betadex and thiazolyl-blue

The present study with aim at enhancing the therapeutic and anti-cancer properties of cisplatin (CPT)-loaded bovine serum albumin (BSA) nanoparticles. The BSA nanoparticles containing CPT (CPT-BSANPs) were successfully prepared by the desolvation technique. The physicochemical characterization of the CPT-BSANPs were used by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The particle size of CPT-BSANPs was found less than 200 nm with 75.02 ± 0.15% entrapment efficiency (EE), while zeta potential and PDI were -17.6 mV and 0.2, respectively.

Topics: Albumins; Animals; Antineoplastic Agents; beta-Cyclodextrins; Cattle; Cell Death; Cell Survival; Cisplatin; Dose-Response Relationship, Drug; Drug Delivery Systems; Endocytosis; Flow Cytometry; Humans; MCF-7 Cells; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Nanomedicine; Nanoparticles; Particle Size; Serum Albumin, Bovine; Spectroscopy, Fourier Transform Infrared; Tetrazolium Salts; Thiazoles

In this work, a simple one-step method is first employed to produce the bromoisobutyryl-terminated 2-hydroxypropyl-β-cyclodextrin (HPCD-Br). The pendant epoxy groups of poly(glycidyl methacrylate) block prepared via ATRP from HPCD-Br can be reacted with ethanolamine to produce HPCD-PGEA which exhibits much lower cytotoxicity and better gene transfection yield than polyethylenimine (25 kDa) in COS7 and HepG2 cell lines. Moreover, poly((2-dimethyl amino)ethyl methacrylate) blocks can be incorporated into low-molecular-weight HPCD-PGEA via "click" reaction to further enhance the gene transfection efficiency in HepG2 cell lines.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Animals; beta-Cyclodextrins; Cell Survival; Chlorocebus aethiops; Click Chemistry; COS Cells; Electrophoretic Mobility Shift Assay; Ethanolamine; Genetic Vectors; Hep G2 Cells; Humans; Magnetic Resonance Spectroscopy; Methacrylates; Nylons; Plasmids; Polymerization; Polymethacrylic Acids; Tetrazolium Salts; Thiazoles; Transfection

A new self-assembly nanoprobe, mercaptoethylamine-modified-gold nanoparticles-Lysine-bridged-bis(β-cyclodextrins)-fluorescein (MGNPs-Lys-bis(β-CDs)-FL), based on fluorescence resonance energy transfer (FRET) was developed for determination of trypsin firstly in biological systems. With the Lys-bis(β-CDs)-FL complex as an energy donor and mercaptoethylamine (MEA)-modified gold nanoparticles (MGNPs) as an energy acceptor, the two parts assemble an efficient FRET nanoprobe through an amide bond. Trypsin is specific for the hydrolysis of amide linkages of lysine. Therefore, in the presence of trypsin, the nanoprobe is cleaved by trypsin on the binding sites of amide with good specificity and sensitivity, resulting in the fluorescence recovery of the quenched FL. The nanoprobe has good biological applicability and provides a potential assay for further clinical research of trypsin in biosystems.

Topics: beta-Cyclodextrins; Cell Line, Tumor; Coloring Agents; Dimerization; Fluorescence Resonance Energy Transfer; Gold; Humans; Mercaptoethylamines; Metal Nanoparticles; Microscopy, Confocal; Sensitivity and Specificity; Tetrazolium Salts; Thiazoles; Trypsin

The transport of alendronate through Caco-2 monolayers in the absence and presence of absorption enhancers (sodium taurocholate-STC and dimethyl-beta-cyclodextrin-DM-beta-CD) was studied. The viability of Caco-2 cells was determined by MTT assay. The effects of the experiment period and serum existence in Dubelco's Modified Eagle's Medium (DMEM) on cell viability were examined. The least toxic concentrations of alendronate, STC and DM-beta-CD were found as 0.2% (w/v), 5 mM and 0.3% (w/v), respectively. Transport experiments were performed with these concentrations in DMEM supplemented with serum for an 8 h period. DM-beta-CD increased the transport of alendronate through Caco-2 monolayers significantly. No significance was observed with STC. Cell integrity was determined by measuring the electrical resistance values at the end of the transport experiments and found to be decreased to a greater extent with DM-beta-CD. These results indicate that DM-beta-CD is a promising agent for improving the transport of alendronate.

