydrogenated castor oil and ethanol (3/1) showed the largest o/w microemulsion region in the phase diagram. The average droplet size of the microemulsions was < 150 nm, and the hemolysis test showed this formulation to be nontoxic to red blood cells. The pharmacokinetic profiles of the ITZ-microemulsion for itraconazole and its major metabolite, hydroxyitraconazole, were compared with those of a PEG 400 solution and cyclodextrin formulations in rats. Overall, these results highlight the potential of an ITZ-microemulsion formulation for the parenteral route.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; Antifungal Agents; Benzyl Alcohol; beta-Cyclodextrins; Castor Oil; Chemistry, Pharmaceutical; Emulsions; Ethanol; Excipients; Hemolysis; Injections, Intravenous; Itraconazole; Male; Particle Size; Polyethylene Glycols; Rats; Rats, Sprague-Dawley; Solubility; Solvents; Surface-Active Agents; Triglycerides; Water

A unique multibranched cyclomaltooligosaccharide (cyclodextrin, CD) of 6(1),6(3),6(5)-tri-O-alpha-maltosyl-cyclomaltoheptaose [6(1),6(3),6(5)-tri-O-alpha-maltosyl-beta-cyclodextrin, (G(2))(3)-betaCD] was prepared. The physicochemical and biological properties of (G(2))(3)-betaCD were determined together with those of monobranched CDs (6-O-alpha-D-glucopyranosyl-alpha-cyclodextrin (G(1)-alphaCD), 6-O-alpha-D-glucopyranosyl-beta-cyclodextrin (G(1)-betaCD), and 6-O-alpha-maltosyl-beta-cyclodextrin (G(2)-betaCD)). NMR spectra of (G(2))(3)-betaCD were measured using various 2D NMR techniques. The solubility of (G(2))(3)-betaCD in water and MeOH-water solutions was extremely high in comparison with nonbranched betaCD and was about the same as that of the other monobranched betaCDs. The formation of an inclusion complex of (G(2))(3)-betaCD with stereoisomers (estradiol, retinoic acid, quinine, citral, and glycyrrhetinic acid) depends on the cis-trans isomers of guest compounds. The cis isomers of estradiol, retinoic acid, and glycyrrhetinic acid were included more than their trans isomers, while the trans isomers of citral and quinine fit more tightly than their cis isomers. (G(2))(3)-betaCD was the most effective host compound in the cis-trans resolution of glycyrrhetinic acid. Among the branched betaCDs, (G(2))(3)-betaCD exhibited the weakest hemolytic activity in human erythrocytes and showed negligible cytotoxicity in Caco-2 cells up to 200 microM. These results indicate unique characteristics of (G(2))(3)-betaCD in some biological responses of cultured cells.

Topics: Alcohols; beta-Cyclodextrins; Caco-2 Cells; Carbohydrate Sequence; Chemical Phenomena; Chemistry, Physical; Chromatography, High Pressure Liquid; Cyclodextrins; Dose-Response Relationship, Drug; Erythrocytes; Hemolysis; Humans; Isomerism; Magnetic Resonance Spectroscopy; Molecular Structure; Solubility; Solutions; Water

Many pathogens utilize the formation of transmembrane pores in target cells in the process of infection. A great number of pore-forming proteins, both bacterial and viral, are considered to be important virulence factors, which makes them attractive targets for the discovery of new therapeutic agents. Our research is based on the idea that compounds designed to block the pores can inhibit the action of virulence factors, and that the chances to find high affinity blocking agents increase if they have the same symmetry as the target pore. Recently, we demonstrated that derivatives of beta-cyclodextrin inhibited anthrax lethal toxin (LeTx) action by blocking the transmembrane pore formed by the protective antigen (PA) subunit of the toxin. To test the broader applicability of this approach, we sought beta-cyclodextrin derivatives capable of inhibiting the activity of Staphylococcus aureus alpha-hemolysin (alpha-HL), which is regarded as a major virulence factor playing an important role in staphylococcal infection. We identified several amino acid derivatives of beta-cyclodextrin that inhibited the activity of alpha-HL and LeTx in cell-based assays at low micromolar concentrations. One of the compounds was tested for the ability to block ion conductance through the pores formed by alpha-HL and PA in artificial lipid membranes. We anticipate that this approach can serve as the basis for a structure-directed drug discovery program to find new and effective therapeutics against various pathogens that utilize pore-forming proteins as virulence factors.

