phytochlorin and Melanoma

phytochlorin has been researched along with Melanoma* in 15 studies

Trials

1 trial(s) available for phytochlorin and Melanoma

ArticleYear
Photodynamic therapy with chlorin e(6) for skin metastases of melanoma.
    Photodermatology, photoimmunology & photomedicine, 2004, Volume: 20, Issue:1

    Photodynamic therapy (PDT) has been successfully applied in clinical settings to destroy neoplasms, but the efficacy of such a treatment is dependent on the type of neoplasm and the photosynthesizer used. Here, we perform a clinical assessment of PDT for skin metastases of pigmented melanoma using chlorin e(6).. PDT with chlorin e(6) photosensitizer was administered to 14 patients with skin metastases from melanoma (10 females, four males, mean age 49.6 years). Chlorin e(6) at a dose of 5 mg/kg of patient's weight was intravenously injected. The treatment course consisted of two courses of PDT exposure 1 h after intravenous chlorin e(6) injection and 24 h post-injection. The light energy density for each skin tumor was 80-120 J/cm(2) per treatment, with a light power density of 250-300 mW/cm(2).. All skin melanoma metastases that received PDT showed complete regression with no recurrence during the study period. The complete response of all skin metastases from melanoma occurred in eight cases after one PDT treatment. In the remaining six individuals, tumors required multiple PDT courses prior to complete regression. No cases of photodermatitis were registered. The Karnofsky performance scale score of the patients with skin metastases from melanoma showed no significant difference before and after PDT. No patients had significant changes in blood cell counts that would indicate chlorin e(6) systemic toxic effect. Blood chemistry and urinalysis did not show any evidence of chlorin e(6) renal and hepatic injury.. PDT with chlorin e(6) for skin metastases from melanoma is effective and well tolerated. Further clinical investigation of PDT with chlorin e(6) is warranted.

    Topics: Chlorophyllides; Female; Humans; Male; Melanoma; Middle Aged; Photochemotherapy; Porphyrins; Radiation-Sensitizing Agents; Skin Neoplasms

2004

Other Studies

14 other study(ies) available for phytochlorin and Melanoma

ArticleYear
Vascular-targeted photodynamic therapy with glucose-conjugated chlorin e6 for dogs with spontaneously occurring tumours.
    Veterinary medicine and science, 2023, Volume: 9, Issue:6

    Photodynamic therapy (PDT) using photosensitisers is a minimally invasive treatment for malignant tumours. However, ideal photosensitisers are not yet established. Recently, we developed a new photosensitiser, glucose-conjugated chlorin e6 (G-Ce6).. To evaluate the clinical efficacy of vascular-targeted PDT (VTP), a type of PDT utilising a short drug-light interval, using G-Ce6 to treat spontaneously occurring tumours in dogs.. Five dogs with spontaneously occurring tumours (malignant melanoma: three; haemangiopericytoma: two; and squamous cell carcinoma: one) were subjected to VTP. These dogs were intravenously injected with G-Ce6 at doses of 1-3 mg/kg 5 min before laser irradiation. Tumours were superficially or interstitially irradiated using a 677-nm diode laser.. Repeated VTP decreased tumour size, yielding complete remission in three dogs. Complications such as oedema surrounding normal tissues and fistulae were observed, and the oedema was self-limiting. The fistula was cured by debriding the necrotic tissues formed after VTP.. Our findings demonstrate that VTP using G-Ce6 had antitumour effects in dogs with spontaneously occurring tumours.

