Photodynamic Efficiency Research Articles

Targeting integrin-rich tumors with temoporfin-loaded vitamin-E-succinate-grafted chitosan oligosaccharide/d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles to enhance photodynamic therapy efficiency

A major challenge in cancer photodynamic therapy (PDT) is the poor tumor selectivity of the photosensitizer. Therefore, temoporfin (mTHPC)-loaded nanoparticles, based on vitamin-E-succinate-grafted chitosan oligosaccharide and cyclic (arginine-glycine-aspartic acid-d-phenylalanine-lysine) (c[RGDfK])-modified d-α-tocopheryl polyethylene glycol 1000 succinate, were prepared (RGD-NPs) and were expected to enhance the accumulation of mTHPC in integrin-rich U87MG tumors. The RGD-NPs generated were 144.9nm in diameter and uniformly spherical. After irradiation, RGD-NPs effectively generated singlet oxygen, and displayed enhanced cellular uptake and cytotoxicity in U87MG cells. The RGD-NPs also penetrated deep into U87MG tumor spheroids, with a tumor-targeting ability and antitumor efficacy superior to those of unmodified nanoparticles in subcutaneous-tumor-bearing nude mice. A histopathological analysis confirmed the increased anticancer efficacy of RGD-NPs, with less systemic toxicity than unmodified nanoparticles. Therefore, the RGD-NPs developed in this study potentially target integrin-rich tumors and enhance the efficiency of PDT.

Quinacridone derivative as a new photosensitizer: Photodynamic effects in cells and in vivo

The lack of ideal photosensitizers is the major limitation for clinical photodynamic therapy (PDT). Quinacridone (QA) is a mass-produced industrial organic pigment. QA derivatives are widely investigated for many applications in various fields, but rarely involved in biological applications. Here we report the PDT effects of N,N'-bis(methylpiperazinylpentyl) QA (QAP) in cells and in vivo. QAP shows low dark-toxicity and high photo-toxicity in cells through generating reactive oxygen species (ROS) under irradiation; and greatly inhibits the tumor growth in a mouse subcutaneous xenograft model after irradiation with a 532 nm laser. The high photodynamic efficiency of QAP shows the great potential of QA derivatives to be a new class of leading compound of photosensitizers in PDT.

A comparative study on the anticancer photodynamic efficiency of curcumin and hypericin

A comparative study on the anticancer photodynamic efficiency of curcumin and hypericin

Mitochondria-targeting near-infrared light-triggered thermosensitive liposomes for localized photothermal and photodynamic ablation of tumors combined with chemotherapy.

Lonidamine, an anticancer drug that acts on mitochondria, has poor water solubility. Mitochondria are the primary source of cellular reactive oxygen species (ROS), which are necessary for photodynamic therapy. Hence, a mitochondria-targeting drug delivery system loaded with Lonidamine and a ROS-produced photosensitizer could improve the bioavailability of Lonidamine and maximize photodynamic therapeutic efficiency. Here we report, for the first time, new IR-780 and Lonidamine encapsulated mitochondria-targeting thermosensitive liposomes (IL-TTSL). DSPE-PEG2000-NH2 was coupled with triphenylphosphine to form DSPE-PEG2K-TPP. The liposomes (IL-TTSL) were self-assembled from DPPC, DSPC, DSPE-PEG2K-TPP, cholesterol, IR-780 and Lonidamine. Coupled linker modified triphenylphosphine (TPP) is cationic and can selectively accumulate several hundred-fold within mitochondria. Once the liposomes are located inside mitochondria, 808 nm laser irradiation could trigger photosensitizer IR-780 to elevate the local temperature, which could be utilized in photothermal therapy and induce the release of Lonidamine from the thermosensitive liposomes. Meanwhile, IR-780 could release ROS for photodynamic therapy in mitochondria and increase photodynamic therapeutic efficiency. Our results showed that the surface modification of the liposomes with triphenylphosphine cations had good mitochondria-targeting ability. The liposomes exhibited good biocompatibility and all components of the empty liposomes were safe to be used in humans. Few reports were related to IR-780 being used in photodynamic therapy and we proved this function of IR-780. Overall, the stealth liposomes provide a promising new strategy to realize mitochondria-targeting thermosensitive chemo-, photodynamic and photothermal combination therapy with a single light source for lung cancer.

