Photobiomodulation therapy facilitates transplantation of dental pulp stem cells for spinal cord injury.

Abstract

BACKGROUND: While dental pulp stem cells (DPSCs) show therapeutic potential for spinal cord injury (SCI), post-traumatic oxidative stress and mitochondrial dysfunction critically compromise grafted cell survival. Photobiomodulation therapy (PBMT) is a noninvasive approach that may enhance regenerative efficacy. This study investigates whether PBMT improves the survival and neural differentiation of transplanted DPSCs in SCI models. METHODS: In vitro, the anti-apoptotic effects of PBMT were investigated in HO-induced DPSCs injury model via TUNEL staining, flow cytometry, biochemical assays and transmission electron microscopy. In vivo, spinal cord restoration was evaluated using behavioral tests and histological staining, and the survival status and neural differentiation of grafted DPSCs were respectively tracked through bioluminescence imaging and immunofluorescent staining in DPSCs co-expressing luciferin and green fluorescent protein (Luc-GFP-DPSCs) transplanted SCI mice with/without PBMT. RESULTS: PBMT demonstrated protective effects by relieving apoptosis and oxidative stress in engrafted DPSCs in vitro. Furthermore, PBMT-assisted DPSCs transplantation significantly promoted cell survival and neural differentiation, achieving superior functional recovery compared to transplantation alone. CONCLUSIONS: PBMT facilitates DPSCs transplantation in SCI through mitigation of oxidative apoptosis and enhancement of grafted cell survival and differentiation.