Berberine Photo-Activation Potentiates Cytotoxicity in Human Astrocytoma Cells through Apoptosis Induction

Photodynamic therapy (PDT) has recently attracted interest as an innovative and adjuvant treatment for different cancers including malignant gliomas. Among these, Glioblastoma (GBM) is the most prevalent neoplasm in the central nervous system. Despite conventional therapeutic approaches that include surgical removal, radiation, and chemotherapy, GBM is characterized by an extremely poor prognosis and a high rate of recurrence. PDT is a physical process that induces tumor cell death through the genesis and accumulation of reactive oxygen species (ROS) produced by light energy interaction with a photosensitizing agent. In this contribution, we explored the potentiality of the plant alkaloid berberine (BBR) as a photosensitizing and cytotoxic agent coupled with a PDT scheme using a blue light source in human established astrocytoma cell lines. Our data mainly indicated for the combined BBR-PDT scheme a potent activation of the apoptosis pathway, through a massive ROS production, a great extent of mitochondria depolarization, and the sub-sequent activation of caspases. Altogether, these results demonstrated that BBR is an efficient photosensitizer agent and that its association with PDT may be a potential anticancer strategy for high malignant gliomas.

Employing bicontinuous-to-micellar transitions in nanostructure morphology for on-demand photo-oxidation responsive cytosolic delivery and off–on cytotoxicity

PEG-b-PPS bicontinuous nanospheres resist degradation and stably retain payloads within cells. When loaded with a photosensitizing agent, these nanospheres demonstrate off–on inducible photo-responsive release of cytotoxic agents into the cytosol of cells.

Fricke Dosimetry as a Tool to Quality Control of Photodynamic Therapy

Photodynamic therapy (PDT) consists of the association of a photosensitizing agent with a light source in order to cause cellular necrosis. Methylene blue, toluidine blue and malachite green are photosensitizers derived from dyes that are widely accepted in medicine, as they have low toxicity and are low cost. PDT is an alternative treatment for cancer, with significant advantages over procedures such as surgery/chemotherapy. Our laboratory has studied the Fricke solution doped with photosensitizers in an approach to obtain a quality control for PDT. The Fricke solution was prepared with ammoniacal ferrous sulfate, sodium chloride and sulfuric acid in water. The solutions modified with photosensitizers were prepared by adding 0.1 g/100 mL of the dyes. A volume of 2.6 ml of the Fricke solution modified with photosensitizers were transferred to test tubes and irradiated. The irradiated solutions had their optical densities measured in a spectrophotometer. The samples were irradiated with LED (Light Emitting Diodes) in acrylic phantoms. The FATA samples irradiated with LED showed the sensitivity of the dosimeters to red, blue, green and yellow light. A calibration curve with correlation coefficient of 0.9884 for the red light was obtained; 0.9752 for blue light; 0.9644 for the green light and 0.9768 for the yellow light. The fact that a sensitivity of the dosimeters to the LED has been occurred indicates that the PDT could be realized with LED, with lower costs than with laser. This work suggested that FATA dosimeters can be used for quality control of PDT.

Efficacy of photodynamic therapy in the treatment of cutaneous leishmaniasis

Introduction: A limited number of case reports have studies the efficacy of Photodynamic Therapy (PDT) in management of Cutaneous Leishmaniasis (CL). Topical PDT is an innovative mode of therapy that works on principle of selective uptake of photosensitizing agent by CL lesions. Current study was conducted to determine efficacy of topical photodynamic therapy of CL. Study Design: Descriptive cross sectional study. Setting: Dermatology outdoor clinic PIMS Islamabad. Period: July 2015 to Jan 2016. Materials & Methods: Total 75 patients (>12 years) of either gender with biopsy proven CL lesions were included after ethical approval. Pregnant or lactating women, those with sensitivity to light or photo sensitizer were excluded. The selected cases were administered once a week sessions of topical 5-ALA PDT therapy. This therapy was continued till 4 weeks and efficacy was observed at 6th week; efficacy labeled as yes if there was no erythema with resolution of papules, plaques or nodules, surrounded by normal healthy skin clinically and the histo-pathological smears revealing absence of amastigotes, otherwise labeled as non-effective. Results: Mean age was 24.37+7.43 years. There were 44(58.67%) females and 31(41.33%) males. Mean duration of disease was 40.29+11.73 days and mean size of lesion was 19.69+9.88 mm. Effective PDT outcome was seen in 67(89.33%) patients at 6th week of therapy. Conclusion: This study concluded that topical photodynamic therapy is an effective method for treatment of Cutaneous Leishmaniasis.