The Possible Therapeutic Impacts of Photobiomodulation and Low-Dose Photodynamic Therapy on Huvecs Towards Angiogenesis: A Comparative in Vitro Analysis

This is the authors' abstract. We don't add key points for this paper.

Photobiomodulation (PBM) is a non-ionizing therapy that promotes faster wound healing and cell proliferation/differentiation. It is recently understood that photodynamic therapy (PDT) may act as PBM when applied at low-level. In this study, a comparative analysis between PBM and low-dose PDT was performed on HUVECs to increase angiogenesis. HUVECs were irradiated at 808-nm of wavelength. Indocyanine green was used as a photosensitizer in PDT applications. Single and triple treatments were employed for both modalities. Their effects were analyzed with cell viability, intracellular ROS, MMP change, NO release, and morphological analysis. The expressions of vascularization-related proteins (VEGF, PECAM-1, and vWf) were determined through immunofluorescence staining and qRT-PCR. Temperature changes during applications were monitored to determine any thermal damages. It was observed that triple PDT application was more successful at increasing cell proliferation and tube-like structure formation with a 20% rate. The level of ROS did not significantly change in all applications. However, the amount of NO release in triple PDT application was nearly 5 times that of the control group, which showed it acted as a key molecule. The vascularization-related proteins were more strongly expressed in PDT applications. It was understood that low-dose PDT can exert a photobiomodulation effect to accelerate vascularization through NO release.