Laser Exposure Systems for Multiwell Plate Photodynamic Therapy (PDT) Treatments: Reactive Oxygen Species Generation and Photocytotoxicity

Abstract

SignificanceThe study demonstrated the development of two low-cost custom laser diode exposure systems for early-stage PDT studies that provide homogenous output power at the target regions at specific wavelengths, during the duration of treatment. ApproachTwo custom laser diode exposure systems were built and optimized for high-throughput PDT applications. The power output for tested laser diodes was quantified and the photosensitizer induced photochemistry was evaluated using a cell-free and an in-vitro assay. ResultsThe experimental results showed that the laser exposure system was suitable for PDT experiments up to 10mW/cm2. The laser power was homogenous for the 4- and 6-well illumination with variable irradiation exposure time. The photoactivation of photosensitizers showed consistent results with the cell-free SOSG and in-vitro NRU assay. ConclusionsThe laser diode systems developed by the authors for use in high throughput PDT experiments, provided uniform and stable output up to 10mW/cm2. Variation between the output power was less than 10%The results obtained using the cell-free SOSG and in-vitro NRU assay were consistent and in agreement with the literature.