An affordable automated LED array system for optimizing photodynamic therapy protocols

Photodynamic therapy (PDT) is a promising minimally invasive alternative cancer treatment that, due to fluorescent properties of the drug (photosensitizer), can be used as a theragnostic agent. The efficacy of this treatment largely relies on the successful activation of the photosensitizer with appropriate light. While certain studies demonstrate comparable outcomes between LED and laser activation, there remains a lack of consensus regarding the differential effects of pulsed versus continuous light. In response to the limited availability of commercially versatile equipment capable of fully controlling pulsed light, we have developed an LED array system for optimizing PDT protocols. The designed equipment is versatile, has an intuitive user-friendly interface, and adapts to sterile conditions required for in-vitro studies. It also enables precise control of light irradiation, allowing to freely modify power, pulse width, frequency, exposure time and wavelength. In this study, the developed LED array system was employed to optimize PDT protocols for breast cancer theragnostic, using Fotoenticine as photosensitizer. The obtained results highlight the importance of appropriate irradiation equipment in PDT lighting protocol optimization. In this sense, significant improvements in therapeutic efficacy were observed when using 10 Hz frequency and 10 or 20% duty cycles. This resulted in a remarkable transition from a non-cytotoxic dose in continuous mode to a fully cytotoxic condition, leading to a >95% enhancement in the therapeutic effect.