    Topics: Animals; Dog Diseases; Dogs; Edema; Glucose; Melanoma; Photochemotherapy

2023
Discovery of an Amino Acid-Modified Near-Infrared Aza-BODIPY Photosensitizer as an Immune Initiator for Potent Photodynamic Therapy in Melanoma.
    Journal of medicinal chemistry, 2022, 02-24, Volume: 65, Issue:4

    The discovery of novel photosensitizers with potent phototoxicity and desirable water solubility is an urgent task for photodynamic therapy. Herein, a series of amino acid-modified aza-BODIPY photosensitizers were synthesized and evaluated. These new PSs exhibited enhanced aqueous solubility, increased

    Topics: Amino Acids; Animals; Aspartic Acid; Boron Compounds; Cell Line, Tumor; Drug Discovery; Female; Humans; Immunotherapy; Melanoma; Mice; Mice, Inbred C57BL; Photochemotherapy; Photosensitizing Agents; Reactive Oxygen Species; Structure-Activity Relationship; Subcellular Fractions; Xenograft Model Antitumor Assays

2022
Investigating the photodynamic efficacy of chlorin e6 by millisecond pulses in metastatic melanoma cells.
    Bioelectrochemistry (Amsterdam, Netherlands), 2021, Volume: 138

    Melanoma is considered the most aggressive type of skin cancer, still without effective treatment. Thus, alternative therapeutic methods are still in demand, and electroporation-supported photodynamic therapy (EP-PDT) of cancer cells seems a promising approach. New developments in EP-PDT aim at enhanced tumor selectivity and biocompatibility by applying a second-generation photosensitizer, i.e., Chlorin e6 (Ce6). We have verified the improved photodynamic effect of Ce6 on skin cancer melanoma (Me45) cells and control (CHO-K1) cells. In this study, we applied 1 or 5 pulses of 10 ms duration and assessed the EP-PDT effect with a variety of tests, such as singlet oxygen scavenger (ABMDMA) photooxidation, oxidoreductive potential measurements, kinetic measurements with fluorescent microscopy, photosensitizer uptake studies, lipid peroxidation level, and actin fibers organization. The optimization of photosensitizer uptake as a function of temperature was also performed. Our results indicated efficient Ce6 delivery into Me45 cells and good photodynamic efficiency enhanced by the electroporation of cancer cells.

    Topics: Biological Transport; Cell Line, Tumor; Chlorophyllides; Humans; Kinetics; Melanoma; Neoplasm Metastasis; Photochemotherapy; Photosensitizing Agents; Porphyrins; Singlet Oxygen; Time Factors

2021
Nanoliposomes co-encapsulating Ce6 and SB3CT against the proliferation and metastasis of melanoma with the integration of photodynamic therapy and NKG2D-related immunotherapy on A375 cells.
    Nanotechnology, 2021, Aug-20, Volume: 32, Issue:45

    Topics: Animals; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chlorophyllides; Female; Humans; Immunotherapy; Killer Cells, Natural; Liposomes; Male; Matrix Metalloproteinase Inhibitors; Melanoma; Mice; Nanoparticles; NK Cell Lectin-Like Receptor Subfamily K; Photochemotherapy; Reactive Oxygen Species; Xenograft Model Antitumor Assays

2021
Efficient Delivery of Chlorin e6 by Polyglycerol-Coated Iron Oxide Nanoparticles with Conjugated Doxorubicin for Enhanced Photodynamic Therapy of Melanoma.
    Molecular pharmaceutics, 2021, 09-06, Volume: 18, Issue:9

    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

2021
A Trojan horse biomimetic delivery strategy using mesenchymal stem cells for PDT/PTT therapy against lung melanoma metastasis.
    Biomaterials science, 2020, Feb-21, Volume: 8, Issue:4

