phytochlorin and Disease-Models--Animal

Photodynamic therapy (PDT) -a minimally invasive anti-cancer therapy-is undergoing experimental studies to increase its anti-cancer effects. This study investigated the influence of iron on the anti-cancer effects of PDT.. PDT was performed in a cancer-bearing mouse model, which was created by using a murine colon carcinoma (CT26) cell line after administration of Photolon and iron. Tumor volume and the results of TdT-mediated dUTP-biotin nick end labeling (TUNEL), 8-OHdG, and TBARS assays were used to measure anti-cancer effect.. On day 14, tumor volume had increased by 49% in the PDT group and decreased by 72% in the iron+PDT group. The percentage of TUNEL-positive cells in tumor tissues was 45% in the PDT group and 69% in the iron+PDT group, suggesting that the proportion of TUNEL-positive cells had increased in the iron+PDT group. The 8-OHdG content in tumor tissues was 33% higher in the iron+PDT group than in the PDT group. The TBARS content in tumor tissues was 46% higher in the iron+PDT group than in the PDT group.. Iron enhances the anti-cancer effect of PDT using Photolon, most likely by increasing oxidative damage.

Topics: Animals; Apoptosis; Cell Line, Tumor; Colonic Neoplasms; Disease Models, Animal; Iron; Mice; Photochemotherapy; Photosensitizing Agents; Porphyrins; Thiobarbituric Acid Reactive Substances

Gliomas are one of the most common types of primary brain tumors. Despite recent advances in the combination of surgery, radiotherapy, systemic therapy (chemotherapy, targeted therapy) and supportive therapy in the multimodal treatment of gliomas, the overall prognosis remains poor and the long‑term survival rate is low. Thus, it is crucial to develop a novel glioma management method. Due to its relatively non‑invasive, selective and repeatable characteristics, photodynamic therapy (PDT) has been investigated for glioma therapy in the past decade, exhibiting higher selectivity and lower side effects compared with those of conventional therapy. However, most of the photosensitizers (PSs) are highly hydrophobic, leading to poor water solubility, rapid degradation with clearance in blood circulation and ultimately, low bioavailability. In the present study, hydrophilic polyethylene glycol (PEG)‑chlorin e6 (Ce6) chelated gadolinium ion (Gd3+) nanoparticles (PEG‑Ce6‑Gd NPs) were synthesized via a chelation and self‑assembly process. Initially, the cell cytotoxicity of PEG‑Ce6‑Gd NPs was evaluated with or without laser irradiation. The in vitro study demonstrated the lack of toxicity of PEG‑Ce6‑Gd NPs to tumor cells in the absence of laser irradiation. However, its toxicity was enhanced under laser irradiation. Moreover, the size and weight of brain tumors were significantly decreased in mice with glioma xenografts, which was further confirmed via histological analysis. Subsequently, the results indicated that the PEG‑Ce6‑Gd NPs had a favorable T1‑weighted contrast performance (0.43 mg ml‑1 s‑1) and were observed to have significant contrast enhancement at the tumor site from 0.25 to 1 h post‑injection in vivo. The favorable MRI, as well as the synergetic photodynamic antitumor effect and antineoplastic ability of PEG‑Ce6‑Gd NPs was identified. It was suggested that PEG‑Ce6‑Gd NPs had great potential in the diagnosis and PDT treatment of gliomas, and possibly other cancer types, with prospects of clinical application in the near future.

Topics: Animals; Brain; Brain Neoplasms; Cell Line, Tumor; Chlorophyllides; Disease Models, Animal; Drug Screening Assays, Antitumor; Female; Gadolinium; Glioma; Humans; Magnetic Resonance Imaging, Interventional; Mice; Multifunctional Nanoparticles; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Porphyrins; Rats

Chlorin e6 (Ce6) is a promising photosensitizer for tumor photodynamic therapy (PDT). However, the efficacy of Ce6 PDT is limited by Ce6's poor water solubility, rapid blood clearance, and inadequate accumulation in the tumor tissue. This problem is tackled in this work, wherein functionalized superparamagnetic iron oxide nanoparticles (IO-NPs) were used as carriers to deliver Ce6 to melanoma. The IO-NPs were coated with polyglycerol (PG) to afford good aqueous solubility. The chemotherapeutic agent doxorubicin (DOX) was attached to the PG coating via the hydrazone bond to afford affinity to the cell membrane and thereby promote the cell uptake. The hydrophobic nature of DOX also induced the aggregation of IO-NPs to form nanoclusters. Ce6 was then loaded onto the IO nanoclusters through physical adsorption and coordination with surface iron atoms, yielding the final composites IO-PG-DOX-Ce6. In vitro experiments showed that IO-PG-DOX-Ce6 markedly increased Ce6 uptake in mouse melanoma cells, leading to much-enhanced photocytotoxicity characterized by intensified reactive oxygen species production, loss of viability, DNA damage, and stimulation of tumor cell immunogenicity. In vivo experiments corroborated the in vitro findings and demonstrated prolonged blood clearance of IO-PG-DOX-Ce6. Importantly, IO-PG-DOX-Ce6 markedly increased the Ce6 distribution and retention in mouse subcutaneous melanoma grafts and significantly improved the efficacy of Ce6-mediated PDT. No apparent vital organ damage was observed at the same time. In conclusion, the IO-PG-DOX NPs provide a simple and safe delivery platform for efficient tumor enrichment of Ce6, thereby enhancing antimelanoma PDT.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Chlorophyllides; Disease Models, Animal; Doxorubicin; Female; Humans; Magnetic Iron Oxide Nanoparticles; Melanoma; Mice; Nanoparticle Drug Delivery System; Photochemotherapy; Skin Neoplasms; Solubility; Tissue Distribution

