chlorophyll-a and Neoplasms

Chlorophyll, a phytochemical responsible for the green pigmentation in plants, has been studied for almost 100 years for its biological activities in humans. Over the past 30 years, the potential chemopreventative activities of both natural chlorophylls and their processed induced derivatives as well as the semisynthetic forms, such as sodium copper chlorophyllin, have been the focus of many research efforts. Established as potential chemopreventative agents with little to no bioavailability themselves, the activities of chlorophyll derivatives were generally ascribed to their ability to modulate mutagen/carcinogen bioavailability, their metabolism, and ultimately their ability to decrease the "exposure" to these carcinogens for humans at risk. More recently, systemic activities of chlorophyll derivatives have been reported to include modulation of oxidative stress and regulation of xenobiotic metabolizing systems and gene expression of systems critical to prevention of initiation and/or progression of cancer including NFE2-related factor 2, nuclear factor kappa B, TGF-β, and β-catenin pathways. With this in mind, the goals of this review are to provide an update to the comprehensive review of Ferruzzi and Blakeslee (2007) to include new insights into the behavior of chlorophyll derivatives in the gut as well as evidence of the systemic bioavailability of chlorophyll derivatives and their metabolites in support of potential impacts in prevention of cancer throughout the body.

Topics: Animals; Anticarcinogenic Agents; Biological Availability; Carcinogens; Chemoprevention; Chlorophyll; Diet; Digestion; Digestive System; Humans; Intestinal Absorption; Mutagens; Neoplasms; Oxidative Stress; Signal Transduction; Xenobiotics

Thylakoids and chloroplasts harbor several vital metabolic processes, but are most importantly associated with photosynthesis. The undisturbed functioning of this process necessitates the ceaseless synthesis of photosynthetic pigments, including closed tetrapyrroles such as chlorophylls (Chls). Chls probably represent the most abundant natural pigment molecules which are via photosynthesis not only crucial for the autotrophic production of food sources for heterotrophic organisms but have also contributed to oxygen production essential for aerobic metabolism. This review first briefly discusses the physico-chemical properties, biosynthesis, occurrence, in vivo localization and roles of the different Chl pigments. Then we provide a detailed overview of their potential applications in the food industry and medicine. These include the use of Chls and their derivatives (different chlorophyllins) as food colorants (identified as E140 and E141 in the European Union).. Different sources used for industrial extraction as well as different factors influencing pigment stability during processing are also critically reviewed. The problems surrounding the nomenclature, the production and the composition of different chlorophyllin mixtures are also discussed.. Finally, a comprehensive overview of the health benefits and potential medicinal applications of these pigments and the future directions of research in these fields are provided.

Topics: Antineoplastic Agents; Antioxidants; Chlorophyll; Chlorophyllides; Food Coloring Agents; Humans; Neoplasms; Photochemotherapy

Pheophorbide a is a clorophyll catabolite that recently has drawn the attention of several investigators for its potential in photodynamic therapy. In this review we summarize its photophysical properties, phototoxicity, cellular localization, biodistribution and PDT activity as a free or conjugated molecule.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Carrier Proteins; Cell Survival; Chlorophyll; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents

In recent years several review articles and books have been published on the use of porphyrin-based compounds in photodynamic therapy (PDT). This critical review is focused on (i) the basic concept of PDT, (ii) advantages of long-wavelength absorbing photosensitizers (PS), (iii) a brief discussion on recent advances in developing PDT agents, and (iv) the various synthetic strategies designed at the Roswell Park Cancer Institute, Buffalo, for developing highly effective long-wavelength PDT agents and their utility in constructing the conjugates with tumor-imaging and therapeutic potential (Theranostics). The clinical status of certain selected PDT agents is also summarized (205 references).

Topics: Animals; Chlorophyll; Esophageal Neoplasms; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents; Porphyrins

The purpose of this review is to call attention in the use of chlorophyll-a and bacteriochlorophyll-a to develop more than 600 photosensitizers (lambda (max) 660 nm-800 nm) during the last 15 years (1990-2005) at the Photodynamic Therapy Center, Roswell Park Cancer Institute, Buffalo. This article mainly includes the chemistry, preclinical results, and brief clinical data of some of the most effective photosensitizers. The utility of the tumor-avid photosensitizers in developing multimodality agents (imaging and therapy) is also presented.

Topics: Bacteriochlorophyll A; Chlorophyll; Diagnostic Imaging; Fullerenes; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents

Vegetables, fruits, and whole grains contain a wide variety of phytochemicals that have the potential to modulate cancer development. There are many biologically plausible reasons why consumption of plant foods might slow or prevent the appearance of cancer. These include the presence in plant foods of such potentially anticarcinogenic substances as carotenoids, chlorophyll, flavonoids, indole, isothiocyanate, polyphenolic compounds, protease inhibitors, sulfides, and terpens. The specific mechanisms of action of most phytochemicals in cancer prevention are not yet clear but appear to be varied. Considering the large number and variety of dietary phytochemicals, their interactive effects on cancer risk may be extremely difficult to assess. Phytochemicals can inhibit carcinogenesis by inhibiting phase I enzymes, and induction of phase II enzymes, scavenge DNA reactive agents, suppress the abnormal proliferation of early, preneoplastic lesions, and inhibit certain properties of the cancer cell.

Topics: Animals; Anticarcinogenic Agents; Carotenoids; Chlorophyll; Flavonoids; Humans; Indoles; Isothiocyanates; Neoplasms; Phenols; Plants, Edible; Polymers; Protease Inhibitors; Sulfides

Topics: Anticarcinogenic Agents; Antimutagenic Agents; Carcinogenicity Tests; Catechin; Chlorophyll; Diet; Hemin; Humans; Mutagenicity Tests; Neoplasms; Risk Factors

Topics: Arteriosclerosis; Chlorophyll; Chlorophyllides; Humans; Inflammation; Neoplasms; Psoriasis; Wound Healing

Recent pilot studies found natural chlorophyll (Chl) to inhibit carcinogen uptake and tumorigenesis in rodent and fish models, and to alter uptake and biodistribution of trace (14)C-aflatoxin B1 in human volunteers. The present study extends these promising findings, using a dose-dose matrix design to examine Chl-mediated effects on dibenzo(def,p)chrysene (DBC)-induced DNA adduct formation, tumor incidence, tumor multiplicity, and changes in gene regulation in the trout. The dose-dose matrix design employed an initial 12,360 rainbow trout, which were treated with 0-4000ppm dietary Chl along with 0-225ppm DBC for up to 4weeks. Dietary DBC was found to induce dose-responsive changes in gene expression that were abolished by Chl co-treatment, whereas Chl alone had no effect on the same genes. Chl co-treatment provided a dose-responsive reduction in total DBC-DNA adducts without altering relative adduct intensities along the chromatographic profile. In animals receiving DBC alone, liver tumor incidence (as logit) and tumor multiplicity were linear in DBC dose (as log) up to their maximum-effect dose, and declined thereafter. Chl co-treatment substantially inhibited incidence and multiplicity at DBC doses up to their maximum-effect dose. These results show that Chl concentrations encountered in Chl-rich green vegetables can provide substantial cancer chemoprotection, and suggest that they do so by reducing carcinogen bioavailability. However, at DBC doses above the optima, Chl co-treatments failed to inhibit tumor incidence and significantly enhanced multiplicity. This finding questions the human relevance of chemoprevention studies carried out at high carcinogen doses that are not proven to lie within a linear, or at least monotonic, endpoint dose-response range.