Topics: Absorption; Alendronate; beta-Cyclodextrins; Biological Transport, Active; Bone Density Conservation Agents; Caco-2 Cells; Cell Membrane Permeability; Cell Survival; Electric Impedance; Excipients; Humans; Taurocholic Acid; Tetrazolium Salts; Thiazoles

During CNS development neurons undergo directional migration to achieve their adult localizations. To study neuronal migration, we used a model cell line of immortalized murine neurons (gonadotropin-releasing hormone expressing neurons; GN11), enriched with caveolins and caveolae invaginations that show in vitro chemotaxis upon serum exposure. Cholesterol depletion with methyl-beta-cyclodextrin induced the loss of caveolae and the inhibition of chemotaxis, thus suggesting that GN11 migration depends upon the structural integrity of caveolae. Polarization of proteins and organelles is a hallmark of cell migration. Accordingly, GN11 cells transmigrating through filter pores exhibited a polarized distribution of caveolin-1 isoform (cav-1) in the leading processes. In contrast, during two-dimensional migration cav-1 and caveolae polarized at the trailing edge. As caveolae are enriched with signaling molecules, we suggest that asymmetrical localization of caveolae may spatially orient GN11 neurons to incoming migratory signals thereby transducing them into directional migration.

Topics: Animals; beta-Cyclodextrins; Caveolae; Caveolins; Cell Line, Transformed; Cell Movement; Chemotaxis; Cholesterol; Gonadotropin-Releasing Hormone; Indoles; Mice; Microscopy, Electron, Transmission; Neurons; Tetrazolium Salts; Thiazoles

Recently we have described an HPMA copolymer conjugate carrying both the aromatase inhibitor aminoglutethimide (AGM) and doxorubicin (Dox) as combination therapy. This showed markedly enhanced in vitro cytotoxicity compared to the HPMA copolymer-Dox (FCE28068), a conjugate that demonstrated activity in chemotherapy refractory breast cancer patients during early clinical trials. To better understand the superior activity of HPMA copolymer-Dox-AGM, here experiments were undertaken using MCF-7 and MCF-7ca (aromatase-transfected) breast cancer cell lines to: further probe the synergistic cytotoxic effects of AGM and Dox in free and conjugated form; to compare the endocytic properties of HPMA copolymer-Dox-AGM and HPMA copolymer-Dox (binding, rate and mechanism of cellular uptake); the rate of drug liberation by lysosomal thiol-dependant proteases (i.e. conjugate activation), and also, using immunocytochemistry, to compare their molecular mechanism of action. It was clearly shown that attachment of both drugs to the same polymer backbone was a requirement for enhanced cytotoxicity. FACS studies indicated both conjugates have a similar pattern of cell binding and endocytic uptake (at least partially via a cholesterol-dependent pathway), however, the pattern of enzyme-mediated drug liberation was distinctly different. Dox release from PK1 was linear with time, whereas the release of both Dox and AGM from HPMA copolymer-Dox-AGM was not, and the initial rate of AGM release was much faster than that seen for the anthracycline. Immunocytochemistry showed that both conjugates decreased the expression of ki67. However, this effect was more marked for HPMA copolymer-Dox-AGM and, moreover, only this conjugate decreased the expression of the anti-apoptotic protein bcl-2. In conclusion, the superior in vitro activity of HPMA copolymer-Dox-AGM cannot be attributed to differences in endocytic uptake, and it seems likely that the synergistic effect of Dox and AGM is due to the kinetics of intracellular drug liberation which leads to enhanced activity.