Currently, the development of polysaccharide, especially chitosan (CS), based drug delivery system to afford magnetic resonance imaging (MRI) guided theranostic cancer therapy remains largely unexplored. Herein, we successfully developed a CS derived polymer (Gd-CS-OA) through chemical conjugation of CS, octadecanoic acid (OA) and gadopentetic acid (GA). After self-assemble into glycolipid nanoparticles to loaded chlorin e6 (Ce6), the resulted Gd-CS-OA/Ce6 was able to realize MRI guided photodynamic therapy (PDT) of cancer. Our results revealed that Gd-CS-OA was able to increase the MRI sensitivity as compared to Gd-DTPA with decent residence time and preferable excretion behavior in vivo. Moreover, the Gd-CS-OA/Ce6 showed negligible hemolysis, satisfactory ROS generation and stability in physiological environments with preferable cellular uptake and enhanced in vitro cytotoxicity (through elevated ROS generation) on 4T1 cells. Most importantly, Gd-CS-OA/Ce6 demonstrated promising in vivo tumor targetability (enhanced penetration and retention effect) and powerful MRI guided tumor ablation through PDT on in situ 4T1 tumor model.

Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Cell Survival; Chitosan; Chlorophyllides; Disease Models, Animal; Drug Delivery Systems; Female; Gadolinium DTPA; Glycolipids; Magnetic Resonance Imaging; Mice; Mice, Inbred BALB C; Nanoparticles; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents; Stearic Acids; Tumor Burden

Screening colonoscopy is crucial in reducing the mortality of colorectal cancer. However, detecting adenomas against the backdrop of an inflamed mucosa (e.g. in ulcerative colitis) remains exceedingly difficult. Therefore, we aimed to improve neoplastic lesion detection by employing a fluorescence-based endoscopic approach. We used the well-established murine AOM/DSS model to induce inflammation-driven carcinogenesis in the colon. In our diagnostic approach, we evaluated Chlorin e6 polyvinylpyrrolidone (Ce6-PVP)-based fluorescence endoscopy in comparison to standard white-light endoscopy. A specialized pathologist then analyzed the histology of the detected lesions. Complementary in vitro studies were performed using human cell lines and a murine organoid system. Ce6-PVP-based fluorescence endoscopy had an improved detection rate of 100% (8/8) in detecting high-grade dysplasias and carcinomas over white-light detection alone with 75% (6/8). Trade-off for this superior detection rate was an increased rate of false positive lesions with an increase in the false discovery rate from 45% for white-light endoscopy to 81% for fluorescence endoscopy. We demonstrate in a proof-of-concept study that Ce6-PVP-based fluorescence endoscopy is a highly sensitive red flag technology to identify biopsy-worthy lesions in the colon.

Topics: Administration, Topical; Animals; Biopsy; Caco-2 Cells; Chlorophyllides; Colitis-Associated Neoplasms; Colonoscopy; Disease Models, Animal; Humans; Mice; Porphyrins; Povidone

With the increase in antibiotic resistance, the development of new antibacterial agents is urgent. Photosensitizers with no detectable resistance are promising antibacterial agents. However, most photosensitizers are insoluble, structurally unstable and ineffective against Gram-negative bacteria due to their negatively charged cell wall that hinder their use. In this study, a novel bacteria-activated photosensitizer ionic liquid was designed and assembled to improve the solubility, stability and antibacterial ability of photodynamic therapy. The cation 1-vinyl-3-dodecyl imidazole has been designed, which has strong binding energy with the major constituent of the cell wall. The anion selected was chlorin e6 (Ce6) since it could respond to the acidic microenvironment of bacterial infection. The Ce6 ionic liquid (Ce6-IL) composed of 1-vinyl-3-dodecyl imidazole and Ce6 not only exhibited bacteria-activated ability because its cation could firmly bond with peptidoglycan in the cell wall, but also had excellent acid responsive ability due to the protonation reaction of COO- in its anion. The binding energy of the cation with peptidoglycan was calculated via molecular dynamics simulation, and the pH-responsive behavior of Ce6-IL was verified via HR-MS. The surface potential, mechanical property, morphology and uptake rate results indicated that the cation could destroy the cell wall and promote the anion Ce6 to enter the bacteria. Due to the dual-mode antibacterial action of its cation and anion, Ce6-IL was more effective against Gram-negative and Gram-positive bacteria than Ce6 alone and had wide-spectrum antibacterial ability. The in vitro studies showed that the IC50 of Ce6-IL against E. coli and S. aureus was reduced by 100 and 10 times, respectively. Furthermore, the in vivo studies indicated that Ce6-IL was more effective for eliminating bacterial infection and could accelerate wound healing. The compatibility test showed that Ce6-IL had low toxicity and exhibited excellent biocompatibility.

