High-power light-emitting diode array design and assembly for practical photodynamic therapy research

Abstract

Q. Spring, "High-power light-emitting diode array design and assembly for practical photodynamic therapy research," J. AbstractSignificance: Commercial lasers, lamps, and light-emitting diode (LED) light sources have stimulated the clinical translation of photodynamic therapy (PDT). Yet, the continued exploration of new photosensitizers (PSs) for PDT often requires separate activation wavelengths for each agent being investigated. Customized light sources for such research frequently come at significant financial or technical cost, especially when compounded over many agents and wavelengths.Aim: LEDs offer potential as a cost-effective tool for new PS and multi-PS photodynamic research. A low-cost-per-wavelength tool leveraging high-power LEDs to facilitate efficient and versatile research is needed to further accelerate research in the field.Approach: We developed and validated a high-power LED array system for benchtop PDT with a modular design for efficient switching between wavelengths that overcome many challenges in light source design. We describe the assembly of a low-cost LED module plus the supporting infrastructure, software, and protocols to streamline typical in vitro PDT experimentation.Results: The LED array system is stable at intensities in excess of 100 mW∕cm 2 with 2.3% variation across the illumination field, competitive with other custom and commercial devices. To demonstrate efficacy and versatility, a primary ovarian cancer cell line was treated with two widely used PSs, aminolevulinic acid and verteporfin, using the LED modules at a clinically relevant 50 J∕cm 2 light dose that induced over 90% cell death for each treatment. Conclusions:Our work provides the community with a tool for new PS and multi-PS benchtop photodynamic research that, unlike most commercial light sources, affords the user a low barrier to entry and low-cost-per-wavelength with the goal of illuminating new insights at the forefront of PDT.

Assessing the photodynamic therapeutic effects of 5‑aminolevulinic acid on human colon cancer cells using light‑emitting diodes

“…More importantly, the present study demonstrated that the type of multi-well plate used in these studies markedly affects the results obtained. It is common practice that black-walled multi-plates are used (19,33). The present study demonstrated that this may restrict light exposure to all the cells in all the wells.…”

“…LEDs can be arranged in into a planner array to increase the irradiated area even further. These arrays can be costly (>$1,000) (19), or low in price (<$25, the present study). Such advantages may render LEDs as a popular light modality in the 5-ALA-PDT of patients with CRC.…”

Light Technology for Efficient and Effective Photodynamic Therapy: A Critical Review

“…All in all, the use of LEDs for PDT was demonstrated in the mid-1990s by Schmid et al in brain tumours of canines treated with porifrin [ 52 ]. Presently, the rapid growth of LEDs led to the development of LED arrays of various wavelengths and handheld systems achieving the high power required for PDT [ 61 , 62 , 63 , 64 ]. For instance, array systems delivering a fluence rate of 100 mW/cm 2 demonstrated a 90% of cell death in ovarian cancer cell line using LED modules reaching a fluence of 50 J/cm 2 [ 62 ].…”

“…Presently, the rapid growth of LEDs led to the development of LED arrays of various wavelengths and handheld systems achieving the high power required for PDT [ 61 , 62 , 63 , 64 ]. For instance, array systems delivering a fluence rate of 100 mW/cm 2 demonstrated a 90% of cell death in ovarian cancer cell line using LED modules reaching a fluence of 50 J/cm 2 [ 62 ]. More recently, LEDs have been used for human breast cancer cell lines showing effective PDT without thermal issues [ 65 ] and for illumination of nanoparticles loaded with the photosensitizer in a human prostate tumour model [ 66 ].…”

Irradiance uniformity optimization for a photodynamic therapy treatment device with 3D scanner

“…17,18 A light-emitting diode (LED) has been successfully applied in the treatment of many skin diseases in PDT due to its high cover area and uniformity. [19][20][21][22] Other light modulators, such as a micromirror, are also used for PDT to achieve homogeneous irradiance by modulating the pulse duty factor. However, the coupling factor of such a device is limited by a digital mirror device.…”