Topics: Animals; Antigens, Bacterial; Bacillus anthracis; Bacterial Toxins; beta-Cyclodextrins; Electrophysiology; Erythrocytes; Hemolysin Proteins; Hemolysis; Ions; Mice; Models, Molecular; Molecular Structure; Rabbits; Staphylococcus aureus

Three positional isomers of 6(I),6(n)-di-O-(beta-L-fucopyranosyl)-cyclomaltoheptaose [6(I),6(n)-di-O-(beta-L-Fuc)-beta-cyclodextrin, -betaCD, n=II-IV] were chemically synthesized using the corresponding authentic compounds, 6(I),6(n)-di-O-(tert-butyldimethylsilyl)-betaCD (n=II-IV), as the fucosyl acceptors, and 2,3,4-tri-O-acetyl-L-fucopyranosyl trichloroacetimidate as the fucosyl donor. Their structures were analyzed by HPLC, MS, and NMR spectroscopy. The hemolytic activities of L-Fuc-betaCDs were lower than that of betaCD, while the solubilities of these branched CDs in water were much higher than that of betaCD. The molecular interaction between these compounds and the fucose-binding lectin Aleuria aurantia lectin (AAL) was investigated using an optical biosensor based on a surface plasmon resonance (SPR) technique. The order of binding affinity, as a function of the fucose-binding position, was 6(I),6(IV)->6(I),6(III)->6(I),6(II)-di-O-(beta-L-Fuc)-betaCD>6-O-(beta-L-Fuc)-betaCD.

Topics: Ascomycota; beta-Cyclodextrins; Biosensing Techniques; Carbohydrate Conformation; Carbohydrate Sequence; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Fucose; Hemolysis; Lectins; Magnetic Resonance Spectroscopy; Mass Spectrometry; Molecular Sequence Data; Pyrans; Surface Plasmon Resonance

Although cell lysis by the hemolytic peptide, melittin, has been extensively studied, the role of specific lipids of the erythrocyte membrane on melittin-induced hemolysis remains unexplored. In this report, we have explored the modulatory role of cholesterol on the hemolytic activity of melittin by specifically depleting cholesterol from rat erythrocytes using methyl-beta-cyclodextrin (MbetaCD). Our results show that the hemolytic activity of melittin is increased by approximately 3-fold upon depletion of erythrocyte membrane cholesterol by approximately 55% without any appreciable loss of phospholipids. This result constitutes the first report demonstrating that the presence of cholesterol inhibits the lytic activity of melittin in its natural target membrane, i.e., the erythrocyte membrane. These results are relevant in understanding the role of cholesterol in the mechanism of action of melittin in the erythrocyte membrane.

Topics: Animals; beta-Cyclodextrins; Cholesterol; Erythrocyte Membrane; Erythrocytes; Hemolysis; Melitten; Rats

We tested the hypothesis that certain membrane-intercalating agents increase the chemical activity of cholesterol by displacing it from its low activity association with phospholipids. Octanol, 1,2-dioctanoyl-sn-glycerol (a diglyceride), and N-hexanoyl-D-erythrosphingosine (a ceramide) were shown to increase both the rate of transfer and the extent of equilibrium partition of human red blood cell cholesterol to methyl-beta-cyclodextrin. These agents also promoted the interaction of the sterol with two cholesterol-specific probes, cholesterol oxidase and saponin. Expanding the pool of bilayer phospholipids with lysophosphatides countered these effects. The three intercalators also protected the red cells against lysis by cholesterol depletion as if substituting for the extracted sterol. As is the case for excess plasma membrane cholesterol, treating human fibroblasts with octanol, diglyceride, or ceramide stimulated the rapid inactivation of their hydroxymethylglutaryl-CoA reductase, presumably through an increase in the pool of endoplasmic reticulum cholesterol. These data supported the stated hypothesis and point to competition between cholesterol and endogenous and exogenous intercalators for association with membrane phospholipids. We also describe simple screens using red cells in a microtiter well format to identify intercalating agents that increase or decrease the activity of membrane cholesterol.