    Mesenchymal stem cell (MSC)-based biomimetic delivery has been actively explored for drug accumulation and penetration into tumors by taking advantage of the tumor-tropic and penetration properties of MSCs. In this work, we further demonstrated the feasibility of MSC-mediated nano drug delivery, which was characterized by the "Trojan horse"-like transport via an endocytosis-exocytosis-endocytosis process between MSCs and cancer cells. Chlorin e6 (Ce6)-conjugated polydopamine nanoparticles (PDA-Ce6) were developed and loaded into the MSCs. Phototherapeutic agents are safe to the MSCs, and their very low dark toxicity causes no impairment of the inherent properties of MSCs, including tumor-homing ability. The MSCs loaded with PDA-Ce6 (MSC-PDA-Ce6) were able to target and penetrate into tumors and exocytose 60% of the payloads in 72 h. The released PDA-Ce6 NPs could penetrate deep and be re-endocytosed by the cancer cells. MSC-PDA-Ce6 tended to accumulate in the lungs and delivered PDA-Ce6 into the tumors after intravenous injection in the mouse model with lung melanoma metastasis. Phototoxicity can be selectively triggered in the tumors by sequentially treating with near-infrared irradiation to induce photodynamic therapy (PDT) and photothermal therapy (PTT). The MSC-based biomimetic delivery of PDA-Ce6 nanoparticles is a potential method for dual phototherapy against lung melanoma metastasis.

    Topics: Administration, Intravenous; Animals; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chlorophyllides; Endocytosis; Humans; Indoles; Lung Neoplasms; Male; Melanoma; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Photochemotherapy; Photosensitizing Agents; Polymers; Porphyrins; Xenograft Model Antitumor Assays

2020
Light-assisted gadofullerene nanoparticles disrupt tumor vasculatures for potent melanoma treatment.
    Journal of materials chemistry. B, 2020, 03-25, Volume: 8, Issue:12

    The traditional photodynamic therapy (PDT) using a photosensitizer and oxygen under light generates reactive oxygen species (ROS) to kill tumor cells. However, its treatment efficiency is limited by insufficient oxygen in tumor cells. Herein, β-alanine modified gadofullerene nanoparticles (GFNPs) were explored to disrupt tumor vasculatures assisted by light for potent melanoma treatment. As tumor vasculatures are oxygen-rich, the yields of photo-induced singlet oxygen (1O2) by GFNPs are not subjected to the hypoxemia of tumor tissues. Different from the small molecule photosensitizer Chlorin e6 (Ce6), GFNPs realize high-efficiency tumor vascular disruption under light observed by using the mice tumor vascular dorsal skin fold chamber (DSFC) model. The tumor vascular disruption efficiency of GFNPs is size-dependent, and the smallest one (hydration diameter of ca. 126 nm) is more efficient. Mechanistically, the high yields of photo-induced 1O2 by GFNPs can lead to the destruction of the tumor vascular endothelial adherent junction protein-VE cadherin and the decrease of tumor vascular endothelial cells-CD31 proteins, inducing rapid tumor necrosis. In conclusion, our work provides an insight into the design of well-sized nanoparticles to powerfully treat melanoma assisted by light, as well as greatly extending the applications of PDT for robust tumor therapy.

    Topics: Animals; beta-Alanine; Cell Death; Chlorophyllides; Female; Fullerenes; Light; Melanoma; Mice; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Particle Size; Photochemotherapy; Photosensitizing Agents; Porphyrins; Singlet Oxygen; Skin Neoplasms; Surface Properties

2020
Polymer-free cubosomes for simultaneous bioimaging and photodynamic action of photosensitizers in melanoma skin cancer cells.
    Journal of colloid and interface science, 2018, Jul-15, Volume: 522

    We designed novel polymer-free cubic bicontinuous liquid crystalline dispersions (cubosomes) using monoolein as molecular building block, phospholipids as stabilizers, propylene glycol as hydrotrope. Their kinetic stability was evaluated by analysing the backscattering profiles upon ageing, and the most stable formulation was chosen as potential photosensitizers delivery vehicle for photodynamic therapy (PDT) of human skin melanoma cells. Morphological and topological features of such formulation alternatively loaded with Chlorin e6 or meso-Tetraphenylporphine-Mn(III) chloride photosensitizing dyes were investigated by cryo-TEM, DLS, and SAXS. Bioimaging studies demonstrated that Me45 and MeWo cell lines effectively internalized these cubosomes formulations. Particularly, photodynamic activity experiments proved both the very low cytotoxicity of the cubosomes formulation loaded with Chlorin e6 dye in the "dark" condition, and its significant cytotoxic effect after photoirradiation. The toxic effect recorded when the photosensitizer was encapsulated within the cubosomes was shown to be one order of magnitude higher than that caused by the free photosensitizer. This is the first report of biocompatible polymer-free cubosomes for potential application in both PDT and bioimaging of skin malignant melanoma.