Topics: Animals; Anions; Anti-Bacterial Agents; Biocompatible Materials; Cations; Chlorophyllides; Computer Simulation; Disease Models, Animal; Dose-Response Relationship, Drug; Escherichia coli; Female; Humans; Ionic Liquids; Microbial Sensitivity Tests; Photochemotherapy; Porphyrins; Rabbits; Staphylococcus aureus; Structure-Activity Relationship; Wound Healing

Photodynamic therapy (PDT) is an approved modality for the treatment of various types of maligancies and diseased states. However, most of the available photosensitizers (PS) are highly hydrophobic, which limits their solubility and dispersion in biological fluids and can lead to self-quenching and sub-optimal therapeutic efficacy. In this study, chlorin e6 (Ce6)-coated superparamagnetic iron oxide nanoparticle (SPION) nanoclusters (Ce6-SCs) were prepared via an oil-in-water emulsion. The physical-chemical properties of the Ce6-SCs were systematically evaluated. Dual-mode imaging and PDT was subsequently performed in tumor-bearing mice. Chlorin e6 is capable of solubilizing hydrophobic SPION into stable, water-soluble nanoclusters without the use of any additional amphiphiles or carriers. The method is reproducible and the Ce6-SCs are highly stable under physiological conditions. The Ce6-SCs have an average diameter of 92 nm and low polydispersity (average PDI < 0.2). Encapsulation efficiency of both Ce6 and SPION is ≈100%, and the total Ce6 payload can be as high as 56% of the total weight (Ce6 + Fe). The Ce6-SCs localize within tumors via enhanced permeability and retention and are detectable by magnetic resonance (MR) and optical imaging. With PDT, Ce6-SCs demonstrate high singlet oxygen generation and produce a significant delay in tumor growth in mice.

Topics: Animals; Cell Death; Cell Line, Tumor; Chlorophyllides; Dextrans; Diagnostic Imaging; Disease Models, Animal; Human Umbilical Vein Endothelial Cells; Humans; Magnetic Resonance Imaging; Magnetite Nanoparticles; Mice, Nude; Neoplasms; Optical Imaging; Photochemotherapy; Porphyrins; Singlet Oxygen; Theranostic Nanomedicine; Tumor Burden

The use of polymeric carriers to deliver hydrophobic photosensitizers has been widely discussed as a way to improve both fluorescence diagnostic and photodynamic therapy (PDT) of cancers; however, the photophysical and pharmacokinetic parameters, as well as the PDT activity, of such modifications have, until now, only been poorly investigated. The purpose of the present study was to explore the efficacy of PDT with the formulation of the photosensitizer chlorin e6 (Ce6) in combination with polyvinyl alcohol (PVA) in comparison with Ce6 alone and with the clinical drug, Photodithazine in a mouse tumor model. We also investigated the photoactivity of the Ce6-PVA in a model reaction of tryptophan oxidation, analyzed the polymer-Ce6 interaction using fluorescence spectroscopy and atomic-force microscopy, and tested the phototoxicity in vitro. Using fluorescence imaging in vivo we found that injection to mice of Ce6 in a formulation with PVA resulted in a higher tumor-to-normal ratio and greater photobleaching when compared with either the use of Ce6 alone, or with the effects of Photodithazine. Tumor growth study and histological examination of CT26 tumors revealed fast, reproducible tumor regression and more advanced necrosis after PDT with Ce6-PVA. The higher photoactivity of the Ce6-PVA complex was confirmed in a model reaction of tryptophan oxidation and in cultured cells. Therefore, encapsulation of Ce6 in PVA represents a promising strategy for further increasing the selectivity and efficacy of PDT.

Topics: Animals; Cell Line, Tumor; Cell Survival; Chlorophyllides; Disease Models, Animal; Mice; Mice, Inbred BALB C; Microscopy, Atomic Force; Microscopy, Confocal; Neoplasms; Oxidation-Reduction; Photochemotherapy; Photosensitizing Agents; Polyvinyl Alcohol; Porphyrins; Reactive Oxygen Species; Spectrometry, Fluorescence; Transplantation, Homologous; Tryptophan; Whole Body Imaging

