Wireless Portable Evaluation Platform for Photodynamic Therapy: In vitro Assays on Human Gastric Adenocarcinoma Cells

Photodynamic Therapy (PDT) is a technique used in the selective destruction of cancer cells and requires the previous knowledge of light dosimetry and photosensitizer drug (PS) concentration to apply on cells. Therefore, a laboratory platform is required for further evaluation, e.g. to make evaluation and assays on previously collected cells by biopsy to determine the best combination of light dose and PS concentration. In this context, this paper presents a low-cost, low-sized and flexible Wireless Portable Evaluation Platform for PDT assays on cells. The W-PEP was tested and evaluated using assays with Human Gastric Adenocarcinoma (AGS) cells. The AGS cells were exposed to the 5-aminolevulinic acid (ALA), which is a precursor of the photosensitive agent Protoporphyrin IX (PpIX) with absorption at 635nm. The W-PEP is composed by 16 small-sized LEDs matrix with peak transmittance at 634nm mounted in a PCB and controlled by ESP32-DevKitC ^® , a power bank to supply the lighting and the controlling systems and 3D printed components specially designed to allow portability and PDT assays. A graphical user interface (GUI) application for mobile devices was developed allowing the bi-directional communication between the smartphone and W-PEP via Bluetooth. The measurements with AGS cells proved this W-PEP was effective in its purpose and promoted cell death in samples treated with ALA and a final light dose of 5J/cm ² after 49 minutes of light exposure. This W-PEP has 140mm of both length and width, 75mm of height and costs about $82.10. To finish, this system checks the optimal conditions that will be applied in the treatment after, thereby decreasing the costs and time of the application.