Topics: beta-Cyclodextrins; Binding, Competitive; Cell Membrane; Ceramides; Cholesterol; Cholesterol Oxidase; Cyclodextrins; Diglycerides; Dose-Response Relationship, Drug; Endoplasmic Reticulum; Erythrocytes; Fibroblasts; Hemolysis; Humans; Hydroxymethylglutaryl CoA Reductases; Hypercholesterolemia; Lipid Bilayers; Oxygen; Phospholipids; Saponins; Time Factors

This study was designed to synthesize, characterize and investigate the drug inclusion property of a series of novel cationic beta-cyclodextrin polymers (CPbetaCDs). Proposed water-soluble polymers were synthesized from beta-cyclodextrin (beta-CD), epichlorohydrin (EP) and choline chloride (CC) through a one-step polymerization procedure by varying molar ratio of EP and CC to beta-CD. Physicochemical properties of the polymers were characterized with colloidal titration, nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and aqueous solubility determination. The formation of naproxen/CPbetaCDs inclusion complexes was confirmed by NMR and fourier transform infrared spectroscopy (FT-IR). Cationic beta-CD polymers showed better hemolytic activities than parent beta-CD and neutral beta-CD polymer in hemolysis test. The morphological study of erythrocytes revealed a cell membrane invagination induced by the cationic groups. The effects of molecular weight and charge density of the polymers on their inclusion and release performance of naproxen were also investigated through phase-solubility and dissolution studies. It was found that the cationic beta-CD polymers with high molecular weight or low charge density exhibited better drug inclusion and dissolution abilities.

Topics: beta-Cyclodextrins; Cyclodextrins; Drug Carriers; Erythrocytes; Hemolysis; Humans; In Vitro Techniques; Magnetic Resonance Spectroscopy; Molecular Weight; Naproxen; Polymers; Solubility; Spectroscopy, Fourier Transform Infrared; Water

In this study, we report the formulation and in vivo evaluation of etomidate in an aqueous solution using sulfobutyl ether-7 beta-cyclodextrin (SBE-CD, Captisol) as a solubilizing agent. The phase-solubility behavior of etomidate as a function of SBE-CD concentration was evaluated, and accelerated solution stability studies of 2 mg/mL etomidate in a 5% w/v SBE-CD solution were conducted. The intravenous administration of the SBE-CD etomidate formulation in dogs was compared with Amidate, the commercial etomidate drug product formulated with propylene glycol as a cosolvent. The etomidate plasma concentration-time data were fit to a three-compartment mamillary model and the derived standard pharmacokinetic parameters were not statistically different between the two formulations (n = 4, p > 0.050). Concurrent pharmacodynamic analysis provided statistically equivalent maximum effects and median inhibitory concentrations for the two formulations. In vivo hemolysis after intravenous administration of Amidate was 10-fold higher than the SBE-CD formulation. Whereas Amidate cannot be given subcutaneously because of the cosolvent in the formulation, a 12 mg/mL aqueous solution of etomidate in 20% (w/v) SBE-CD was well tolerated by this route. The results suggest that the SBE-CD formulation is a viable clinical drug product with a reduced side-effect profile.

Topics: Adjuvants, Pharmaceutic; Animals; beta-Cyclodextrins; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Dogs; Drug Stability; Etomidate; Hemolysis; In Vitro Techniques; Injections, Intravenous; Injections, Subcutaneous; Male; Models, Biological; Pharmaceutical Solutions; Propylene Glycol; Solubility; Time Factors

The hemolytic behavior of a novel cytoprotective agent, DY-9760e (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate) was investigated using rabbit erythrocytes. Further, the effects of water-soluble cyclodextrin derivatives, such as 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD) and sulfobutyl ether of beta-cyclodextrin (SBE-beta-CyD), on the hemolytic activity of DY-9760e were studied. DY-9760e induced hemolysis at concentrations >0.2-0.3 mM in phosphate buffered saline (PBS) of pH 4.0 and 6.0, where DY-9760e is predominantly in dicationic and monocationic forms, respectively. The hemolytic activity of the monocationic DY-9760e was higher than that of the dicationic species, and the hemolysis at pH 4.0 involved the formation of methemoglobin. DY9760e induced the morphological change of erythrocytes towards membrane invagination at both pH 4.0 and 6.0. SBE7-beta-CyD significantly suppressed the DY-9760e-induced hemolysis and morphological change at both pH 4.0 and 6.0, as well as the formation of methemoglobin at pH 4.0. On the other hand, HP-beta-CyD suppressed only the hemolysis, but neither the morphological change nor the formation of methemoglobin. In addition, the inhibitory effect of SBE7-beta-CyD on the hemolysis was greater than that of HP-beta-CyD. The superior inhibitory effect of SBE7-beta-CyD on the DY-9760-induced hemolysis, the morphological change, and the formation of methemoglobin may be attributable to the formation of a stable inclusion complex with DY-9760e and to the weaker hemolytic activity of SBE7beta-CyD than HP-beta-CyD. These results suggest potential use of SBE7-beta-CyD as a parenteral carrier for DY-9760e.