Topics: Animal Feed; Animals; Benzopyrenes; Chlorophyll; Diet; Dose-Response Relationship, Drug; Fish Diseases; Gene Expression Regulation; Neoplasms; Oncorhynchus mykiss

Topics: Animals; Chlorophyll; CRISPR-Cas Systems; Gene Editing; Mice; Micelles; Neoplasms; NF-E2-Related Factor 2; Photochemotherapy

To investigate and compare the pharmacokinetic profile and anti-cancer activity of fluorinated and iodinated photosensitizers (PSs), the 3-(1'-(

Topics: Animals; Cell Line, Tumor; Chlorophyll; Chlorophyll A; Male; Mice; Neoplasms; Photochemotherapy; Photosensitizing Agents

Inspired by natural saccharide-protein complexes, a stimuli-responsive biodegradable and branched glycopolymer-pyropheophorbide-a (Ppa) conjugate (BSP) with saccharide units for cancer therapy is constructed. A linear glycopolymeric conjugate (LSP), a branched glycopolymeric conjugate (BShP) from Ppa with long carbon chains, and a branched conjugate (BHSP) based on poly[N-(2-hydroxypropyl) methacrylamide] (polyHPMA) without saccharide units are prepared as controls. Through structure-activity relationship studies, BSP with a 3D network structure forms stable nanostructures via weak intermolecular interactions, regulating the stacking state of Ppa to improve the singlet oxygen quantum yield and the corresponding photodynamic therapy (PDT) effect. BSP shows high loading of olaparib, and are further coated with tumor cell membranes, resulting in a biomimetic nanomedicine (CM-BSPO). CM-BSPO shows highly efficient tumor targeting and cellular internalization properties. The engulfment of CM-BSPO accompanied with laser irradiation results in a prominent antitumor effect, evidenced by disruption of cell cycles in tumor cells, increased apoptosis and DNA damage, and subsequent inhibition of repair for damaged DNA. The mechanism for the synergistic effect from PDT and olaparib is unveiled at the genetic and protein level through transcriptome analysis. Overall, this biodegradable and branched glycopolymer-drug conjugate could be effectively optimized as a biomimetic nanomedicine for cancer therapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; Biomimetic Materials; Cell Line, Tumor; Chlorophyll; DNA Damage; Drug Carriers; Genomic Instability; Humans; Light; Mice; Nanomedicine; Nanostructures; Neoplasms; Photochemotherapy; Phthalazines; Piperazines; Polymethacrylic Acids; Polysaccharides; Reactive Oxygen Species

Topics: Animals; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 2; Biological Transport; Cell Proliferation; Chlorophyll; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Flow Cytometry; Furocoumarins; HCT116 Cells; Heterografts; High-Throughput Screening Assays; Humans; Irinotecan; Mice; Neoplasm Proteins; Neoplasms

Biomarker-activatable theranostic formulations offer the potential for removing specific tumors with a high diagnostic accuracy and a significant pharmacological effect. Herein, we developed a novel activatable theranostic nanoformulation UAS-PD [upconversion nanophosphor (UCNP)-aptamer/ssDNA-pyropheophorbide-a (PPA)-doxyrubicin (DOX)], which can recognize specific cancer cells with sensitivity and trigger the localized photodynamic destruction and enhanced chemotherapy. UAS-PD was constructed by the conjugation of UCNPs and aptamer probes containing the photosensitizer PPA and the chemotherapeutic drug DOX. When cancer cells are present, the UAS-PD specifically binds to PTK7, an overexpressed protein present on the surface of cancer cells, through conformational recombination of the aptamer structure and switches its upconversion luminescence from 655 to 540 nm. This long-lived ratiometric optical signal provides an ultrasensitive detection limit as low as 3.9 nM for PTK7. Changes in the conformation of UAS-PD can also induce PPA to approach UCNPs, which can produce cytotoxic singlet oxygens under near-infrared excitation to destroy the cell membrane and enhance its permeability for the simultaneously released DOX that targets cellular DNA degradation, which results in a highly effective tumor-killing effect by synergistic extra-intracellular sequential damage.

Topics: Animals; Antineoplastic Agents; Aptamers, Nucleotide; Cell Adhesion Molecules; Cell Line, Tumor; Chlorophyll; Doxorubicin; Female; Humans; Light; Mice, Nude; Nanoparticles; Neoplasms; Photochemotherapy; Photosensitizing Agents; Receptor Protein-Tyrosine Kinases; Singlet Oxygen; Theranostic Nanomedicine; Xenograft Model Antitumor Assays

In combination therapy, synergetic effects of drugs and their efficient delivery are essential. Herein, we screened 12 anticancer drugs for combination with photodynamic therapy (PDT) using pheophorbide a (Pba). On the basis of combination index (CI) values in cell viability tests, we selected tirapazamine (TPZ) and developed self-assembled gelatin nanoparticles (NPs) containing both Pba and TPZ. The resulting TPZ-Pba-NPs showed a synergetic effect to kill tumor cells because TPZ was activated under the hypoxic conditions that originated from the PDT with Pba and laser irradiation. After they were injected into tumor-bearing mice via the tail vein, TPZ-Pba-NPs showed 3.17-fold higher blood concentration and 4.12-fold higher accumulation in tumor tissue 3 and 24 h postinjection, respectively. Upon laser irradiation to tumor tissue, TPZ-Pba-NPs successfully suppressed tumor growth by efficient drug delivery and synergetic effects

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Chlorophyll; Drug Carriers; Drug Screening Assays, Antitumor; Drug Synergism; Drug Therapy; Gelatin; Light; Mice, Inbred C3H; Nanoparticles; Neoplasms; Photochemotherapy; Photosensitizing Agents; Reactive Oxygen Species; Tirapazamine

Topics: Adult; Aged; Aged, 80 and over; Air Pollutants; Air Pollution; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Anti-Inflammatory Agents; Antibodies, Monoclonal, Humanized; Antigens, Surface; Antineoplastic Agents; Antioxidants; Antiviral Agents; Aporphines; Atherosclerosis; Benzoyl Peroxide; beta Catenin; Biofilms; Biomarkers; Brain; Cannabis; Carcinoma, Squamous Cell; Case-Control Studies; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Line; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Child; China; Chlorides; Chlorophyll; Cholesterol, LDL; Coinfection; Corylus; Cross-Sectional Studies; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Developmental Disabilities; Disease Models, Animal; Drug Evaluation, Preclinical; Drug Screening Assays, Antitumor; Electroencephalography; Environmental Exposure; Enzyme Inhibitors; Epilepsy, Generalized; Ethnicity; Female; Fertilization in Vitro; Fluorescent Dyes; Follow-Up Studies; Forecasting; Glutamate Carboxypeptidase II; Glycine; Half-Life; Head and Neck Neoplasms; Health Communication; Heart Ventricles; Hepacivirus; Hepatitis C; Heterosexuality; HIV Infections; Humans; Hypercholesterolemia; Immunoassay; Inhalation Exposure; Isocitrate Dehydrogenase; Laryngeal Neoplasms; Ligands; Light; Lipopolysaccharide Receptors; Liver Cirrhosis; Lung; Lung Neoplasms; Magnetic Resonance Imaging, Cine; Male; Maternal Age; Mechanical Phenomena; Mice; Mice, Nude; Mice, SCID; Microglia; MicroRNAs; Microscopy, Fluorescence; Microsomes, Liver; Middle Aged; Minority Groups; Mitochondrial Membrane Transport Proteins; Models, Biological; Molecular Structure; Molecular Weight; Monte Carlo Method; Muscle Hypotonia; Mutagenesis, Site-Directed; Mutation, Missense; Natriuretic Peptide, Brain; Neoplasms; Nickel; Nitric Oxide; Optical Imaging; Oxides; Particle Size; Particulate Matter; PCSK9 Inhibitors; Peptide Fragments; Phenotype; Photochemotherapy; Photosensitizing Agents; Phytochemicals; Piper; Placenta Growth Factor; Plant Extracts; Plant Leaves; Plant Stems; Platinum; Point-of-Care Testing; Population Surveillance; Postpartum Period; Pregnancy; Pregnancy, Twin; Prevalence; Prospective Studies; Prostatic Neoplasms; Pseudomonas aeruginosa; Pyridines; Pyridones; Racial Groups; Rats; Respiratory Physiological Phenomena; Retrospective Studies; Risk Factors; RNA, Long Noncoding; Semiconductors; Sexual and Gender Minorities; Sexual Behavior; Social Media; Sodium; Solubility; Stereoisomerism; Stochastic Processes; Structure-Activity Relationship; Substance-Related Disorders; Sustained Virologic Response; Sweat; Temperature; Time Factors; Tissue Distribution; Titanium; Transplantation, Heterologous; Tumor Cells, Cultured; Tungsten; Tyramine; United States; Up-Regulation; Ventricular Dysfunction, Left; Ventricular Function, Left; Veterans; Xenograft Model Antitumor Assays; Young Adult

Photodynamic therapy (PDT) has gained much attention in tumor therapy because of its special advantages. PDT heavily depends on the oxygen, yet the tumor microenvironment (TME) is a hypoxic and acid milieu, which weakens the PDT effect. Based on the consideration that the TME deteriorated by the PDT oxygen consumption could activate the hypoxic-sensitive small-molecule drug, we designed and prepared an integrated nanocomposite including zirconium ion metal organic framework (carrier), pyropheophorbide-a (PPa, photosensitizer), and 6-amino flavone (AF, hypoxic-sensitive drug), aiming to exert a cascaded PDT-chemotherapy (CT) antitumor effect and to solve the hypoxic challenge. The prepared nanocomposite showed great stability under the physiological (pH 7.4) condition and could continuously release PPa and AF under slightly acidic pH condition (pH 6.4), suggesting a tumor microenvironment responsive feature. Systematical in vitro and in vivo researches under various conditions (light, dark, hypoxic and normoxic) have showed that the obtained Zr-MOF@PPa/AF@PEG nanoparticles (NPs) had good biocompatibility and could achieve efficient antitumor effects based on PDT- chemotherapy (CT) cascade process. Finally, bright red fluorescence was observed in the tumor cells after internalization implying an application potential in tumor imaging.