While immunotherapy has become a highly promising paradigm for cancer treatment in recent years, it has long been recognized that photodynamic therapy (PDT) has the ability to trigger antitumor immune responses. However, conventional PDT triggered by visible light has limited penetration depth, and its generated immune responses may not be robust enough to eliminate tumors. Herein, upconversion nanoparticles (UCNPs) are simultaneously loaded with chlorin e6 (Ce6), a photosensitizer, and imiquimod (R837), a Toll-like-receptor-7 agonist. The obtained multitasking UCNP-Ce6-R837 nanoparticles under near-infrared (NIR) irradiation with enhanced tissue penetration depth would enable effective photodynamic destruction of tumors to generate a pool of tumor-associated antigens, which in the presence of those R837-containing nanoparticles as the adjuvant are able to promote strong antitumor immune responses. More significantly, PDT with UCNP-Ce6-R837 in combination with the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) checkpoint blockade not only shows excellent efficacy in eliminating tumors exposed to the NIR laser but also results in strong antitumor immunities to inhibit the growth of distant tumors left behind after PDT treatment. Furthermore, such a cancer immunotherapy strategy has a long-term immune memory function to protect treated mice from tumor cell rechallenge. This work presents an immune-stimulating UCNP-based PDT strategy in combination with CTLA-4 checkpoint blockade to effectively destroy primary tumors under light exposure, inhibit distant tumors that can hardly be reached by light, and prevent tumor reoccurrence via the immune memory effect.

Topics: Animals; Cell Line, Tumor; Chlorophyllides; Colonic Neoplasms; Colorectal Neoplasms; CTLA-4 Antigen; Disease Models, Animal; Female; HeLa Cells; Humans; Imiquimod; Immunotherapy; Mice; Mice, Inbred BALB C; Nanoparticles; Photochemotherapy; Photosensitizing Agents; Porphyrins

Mesoporous silica nanoparticles (MSNs), with their large surface area and tunable pore sizes, have been widely applied for anticancer therapeutic cargos delivery with a high loading capacity. However, easy aggregation in saline buffers and limited blood circulation lifetime hinder their delivery efficiency and the anticancer efficacy. Here, new multifunctional MSNs-supported red-blood-cell (RBC)-mimetic theranostic nanoparticles with long blood circulation, deep-red light-activated tumor imaging and drug release were reported. High loading capacities were achieved by camouflaging MSNs with RBC membrane to co-load an anticancer drug doxorubicin (Dox) (39.1 wt%) and a near-infrared photosensitizer chlorin e6 (Ce6) (21.1 wt%). The RBC membrane-coating protected drugs from leakage, and greatly improved the colloidal stability of MSNs, with negligible particle size change over two weeks. Upon an external laser stimuli, the RBC membrane could be destroyed, resulting in 10 times enhancement of Dox release. In a 4T1 breast cancer mouse model, the RBC-mimetic MSNs could realize

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Chlorophyllides; Disease Models, Animal; Doxorubicin; Drug Carriers; Drug Liberation; Erythrocyte Membrane; Lasers; Mice; Nanoparticles; Photosensitizing Agents; Porphyrins; Silicon Dioxide

Many drug controlled release methods have been integrated in multifunctional nanoparticles, such as pH-, redox-, temperature-, enzyme-, and light-responsive release. However, few report is associated with the ROS responsive drug controlled release. Herein, a thioketal linker-based ROS responsive drug (camptothecin conjugated with thioketal linker, abbreviated as TL-CPT) was prepared and the thioketal linker could be cleaved by ROS(reactive oxygen species). To achieve cancer simultaneous optical imaging, photodynamic therapy and chemotherapy, the photosensitizer Chlorin e6(Ce6), TL-CPT and carboxyl-mPEG were loaded on the upconversion nanoparticles (UCNPs), which were named as Ce6-CPT-UCNPs. Under 980 nm laser irradiation, Ce6-CPT-UCNPs emitted a narrow emission band at 645-675 nm which was overlapped with Ce6 absorption peak. Ce6 absorbed the light to produce ROS, which was used for photodynamic therapy and to cleave the thioketal linker in Ce6-CPT-UCNPs to release camptothecin for chemotherapy. Meanwhile, Ce6 absorbed the light, was used for near-infrared fluorescence imaging. The in vivo biodistribution studies showed that the prepared nanoparticles had high orthotopic lung cancer targeting efficiency. The in vivo therapeutic results demonstrated that NCI-H460 lung cancers could be completely eliminated by combining chemo- and photodynamic therapy under 980 nm laser irradiation. The prepared multifunctional Ce6-CPT-UCNPs have great potential in applications such as cancer targeted fluorescent imaging, simultaneous ROS activated chemo- and photodynamic therapy in near future.