Topics: Animals; beta-Cyclodextrins; Cyclodextrins; Cytoprotection; Erythrocytes; Hemolysis; Indazoles; Rabbits

Parameters that influence the precipitation of the beta-cyclodextrin (beta-CD) inclusion complexes of the antimycotics miconazole and econazole were investigated. The mechanistic reason for the superior antimycotic activity of the miconazole inclusion complex was studied. The toxicity of the complex was estimated. The temperature, the buffer strength, and the effect of the addition of hydrotropic agents on the CD solubility diagrams for the antimycotics were estimated. The miconazole and the CD dissolution rate for the complex was measured. The hemolytic activity of the miconazole inclusion complex, the physical mixture, miconazole, and the nitrate salt were compared. The toxicity on TR146 oral cell layers was measured. Lowering the temperature meant that both complexes precipitated at lower CD concentrations. Addition of hydrotropic agents and variation of the buffer strength affected the solubility diagrams. The dissolution medium was supersaturated with miconazole. The supersaturation was not disclosed by the traditional method to analyze for drug supersaturation. The miconazole complex was more toxic to erythrocytes than the physical mixture. On the other hand, the toxic effects of the two products on the TR146 cell layers were similar. Lowering the temperature eased the isolation of genuine CD inclusion complexes of miconazole and econazole. The miconazole supersaturation is likely to be the reason for the superior antimycotic activity of the complex. The complex and the physical mixture had about the same toxicity on TR146 cell layers.

Topics: Antifungal Agents; beta-Cyclodextrins; Cell Culture Techniques; Cell Line; Cell Survival; Cyclodextrins; Drug Interactions; Econazole; Erythrocytes; Hemolysis; Humans; Hydrogen-Ion Concentration; Miconazole; Mouth; Nitrates; Solubility; Temperature; Water

Acetyl groups were introduced to the hydroxyl groups of heptakis(2, 6-di-O-methyl)-beta-cyclodextrin (DM-beta-CyD), and the resulting heptakis(2,6-di-O-methyl-3-O-acetyl)-beta-CyD (DMA-beta-CyD) was evaluated for the inclusion property and hemolytic activity. It was confirmed by means of NMR and mass spectroscopies that in the DMA-beta-CyD molecule, all seven hydroxyl groups at the 3-position were substituted by acetyl groups. Thus, it has the degree of substitution (DS) of 7, whereas DMA4-beta-CyD with the lower substitution (DS 3.8) was a mixture of components with different DS. The aqueous solubility of DMA-beta-CyD was higher than those of beta-CyD, DM-beta-CyD, and heptakis(2,3,6-tri-O-methyl)-beta-CyD (TM-beta-CyD). The hydrophobicity of the whole molecule, assessed from measurements of surface tension, increased in the order of DM-beta-CyD < DMA-beta-CyD < TM-beta-CyD. The half-life of DMA-beta-CyD for hydrolysis in pH 9.5 and 60 degrees C was about 19 h, and there was only slight liberation of acetic acid in rabbit plasma and carboxylesterase (EC 3.1.1.1) at 37 degrees C. DMA-beta-CyD had an inclusion ability similar to that of TM-beta-CyD for p-hydroxybenzoic acid esters with different alkyl chain lengths and an antiinflammatory drug, flurbiprofen, although it was inferior to that of DM-beta-CyD. The hemolytic activity and rabbit muscular irritation of DMA-beta-CyDs were much weaker than those of DM-beta-CyD: no hemolysis was observed even in the presence of 0.1 M DMA-beta-CyD with DS 7. The results suggest that the water-soluble CyD derivative with superior bioadaptability and inclusion ability can be prepared by properly designing substituents at the 3-position and by optimally controlling their degree of substitution.

