The effect of combined low-level nd: YAG laser with mesenchymal stem cells in the healing of diabetic wounds: an experimental study.

Although the role of low-level laser therapy (LLLT) and human adipose-derived stem cells (hADSC) in accelerating diabetic wound healing has been proven, their synergistic effect is still debated. This study aimed to evaluate the individual and combined effects of LLLT and hADSC on wound healing and on biomechanical parameters in type 2 diabetic rabbits. In this experimental study, 40 rabbits with type 2 diabetes (induced by streptozotocin (STZ)) were included. Rabbits were randomly assigned with equal ratios to 4 groups, including the control group (group A), hADSCs alone (group B), the laser alone (group C), and the combined group of hADSCs cells with laser (group D). 30 days after diabetes, two wounds were created on the back of each rabbit. Immediately after creating a wound, hADSC was injected into two parts of the wound. In the laser groups, the wound site was treated with a low-power 660 nm laser for 4 weeks daily for 20-30 s. The number of closed wounds in the treatment group was evaluated 7, 15 and 30 days after the treatment. On the 15th and 30th days, a standard sample of each healing wound was sent for biomechanical evaluation. Thirty days after treatment, the combined effect of LLLT + hADSCs was superior to their individual effects on wound healing and biomechanical parameters (mean bending stiffness, maximum force, high-stress load, and energy absorption), while their individual effects were similar. Fifteen days after treatment, the effect of LLLT alone was superior to hADSCs alone for wound healing and improvement of biomechanical parameters. LLLT and hADSCs, individually and in combination, were superior in diabetic wound healing and biomechanical parameters compared to the control group in type 2 diabetic rabbits. The combined effect of LLLT with hADSCs was superior to their individual effects.