Topics: Animals; Antineoplastic Agents, Phytogenic; Camptothecin; Cell Line, Tumor; Chlorophyllides; Disease Models, Animal; Drug Carriers; Drug Therapy; Humans; Infrared Rays; Lung Neoplasms; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Optical Imaging; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents; Reactive Oxygen Species; Theranostic Nanomedicine; Treatment Outcome

The present study was designed to evaluate the therapeutic potential of antimicrobial photodynamic therapy (PDT) using chlorin e6 with halogen light against acne bacteria-induced inflammation.. Highly purified chlorin e6 (Ce6), as a second generation photosensitizer, was synthesized from Spirulina chlorophyll. To evaluate the antimicrobial property of Ce6-mediated PDT with halogen light, the broth microdilution method and two-color fluorescence assay were used. The free radicals generated upon irradiating Ce6 with halogen light were measured using 2,7-dichlorofluorescin diacetate. Propionibacterium acnes was intradermally injected into the left ear of the ICR mice, and the anti-inflammatory effect of Ce6-mediated PDT with halogen light was measured by the histological examination. The expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) as well as pro-inflammatory cytokines were also measured by Western blotting.. Chlorin e6-mediated PDT with halogen light (30,000 lx) inactivated various skin bacteria, including P. acnes in a dose-dependent manner. The MIC99 value against P. acnes (KCTC3314) of Ce6 with light was >0.49 μg/ml, whereas the MIC99 for Ce6 alone was >31.25 μg/ml. Ce6-mediated PDT suppressed the expression of P. acnes-induced pro-inflammatory cytokines and iNOS, but not COX-2 in a mouse model.. This study showed a remarkable therapeutic effect of chlorin e6-mediated PDT with halogen light against P. acnes-induced inflammation. Our results suggest for the first time the potential of Ce6-mediated PDT with halogen light as a more effective and safer alternative treatment to antibiotic therapy against pathogenic infections of the skin.

Topics: Acne Vulgaris; Animals; Blotting, Western; Chlorophyllides; Cyclooxygenase 2; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Halogens; Inflammation; Male; Mice; Mice, Inbred ICR; Nitric Oxide Synthase Type II; Photochemotherapy; Porphyrins; Propionibacterium acnes; Radiation-Sensitizing Agents

Optical energy can trigger a variety of photochemical processes useful for therapies. Owing to the shallow penetration of light in tissues, however, the clinical applications of light-activated therapies have been limited. Bioluminescence resonant energy transfer (BRET) may provide a new way of inducing photochemical activation. Here, we show that efficient bioluminescence energy-induced photodynamic therapy (PDT) of macroscopic tumors and metastases in deep tissue. For monolayer cell culture in vitro incubated with Chlorin e6, BRET energy of about 1 nJ per cell generated as strong cytotoxicity as red laser light irradiation at 2.2 mW/cm(2) for 180 s. Regional delivery of bioluminescence agents via draining lymphatic vessels killed tumor cells spread to the sentinel and secondary lymph nodes, reduced distant metastases in the lung and improved animal survival. Our results show the promising potential of novel bioluminescence-activated PDT.

Topics: Animals; Chlorophyllides; Disease Models, Animal; Humans; Lasers; Luminescence; Mice, Inbred C57BL; Neoplasms; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents

To investigate whether an intravenously injected cathepsin-B activatable theranostic agent (L-SR15) would be cleaved in and release a fluorescent agent (chlorin-e6) in mouse atheromata, allowing both the diagnostic visualization and therapeutic application of these fluorophores as photosensitizers during photodynamic therapy to attenuate plaque-destabilizing cathepsin-B activity by selectively eliminating macrophages.. Thirty-week-old apolipoprotein E knock-out mice (n=15) received intravenous injection of L-SR15 theranostic agent, control agent D-SR16, or saline 3× (D0, D7, D14). Twenty-four hours after each injection, the bilateral carotid arteries were exposed, and Cy5.5 near-infrared fluorescent imaging was performed. Fluorescent signal progressively accumulated in the atheromata of the L-SR15 group animals only, indicating that photosensitizers had been released from the theranostic agent and were accumulating in the plaque. After each imaging session, photodynamic therapy was applied with a continuous-wave diode-laser. Additional near-infrared fluorescent imaging at a longer wavelength (Cy7) with a cathepsin-B-sensing activatable molecular imaging agent showed attenuation of cathepsin-B-related signal in the L-SR15 group. Histological studies demonstrated that L-SR15-based photodynamic therapy decreased macrophage infiltration by inducing apoptosis without significantly affecting plaque size or smooth muscle cell numbers. Toxicity studies (n=24) showed that marked erythematous skin lesion was generated in C57/BL6 mice at 24 hours after intravenous injection of free chlorin-e6 and ultraviolet light irradiation; however, L-SR15 or saline did not cause cutaneous phototoxicity beyond that expected of ultraviolet irradiation alone, neither did we observe systemic toxicity or neurobehavioral changes.. This is the first study showing that macrophage-secreted cathepsin-B activity in atheromata could be attenuated by photodynamic therapy using a protease-mediated theranostic agent.