Topics: Animals; beta-Cyclodextrins; Chemical Phenomena; Chemistry, Physical; Cholesterol; Cyclodextrins; Erythrocytes; Excipients; Hemolysis; Hydrolysis; In Vitro Techniques; Irritants; Muscular Diseases; Rabbits; Solubility; Spectrometry, Fluorescence

The effects of beta-cyclodextrin complexation on the photochemical and photosensitizing properties of tolmetin have been investigated. Absorption, emission, circular dichroism and NMR measurements were used to characterize the host-guest complex. Nanosecond laser flash photolysis and steady-state photolysis experiments were performed to clarify the photoreactivity of the drug in the macrocycle. The decarboxylation of the drug is markedly reduced upon inclusion and the rate constants of the decay of the transient intermediates involved in tolmetin photodecomposition were slowed down due to their incorporation in the hydrophobic cavity. This also influenced the distribution of the stable photoproducts. A remarkable cyclodextrin-mediated protection against the tolmetin-photoinduced damage on biological substrates was observed. A rationale for these biological effects is provided.

Topics: beta-Cyclodextrins; Cyclodextrins; Hemolysis; Humans; In Vitro Techniques; Lipid Peroxidation; Photochemistry; Photolysis; Photosensitizing Agents; Plasmids; Tolmetin

Three positional isomers of 6(1),6n-di-O-alpha-D-glucosyl-cyclomaltoheptaose [1,n-(G)2-beta CDs; n = 2-4] which existed in the digests with glucoamylase of the products from cyclomaltoheptaose (beta-cyclodextrin, beta CD) and maltose with Klebsiella pneumoniae pullulanase, were purified by HPLC. The solubilities of two isomers of those doubly branched beta CDs, 1,2- and 1,3-(G)2-beta CDs, in water were much higher than those of parent non-branched beta CD and mono-branched beta CD, 6-O-alpha-D-glucosyl-beta CD (G-beta CD), while the solubility of another isomer, 1,4-(G)2-beta CD, was significantly lower than these two isomers, though it was higher than that of beta CD. On the other hand, the solubilities of 1,2- and 1,3-isomers in 10, 30, and 50% (v/v) aqueous methanol at 25 degrees C were independent of methanol concentrations and their solubilities were the same as those in water at 25 degrees C. However, that of 1,4-isomer increased with increasing methanol concentrations. The hemolytic activities of 1,n-(G)2-beta CDs on human erythrocytes in isotonic solution were lower than those of G-beta CD and beta CD, and became weaker in the order of 1,4- > 1,2- > 1,3-isomers. The complex-forming abilities of 1,n-(G)2-beta CDs for digitoxin, digoxin, fluorometholone, flurbiprofen, hydrocortisone acetate, and norfloxacin were about the same as those of beta CD and G-beta CD, whereas reserpine was more difficult to include within 1,n-(G)2-beta CDs than beta CD and G-beta CD. Nevertheless, the solubilities of those guest compounds were much more enhanced by 1,n-(G)2-beta CDs and G-beta CD than by beta CD.

Topics: beta-Cyclodextrins; Chemical Phenomena; Chemistry, Physical; Chromatography, High Pressure Liquid; Cyclodextrins; Erythrocytes; Hemolysis; Humans; Isomerism; Solubility

Cyclodextrins improve the water-solubility of drugs and can mask their haemolytic effect in parenteral use. Because the mechanism by which bile acids induce haemolysis is poorly understood, it has been investigated in the presence of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD). The haemolytic effect of 1.8 mM solutions of cholic acid, chenodeoxycholic acid (CDCA), deoxycholic acid and ursodeoxycholic acid (UDCA) in isotonic buffer at pH 7.4 was investigated at 37 degrees C in the presence of HP-beta-CyD at concentrations from 0.18 to 32 mM. No haemolytic effect was evident for cholic acid and UDCA. The haemolytic effect of the other bile acids was reduced by addition of HP-beta-CyD and was prevented at a molar ratio of 1:1 owing to complex formation. An HP-beta-CyD:bile acid molar ratio greater than 5:1 had a different effect on the erythrocyte membrane, irrespective of the identity of the bile acid; the effect was in accordance with the complexion affinities. In the absence of HP-beta-CyD, the haemolytic effect of CDCA and deoxycholic acid appeared related to their capacity to form a surface monolayer and to solubilize the components of the erythrocyte membrane. The haemolytic effect observed after complexation of the bile acids appeared to be solely the effect of HP-beta-CyD, which was able to form a reversible inclusion complex with lipophilic components of the erythrocyte membranes at concentrations higher than 12 mM.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; beta-Cyclodextrins; Bile Acids and Salts; Cholesterol; Cyclodextrins; Erythrocyte Membrane; Erythrocytes; Hemolysis; Humans; In Vitro Techniques; Solubility; Surface Tension