Topics: Animals; Biocompatible Materials; Cell Line, Tumor; Cell Survival; Chlorophyll; Drug Liberation; Female; Flavonoids; Humans; Metal-Organic Frameworks; Mice; Mice, Inbred BALB C; Nanocomposites; Neoplasms; Photochemotherapy; Polyethylene Glycols; Singlet Oxygen; Theranostic Nanomedicine; Tumor Microenvironment; Zirconium

To determine the impact of delivery vehicles in photosensitizing efficacy of HPPH, a hydrophobic photosensitizer was dissolved in various formulations: 1% Tween 80/5% dextrose, Pluronic P-123 and Pluronic F-127 in 0.5%, 1% and 2% phosphate buffer solutions (PBS). HPPH was also conjugated to Pluronic F-127, and the resulting conjugate (PL-20) was formulated in PBS. Among the different delivery vehicles, only Pluronic P-123 displayed significant vehicle cytotoxicity, whereas Pluronic F127 was nontoxic. Compared to PL-20, HPPH formulated in Tween80 and Pluronic F-127 showed higher cell-uptake, but lower long-term retention in Colon26 cell compared to PL-20. The higher retention of PL-20 was similarly observed during in vivo uptake with BALB/c mice baring Ct26 tumors. In contrast to the in vitro uptake experiments, PL-20 showed slightly higher uptake compared to HPPH formulated in Tween or Pluronic-F127. A significant difference in pharmacokinetic profile was also observed between the HPPH-Pluronic formulation and PL-20. Under similar in vivo treatment parameters (drug dose 0.47 µmol kg

Topics: Animals; Cell Line, Tumor; Chlorophyll; Humans; Mice; Mice, Inbred BALB C; Neoplasms; Photochemotherapy; Photosensitizing Agents; Poloxamer; Xenograft Model Antitumor Assays

Combination therapy provides an efficient way to overcome the potential multidrug resistance and enhance anticancer efficacy. In this work, a biodegradable pH-responsive hollow mesoporous silica nanoparticle (HMSN-GM-CS-FA) was developed for co-delivery of pheophorbide a (PA) and doxorubicin (DOX). This drug delivery system possessed controlled particle size and larger inner hollow core, which endowed the nanoparticle with excellent encapsulation capacities. The uptake efficiency of drug loaded nanoparticles HMSNs-GM-CS-FA@DOX/PA in cancer cells was greatly improved by folic acid-mediated endocytosis. The nanocarrier showed excellent drug controlled release properties based on the pH-dependent swelling effect of the coating layer. More importantly, the nanoplatform could fully combine photothermal-, photodynamic- and chemotherapies to develop synergistic antitumor efficacy. This strategy of integrating multi-therapeutic functions in one single formulation promised a powerful route to construct intelligent co-delivery carriers for efficient combinational clinical application.

Topics: Antineoplastic Agents; Chitosan; Chlorophyll; Combined Modality Therapy; Doxorubicin; Drug Delivery Systems; Drug Liberation; Drug Resistance, Multiple; Endocytosis; Humans; Hydrogen-Ion Concentration; Metal Nanoparticles; Neoplasms; Silicon Dioxide

Biodistribution of photosensitizer (PS) in photodynamic therapy (PDT) can be assessed by fluorescence imaging that visualizes the accumulation of PS in malignant tissue prior to PDT. At the same time, excitation of the PS during an assessment of its biodistribution results in premature photobleaching and can cause toxicity to healthy tissues. Combination of PS with a separate fluorescent moiety, which can be excited apart from PS activation, provides a possibility for fluorescence imaging (FI) guided delivery of PS to cancer site, followed by PDT.. In this work, we report nanoformulations (NFs) of core-shell polymeric nanoparticles (NPs) co-loaded with PS [2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a, HPPH] and near infrared fluorescent organic dyes (NIRFDs) that can be excited in the first or second near-infrared windows of tissue optical transparency (NIR-I, ~ 700-950 nm and NIR-II, ~ 1000-1350 nm), where HPPH does not absorb and emit. After addition to nanoparticle suspensions, PS and NIRFDs are entrapped by the nanoparticle shell of co-polymer of N-isopropylacrylamide and acrylamide [poly(NIPAM-co-AA)], while do not bind with the polystyrene (polySt) core alone. Loading of the NIRFD and PS to the NPs shell precludes aggregation of these hydrophobic molecules in water, preventing fluorescence quenching and reduction of singlet oxygen generation. Moreover, shift of the absorption of NIRFD to longer wavelengths was found to strongly reduce an efficiency of the electronic excitation energy transfer between PS and NIRFD, increasing the efficacy of PDT with PS-NIRFD combination. As a result, use of the NFs of PS and NIR-II NIRFD enables fluorescence imaging guided PDT, as it was shown by confocal microscopy and PDT of the cancer cells in vitro. In vivo studies with subcutaneously tumored mice demonstrated a possibility to image biodistribution of tumor targeted NFs both using HPPH fluorescence with conventional imaging camera sensitive in visible and NIR-I ranges (~ 400-750 nm) and imaging camera for short-wave infrared (SWIR) region (~ 1000-1700 nm), which was recently shown to be beneficial for in vivo optical imaging.. A combination of PS with fluorescence in visible and NIR-I spectral ranges and, NIR-II fluorescent dye allowed us to obtain PS nanoformulation promising for see-and-treat PDT guided with visible-NIR-SWIR fluorescence imaging.

Topics: Acrylic Resins; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Survival; Chlorophyll; Drug Compounding; Fluorescent Dyes; Humans; Hydrophobic and Hydrophilic Interactions; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Structure; Nanocapsules; Neoplasms; Optical Imaging; Photochemotherapy; Photosensitizing Agents; Polymers; Polystyrenes; Singlet Oxygen; Tissue Distribution

Metabolic demand of cancer is quite unique compared to normal tissues and this is an emerging hallmark of cancer, which brings a potential opportunity to discover drugs that target cancer cell metabolism. Herein, the development of a dendronized pyropheophorbide a (Ppa)-conjugated polymer (DPP) is reported, and a linear Ppa-conjugated polymer (LPP) is reported as a control. DPP is found to disturb cellular metabolism including increased energy depletion, dysfunctional H

Topics: Animals; Cell Line, Tumor; Cell Survival; Chlorophyll; Humans; Lasers; Mice; Nanostructures; Neoplasms; Photochemotherapy; Photosensitizing Agents; Polymers; Tissue Distribution; Xenograft Model Antitumor Assays

A nanoemulsion with a porphyrin shell (NewPS) was created by the self-assembly of porphyrin salt around an oil core. The NewPS system has excellent colloidal stability, is amenable to different porphyrin salts and oils, and is capable of co-loading with chemotherapeutics. The porphyrin salt shell enables porphyrin-dependent optical tunability. The NewPS consisting of pyropheophorbide a mono-salt has a porphyrin shell of ordered J-aggregates, which produced a narrow, red-shifted Q-band with increased absorbance. Upon nanostructure dissociation, the fluorescence and photodynamic reactivity of the porphyrin monomers are restored. The spectrally distinct photoacoustic imaging (at 715 nm by intact NewPS) and fluorescence increase (at 671 nm by disrupted NewPS) allow the monitoring of NewPS accumulation and disruption in mice bearing KB tumors to guide effective photodynamic therapy. Substituting the oil core with Lipiodol affords additional CT contrast, whereas loading paclitaxel into NewPS facilitates drug delivery.