    Topics: Cell Line, Tumor; Cell Proliferation; Cell Survival; Chlorophyllides; Drug Carriers; Glycerides; Humans; Kinetics; Liquid Crystals; Manganese; Melanoma; Melanoma, Cutaneous Malignant; Metalloporphyrins; Optical Imaging; Particle Size; Photochemotherapy; Photosensitizing Agents; Porphyrins; Propylene Glycol; Skin Neoplasms; Surface Properties

2018
Crosslinked self-assembled nanoparticles for chemo-sonodynamic combination therapy favoring antitumor, antimetastasis management and immune responses.
    Journal of controlled release : official journal of the Controlled Release Society, 2018, 11-28, Volume: 290

    Sonodynamic therapy (SDT) has been proposed as a new modality for cancer management through low-intensity ultrasound induced activation of sonosensitizers. Here, we designed a novel redox/enzyme/ultrasound responsive chondroitin sulfate-chlorin e6-lipoic acid nanoplatform loading docetaxel, combining SDT and chemotherapy, for antiproliferation and antimetastasis of melanoma. The reversibly crosslinked and self-assembled nanoparticles possessed monodispersive size distribution, stability in physical conditions, while showing increased uptake with rapid drug release in simulated tumor microenvironment (reductive potentials and degradative hyaluronidase-1). With synthesized ultrasound sensitive polymer backbones, SDT induced the generation of cellular reactive oxygen species and mitochondrial damage, exerting the apoptotic effect through the release of cytochrome C, the expression of cleaved caspase-9 followed by the functional cleaved caspase-3. Chemo-sonodynamic therapy not only inhibited tumor growth and metastasis with reduced metastatic protein expression, but also caused immune response via the release of tumor-associated antigens. It was initially demonstrated that SDT could induce the tumor cell death, therefore having potentials to recruit cytotoxic lymphocytes into tumor sites. Notably, the nanoplatforms exhibited good in vivo stability and blood compatibility, indicating the safety and efficiency in drug delivery. Our work thus presents a convenient approach to fabricate intelligent multifunctional nanoparticles and paves a path for effective cancer therapies.

    Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Chlorophyllides; Chondroitin Sulfates; Combined Modality Therapy; Docetaxel; Melanoma; Mice, Inbred C57BL; Nanoparticles; Porphyrins; Thioctic Acid; Ultrasonic Therapy

2018
Biodegradable nanocomplex from hyaluronic acid and arginine based poly(ester amide)s as the delivery vehicles for improved photodynamic therapy of multidrug resistant tumor cells: An in vitro study of the performance of chlorin e6 photosensitizer.
    Journal of biomedical materials research. Part A, 2017, Volume: 105, Issue:5

    Photodynamic therapy (PDT), which enables the localized therapeutic effect by light irradiation, provides an alternative and complementary modality for the treatment of tumor. However, the aggregation of photosensitizers in acidic microenvironment of tumor and the non-targeted distribution of photosensitizers in normal tissues significantly affect the PDT efficiency. In this study, we developed a biodegradable nanocomplex HA-Arg-PEA from hyaluronic acid (HA) and arginine based poly(ester amide)s (Arg-PEA) as the nanocarrier for chlorin e6 (Ce6). HA enhanced the tumor-specific endocytosis mediated by the overexpression of CD44 receptor. Arg-PEA not only provide electrostatic interaction with HA to form self-assembled nanostructure, but also improve the monomerization of Ce6 at physiological pH as well as mildly acidic pH. The biodegradable characteristic of HA-Arg-PEA nanocomplex enabled the intracellular delivery of Ce6, in which its release and generation of singlet oxygen can be accelerated by enzymatic degradation of the carrier. The in vitro PDT efficiency of Ce6-loaded HA-Arg-PEA nanocomplex was examined in CD44 positive MDA-MB-435/MDR multidrug resistant melanoma cells. CD44-mediated uptake of Ce6-loaded HA-Arg-PEA nanocomplex significantly improved Ce6 level in MDA-MB-435/MDR cells within short incubation time, and the PDT efficiency in inhibiting multidrug resistant tumor cells was also enhanced at higher Ce6 concentrations. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1487-1499, 2017.

