Isolation, Identification, and Biological Activities of a New Chlorin e6 Derivative
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ABSTRACT:
SUBMITTER: Pandit R
PROVIDER: S-EPMC11240924 | biostudies-literature | 2024 Jun
REPOSITORIES: biostudies-literature
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Project description:Syntheses of three new chlorin e6 conjugates for PDT of tumors are reported. One of the new compounds 17 is conjugated with lysine at the 131-position, but the others are mono-conjugated 14 or diconjugated 15 with the non-amino acid species ethanolamine. Cellular experiments with the three new compounds and previously synthesized non-amino acid 152-conjugates (7-10), 131-monoconjugates 14, 16, and a 131,152-diconjugate 12 are reported. In vitro cytotoxicity experiments show that the 131-conjugates are more toxic than the 152-conjugates, and the most toxic derivative (dark- and photo-toxicity) is the 131-ethylenediamine conjugate 11. The most useful PDT photosentitizers appear to be the ethanolamine derivatives, conjugated at the 152- and the 131,152-positions; these show high phototoxicity but relatively low dark toxicity compared with 11, and also the highest dark/photo cytotoxicity ratios.
| S-EPMC5646832 | biostudies-literature
Project description:The taccalonolides are a unique class of microtubule stabilizers that do not bind directly to tubulin. Three new taccalonolides, Z, AA, and AB, along with two known compounds, taccalonolides R and T, were isolated from Tacca chantrieri and Tacca integrifolia. Taccalonolide structures were determined by 1D and 2D NMR methods. The biological activities of the new taccalonolides, as well as taccalonolides A, B, E, N, R, and T, were evaluated. All nine taccalonolides display microtubule stabilizing activity, but profound differences in antiproliferative potencies were noted, with IC(50) values ranging from the low nanomolar range for taccalonolide AA (32 nM) to the low micromolar range for taccalonolide R (13 μM). These studies demonstrate that diverse taccalonolides possess microtubule stabilizing properties and that significant structure-activity relationships exist. In vivo antitumor evaluations of taccalonolides A, E, and N show that each of these molecules has in vivo antitumor activity.
| S-EPMC3180930 | biostudies-literature
Project description:To improve the tumor-targeting efficacy of photodynamic therapy, biotin was conjugated with chlorin e6 to develop a new tumor-targeting photosensitizer, Ce6-biotin. The Ce6-biotin had good water solubility and low aggregation. The singlet-oxygen generation rate of Ce6-biotin was slightly increased compared to Ce6. Flow cytometry and confocal laser scanning microscopy results confirmed Ce6-biotin had higher binding affinity toward biotin-receptor-positive HeLa human cervical carcinoma cells than its precursor, Ce6. Due to the BR-targeting ability of Ce6-biotin, it exhibited stronger cytotoxicity to HeLa cells upon laser irradiation. The IC50 against HeLa cells of Ce6-biotin and Ce6 were 1.28 µM and 2.31 µM, respectively. Furthermore, both Ce6-biotin and Ce6 showed minimal dark toxicity. The selectively enhanced therapeutic efficacy and low dark toxicity suggest that Ce6-biotin is a promising PS for BR-positive-tumor-targeting photodynamic therapy.
| S-EPMC8658943 | biostudies-literature
Project description:BackgroundImproving the water solubility of hydrophobic photosensitizer and increasing its accumulation in tumor tissue are essential for in vivo photodynamic therapy (PDT). Considering commercialization or clinical application in future, it will be promising to achieve these purposes by developing new agents with simple and non-toxic structure.ResultsWe conjugated multiple chlorin e6 (Ce6) molecules to gelatin polymer, synthesizing two types of gelatin-Ce6 conjugates with different amounts of Ce6: gelatin-Ce6-2 and gelatin-Ce6-8. The resulting conjugates remained soluble in aqueous solutions for a longer time than hydrophobic Ce6. The conjugates could generate singlet oxygen and kill tumor cells upon laser irradiation. After intravenous injection into SCC-7 tumor-bearing mice, gelatin-Ce6-2 showed prolonged blood circulation and highly increased accumulation in tumor tissue as observed in real-time imaging in vivo. After laser irradiation, gelatin-Ce6-2 suppressed tumor growth completely and enabled improved PDT compared to free Ce6 and gelatin-Ce6-8.ConclusionsThis work demonstrates that a simple structure based on photosensitizer and gelatin can highly improve water solubility and stability. Superior tumor tissue accumulation and increased therapeutic efficacy of gelatin-Ce6 during in vivo PDT showed its high potential for clinical application.