Topics: Animals; Chlorophyll; Drug Carriers; Emulsions; Ethiodized Oil; Humans; KB Cells; Mice, Nude; Nanoparticles; Neoplasms; Paclitaxel; Particle Size; Photoacoustic Techniques; Porphyrins; Theranostic Nanomedicine; Xenograft Model Antitumor Assays

Chemoimmunotherapy by systemic administration of individual regimens suffers from inconsistent pharmacokinetics profiles, low tumor specificity, and severe side effects. Despite promising nanoparticle-based codelivery approaches in therapeutics, the pathophysiological barriers of solid tumors are a hurdle for tumor accumulation and deep penetration of the drug-loaded nanoparticles. A light-inducible nanocargo (LINC) for immunotherapy is reported. LINC is composed of a reduction-responsive heterodimer of photosensitizer pheophorbide A (PPa) and indoleamine 2,3-dioxygenase 1 (IDO-1) inhibitor, i.e., NLG919, and a light-activatable prodrug of oxaliplatin (OXA). LINC administrated through intravenous injection is passively accumulated at the tumor site to generate near-infrared (NIR) fluorescence signal. Under fluorescence imaging guidance, the first-wave of NIR laser irradiation induce reactive oxygen species (ROS) generation, trigger cleavage of the polyethylene glycol (PEG) corona, and thus promote tumor retention and deep penetration of LINC. When exposed to the second-wave NIR laser illumination, LINC efficiently elicits the immune response and promotes intratumoral infiltration of cytotoxic T lymphocytes (CTLs). Furthermore, NLG919 delivered by LINC reverses the immunosuppressive tumor microenvironment by suppressing IDO-1 activity. Chemoimmunotherapy with LINC inhibit the tumor growth, lung metastasis, and tumor recurrence. The light-inducible self-amplification strategy for improved drug delivery and immunotherapy shows potential.

Topics: Animals; Chlorophyll; Dimerization; Drug Carriers; Immunotherapy; Light; Mice; Mice, Inbred BALB C; Nanostructures; Neoplasms; Photochemotherapy; Photosensitizing Agents; Reactive Oxygen Species; T-Lymphocytes, Cytotoxic

Pyropheophorbide a (Pyro) is a promising photosensitizer; however, it has no tumor selectivity and enrichment capability. In our former work, the prepared folic acid (FA)-Pyro conjugates showed considerably improved tumor accumulation and photodynamic therapy (PDT) activity in cell- and animal-based studies. However, the targeting capability, selectivity and water solubility of the conjugate remain problematic. Here, we evaluated the installation of hydrophilic polyethylene glycol chains as the linker between Pyro and FA, by avoiding direct conjugation of Pyro with FA, aiming to improve tumor selectivity and accumulation. However, PEGylation may have negative effects on the PDT activity and cutaneous phototoxicity. Therefore, we chose various lengths of PEGs as linkers to optimize the molecular weight, hydrophilicity, and PDT activity and, thus, to balance the tumor selectivity and biological function of the conjugate. One optimized conjugate, Pyro-PEG1K-FA, exhibited excellent tumor enrichment and was able to eradicate subcutaneous tumors at a considerably reduced dose. We report the synthesis and characterization of these conjugates as well as the evaluation of their tumor accumulation ability and the corresponding PDT efficiency through in vitro and in vivo experiments.

Topics: Animals; Cell Line, Tumor; Cell Survival; Chlorophyll; Drug Carriers; Female; Folic Acid; Humans; Hydrophobic and Hydrophilic Interactions; Injections, Intravenous; Mice; Neoplasms; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Solubility; Tissue Distribution; Toxicity Tests, Acute; Xenograft Model Antitumor Assays

Photosensitizer-based photodynamic therapy (PDT) has attracted great attention in cancer treatment. However, achieving efficient delivery of photosensitizers is still a great challenge for their clinical applications. The photosensitizer-encapsulating delivery nanosystem usually suffers from poor stability, complex preparation process and low drug loading. Herein, we utilize a surfactant-like chemotherapeutic agent, mitoxantrone (MTX), as a nanocarrier to deliver a photosensitizer pyropheophorbide a (PPa) for antitumor therapy. MTX consists of aromatic rings (hydrophobic part) and two amino-groups and two hydroxyl-groups (hydrophilic part) with planar structure, which could interact with PPa via π-π stacking, hydrophobic interactions, intermolecular hydrogen bonding and electrostatic interactions. This system (PPa@MTX) spontaneously forms near-spherical nanostructures (∼150 nm), has a high loading capacity for PPa (56.5%) and exhibits a pH-responsive drug release manner in vitro. In vivo antitumor efficacy evaluations show that the pegylated PPa@MTX nanosystem has increased accumulation in tumor tissues and enhanced antitumor efficacy in female BALB/c mice bearing murine mammary carcinoma (4T1) tumor cells, compared to free PPa. Employing the surfactant-like drug as nanocarriers, our results show that the "drug-delivering-drug" strategy is a good foundation for the development of novel PDT-based drug delivery system against cancer.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Chlorophyll; Drug Carriers; Drug Delivery Systems; Drug Liberation; Female; Mice, Inbred BALB C; Mitoxantrone; Nanostructures; Neoplasms; Photosensitizing Agents; Surface-Active Agents

Combination chemotherapy now becomes the most standard cancer treatment protocol. Here, we present a core-shell type polymeric microgel (CSPM) which combines photodynamic and chemo therapeutic modalities in one-pot system. CSPM localizes in the malignant lesion after intratumoral injection, releases reactive oxygen species (ROS) and anticancer drug (5'-deoxy-5-fluorocytidine; DFCR) under the near-infrared (NIR) laser treatment. Pheophorbide A (PheoA)-linked poly(hydroxyethyl methacrylate) (poly-HEMA) was designated to a ROS-generating core, and chemically covered with a chitosan shell. In addition, phenylboronic acid was employed in chitosan shells and linked to DFCR to form an ROS cleavable boronic ester. The core-shell structure of CSPM was determined by transmission electron microscopy. NIR-responsive photodynamic ROS generation was confirmed by the oxidative reduction of 9,10-dimethylanthracene (a fluorescent dye), and the cascadic release of DFCR by ROS was confirmed by a release study and a live and dead cell imaging study. Typically, poly-HEMA cored microgel increased its volume by 48.9-fold after absorption of body fluid. This swelling property ensured CSPM was retained in tumor tissues after subtumoral injection and the suitability of CSPM for locoregional phototherapy. The therapeutic effect of CSPM was attributed to the combined, cascadic deliveries of cytotoxic ROS and DFCR and confirmed by growth inhibition studies in in vitro pancreatic cancer cells and in vivo colon cancer mouse model.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Chlorophyll; Combined Modality Therapy; Delayed-Action Preparations; Deoxycytidine; Humans; Infrared Rays; Laser Therapy; Mice, Inbred BALB C; Microgels; Neoplasms; Polyhydroxyethyl Methacrylate; Reactive Oxygen Species; Water

Current approaches in use of water-insoluble photosensitizers for photodynamic therapy (PDT) of cancer often demand a nano-delivery system. Here, we report a photosensitizer-loaded biocompatible nano-delivery formulation (PPaN-20) whose size was engineered to ca. 20nm to offer improved cell/tissue penetration and efficient generation of cytotoxic singlet oxygen. PPaN-20 was fabricated through the physical assembly of all biocompatible constituents: pyropheophorbide-a (PPa, water-insoluble photosensitizer), polycaprolactone (PCL, hydrophobic/biodegradable polymer), and Pluronic F-68 (clinically approved polymeric surfactant). Repeated microemulsification/evaporation method resulted in a fine colloidal dispersion of PPaN-20 in water, where the particulate PCL matrix containing well-dispersed PPa molecules inside was stabilized by the Pluronic corona. Compared to a control sample of large-sized nanoparticles (PPaN-200) prepared by a conventional solvent displacement method, PPaN-20 revealed optimal singlet oxygen generation and efficient cellular uptake by virtue of the suitably engineered size and constitution, leading to high in vitro phototoxicity against cancer cells. Upon administration to tumor-bearing mice by peritumoral route, PPaN-20 showed efficient tumor accumulation by the enhanced cell/tissue penetration evidenced by in vivo near-infrared fluorescence imaging. The in vivo PDT treatment with peritumorally administrated PPaN-20 showed significantly enhanced suppression of tumor growth compared to the control group, demonstrating great potential as a biocompatible photosensitizing agent for locoregional PDT treatment of cancer.

Topics: Animals; Biocompatible Materials; Chlorophyll; Drug Delivery Systems; Flow Cytometry; HeLa Cells; Humans; Male; Mice; Mice, Nude; Nanoparticles; Nanotechnology; Neoplasms; NIH 3T3 Cells; Particle Size; Photobleaching; Photochemotherapy; Photosensitizing Agents; Polyesters; Polymers; Singlet Oxygen

Advanced colorectal cancer is one of the deadliest cancers, with a 5-year survival rate of only 12% for patients with the metastatic disease. Checkpoint inhibitors, such as the antibodies inhibiting the PD-1/PD-L1 axis, are among the most promising immunotherapies for patients with advanced colon cancer, but their durable response rate remains low. We herein report the use of immunogenic nanoparticles to augment the antitumour efficacy of PD-L1 antibody-mediated cancer immunotherapy. Nanoscale coordination polymer (NCP) core-shell nanoparticles carry oxaliplatin in the core and the photosensitizer pyropheophorbide-lipid conjugate (pyrolipid) in the shell (NCP@pyrolipid) for effective chemotherapy and photodynamic therapy (PDT). Synergy between oxaliplatin and pyrolipid-induced PDT kills tumour cells and provokes an immune response, resulting in calreticulin exposure on the cell surface, antitumour vaccination and an abscopal effect. When combined with anti-PD-L1 therapy, NCP@pyrolipid mediates regression of both light-irradiated primary tumours and non-irradiated distant tumours by inducing a strong tumour-specific immune response.