Topics: Animals; Apolipoproteins E; Carotid Arteries; Cathepsin B; Chlorophyllides; Disease Models, Animal; Drug Eruptions; Erythema; Injections, Intravenous; Mice; Mice, Knockout; Photochemotherapy; Photosensitizing Agents; Plaque, Atherosclerotic; Porphyrins; Random Allocation; Reference Values

Photodynamic therapy (PDT) has been recommended as an alternative therapy for various diseases including microbial infection. Recently, we developed a new method for the preparation of highly pure chlorin e(6) (Ce(6)), which has been widely used as a second-generation photosensitizer. PDT using Ce(6) was very effective for inhibition of in vitro growth of several bacterial strains. To clarify a possibility for its clinical application, in this study, we examined in vitro and in vivo antimicrobial effects of Ce(6)-mediated PDT in mice model of skin infection of Staphylococcus aureus Xen29. Inhibition zone analysis and colony forming unit (CFU) count revealed that Ce(6)-mediated PDT inhibited effectively in vitro bacterial growth. In addition, biofilm formation ability of S. aureus Xen29 was decreased by Ce(6)-mediated PDT. In vivo experiment, mice receiving Ce(6)-mediated PDT exhibited less intensity of bioluminescent signal, showing significant inhibition of bacterial growth. Furthermore, in histopathological examination, marked neutrophilic infiltration and massive bacterial colonies were seen in control mice and mice receiving laser or Ce(6) alone, but not in mice treated with PDT. These results suggest that PDT using Ce(6) extracted by our new method can be clinically useful against bacterial infectious diseases.

Topics: Animals; Anti-Infective Agents; Chlorophyllides; Colony Count, Microbial; Disease Models, Animal; Male; Mice; Mice, Inbred BALB C; Photochemotherapy; Photosensitizing Agents; Porphyrins; Skin Diseases; Staphylococcal Infections; Staphylococcus aureus

The aim of this study was to investigate the low-power density sonication, sonodynamic therapy (SDT) with Photolon and combination of SDT and photodynamic therapy (PDT) with Photolon for the ablation of glioma C6 tumor model in rats.. The study was performed on 50 rats bearing glioma C6. The tumors were sonicated with/without prior intravenous injection of photosensitizer (PS) Photolon (2.5 mg/kg b.w). Sonication was performed with 0.4; 0.7 and 1.0 W/cm² power density at 1 MHz frequency for 10 min, 2.0 h after Photolon administration using BTL-5710 Sono (BTL Industries Limited, Great Britain). PDT was carried out 2.5 h after Photolon administration using diode laser with 661 nm wavelength (IMAF-AXICON, Minsk, Republic of Belarus) at doses of 50 and 100 J/cm² with 0,17 W/cm² fluence rate. Assessment of tumor response was performed by vital staining with Evans blue and pathologic examination.. The maximal tumor necrosis area that underwent sonication (1 MHz; 0.7 W/cm²; 10 min.) followed by PDT at a dose of 100 J/cm² was 100%.. This is the first report to demonstrate the benefits of sono-photodynamic therapy (SPDT) consisting of low-power density ultrasound and PDT for the treatment of malignant glioma models.

Topics: Animals; Brain Neoplasms; Chlorophyllides; Combined Modality Therapy; Disease Models, Animal; Glioma; Photochemotherapy; Photosensitizing Agents; Porphyrins; Povidone; Protoporphyrins; Rats; Sonication; Ultrasonic Therapy

Methicillin-resistant Staphylococcus aureus (MRSA) skin infections are now known to be a common and important problem in the Unites States. The objective of this study was to investigate the efficacy of photodynamic therapy (PDT) for the treatment of MRSA infection in skin abrasion wounds using a mouse model.. A mouse model of skin abrasion wound infected with MRSA was developed. Bioluminescent strain of MRSA, a derivative of ATCC 33591, was used to allow the real-time monitoring of the extent of infection in mouse wounds. PDT was performed with the combination of a polyethylenimine (PEI)-ce6 photosensitizer (PS) and non-coherent red light. In vivo fluorescence imaging was carried out to evaluate the effect of photobleaching of PS during PDT.. In vivo fluorescence imaging of conjugate PEI-ce6 applied in mice indicated the photobleaching effect of the PS during PDT. PDT induced on average 2.7 log(10) of inactivation of MRSA as judged by loss of bioluminescence in mouse skin abrasion wounds and accelerated the wound healing on average by 8.6 days in comparison to the untreated infected wounds. Photobleaching of PS in the wound was overcome by adding the PS solution in aliquots.. PDT may represent an alternative approach for the treatment of MRSA skin infections.

Topics: Administration, Cutaneous; Animals; Chlorophyllides; Disease Models, Animal; Female; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred BALB C; Photobleaching; Photochemotherapy; Polyethyleneimine; Porphyrins; Radiation-Sensitizing Agents; Staphylococcal Skin Infections; Wound Infection