The hemolytic activity of beta-cyclodextrin (beta-CyD) on rabbit erythrocytes was reduced by the introduction of negatively-charged groups onto the hydroxyls of beta-CyD; the membrane disrupting abilities decreased in the order of beta-CyD > 2-hydroxypropyl-beta-CyD (HP-beta-CyD) > sulfobutyl-beta-CyD (SB-beta-CyD) >> beta-CyD sulfate (S-beta-CyD). Under pre-hemolytic concentrations, both beta-CyD and SB-beta-CyD induced shape changes of membrane invagination on the erythrocytes. In sharp contrast, S-beta-CyD showed biphasic effect on the shape of the erythrocytes; i.e. the crenation at relatively low concentrations and the invagination at higher concentrations. The S-beta-CyD-induced membrane crenation arose from a direct action on the membranes rather than cell metabolism-mediated effects. Unlike beta-CyD, S-beta-CyD was found to bind to the erythrocytes and may be confined to the outer surface of the membrane bilayer, which may expand the exterior layer relative to the cytoplasmic half, thereby inducing the cells to crenate. On the other hand, the membrane invagination mediated by the three beta-CyDs was initiated by extracting specific membrane lipids from the cells, depending upon their inclusion abilities, subsequently leading to the lysis of the cells. These results indicate that SB-beta-CyD and S-beta-CyD interact with the erythrocyte membranes in a differential manner and possess lower membrane disrupting abilities than the parent beta-CyD and HP-beta-CyD.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; Anions; beta-Cyclodextrins; Cyclodextrins; Erythrocyte Membrane; Hemolysis; Rabbits

The inclusion mode of beta-cyclodextrin sulfate (beta-CyD-sul) with a cationic drug, chlorpromazine, was investigated, and the effect of beta-CyD-sul on the hemolytic activity of chlorpromazine was compared with that of parent beta-CyD. The interaction of beta-CyD-sul with chlorpromazine was weaker than that of parent beta-CyD, probably because of the steric or electrostatic repulsion between anionic sulfate groups and hydrophobic phenothiazine moiety. Spectroscopic studies, including pH- and salt-effects, as well as thermodynamic parameters, suggested that both electrostatic and hydrophobic interactions are operative in the inclusion complexation of beta-CyD-sul with chlorpromazine. The inhibiting effect of parent beta-CyD on the chlorpromazine-induced hemolysis of rabbit erythrocytes was accounted for by the decreased fraction of free drug through the complexation. In the case of beta-CyD-sul, the hemolysis and binding of the drug to the erythrocyte membrane was higher than those estimated from the fraction of free drug, probably due to the increased hydrophobicity of the drug through the complexation. However, the chlorpromazine-induced shape change of the erythrocytes was significantly suppressed by beta-CyD-sul, and its inhibiting effect was greater than that of beta-CyD, because of the counterbalance of the opposite effects, i.e., internalization and externalization induced by chlorpromazine and beta-CyD-sul, respectively.

Topics: Animals; beta-Cyclodextrins; Cells, Cultured; Chemistry, Pharmaceutical; Chlorpromazine; Cyclodextrins; Drug Interactions; Erythrocytes; Hemolysis; Pharmaceutical Vehicles; Rabbits

Topics: beta-Cyclodextrins; Cyclodextrins; Dose-Response Relationship, Drug; Erythrocytes; Hemoglobins; Hemolysis; Heparin; Humans; Spectrophotometry

beta-Cyclodextrin (beta-CyD) was found to protect the human erythrocytes from the hemolysis induced with ten phenothiazine neuroleptics in isotonic solution. The hemolytic activities of the phenothiazine-beta-CyD systems appeared to depend upon the free phenothiazine concentration, suggesting that the complexed form of phenothiazines is essentially inactive to cause hemolysis. The binding abilities and surface activities of the complexed form of phenothiazines were much smaller than those of free phenothiazines. These results indicate that the protective effect of beta-CyD may be due to the decrease in the effective hemolytic concentration of phenothiazines by inclusion complexation rather than the stabilizing effect of beta-CyD on the erythrocyte membrane.

Topics: Antipsychotic Agents; beta-Cyclodextrins; Cyclodextrins; Dextrins; Erythrocytes; Hemolysis; Humans; In Vitro Techniques; Phenothiazines; Starch; Surface Tension