Topics: Animals; Apoptosis; B7-H1 Antigen; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Chlorophyll; Coordination Complexes; Cytotoxicity, Immunologic; Disease Models, Animal; Drug Compounding; Immunity; Immunotherapy; Inflammation; Lipids; Male; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Neoplasms; Organoplatinum Compounds; Oxaliplatin; Photochemotherapy; Polymers; Tissue Distribution

The biological potential of a synthetic copper chlorophyll derivative was investigated via in vivo and in vitro experiments. The Cu-chlorophyll derivative photosensitizer (Cu-PH-A) was labeled with (131)I with high efficiency (92.9 ± 4.2%) using the iodogen method. Cell culture studies were performed with the MCF-7 and MDAH-2774 cell lines after radiolabeling. The photosensitizing activity of Cu-PH-A was more effective in MDAH-2774 cells than in MCF-7 cells at a concentration of 50 μM. When the biodistribution in female Albino Wistar rats was examined, uptake of the radiolabeled photosensitizer was maximal in the liver and ovaries after 60 min. It is concluded that radiolabeled Cu-chlorophyll derivative photosensitizer has high uptake in ovaries in normal rats. In addition, the intercellular uptake and PDT efficacy of the Cu-PH-A in MDAH-2774 were good compared with MCF-7 cells. This photosensitizer could be useful for both ovary tumour imaging and PDT.

Topics: Animals; Cell Line, Tumor; Cell Survival; Chlorophyll; Chlorophyllides; Drug Stability; Female; Humans; Molecular Imaging; Neoplasms; Photochemotherapy; Photosensitizing Agents; Rats

A series of chlorophyll a-based chlorins conjugated with pyridyl or quinoxalyl group at different positions were synthesized, characterized and evaluated for their photodynamic effect in vitro. It was found that all the pyridyl and quinoxalyl chlorins showed promising photocytotoxicities but nontoxic without irradiation in HeLa cells, and the substituted types and positions had a significant influence on the photocytotoxicities of the chlorophyll a-based chlorins. All the chlorins with a pyridyl group at the C-D ring end exhibited relatively high photocytotoxicity as compared to those with 3(2)-pyridyl. Among them, compound 12 conjugated with a pyridyl group at its C12 position showed the best photodynamic effect in HeLa cells with an IC50 value of 0.033μM. These facts, associated with the relative high long wavelength absorptions of those chlorins may provide valuable ways to design and prepare promising photosensitizers for application in photodynamic therapy.

Topics: Chlorophyll; Chlorophyll A; HeLa Cells; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents; Porphyrins; Pyridines; Quinoxalines

The accurate diagnosis and proper therapy for cancer are essential to improve the success rate of cancer treatment. Here, we demonstrated that the vitamin Bc -bearing hydrophilic photosensitizer conjugate folic acid-polyethylene glycol-pheophorbideA (FA-PEG-PheoA) has been synthesized for the intracellular diagnosis and photodynamic therapy of a tumor. The synthesized vitamin Bc -bearing hydrophilic photosensitizer conjugate has been characterized for the folic acid receptor expressing the ability to target tumor cells, which is facilitated by the chemical conjugation with folic acid. The vitamin Bc -bearing hydrophilic photosensitizer conjugate internalization mechanism was identified through a competitive inhibition test with free folic acid. We optimized the laser-sensitive, cytotoxicity changeable, vitamin Bc -bearing hydrophilic photosensitizer conjugate concentration, which is non-cytotoxic under normal conditions and specifically cytotoxic toward cancer cells (maximum 69.15%) under laser irradiation conditions used for theranostic agents. The cancer therapeutic and diagnosis effects of synthesized conjugate were confirmed in MDA-MB-231 cells and MDA-MB-231-bearing mice. As a result, the vitamin Bc -bearing hydrophilic photosensitizer conjugate exhibited a highly photodynamic therapeutic effect, which enabled the selective detection of a folic acid receptor expressing cancer using optical imaging.

Topics: Animals; Cell Line, Tumor; Chlorophyll; Folic Acid; Humans; Hydrophobic and Hydrophilic Interactions; Mice; Nanoparticles; Neoplasms; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Theranostic Nanomedicine; Thiamine; Xenograft Model Antitumor Assays

Integrated diagnosis and therapy systems that can offer traceable cancer therapy are in high demand for personalized medicine. Herein, a pH-responsive polymeric probe containing tetraphenylsilole (TPS) with aggregation-induced emission characteristics and pheophorbide A (PheA) photosensitizer (PS) with aggregation-caused quenching property for tracing the whole process of cancer therapy is reported. At physiological conditions (pH 7.4), the probe self-assembles into nanoparticles (NPs), which show weak fluorescence of PheA with low phototoxicity, but strong green fluorescence from TPS for probe self-tracking. Upon uptake by cancer cells and entrapment in lysosomes (pH 5.0), the NPs disassemble to yield weak emission of TPS but strong red fluorescence of PheA with restored phototoxicity for PS activation monitoring. Upon light irradiation, the generated reactive oxygen species can cause lysosomal disruption to trigger cell apoptosis. Meanwhile, the probe leaks to the cytoplasm (pH 7.2), where the TPS fluorescence is restored for in situ visualization of the therapeutic response. The probe design thus represents a novel strategy for traceable cancer therapy.

Topics: Apoptosis; Cell Line, Tumor; Chlorophyll; Cytoplasm; Cytosol; Fluorescent Dyes; Green Fluorescent Proteins; HEK293 Cells; Humans; Hydrogen-Ion Concentration; Lysosomes; MCF-7 Cells; Microscopy, Fluorescence; Nanoparticles; Neoplasms; Photosensitizing Agents; Polylysine; Polymers; Precision Medicine; Reactive Oxygen Species

Drug bioavailability is a key consideration for drug delivery systems. When loaded with doxorubicin, liposomes containing 5 molar % porphyrin-phospholipid (HPPH liposomes) exhibited in vitro and in vivo serum stability that could be fine-tuned by varying the drug-to-lipid ratio. A higher drug loading ratio destabilized the liposomes, in contrast to standard liposomes which displayed an opposite and less pronounced trend. Following systemic administration of HPPH liposomes, near infrared laser irradiation induced vascular photodynamic damage, resulting in enhanced liposomal doxorubicin accumulation in tumors. In laser-irradiated tumors, the use of leaky HPPH liposomes resulted in improved doxorubicin bioavailability compared to stable standard liposomes. Using this approach, a single photo-treatment with 10mg/kg doxorubicin rapidly eradicated tumors in athymic nude mice bearing KB or MIA Paca-2 xenografts.

Topics: Animals; Antibiotics, Antineoplastic; Biological Availability; Chlorophyll; Doxorubicin; Drug Compounding; Drug Stability; Female; HeLa Cells; Humans; Injections, Intravenous; Liposomes; Mice, Nude; Neoplasms; Phospholipids; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Solubility; Tumor Burden; Xenograft Model Antitumor Assays

Type II photodynamic therapy (PDT) is based on the photochemical reactions mediated through an interaction between a photosensitizer, ground-state oxygen ([(3)O2]), and light excitation at an appropriate wavelength, which results in production of reactive singlet oxygen ([(1)O2]rx). We use an empirical macroscopic model based on four photochemical parameters for the calculation of [(1)O2]rx threshold concentration ([(1)O2]rx,sh) causing tissue necrosis in tumors after PDT. For this reason, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH)-mediated PDT was performed interstitially on mice with radiation-induced fibrosarcoma (RIF) tumors. A linear light source at 665 nm with total energy released per unit length of 12 to 100  J/cm and source power per unit length (LS) of 12 to 150  mW/cm was used to induce different radii of necrosis. Then the amount of [(1)O2]rx calculated by the macroscopic model incorporating explicit PDT dosimetry of light fluence distribution, tissue optical properties, and HPPH concentration was correlated to the necrotic radius to obtain the model parameters and [(1)O2]rx,sh. We provide evidence that [(1)O2]rx is a better dosimetric quantity for predicting the treatment outcome than PDT dose, which is proportional to the time integral of the products of the photosensitizer concentration and light fluence rate.