Photodynamic Efficiency of Xanthene Dyes and Their Phototoxicity against a Carcinoma Cell Line: A Computational and Experimental Study

The aim of this study is to assess the insights of molecular properties of the xanthene dyes [fluorescein (FL), Rose Bengal (RB), erythrosin B (EB), and eosin Y (EY)] to correlate systematically their photodynamic efficiency as well as their phototoxicity against a carcinoma cell line. The phototoxicity was evaluated by comparing the values of the medium inhibitory concentration (IC50) upon HEp-2 cells with the xanthene corresponding photodynamic activity using the uric acid as a chemical dosimeter and their octanol-water partition coefficient (log⁡P).RBwas the more cytotoxic dye against HEp-2 cell line and the most efficient photosensitizer in causing photoxidation of uric acid; nevertheless it was the only one characterized as being hydrophobic among the xanthenes studied here. On the other hand, it was observed that the halogen substituents increased the hydrophilicity and photodynamic activity, consistent with the cytotoxic experiments. Furthermore, the reactivity index parameters, electric dipole moment, molecular volume, and the frontier orbitals were also obtained by the Density Functional Theory (DFT). The lowest dipole moment and highest molecular volume ofRBcorroborate with its highest hydrophobicity due to heavy atom substituents like halogens, while the halogen substituents did not affect expressively the electronic features at all.

Photosensitizer–AgNP composite with an ability to selectively recognize pathogen and enhanced photodynamic efficiency

A photosensitizer–AgNP composite could recognise bacteria smartly and showed greater photodynamic efficiency than did the free photosensitizer.

A triple-synergistic strategy for combinational photo/radiotherapy and multi-modality imaging based on hyaluronic acid-hybridized polyaniline-coated WS2 nanodots.

In this study, we report a strategy for integrating hyaluronic acid (HA), polyaniline (PANI), WS2 nanodots (WS2), and chlorin e6 (Ce6) into a single nanoplatform (HA-WS2@PANI/Ce6) for fluorescence, photoacoustic, and computed tomography multi-modality imaging-guided trimodal photothermal/radiation/photodynamic combination therapy of tumors. The WS2 nanodot core is used as the radiosensitizer with the PANI shell as the hyperthermal agent and the photosensitizer reservoir. HA and Ce6 were adsorbed on the outer shell for tumor targeting and photodynamic therapy, respectively. The in vivo trimodal imaging uncovered that HA-WS2@PANI/Ce6 nanoparticles showed enhanced tumor uptake and diagnosis effects after intravenous injection. More importantly, in the in vitro and in vivo experiments, the nanoparticles exhibited an evident near-infrared induced photothermal effect, which remarkably improved the radiation and photodynamic therapy efficiency by accelerating the blood flow and subsequently increasing oxygen supply in the tumor. The nanohybrids were found to be safe to cells in vitro and organs in vivo. Taken together, our current work demonstrates a nanoplatform for multimodal imaging guided targeted triple-therapy, which reveals a potential strategy for tumor treatment.

Photosensitizer localization in amphiphilic block copolymers controls photodynamic therapy efficacy.

Localization of the photosensitizer conjugation site in amphiphilic block copolymers is shown to have a great impact on photodynamic therapy efficiency. To this end, an asymmetric multifunctional derivative of the azadipyrromethene boron difluoride chelate (aza-BODIPY) was synthesized and inserted at specific locations in polypeptide-based rod-coil amphiphilic block copolymers. A study of the photophysical properties of the vesicle nanocarriers, obtained by self-assembly of these copolymers, as well as in vitro tests on two cancer cell lines were performed. This study aims at providing guidelines for the optimization of the synthetic design of therapeutic nanomedicines with minimal amounts of photosensitive molecules.

Evaluation of Photodynamic Inactivation Efficiency Using Conventional and Decorative Light-Emitting Diode Lamps

Evaluation of Photodynamic Inactivation Efficiency Using Conventional and Decorative Light-Emitting Diode Lamps

The photodynamic efficiency of phenothiazinium dyes is aggregation dependent

Effectiveness increased in the order of Azure A < Azure B < Methylene Blue while aggregation increased in the order of Methylene Blue < Azure B < Azure A.