| S-EPMC6449946 | biostudies-literature
Project description:Chlorin e6 (Ce6) is among the most used sensitizers in photodynamic (PDT) and sonodynamic (SDT) therapy; its low solubility in water, however, hampers its clinical exploitation. Ce6 has a strong tendency to aggregate in physiological environments, reducing its performance as a photo/sono-sensitizer, as well as yielding poor pharmacokinetic and pharmacodynamic properties. The interaction of Ce6 with human serum albumin (HSA) (i) governs its biodistribution and (ii) can be used to improve its water solubility by encapsulation. Here, using ensemble docking and microsecond molecular dynamics simulations, we identified the two Ce6 binding pockets in HSA, i.e., the Sudlow I site and the heme binding pocket, providing an atomistic description of the binding. Comparing the photophysical and photosensitizing properties of Ce6@HSA with respect to the same properties regarding the free Ce6, it was observed that (i) a red-shift occurred in both the absorption and emission spectra, (ii) a maintaining of the fluorescence quantum yield and an increase of the excited state lifetime was detected, and (iii) a switch from the type II to the type I mechanism in a reactive oxygen species (ROS) production, upon irradiation, took place.
| S-EPMC10005744 | biostudies-literature
Project description:The aim of this study is to prepare redox-sensitive nanophotosensitizers for the targeted delivery of chlorin e6 (Ce6) against cervical cancer. For this purpose, Ce6 was conjugated with β-cyclodextrin (bCD) via a disulfide bond, creating nanophotosensitizers that were fabricated for the redox-sensitive delivery of Ce6 against cancer cells. bCD was treated with succinic anhydride to synthesize succinylated bCD (bCDsu). After that, cystamine was attached to the carboxylic end of bCDsu (bCDsu-ss), and the amine end group of bCDsu-ss was conjugated with Ce6 (bCDsu-ss-Ce6). The chemical composition of bCDsu-ss-Ce6 was confirmed with 1H and 13C NMR spectra. bCDsu-ss-Ce6 nanophotosensitizers were fabricated by a dialysis procedure. They formed small particles with an average particle size of 152.0 ± 23.2 nm. The Ce6 release rate from the bCDsu-ss-Ce6 nanophotosensitizers was accelerated by the addition of glutathione (GSH), indicating that the bCDsu-ss-Ce6 nanophotosensitizers have a redox-sensitive photosensitizer delivery capacity. The bCDsu-ss-Ce6 nanophotosensitizers have a low intrinsic cytotoxicity against CCD986Sk human skin fibroblast cells as well as Ce6 alone. However, the bCDsu-ss-Ce6 nanophotosensitizers showed an improved Ce6 uptake ratio, higher reactive oxygen species (ROS) production, and phototoxicity compared to those of Ce6 alone. GSH addition resulted in a higher Ce6 uptake ratio, ROS generation, and phototoxicity than Ce6 alone, indicating that the bCDsu-ss-Ce6 nanophotosensitizers have a redox-sensitive biological activity in vitro against HeLa human cervical cancer cells. In a tumor xenograft model using HeLa cells, the bCDsu-ss-Ce6 nanophotosensitizers efficiently accumulated in the tumor rather than in normal organs. In other words, the fluorescence intensity in tumor tissues was significantly higher than that of other organs, while Ce6 alone did not specifically target tumor tissue. These results indicated a higher anticancer activity of bCDsu-ss-Ce6 nanophotosensitizers, as demonstrated by their efficient inhibition of the growth of tumors in an in vivo animal tumor xenograft study.
| S-EPMC10648776 | biostudies-literature
Project description:The therapeutic effect of photodynamic therapy (PDT) is highly dependent on the intracellular production of reactive oxygen species (ROS). However, the ROS generated by photosensitizers can be consumed by the highly concentrated glutathione (GSH) in tumor cells, severely impairing the therapeutic effect of PDT. Herein, we synthesized a GSH-scavenging copolymer to deliver photosensitizer chlorin e6 (Ce6). The pyridyl disulfide groups, which have faster reactivity with the thiol groups of GSH than other disulfide groups, were grafted onto a hydrophobic block to encapsulate the Ce6. Under NIR irradiation, the Ce6 generated ROS to kill tumor cells, and the pyridyl disulfide groups depleted the GSH to prevent ROS consumption, which synergistically enhanced the therapeutic effect of PDT. In vitro and in vivo experiments confirmed the combinatory antitumor effect of Ce6-induced ROS generation and the pyridyl disulfide group-induced GSH depletion. Therefore, the pyridyl disulfide group-grafted amphiphilic copolymer provides a more efficient strategy for enhancing PDT and has promising potential for clinical application.