Topics: Animals; Chlorophyll; Disease Models, Animal; Female; Fibrosarcoma; Light; Mice; Mice, Inbred C3H; Necrosis; Neoplasms; Photochemotherapy; Photosensitizing Agents; Radiometry; Singlet Oxygen

Graphene, a 2-dimensional carbon nanomaterial, has attracted wide attention in biomedical applications, owing to its intrinsic physical and chemical properties. In this work, a photosensitizer molecule, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-alpha (HPPH or Photochlor®), is loaded onto polyethylene glycol (PEG)-functionalized graphene oxide (GO) via supramolecular π-π stacking. The obtained GO-PEG-HPPH complex shows high HPPH loading efficiency. The in vivo distribution and delivery were tracked by fluorescence imaging as well as positron emission tomography (PET) after radiolabeling of HPPH with (64)Cu. Compared with free HPPH, GO-PEG-HPPH offers dramatically improved photodynamic cancer cell killing efficacy due to the increased tumor delivery of HPPH. Our study identifies a role for graphene as a carrier of PDT agents to improve PDT efficacy and increase long-term survival following treatment.

Topics: Animals; Cell Line, Tumor; Cell Survival; Chlorophyll; Copper Radioisotopes; Graphite; Mice; Microscopy, Fluorescence; Multimodal Imaging; Nanoparticles; Neoplasms; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Positron-Emission Tomography

Photodynamic therapy (PDT) has emerged as an effective treatment for various solid tumors. The transcription factor NRF2 is known to protect against oxidative and electrophilic stress; however, its constitutive activity in cancer confers resistance to anti-cancer drugs. In the present study, we investigated NRF2 signaling as a potential molecular determinant of pheophorbide a (Pba)-based PDT by using NRF2-knockdown breast carcinoma MDA-MB-231 cells. Cells with stable NRF2 knockdown showed enhanced cytotoxicity and apoptotic/necrotic cell death following PDT along with increased levels of singlet oxygen and reactive oxygen species (ROS). A confocal microscopic visualization of fluorogenic Pba demonstrated that NRF2-knockdown cells accumulate more Pba than control cells. A subsequent analysis of the expression of membrane drug transporters showed that the basal expression of BCRP is NRF2-dependent. Among measured drug transporters, the basal expression of breast cancer resistance protein (BCRP; ABCG2) was only diminished by NRF2-knockdown. Furthermore, after incubation with the BCRP specific inhibitor, differential cellular Pba accumulation and ROS in two cell lines were abolished. In addition, NRF2-knockdown cells express low level of peroxiredoxin 3 compared to the control, which implies that diminished mitochondrial ROS defense system can be contributing to PDT sensitization. The role of the NRF2-BCRP pathway in Pba-PDT response was further confirmed in colon carcinoma HT29 cells. Specifically, NRF2 knockdown resulted in enhanced cell death and increased singlet oxygen and ROS levels following PDT through the diminished expression of BCRP. Similarly, PDT-induced ROS generation was substantially increased by treatment with NRF2 shRNA in breast carcinoma MCF-7 cells, colon carcinoma HCT116 cells, renal carcinoma A498 cells, and glioblastoma A172 cells. Taken together, these results indicate that the manipulation of NRF2 can enhance Pba-PDT sensitivity in multiple cancer cells.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Breast Neoplasms; Cell Line, Tumor; Chlorophyll; Colonic Neoplasms; Female; Gene Knockdown Techniques; Gene Silencing; Genetic Vectors; Humans; Laser Therapy; Lasers; Lentivirus; Neoplasm Proteins; Neoplasms; NF-E2-Related Factor 2; Peroxiredoxin III; Photochemotherapy; Radiation-Sensitizing Agents; Reactive Oxygen Species; RNA, Small Interfering; Transduction, Genetic

We designed a cancer-cell specific photosensitizer nano-carrier by synthesizing pheophorbide a (PheoA) conjugated glycol chitosan (GC) with reducible disulfide bonds (PheoA-ss-GC). The amphiphilic PheoA-ss-GC conjugates self-assembled in aqueous condition to form core-shell structured nanoparticles (PheoA-ss-CNPs) with good colloidal stability and switchable photoactivity. The photoactivity of PheoA-ss-CNPs in an aqueous environment was greatly suppressed by the self-quenching effect, which enabled the PheoA-ss-CNPs to remain photo-inactive and in a quenched state. However, after the cancer cell-specific uptake, the nanoparticular structure instantaneously dissociated by reductive cleavage of the disulfide linkers, followed by an efficient dequenching process. Compared to non-reducible PheoA-conjugated GC-NPs with stable amide linkages (PheoA-CNPs), PheoA-ss-CNPs rapidly restored their photoactivity in response to intracellular reductive conditions, thus presenting higher cytotoxicity with light treatment. In addition, the PheoA-ss-CNPs presented prolonged blood circulation in vivo compared to free PheoA, demonstrating enhanced tumor specific targeting behavior through the enhanced permeation and retention (EPR) effect. The enhanced tumor accumulation of PheoA-ss-CNPs enabled tumor therapeutic efficacy that was more efficient than free PheoA in tumor-bearing mice. Based on the enhanced intracellular release for cytosolic high dose and switchable photoactivity mechanism for reduced side effects, these results suggest that PheoA-ss-CNPs have good potential for photodynamic therapy (PDT) in cancer treatment.

Topics: Animals; Chitosan; Chlorophyll; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Neoplasms; Oxidation-Reduction; Photochemotherapy; Radiation-Sensitizing Agents

In this study, we developed a new photosensitizer (PS)-conjugated hybrid nanoparticle comprised of gold nanoparticle (AuNP) as an efficient energy quencher, polysaccharide heparin and a second generation PS, pheophorbide a (PhA) for PDT. The hybrid nanoparticles (PhA-H/AuNPs) with an average size of 40nm were prepared by surface coating of AuNPs with PhA conjugated heparins via gold-thiol interaction. The glutathione (GSH)-mediated switchable photoactivity of the PhA-H/AuNPs was observed by fluorescence quenching and dequenching behaviors in the absence and presence of GSH. The photoactivity was significantly suppressed in aqueous media, but instantaneously restored at the GSH-rich intracellular environment to generate a strong fluorescence signal together with active production of singlet oxygen species with light treatment. In vitro cell tests revealed marked phototoxicity and high intracellular uptake of PhA-H/AuNPs in contrast with free PhA. The PhA-H/AuNPs also exhibited a prolonged circulation characteristic, enhanced tumor specificity, and improved photodynamic therapeutic efficacy compared with free PhA in tumor-bearing mice. As a result, the PhA-H/AuNPs may serve as an effective smart nanomedicine platform for PDT and have great potential for the clinical treatment of various tumors.

Topics: Animals; Cell Line, Tumor; Chlorophyll; Drug Carriers; Glutathione; Gold; Heparin; Humans; Light; Metal Nanoparticles; Mice; Mice, Nude; Neoplasms; Photochemotherapy; Photosensitizing Agents; Tumor Burden

Previous reports from our laboratory have shown that a bifunctional agent obtained by conjugating a photosensitizer (HPPH) to a cyanine dye (CD) can be used for fluorescence image-guided treatment of tumor by photodynamic therapy (PDT). However, the resulting HPPH-CD conjugate showed a significant difference between the tumor-imaging and therapeutic doses. It was demonstrated that the singlet oxygen ( (1) O 2 (*), a key cytotoxic agent in PDT) produced by the conjugate upon excitation of the HPPH moiety was partially quenched by the CD-moiety; this resulted in a reduced PDT response when compared to HPPH-PDT under similar treatment parameters. To improve the therapeutic potential of the conjugate, we synthesized a series of dual functional agents in which one or two HPPH moieties were separately conjugated to three different dyes (Cypate, modified IR820 or modified IR783). The newly synthesized conjugates were compared with our lead compound HPPH-CD in terms of photophysical properties, in vitro and in vivo PDT efficacy, tumor uptake and imaging potential. Among the analogs investigated, the conjugate, in which two HPPH moieties were linked to the modified IR820 produced enhanced tumor uptake and tumor contrast in both Colon 26 (a murine Colon carcinoma) and U87 (a human glioblastoma) cell lines. The long-term PDT efficacy (cure) of this conjugate in BALB/c mice, bearing Colon 26 tumors was also enhanced; however, its efficacy in Nude mice bearing U87 tumors was slightly reduced. It was also found that in all the conjugates the singlet oxygen generation and, consequently, PDT efficacy were compromised by a competing pathway, whereby an electronic excitation of HPPH, the energy donor, is deactivated through an electronic excitation energy transfer (Forster Resonance Energy Transfer, FRET) to the CD fluorophore, the energy acceptor, resulting in overall reduction of the singlet oxygen production. Conjugates with increased FRET showed reduced singlet oxygen production and PDT efficacy. Among the conjugates investigated, the bifunctional agent in which two HPPH moieties were linked to the benzoindole-based cyanine dye 11 showed superiority over the lead candidate 9 (mono HPPH-cyanine dye).