Photosensitizer based fluorescence imaging and spectroscopy is fast becoming a promising approach for cancer detection. The purpose of this study was to examine the use of the photosensitizer chlorin e6 (Ce6) formulated in polyvinylpyrrolidone (PVP) as a potential exogenous fluorophore for fluorescence imaging and spectroscopic detection of human cancer tissue xenografted in preclinical models as well as in a patient.. Fluorescence imaging was performed on MGH human bladder tumor xenografted on both the chick chorioallantoic membrane (CAM) and the murine model using a fluorescence endoscopy imaging system. In addition, fiber optic based fluorescence spectroscopy was performed on tumors and various normal organs in the same mice to validate the macroscopic images. In one patient, fluorescence imaging was performed on angiosarcoma lesions and normal skin in conjunction with fluorescence spectroscopy to validate Ce6-PVP induced fluorescence visual assessment of the lesions.. Margins of tumor xenografts in the CAM model were clearly outlined under fluorescence imaging. Ce6-PVP-induced fluorescence imaging yielded a specificity of 83% on the CAM model. In mice, fluorescence intensity of Ce6-PVP was higher in bladder tumor compared to adjacent muscle and normal bladder. Clinical results confirmed that fluorescence imaging clearly captured the fluorescence of Ce6-PVP in angiosarcoma lesions and good correlation was found between fluorescence imaging and spectral measurement in the patient.. Combination of Ce6-PVP induced fluorescence imaging and spectroscopy could allow for optical detection and discrimination between cancer and the surrounding normal tissues. Ce6-PVP seems to be a promising fluorophore for fluorescence diagnosis of cancer.

Topics: Animals; Cell Line, Tumor; Chick Embryo; Chlorophyllides; Chorioallantoic Membrane; Disease Models, Animal; Luminescent Measurements; Mice; Mice, Inbred C57BL; Mice, Nude; Microscopy, Fluorescence; Porphyrins; Povidone; Protoporphyrins; Sensitivity and Specificity; Spectrometry, Fluorescence; Urinary Bladder Neoplasms

Recent investigations have established that tumour cells treated in vitro by photodynamic therapy (PDT) can be used for generating potent vaccines against cancers of the same origin. In the present study, cancer vaccines were prepared by treating mouse SCCVII squamous cell carcinoma cells with photosensitiser chlorin e6-based PDT and used against poorly immunogenic SCCVII tumours growing in syngeneic immunocompetent mice. The vaccine potency increased when cells were post-incubated in culture after PDT treatment for 16 h before they were injected into tumour-bearing mice. Interfering with surface expression of phosphatidylserine (annexin V treatment) and apoptosis (caspase inhibitor treatment) demonstrated that this post-incubation effect is affiliated with the expression of changes associated with vaccine cell death. The cured mice acquired resistance to re-challenge with the same tumour, while the engagement of cytotoxic T lymphocytes was demonstrated by detection of high numbers of degranulating CD8+ cells in vaccinated tumours. The vaccines prepared from ex vivo PDT-treated SCCVII tumour tissue were also highly effective, implying that surgically removed tumour tissue can be directly used for PDT vaccines. This opens attractive prospects for employing PDT vaccines tailored for individual patients targeting specific antigens of the patient's tumour.

Topics: Animals; Cancer Vaccines; Carcinoma, Squamous Cell; Cell Death; Cell Proliferation; Chlorophyllides; Cytotoxicity, Immunologic; Disease Models, Animal; Female; Injections, Subcutaneous; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Photochemotherapy; Photosensitizing Agents; Porphyrins; Time Factors

In the neocortex, the effectiveness of potential cellular repopulation therapies for diseases involving neuronal loss may depend critically on whether newly incorporated cells can differentiate appropriately into precisely the right kind of neuron, re-establish precise long-distance connections, and reconstruct complex functional circuitry. Here, we test the hypothesis that increased efficiency of connectivity could be achieved if precursors could be more fully differentiated toward desired phenotypes. We compared embryonic neuroblasts and immature murine neurons subregionally dissected from either embryonic day 17 (E17) (Shin et al., 2000) or E19 primary somatosensory (S1) cortex and postnatal day 3 (P3) purified callosal projection neurons (CPNs) with regard to neurotransmitter and receptor phenotype and afferent synapse formation after transplantation into adult mouse S1 cortex undergoing targeted apoptotic degeneration of layer II/III and V CPNs. Two weeks after transplantation, neurons from all developmental stages were found dispersed within layers II/III and V, many with morphological features typical of large pyramidal neurons. Retrograde labeling with FluoroGold revealed that 42 +/- 2% of transplanted E19 immature S1 neurons formed connections with the contralateral S1 cortex by 12 weeks after transplantation, compared with 23 +/- 7% of E17 neurons. A greater percentage of E19-derived neurons received synapses (77 +/- 1%) compared with E17-derived neurons (67 +/- 2%). Similar percentages of both E17 and E19 donor-derived neurons expressed neurotransmitters and receptors [glutamate, aspartate, GABA, GABA receptor (GABA-R), NMDA-R, AMPA-R, and kainate-R] appropriate for endogenous adult CPNs progressively over a period of 2-12 weeks after transplantation. Although P3 fluorescence-activated cell sorting-purified neurons also expressed these mature phenotypic markers after transplantation, their survival in vivo was poor. We conclude that later-stage and region-specific immature neurons develop a mature CPN phenotype and make appropriate connections with recipient circuitry with increased efficiency. However, at postnatal stages of development, limitations in survival outweigh this increased efficiency. These results suggest that efforts to direct the differentiation of earlier precursors precisely along specific desired neuronal lineages could potentially make possible the highly efficient reconstruction of complex neocortical and other CNS circuitr