Topics: Aminoglutethimide; Antineoplastic Agents; Apoptosis; beta-Cyclodextrins; Breast Neoplasms; Cell Survival; Chlorpromazine; Cytochalasin B; Doxorubicin; Endocytosis; Female; Flow Cytometry; Humans; Immunohistochemistry; Ki-67 Antigen; Kinetics; Liver; Lysosomes; Methacrylates; Microscopy, Confocal; Proto-Oncogene Proteins c-bcl-2; Tetrazolium Salts; Thiazoles

Cyclodextrins (CDs) are widely used materials and still in the focus of drug development. In spite of the extensive studies, there is limited information about the cytotoxic effect of different derivatives. This study compares the cytotoxic effect of methylated beta-CDs and some ionic derivatives. The methylated CDs involved in this study differ in the number and position of the methyl substituents. Heptakis(2,6-di-O-methyl)-beta-CD (DIMEB) with a degree of substitution (DS) of 14 has two methyl groups in all of the seven glucose subunits mostly at O-2 and O-6 position, each OH group is methylated in heptakis(2,3,6-tri-O-methyl)-beta-CD (TRIMEB) (DS = 21), and an unsystematic substitution is realized in randomly methylated beta-CD (RAMEB). DS is defined as the number of substituents per cyclodextrin ring. Using the above definition, the DS for RAMEB is 12.6. To see the effect of the ionic groups an anionic and a cationic CD derivative were also investigated: (2-hydroxy-3-N,N,N-trimethylamino)propyl beta-CD (QABCD) (DS = 2) and carboxymethylated beta-CD (CMBCD) (DS = 3,5). The in vitro cell toxicity decreases in the order of DIMEB > TRIMEB > or = RAMEB > QABCD > CMBCD. Ionic beta-CDs were less toxic than the methylated derivatives.

Topics: Antineoplastic Agents; beta-Cyclodextrins; Cell Line, Tumor; Cell Survival; HeLa Cells; Humans; Indicators and Reagents; Methylation; Tetrazolium Salts; Thiazoles

By using nerve growth factor-differentiated PC12 cells as a model for sympathetic neurons, we have recently shown that cholesterol oxides are toxic to cells of neural origin. Since lipid metabolism is known to be involved in some pathological conditions associated with the visual system, we sought to extend this line of research by studying the potential cytotoxicity of cholesterol oxides on primary cultures derived from neuroretinas.. Dissociated cultures derived from neuroretinas of 1-day-old Sprague-Dawley rats were used in this series of studies. Immunohistochemical staining was used to identify neuronal and glial cell types in these cultures. MTT assay was used to determine the cytotoxicity of cholesterol oxides, including 7-beta-OH-, 7-keto-, 19-OH-, 22(R)-OH-, 22(S)-OH- and 25-OH-cholesterol.. Among the cholesterol oxides tested, 7-beta-OH- and 7-keto-cholesterol were the most effective in causing cell death, such that 20 micrograms/ml (50 microM) of these agents killed approximately 80% of cells in 3 days. A time-dependent experiment indicated that 10 micrograms/ml of 7-beta-cholesterol was able to kill 50% of cells in approximately 5 h. A number of pharmacological agents were tested for their ability to prevent cell death induced by cholesterol oxides. Among them, vitamin E and methyl-beta-cyclodextrin were able to prevent cholesterol oxide-induced cell death in a dose-dependent manner.. These results suggest that, in addition to causing pathological changes in cells directly involved in atherosclerosis, cholesterol oxides may be toxic to cells derived from neuroretinas.

Topics: Animals; Animals, Newborn; beta-Cyclodextrins; Cell Death; Cell Survival; Cells, Cultured; Coloring Agents; Cyclodextrins; Dose-Response Relationship, Drug; Hydroxycholesterols; Immunoenzyme Techniques; Neuroglia; Neurons; Rats; Rats, Sprague-Dawley; Retina; Tetrazolium Salts; Thiazoles; Vitamin E