Topics: Animals; Chlorophyll; Disease Models, Animal; Fluorescent Dyes; Humans; Indoles; Mice, Nude; Neoplasms; Optical Imaging; Pathology, Clinical; Photochemotherapy; Staining and Labeling

ATP-binding cassette (ABC) drug transporters ABCB1 [P-glycoprotein (Pgp)] and ABCG2 are expressed in many tissues including those of the intestines, the liver, the kidney and the brain and are known to influence the pharmacokinetics and toxicity of therapeutic drugs. In vitro studies involving their functional characteristics provide important information that allows improvements in drug delivery or drug design. In this study, we report use of the BacMam (baculovirus-based expression in mammalian cells) expression system to express and characterize the function of Pgp and ABCG2 in mammalian cell lines. BacMam-Pgp and BacMam-ABCG2 baculovirus-transduced cell lines showed similar cell surface expression (as detected by monoclonal antibodies with an external epitope) and transport function of these transporters compared to drug-resistant cell lines that overexpress the two transporters. Transient expression of Pgp was maintained in HeLa cells for up to 72 h after transduction (48 h after removal of the BacMam virus). These BacMam-baculovirus-transduced mammalian cells expressing Pgp or ABCG2 were used for assessing the functional activity of these transporters. Crude membranes isolated from these cells were further used to study the activity of these transporters by biochemical techniques such as photo-cross-linking with transport substrate and adenosine triphosphatase assays. In addition, we show that the BacMam expression system can be exploited to coexpress both Pgp and ABCG2 in mammalian cells to determine their contribution to the transport of a common anticancer drug substrate. Collectively, these data demonstrate that the BacMam-baculovirus-based expression system can be used to simultaneously study the transport function and biochemical properties of ABC transporters.

Topics: Animals; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Baculoviridae; Biological Transport; Cell Line, Tumor; Cell Membrane; Chlorophyll; Doxorubicin; Drug Evaluation, Preclinical; Drug Resistance, Neoplasm; Genetic Vectors; Humans; Mammals; Mitoxantrone; Neoplasm Proteins; Neoplasms; Radiation-Sensitizing Agents; Recombinant Proteins; Transduction, Genetic

Using stereoselective aldol-like condensation as a key methodology, a series of chlorophyll a-based long wavelength cationic chlorins were synthesized using methyl pyropheophorbide a (MPPa) and purpurin-18-N-methoxylimide methyl ester as starting materials. Such long wavelength cationic chlorins possess covalently linked cationic moieties (pyridinium or quinolinium) on the peripheral of their tetrapyrrole macrocycles. It was found that all long wavelength cationic chlorins showed their longest absorption maxima in the range of 712-763nm, making them potential photosensitizers in photodynamic therapy. The results of preliminary experiments probing in vitro photodynamic effects showed that the purpurinimide derivatives exhibit relatively high phototoxicity in HeLa cells as compared to MPPa derivatives.

Topics: Cell Survival; Chlorophyll; Chlorophyll A; HeLa Cells; Humans; Neoplasms; Photochemotherapy; Photosensitizing Agents; Porphyrins; Stereoisomerism

Pheophorbide-a, a chlorine based photosensitizer known to be selectively accumulated in cancer cells, was conjugated with anticancer drugs, doxorubicin and paclitaxel in the purpose of selective cancer diagnosis and therapy. Pheophorbide-a was conjugated with anticancer drugs via directly and by the use of selective cleavage linkers in cancer cell. The fluorescence of pheophorbide-a and doxorubicin conjugate by excitation at 420 or 440 nm was greatly diminished possibly by the energy transfer mechanism between two fluorescent groups. However, upon treatment in cancer cells, the conjugate showed to be cleaved to restore each fluorescence of pheophorbide-a and doxorubicin after 48 h of incubation. Also, pheophorbide-a conjugates either with doxorubicin and paclitaxel inhibited the growth of various cancer cells more potently than pheophorbide-a, which displayed very weak inhibitory activity. The results indicated that the pheophorbide-a conjugates with anticancer drugs could be utilized for selective cancer therapy as well as for the fluorescence detection of cancer.

Topics: Animals; Antineoplastic Agents; Cell Proliferation; Cell Survival; Chlorophyll; Dose-Response Relationship, Drug; Doxorubicin; Drug Screening Assays, Antitumor; Fluorescence; Fluorescent Dyes; HeLa Cells; Humans; Mice; Mice, Inbred C3H; Microscopy, Confocal; Molecular Conformation; Neoplasms; Paclitaxel; Spectrometry, Fluorescence; Stereoisomerism; Structure-Activity Relationship; Tissue Distribution; Tumor Cells, Cultured

Conjugates of 3-(1'-hexyloxyethyl)-3-devinyl pyropheophorbide-a (HPPH) with multiple Gd(III)aminobenzyl diethylenetriamine pentacetic acid (ADTPA) moieties were evaluated for tumor imaging and photodynamic therapy (PDT). In vivo studies performed in both mice and rat tumor models resulted in a significant MR signal enhancement of tumors relative to surrounding tissues at 24 h postinjection. The water-soluble (pH: 7.4) HPPH-3Gd(III) ADTPA conjugate demonstrated high potential for tumor imaging by MR and fluorescence. This agent also produced long-term tumor cures via PDT. An in vivo biodistribution study with the corresponding (14)C-analogue also showed significant tumor uptake 24 h postinjection. Toxicological evaluations of HPHH-3Gd(III)ADTPA administered at and above imaging/therapeutic doses did not show any evidence of organ toxicity. Our present study illustrates a novel approach for the development of water-soluble "multifunctional agents", demonstrating efficacy for tumor imaging (MR and fluorescence) and phototherapy.

Topics: Animals; Chlorophyll; Fluorescence; Gadolinium; Magnetic Resonance Imaging; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Neoplasms; Photochemotherapy; Rats

Human diet may contain many mutagenic or carcinogenic aromatic compounds as well as some beneficial physiologically active dietary components, especially plant food phytochemicals, which act as mutagenesis or carcinogenesis inhibitors. This study compared the binding properties of natural compounds in the human diet (caffeine, theophylline, theobromine, and resveratrol) with a water-soluble derivative of chlorophyll to bind to acridine orange, a known mutagen. An analysis was conducted to determine which substances were effective binding agents and may thus be useful in prevention of chemical-induced mutagenesis and carcinogenesis. Data indicated that in order to bind 50% of the mutagen in a complex, less than twice the concentration of chlorophyllin was needed, the resveratrol concentration was 20-fold higher, while a 1000-fold or even 10,000-fold excess of xanthines were required to bind acridine orange.

Topics: Acridine Orange; Antineoplastic Agents; Biophysical Phenomena; Caffeine; Carcinogens; Chlorophyll; Chlorophyllides; Diet; DNA; Humans; Male; Mutagens; Neoplasms; Theobromine; Theophylline; Xanthines

Two positional isomers of purpurinimide, 3-[1'-(3-iodobenzyloxyethyl)] purpurin-18-N-hexylimide methyl ester 4, in which the iodobenzyl group is present at the top half of the molecule (position-3), and a 3-(1'-hexyloxyethy)purpurin-18-N-(3-iodo-benzylimide)] methyl ester 5, where the iodobenzyl group is introduced at the bottom half (N-substitued cyclicimide) of the molecule, were derived from chlorophyll-a. The tumor uptake and phototherapeutic abilities of these isomers were compared with the pyropheophorbide analogue 1 (lead compound). These compounds were then converted into the corresponding 124I-labeled PET imaging agents with specific activity >1 Ci/micromol. Among the positional isomers 4 and 5, purpurinimide 5 showed enhanced imaging and therapeutic potential. However, the lead compound 1 derived from pyropheophorbide-a exhibited the best PET imaging and PDT efficacy. For investigating the overall lipophilicity of the molecule, the 3-O-hexyl ether group present at position-3 of purpurinimide 5 was replaced with a methyl ether substituent, and the resulting product 10 showed improved tumor uptake, but due to its significantly higher uptake in the liver, spleen, and other organs, a poor tumor contrast in whole-body tumor imaging was observed.