Topics: Animals; Apoptosis; Brain Tissue Transplantation; Cell Differentiation; Cell Movement; Cell Survival; Chlorophyllides; Corpus Callosum; Disease Models, Animal; Female; Fetal Tissue Transplantation; Fluorescent Dyes; Graft Survival; Infrared Rays; Lasers; Male; Mice; Mice, Inbred C57BL; Microspheres; Neocortex; Neurodegenerative Diseases; Neurons; Neurotransmitter Agents; Porphyrins; Radiation-Sensitizing Agents; Receptors, Neurotransmitter; Somatosensory Cortex; Stilbamidines; Synapses

Photoimmunotherapy (using a monoclonal antibody-targeted photosensitizer and red light) may be a strategy to overcome the limitations inherent in photodynamic therapy of liver tumors. The aims of this study were (a) to test the efficacy of selective treatment of hepatic metastases of colorectal cancer in an orthotopic murine xenograft using the murine monoclonal antibody 17.1A conjugated to the photosensitizer chlorin(e6), and (b) to compare the tumor response after the same light dose was delivered at two different fluence rates. Based on previous biodistribution studies that had shown that the photoimmunoconjugate with a polyanionic charge had both a higher absolute tumor chlorin(e6) content and a greater tumor:normal liver ratio than those obtained with a photoimmunoconjugate bearing a polycationic charge, mice were treated 3 h after i.v. injection of the polyanionic 17.1A chlorin(e6) conjugate or unconjugated photosensitizer. Red light was delivered into the liver tumor by an interstitial fiber, and tumor response end points were total tumor weight in the short term and survival in the long term. There was a highly significant reduction (<20% of controls; P = 0.0035) in the weight of the tumors in the mice treated with photoimmunotherapy, and the median survival increased from 62.5 to 102 days (P = 0.015). Photodynamic therapy with free chlorin(e6) produced a smaller decrease in tumor weight and a smaller extension of survival, neither of which were statistically significant. A comparison of photoimmunotherapy with 10 J of light delivered at 30 or 300 mW showed that the higher fluence rate prolonged survival significantly more than the lower fluence rate. This may have been because the high fluence rate gave a contribution of laser-induced hyperthermia to the photodamage. Correlation studies showed that the amount of normal liver remaining at necropsy correlated best with survival. Photoimmunotherapy shows efficacy in destroying liver tumors, and future studies should maximize selectivity to minimize the destruction of normal liver.

Topics: Animals; Antibodies, Monoclonal; Chlorophyllides; Combined Modality Therapy; Disease Models, Animal; Female; HT29 Cells; Humans; Immunoconjugates; Immunotherapy; Liver Neoplasms, Experimental; Mice; Mice, Nude; Neoplasm Transplantation; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents; Time Factors

Photosensitizers, such as Photofrin II or Chloroaluminum-sulfonated phthalocyanine accumulate at sites of arterial injury. We have exploited this property to develop a model of photodynamic therapy (PDT) for intimal hyperplasia. The fluorescent probe [maleylated-bovine serum albumin (mal-BSA) conjugated with Texas-red] can be selectively targeted to intimal macrophages and smooth muscle cells recruited during formation of hyperplasia via a receptor-mediated mechanism.. In this study, the photosensitizer chlorin e6 (Cle6) was conjugated to mal-BSA in a rat model of intimal hyperplasia, then tested the efficacy of the ligand conjugation to photosensitizer (mal-BSA/Cle6) in PDT of intimal hyperplasia. Arterial wall injury was produced by a balloon catheter pulled through the abdominal aorta of the rat to create a model of intimal hyperplasia. Fluorescent compounds were injected two weeks after injury.. Four hours after injection, the intensity of fluorescence achieved with injection of mal-BSA/Cle6 was higher for intimal hyperplastic lesions as compared to control areas. BSA-Cle6 unconjugated did not demonstrate such delivery. Two weeks after balloon injury, the injured aorta was irradiated externally with an argon pumped dye laser four hours following the photosensitizer injection. We employed two total radiant exposures: 20 J/cm2 and 40 J/cm2. Forty-eight hours after PDT, the arteries were examined histologically. Intimal hyperplastic cells were significantly reduced by PDT in the mal-BSA/Cle6 injected group (40-100%) versus the Cle6 group (0-20%).. Mal-BSA/Cle6 is taken up efficiently by a scavenger pathway, localizes in areas of intimal hyperplasia, and functions as a photosensitizer for PDT.

Topics: Animals; Aorta, Abdominal; Aorta, Thoracic; Aortic Diseases; Binding, Competitive; Chlorophyllides; Disease Models, Animal; Drug Carriers; Follow-Up Studies; Hyperplasia; Injections, Intravenous; Male; Microscopy, Fluorescence; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents; Rats; Rats, Sprague-Dawley; Serum Albumin, Bovine; Tunica Intima