Synthesis of mono-, di- and triporphyrin building blocks by click chemistry for photodynamic therapy application

In the present work, we describe a successful strategy centered on the use of click chemistry to synthesize mono-, di- and triporphyrin building blocks named [ZnTPP]1, [ZnTPP]2 and [ZnTPP]3. The number of photosensitizers (ZnTPP unit) coupled to the building blocks does not seem to dramatically modify the photophysical properties of the photosensitizer in terms of fluorescence and singlet oxygen formation, quantum yields and lifetime. These building blocks, obtained in high yield, could be combined with a targeting agent (vector) to create new photosensitizer-vector conjugates to investigate the optimum ratio of photosensitizer needed for maximum photodynamic therapy efficiency.

Astaxanthin conjugated polypyrrole nanoparticles as a multimodal agent for photo-based therapy and imaging

Polymeric nanoparticles are emerging as promising candidates for photo-based therapy and imaging due to their versatile chemical properties and easy fabrication and functionalization. In the present study we synthesized polypyrrole nanoparticles by stabilization with astaxanthin conjugated bovine serum albumin polymer (PPy@BSA-Astx). The synthesized nanoparticles were biocompatible with MBA-MD-231 and HEK-293 cells. Interestingly, the fabricated nanoparticles produced reactive oxygen species under 808-nm laser exposure and exerted a hyperthermic effect when the power density of the laser was increased. The photodynamic efficiency of PPy@BSA-Astx was measured by DPBF assay, and it was found to generate sufficient amount of reactive radicals to kill the cells at a power density of 0.3W/cm2. In photothermal aspect, the temperature level was reached to 57°C within 5min at 1W/cm2 power density, at the concentration of 50μg/mL. The in vitro cell toxicity studies showed concentration dependent photothermal and photodynamic toxicity. Fluorescence microscopic investigation explored the cell death and intra-cellular organ destruction by photodynamic treatment. In addition, we observed a strong photoacoustic signal from a tissue mimicking phantom study of nanoparticle treated MBA-MD-231 cells. In conclusion, the fabricated PPy@BSA-Astx nanoparticles can be used as photoacoustic imaging based prognostic agents for photothermal or photodynamic treatment.

Control of Listeria innocua biofilms by biocompatible photodynamic antifouling chitosan based materials

New materials obtained through the incorporation of meso-tetraarylporphyrins, bearing phenyl or pentafluorophenyl groups at the meso positions with or without acid groups, in chitosan films have been prepared and characterized in detail. The efficiency of these porphyrinic-chitosan films (PS-CF) to prevent Listeria innocua attachment and subsequent biofilm formation was evaluated under different irradiation protocols (dark, light, light + dark, dark + light). All tested porphyrinic-chitosan films were photostable and effective in reducing Listeria innocua attachment during a period of 24 h exposure to white light. Biofilm development was nearly completely inhibited in two of the PS-CF films (one containing the 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin and the other one of the thio-carboxylate porphyrins) after being exposed to white light for 24 h followed by incubation in the dark for 48 h. Experiments with the non-immobilized porphyrins against cell suspensions of the same Listeria innocua strain showed that, the photodynamic inactivation efficiency was dependent on porphyrin. The demonstrated antimicrobial activity of PS-CF films, associated with the easy recovery of these films, make them promising photodynamic antifouling materials.

The role of galectin-1 in in vitro and in vivo photodynamic therapy with a galactodendritic porphyrin

Conventional photodynamic agents used in clinic are porphyrin-based photosensitizers. However, they have low tumour selectivity, which may induce unwanted side-effects and damage to healthy tissues. In this study, we used a porphyrin with dendritic units of galactose (PorGal8) developed by us, which can target the galactose-binding protein, galectin-1, known to be overexpressed in many tumour tissues. In vitro and in vivo studies had been conducted for the validation of PorGal8 effectiveness. We showed a specific uptake of PorGal8 and induction of apoptotic cell death by generating oxidative stress and alterations in the cytoskeleton of bladder cancer cells overexpressing galectin-1. We further validated the photodynamic efficiency of PorGal8 in athymic nude mice (Balb/c nu/nu) bearing subcutaneously implanted luciferase-positive bladder cancer xenografts, overexpressing galectin-1 protein. PorGal8 (5 μmol/kg, intraperitoneal), injected 24 h before light delivery (50.4 J/cm2), inhibited tumour growth. We conclude that the use of PorGal8 enables selective target and cytotoxicity by photodynamic therapy in cancer cells overexpressing galectin-1, preventing undesired phototoxicity in the surrounding healthy tissues.