Topics: Animals; Anthraquinones; Chlorophyll; Chlorophyll A; Iodine Radioisotopes; Iodobenzenes; Isomerism; Mice; Neoplasms; Photochemotherapy; Photosensitizing Agents; Positron-Emission Tomography; Tissue Distribution

Photodynamic therapy is a recently developed anticancer treatment that utilizes the generation of singlet oxygen and other reactive oxygen species in cancer tissue. Nrf2, an NF-E2-related transcription factor, plays a pivotal role in transcriptional upregulation of many target genes, including those for metabolizing enzymes and transporters essential for cellular defense in response to oxidative stress. In the present study, we examined the potential involvement of Nrf2 in the induction of human ABC transporter ABCG2 and heme oxygenase-1 (HO-1). When HepG2 cells were incubated with non-toxic concentrations of delta-aminolevulinic acid, protoporphyrin IX, or pheophorbide a and then exposed to visible light for 90 min, the mRNA level of HO-1 began increasing markedly, reaching the maximal level in 4 h. Following the transient induction of HO-1, the mRNA level of ABCG2 gradually increased in a time-dependent manner, whereas the ABCB6 mRNA level was little affected. Nrf2-specific siRNA treatments suppressed the induction of both ABCG2 and HO-1 after the photoactivation of porphyrins, suggesting that Nrf2 is a common regulator for transcriptional activation of the ABCG2 and HO-1 genes. On the other hand, the mRNA level of HO-1 was remarkably enhanced by Zn(2+)-protoporphyrin IX or hemin even in the absence of light. This induction may be attributed to inactivation of Bach1, a repressor for the HO-1 gene, by those compounds. Since patients have demonstrated individual defferences in their response to photodynamic therapy, transcriptional activation of the ABCG2 and HO-1 genes in cancer cells may affect patients' responses to photodynamic therapy.

Topics: Aminolevulinic Acid; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Benzothiazoles; Blotting, Western; Cell Line, Tumor; Chlorophyll; Chromatography, High Pressure Liquid; Diamines; Electrophoresis, Polyacrylamide Gel; Fluorescent Dyes; Heme Oxygenase-1; Humans; Neoplasm Proteins; Neoplasms; NF-E2-Related Factor 2; Organic Chemicals; Oxidative Stress; Photochemistry; Photochemotherapy; Photosensitizing Agents; Porphyrins; Protoporphyrins; Quinolines; RNA, Messenger; RNA, Small Interfering; Transfection

Photodynamic therapy (PDT) uses a photosensitizer activated by light, in an oxygen-rich environment, to destroy malignant tumors. Clinical trials of PDT at Roswell Park Cancer Institute (RPCI) use the photosensitizers Photofrin, Photochlor, and 5-ALA-induced protoporphyrin IX (PpIX). In some studies the concentrations of photosensitizer in blood, and occasionally in tumor tissue, were obtained. Pharmacokinetic (PK) data from these individual studies were pooled and analyzed. This is the first published review to compare head-to-head the PK of Photofrin and Photochlor.. Blood and tissue specimens were obtained from patients undergoing PDT at RPCI. Concentrations of Photofrin, Photochlor, and PpIX were measured using fluorescence analysis. A non-linear mixed effects modeling approach was used to analyze the PK data for Photochlor (up to 4 days post-infusion; two-compartment model) and a simpler multipatient-data-pooling approach was used to model PK data for both Photofrin and Photochlor (at least 150 days post-infusion; three-compartment models). Physiological parameters were standardized to correspond to a standard (70 kg; 1.818 m2 surface area) man to facilitate comparisons between Photofrin and Photochlor.. Serum concentration-time profiles obtained for Photofrin and Photochlor showed long circulating half-lives, where both sensitizers could be found more than 3 months after intravenous infusion; however, estimated plasma clearances (standard man) were markedly smaller for Photofrin (25.8 ml/hour) than for Photochlor (84.2 ml/hour). Volumes of distribution of the central compartment (standard man) for both Photofrin and Photochlor were about the size (3.14 L, 4.29 L, respectively) of plasma volume, implying that both photosensitizers are almost 100% bound to serum components. Circulating levels of PpIX were generally quite low, falling below the level of instrument sensitivity within a few days after topical application of 5-ALA.. We have modeled the PK of Photochlor and Photofrin. PK parameter estimates may, in part, explain the relatively long skin photosensitivity attributed to Photofrin but not Photochlor. Due to the potential impact and limited experimental PK data in the PDT field further clinical studies of photosensitizer kinetics in tumor and normal tissues are warranted.

Topics: Administration, Topical; Aminolevulinic Acid; Chlorophyll; Dihematoporphyrin Ether; Fluorometry; Half-Life; Humans; Infusions, Intravenous; Neoplasms; Photosensitizing Agents

Photodynamic therapy is an effective and often curative treatment for certain solid tumors. The porphyrin-based photosensitizer Photofrin, the only Food and Drug Administration-approved drug for this therapy, suffers from certain disadvantages: its complex chemical nature; retention by skin (leading to protracted cutaneous photosensitivity); and less than optimal photophysical properties. In this study, we examine the population pharmacokinetics and cutaneous phototoxicity of 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH), a chlorin-type photosensitizer with more favorable photophysical properties. HPPH plasma concentration-time data were obtained in 25 patients enrolled in Phase I-II clinical trials for the treatment of partially obstructive esophageal carcinoma, high-grade dysplasia associated with Barrett's esophagus, carcinoma of the lung, or multiple basal cell carcinomas. Doses of 3, 4, 5, or 6 mg/m(2) were administered as 1-h i.v. infusions. The pharmacokinetic data for each patient were fitted with a standard two-compartment (biexponential) model with continuous infusion. The model fitting approach was iteratively reweighted nonlinear regression, with weights equal to the reciprocal of the square of the predicted HPPH plasma concentrations. The complete set of data for all 25 patients was then fitted simultaneously with nonlinear mixed effects modeling. Cutaneous phototoxicity responses were determined, as a function of time after HPPH infusion, following exposure to various doses of light from a solar simulator. The estimates of the population mean (variance) for each parameter were as follows: volume of distribution (V(C)), 2.40 liters/m(2) (0.259); steady-state volume (V(SS)), 9.58 liters/m(2) (11.6); systemic clearance (CL), 0.0296 liter/h/m(2) (0.000094); and distributional clearance (CL(D)), 0.144 liter/h/m(2) (0.00166). These parameters were independent of dose. Clearance increased with age. A relative error model was used for the difference in the raw and fitted data, and the overall coefficient of variation estimate across all of the data was 14.5%. The estimated mean population alpha and beta half-lives (95% confidence interval) were 7.77 h (3.46-17.6 h) and 596 h (120-2951 h), respectively. High-performance liquid chromatography analysis of serum showed no circulating HPPH metabolites, and in vitro incubation of HPPH with human liver microsomal preparations resulted in no metabolite or glucuronic acid-HPPH conjugate production.

Topics: Adult; Aged; Aged, 80 and over; Barrett Esophagus; Blood Proteins; Carcinoma, Basal Cell; Chlorophyll; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Esophageal Neoplasms; Humans; Lung Neoplasms; Middle Aged; Neoplasms; Photochemotherapy; Photosensitizing Agents; Skin; Skin Neoplasms

Topics: Chlorophyll; Humans; Neoplasms; Photochemotherapy

Cancer is a process of acquisition of an increased variety of cell functions by originally differentiated cells due to the failure of other organs to maintain their specific functions. Cancer cells take over functions of other organs or even other systems, that are chronically decompensated. The organ specific metabolites play an essential role in this process. Cancer is a reactive mechanism of the body to compensate for functions of decompensated organs (systems), in order to try to save life. Consequently, addition of the body's own or similar cancer extracts may be of great value in cancer treatment. A philosophic view of cancer will be briefly discussed.

Topics: Cell Differentiation; Chlorophyll; Humans; Mitosis; Models, Biological; Neoplasm Metastasis; Neoplasms; Oxygen

Topics: Animals; Chlorophyll; Cholesterol; Free Radicals; Humans; Light; Neoplasms; Oxygen; Photochemistry; Photosensitivity Disorders

Topics: Antineoplastic Agents; Chlorophyll; Cystine; Homocysteine; Humans; Leukocyte Disorders; Leukocytosis; Leukopenia; Neoplasms

Topics: Antineoplastic Agents; Chlorophyll; Cystine; Homocysteine; Humans; Leukocyte Disorders; Leukocytosis; Leukopenia; Neoplasms

Topics: Chlorophyll; Chlorophyllides; Humans; Neoplasms

Topics: Chamomile; Chlorophyll; Female; Genitalia; Genitalia, Female; Humans; Leukorrhea; Necrosis; Neoplasms; Plants; Radiation

Topics: Chlorophyll; Chlorophyll A; Deodorants; Humans; Neoplasms