    Topics: Arginine; Biodegradable Plastics; Cell Line, Tumor; Chlorophyllides; Drug Carriers; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Hyaluronic Acid; Melanoma; Photosensitizing Agents; Polyesters; Porphyrins

2017
Developing a dermatological photodiagnosis system by optical image analyses and in vivo study.
    Photodiagnosis and photodynamic therapy, 2016, Volume: 15

    Dermatological photodynamic therapy (DPDT) involves using systematic photosensitizers in combination with light irradiation treatment to eliminate cancer cells. Therefore, a noninvasive fluorescence photodiagnosis system is critical in DPDT for diagnosing target tissues and demarcating the margin of normal tissues. This study proposes a 375-nm ring LED light module in fluorescence imaging for DPDT applications. Image reproducibility (I.R.) and image interference (I.I.) analysis were performed. The results showed that the I.R. value of this fluorescence diagnostic system was higher than 99.0%, and the I.I. from external light sources was lower than 3.0%. In addition, the result of an in vivo study showed that the Chlorin e6 red fluorescence and the scope of distribution of B16-F10 melanoma cells in a mouse ear's vein could be measured clearly using our device; however, the comparison studio with 395-nm LED lights could not focus or capture the red fluorescence effectively.

    Topics: Animals; Cell Line, Tumor; Chlorophyllides; Dermoscopy; Equipment Design; Equipment Failure Analysis; Fluorescent Dyes; Lighting; Melanoma; Mice; Mice, Nude; Microscopy, Fluorescence; Photography; Porphyrins; Reproducibility of Results; Sensitivity and Specificity; Skin Neoplasms

2016
Dual-effect liposomes encapsulated with doxorubicin and chlorin e6 augment the therapeutic effect of tumor treatment.
    Lasers in surgery and medicine, 2015, Volume: 47, Issue:1

    Long circulating doxorubicin (Dox)-loaded PEGylated liposomes are clinically safer than the free form due to the significant reduction of cardiac toxicity. However, the therapeutic efficacy of the PEGylated liposome could further be improved if poor diffusivity and slow drug release of the liposome in tumor interstitium can be overcome. In this study, a dual-effect liposome triggered by photodynamic effect was developed to improve the therapeutic efficacy of Dox-loaded PEGylated liposomes.. Dox and chlorin e6 (Ce6) were co-encapsulated in PEGylated liposomes (named as PL-Dox-Ce6). To induce the drug release, photodynamic effect was triggered by the light irradiation of a 662 nm diode laser. The cellular distribution of Dox and Ce6 was examined under confocal microscope. The in vitro and in vivo cytotoxicity of PL-Dox-Ce6 was determined via the colony formation assay and the synergistic C26 tumor model, respectively.. The cellular distribution of PL-Dox-Ce6 was in the cytoplasmic area; while under light irradiation, Dox was co-localized with nuclear staining positive signals. The cellular cytotoxicity of PL-Dox-Ce6 was significantly higher than the controls including liposomes encapsulating either Dox (PL-Dox) or Ce6 (PL-Ce6). The in vivo treatment efficacy of PL-Dox-Ce6 determined in the C26 tumor model reveals a significant therapeutic effect compared to that of PL-Ce6 and PL-Dox alone or in combination.. This study indicates that this dual-effect PEGylated liposome could provide clinical advantages in the combination regimen of photodynamic therapy and chemotherapy.

    Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Cell Survival; Chlorophyllides; Colonic Neoplasms; Doxorubicin; Humans; Lasers, Semiconductor; Liposomes; Male; Melanoma; Mice; Mice, Inbred BALB C; Neoplastic Stem Cells; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Porphyrins; Random Allocation; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays

2015
Photodynamic therapy of melanoma skin cancer using carbon dot - chlorin e6 - hyaluronate conjugate.
    Acta biomaterialia, 2015, Volume: 26

    Despite wide application of photodynamic therapy (PDT) for the treatment of melanoma skin cancers, there are strong biomedical unmet needs for the effective generation of singlet oxygen after targeted delivery of photosensitizers. Here, we investigated a facile PDT of melanoma skin cancer using transdermal carbon dot - chlorine e6 - hyaluronate (Cdot-Ce6-HA) conjugates. The Cdot-Ce6-HA conjugate was synthesized by the coupling reaction of diaminohexane modified HA (DAH-HA) with the carboxylic group of Ce6. The singlet oxygen generation of Cdot-Ce6-HA conjugates in aqueous solution was more significant than that of free Ce6. The enhanced transdermal and intracellular delivery of Cdot-Ce6-HA conjugates to B16F10 melanoma cells in tumor model mice were corroborated by confocal microscopy and two-photon microscopy. The laser irradiation after topical treatment with Cdot-Ce6-HA conjugates resulted in complete suppression of melanoma skin cancers. The antitumor effect was confirmed by histological analysis with H&E staining and TUNEL assay for tumor apoptosis. Taken together, we could confirm the feasibility of Cdot-Ce6-HA conjugate for transdermal PDT of melanoma skin cancers.. To our knowledge, this is the first report on a facile transdermal photodynamic therapy (PDT) of melanoma skin cancer using carbon dot - chlorine e6 - hyaluronate (Cdot-Ce6-HA) conjugates. We found that the singlet oxygen generation of Cdot-Ce6-HA conjugates in aqueous solution was more significant than that of free Ce6. Confocal microscopy and two-photon microscopy clearly confirmed the enhanced transdermal and intracellular delivery of Cdot-Ce6-HA conjugates to B16F10 melanoma cells in tumor model mice. Taken together, we could confirm the feasibility of Cdot-Ce6-HA conjugate for transdermal PDT of melanoma skin cancers.

    Topics: Administration, Cutaneous; Animals; Apoptosis; Carbon; Cell Line, Tumor; Cell Survival; Chlorophyllides; Diffusion; Melanoma; Mice; Mice, Nude; Nanocapsules; Nanoconjugates; Photochemotherapy; Photosensitizing Agents; Porphyrins; Quantum Dots; Skin Neoplasms

2015
Dynamics of photoinduced cell plasma membrane injury.
    Biophysical journal, 1995, Volume: 68, Issue:5

    We have developed a video microscopy system designed for real-time measurement of single cell damage during photolysis under well defined physicochemical and photophysical conditions. Melanoma cells cultured in vitro were treated with the photosensitizer (PS), tin chlorin e6 (SnCe6) or immunoconjugate (SnCe6 conjugated to a anti-ICAM monoclonal antibody), and illuminated with a 10 mW He/Ne laser at a 630 nm wavelength. Cell membrane integrity was assessed using the vital dye calcein-AM. In experiments in which the laser power density and PS concentration were varied, it was determined that the time lag before cell rupture was inversely proportional to the estimated singlet oxygen flux to the cell surface. Microscopic examination of the lytic event indicated that photo-induced lysis was caused by a point rupture of the plasma membrane. The on-line nature of this microscopy system offers an opportunity to monitor the dynamics of the cell damage process and to gain insights into the mechanism governing photolytic cell injury processes.

    Topics: Cell Line; Cell Membrane; Chlorophyllides; Fluoresceins; Humans; Kinetics; Lasers; Light; Melanoma; Microscopy, Video; Oxygen; Photochemistry; Photolysis; Photosensitizing Agents; Porphyrins; Radiation-Sensitizing Agents; Singlet Oxygen; Time Factors; Tumor Cells, Cultured

1995