Size-Dependent Photodynamic Anticancer Activity of Biocompatible Multifunctional Magnetic Submicron Particles in Prostate Cancer Cells.

In this study, newly designed biocompatible multifunctional magnetic submicron particles (CoFe2O4-HPs-FAs) of well-defined sizes (60, 133, 245, and 335 nm) were fabricated for application as a photosensitizer delivery agent for photodynamic therapy in cancer cells. To provide selective targeting of cancer cells and destruction of cancer cell functionality, basic cobalt ferrite (CoFe2O4) particles were covalently bonded with a photosensitizer (PS), which comprises hematoporphyrin (HP), and folic acid (FA) molecules. The magnetic properties of the CoFe2O4 particles were finely adjusted by controlling the size of the primary CoFe2O4 nanograins, and secondary superstructured composite particles were formed by aggregation of the nanograins. The prepared CoFe2O4-HP-FA exhibited high water solubility, good MR-imaging capacity, and biocompatibility without any in vitro cytotoxicity. In particular, our CoFe2O4-HP-FA exhibited remarkable photodynamic anticancer efficiency via induction of apoptotic death in PC-3 prostate cancer cells in a particle size- and concentration-dependent manner. This size-dependent effect was determined by the specific surface area of the particles because the number of HP molecules increased with decreasing size and increasing surface area. These results indicate that our CoFe2O4-HP-FA may be applicable for photodynamic therapy (PDT) as a PS delivery material and a therapeutic agent for MR-imaging based PDT owing to their high saturation value for magnetization and superparamagnetism.

Zinc phthalocyanine-conjugated with bovine serum albumin mediated photodynamic therapy of human larynx carcinoma

Phthalocyanines, which are classified as second-generation photosensitizers, have advantageous photophysical properties, and extensive studies have demonstrated their potential applications in photodynamic therapy. The present work describes the preparation of a new zinc phthalocyanine conjugated to bovine serum albumin (compound 4a) and its photodynamic efficiency in human larynx-carcinoma cells (HEp-2 cells). The unconjugated precursor (compound 4) was also studied. Compounds 4 and 4a penetrated efficiently into the cell, exhibiting cytoplasmic localization, and showed no cytotoxicity in the dark. However, high photodynamic activities were observed in HEp-2 cells after treatments with 5 µM photosensitizers and 4.5 J cm−2 light. These conditions were sufficient to decrease the cell viability to 57.93% and 32.75% for compounds 4 and 4a, respectively. The present results demonstrated high photodynamic efficiency of zinc phthalocyanine conjugated with bovine serum albumin in destroying the larynx-carcinoma cells.

Manipulation of novel nano-prodrug composed of organic pigment-based hybrid network and its optical uses

Here we developed the first case of pyropheophorbide-a-loaded PEGylated-hybrid carbon nanohorns (CNH-Pyro) to study tumor targeting therapy. During incubation with living cells, CNH-Pyro exhibited very intense red emissions. The intracellular imaging results were carried out by flow cytometry based on four different kinds of cell lines (including three adherent cell lines and one suspension cell line). Compared with free pyropheophorbide-a, CNH-Pyro demonstrated enhanced photodynamic tumor ablation efficiency during in vitro experiments due to improved biocompatibility of the hybrid nanomaterial and the photothermal therapy effect derived from carbon-network structure. Trypan blue staining experiments supported that the cell fate was dependent on the synergistic effects of both CNH-Pyro and laser irradiations. These results indicated that the chlorin-entrapped carbon nanohorns could provide powerful delivery vehicles for increasing photodynamic efficacy and possess early identification of the disease.