| S-EPMC9346557 | biostudies-literature
Project description:This work aims to prepare pure Chlorin e6 (Ce6) and establish Ce6-mediated photodynamic therapy (Ce6-PDT) as a better therapy option for canine tumors as well as mouse tumor models. Five dogs suffering from various cancers were treated with Ce6-PDT from one to several times. After receiving the Ce6 (2.5 mg/kg) for 3 h, tumors were illuminated superficially or interstitially with 660 nm light. Two dogs underwent Ce6-guided fluorescence imaging by photodynamic diagnosis (PDD). Cell proliferation and apoptosis were detected by the 4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and western blot assay, respectively. Ce6-PDT efficacy was also determined using melanoma and pancreatic cancer mouse models. Two veterinary patients with mammary carcinoma and histiocytic sarcoma had their tumors significantly diminished and showed improved health after receiving Ce6-PDT. Moreover, in the cases of canine tumors, the adjunctive use of Ce6-PDD revealed cancers that were not visible with white light viewing and provided a visual contrast from surrounding tissues. Also, in vivo, Ce6-PDT remarkably reduced melanoma and pancreatic tumors in the mouse model. These findings could pave the way for a better understanding of the underlying processes of Ce6-PDT, making it an effective and safe candidate for use in human and veterinary applications to abolish various cancers.
| S-EPMC9782963 | biostudies-literature
Project description:BackgroundLayered double hydroxides (LDHs) are one type of 2-dimensional material with unique structure and strongly positive surface charge. Particularly, LDHs can be exfoliated by mono-layered double hydroxides (MLHs) as a single layer, showing an increased surface area. Therefore, there is a large focus on LDHs for drug delivery applications. Furthermore, most photosensitizers are hydrophobic that they cannot be soluble in aqueous solvents. Herein, we designed a simple way to solubilize hydrophobic photosensitizers by MLH with electrostatic interactions for anticancer photodynamic therapy (PDT), which has tremendous therapeutic advantages. The photosensitizer solubilized via loading on the MLH exhibited fluorescence and singlet oxygen-generation activities in aqueous solvent without chemical modification, resulting in photo-mediated anticancer treatment.MethodsNegatively charged hydrophobic photosensitizers, chlorin e6 (Ce6) were solubilized by loading on the MLHs through the electrostatic interaction between positively charged MLHs. MLH/Ce6 complexes evaluated for physico-chemical characterization, pH-sensitive release property, in vitro photocytotoxicity, and in vivo tumor ablation.ResultsThe photosensitizer solubilized via MLH exhibited fluorescence intensity and singlet-oxygen generation activities in aqueous solvent without chemical modification, resulting photocytotoxicity in cancer cells. The encapsulation efficiency of Ce6 increased to 21.2% through MLH compared to 0.6% when using LDH. In tumor-bearing mice, PDT with solubilized MLH/Ce6 indicated a tumor-suppressing effect approximately 3.4-fold greater than that obtained when Ce6 was injected alone.ConclusionsThis study provided the solubilized Ce6 by the MLH in a simple way without chemical modification. We demonstrated that MLH/Ce6 complexes would have a great potential for anticancer PDT.
| S-EPMC9188148 | biostudies-literature
Project description:In photodynamic therapy (PDT), chlorin e6 (Ce6), with its high phototoxic potential and strong absorption of visible light, penetrates deeply into photodamaged tissue. However, despite this fact, the direct application of Ce6 to PDT has been limited by its low water solubility and poor cancer cell localization. To ameliorate this situation, we report herein on the use of a hydrophilic nanoconjugate (DC) comprised of Ce6 and poly(amidoamine) dendrimer, which improves the water solubility and intracellular uptake of Ce6, thereby enhancing PDT efficacy. The synthesis of DC was verified by ¹H nuclear magnetic resonance (NMR) analysis, and the coupling ratio of Ce6 introduced onto DC was 2.64. The prepared DC was spherical, with an average diameter of 61.7 ± 3.5 nm. In addition, the characteristic ultraviolet-visible absorption bands of DC in distilled water were similar to those of free Ce6 in dimethyl sulfoxide (DMSO), indicating that the Ce6 chromophore did not change upon conjugation. Investigation using fluorescence spectroscopy and confocal microscopy revealed a greater intracellular uptake of DC than of Ce6 alone. Moreover, DC exhibited significantly increased phototoxicity to human cervical cancer cells, mostly because of apoptotic cell death. These results imply that DC is a candidate for the clinical treatment of PDT.
| S-EPMC6027052 | biostudies-literature