Photobiomodulation promotes osteogenic differentiation of mesenchymal stem cells and increases P-Akt levels in vitro

Bone defects are common orthopedic conditions, and due to the limited regenerative capacity of bone tissue, their repair remains a challenge in orthopedic surgery. Mesenchymal stem cells (MSCs) have demonstrated strong potential for osteogenic differentiation; however, their efficiency in vivo remains restricted, particularly in terms of differentiation and migration. Photobiomodulation (PBM), a non-invasive therapeutic technique, has shown great promise in promoting stem cell differentiation. In this study, we cultured human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro and treated them with 635/808 nm laser light. We measured alkaline phosphatase (ALP) activity, mineralized nodule formation, and the expression of osteogenesis-related genes and factors after 7, 14, and 21 days. The results showed that PBM treatment significantly enhanced hUCMSC proliferation and osteogenic differentiation. The mechanism behind this effect involves PBM activating the upstream Akt signaling pathway, increasing P-Akt expression, and elevating reactive oxygen species (ROS) levels to induce mild oxidative stress. This process enhances ALP activity, mineralized nodule formation, and the expression of osteogenesis-related genes and factors, thus promoting the osteogenic differentiation of hUCMSCs.