Self-assembled polymeric vectors mixtures: characterization of the polymorphism and existence of synergistic effects in photodynamic therapy

The objective of this work was to assess the relation between the purity of polymeric self-assemblies vectors solution and their photodynamic therapeutic efficiency. For this, several amphiphilic block copolymers of poly(ethyleneoxide-b-ε-caprolactone) have been used to form self-assemblies with different morphologies (micelles, worm-like micelles or vesicles). In a first step, controlled mixtures of preformed micelles and vesicles have been characterized both by dynamic light scattering and asymmetrical flow field flow fractionation (AsFlFFF). For this, a custom-made program, STORMS, was developed to analyze DLS data in a thorough manner by providing a large set of fitting parameters. This showed that DLS only sensed the larger vesicles when the micelles/vesicles ratio was 80/20 w/w. On the other hand, AsFlFFF allowed clear detection of the presence of micelles when this same ratio was as low as 10/90. Subsequently, the photodynamic therapy efficiency of various controlled mixtures was assessed using multicellular spheroids when a photosensitizer, pheophorbide a, was encapsulated in the polymer self-assemblies. Some mixtures were shown to be as efficient as monomorphous systems. In some cases, mixtures were found to exhibit a higher PDT efficiency compared to the individual nano-objects, revealing a synergistic effect for the efficient delivery of the photosensitizer. Polymorphous vectors can therefore be superior in therapeutic applications.

Inclusion complexation with β-cyclodextrin derivatives alters photodynamic activity and biodistribution of meta-tetra(hydroxyphenyl)chlorin

Application of meta-tetra(hydroxyphenyl)chorin (mTHPC) one of the most effective photosensitizer (PS) in photodynamic therapy of solid tumors encounters several complications resulting from its insolubility in aqueous medium. To improve its solubility and pharmacokinetic properties, two modified β-cyclodextrins (β-CDs) methyl-β-cyclodextrin (M-β-CD) and 2-hydroxypropyl-β-cyclodextrin (Hp-β-CD) were proposed. The aim of this work was to evaluate the effect of β-CDs on mTHPC behavior at various stages of its distribution in vitro and in vivo. For this purpose, we have studied the influence of the β-CDs on mTHPC binding to the serum proteins, its accumulation, distribution and photodynamic efficiency in HT29 cells. In addition, the processes of mTHPC biodistribution in HT29 tumor bearing mice after intravenous injection of PS alone or with the β-CDs were compared. Interaction of mTHPC with studied β-CDs leads to the formation of inclusion complexes that completely abolishes its aggregation after introduction into serum. It was demonstrated that the β-CDs have a concentration-dependent effect on the process of mTHPC distribution in blood serum. At high concentrations, β-CDs can form inclusion complexes with mTHPC in the blood that can have a significant impact on PS distribution out of the vascular system in solid tissues. Besides, the β-CDs increase diffusion movement of mTHPC molecules that can significantly accelerate the delivery of PS to the targets cells and tissues. In vivo study confirms the fact that the use of β-CDs allows to modify mTHPC distribution processes in tumor bearing animals that is reflected in the decreased level of PS accumulation in skin and muscles, as well as in the increased PS accumulation in tumor. Further studies are underway to verify the optimal protocols of mTHPC/β-CD formulation for photodynamic therapy.

Uptake and photo-toxicity of Foscan®, Foslip® and Fospeg® in multicellular tumor spheroids

In cancer photodynamic therapy (PDT), an efficient and homogeneous intratumoral accumulation of the photosensitizer (PS) is required to induce cell damages in the entire tumor mass after light activation. Thus, in this study we investigated penetration ability and photodynamic efficiency of meta-tetra(hydroxyphenyl)chlorin (m-THPC) in standard formulation (Foscan®) and in its non PEGylated and PEGylated liposomal formulations, Foslip® and Fospeg®, in HeLa multicellular spheroids, as in vitro avascular models of solid tumors. Confocal microscopy studies demonstrated that m-THPC fluorescence was confined in the external cell layers of spheroids with a slightly higher accumulation of Foslip® and Fospeg® with respect to Foscan®. Irradiation with red light, following 24h incubation of spheroids with the m-THPC formulations, caused however photodamages also in cells located in the central part of spheroids, as documented by transmission electron microscopy analyses. Overall, the photodynamic effects of the three m-THPC formulations on HeLa cell spheroids were comparable in terms of cell viability measured with the MTS assay. It is however worth noting that the delivery of m-THPC by liposomes significantly abolished its cytotoxicity in the dark, slightly improved the cellular uptake and, following PDT, promoted cell loss and spheroid disassembling to a higher extent when compared to Foscan®.