Photobiomodulation therapy was more effective than photobiomodulation plus arginine on accelerating wound healing in an animal model of delayed healing wound.

The combined and individual influences of photobiomodulation therapy (PBMT) and arginine on wound strength, stereological parameters, and gene expressions of some related growth factors in ischemic and delayed healing wounds in rats were analyzed. We divided 108 rats into six groups: control, lower energy density (LOW)-PBMT, 2% arginine ointment (Arg 2%), LOW-PBMT + Arg 2%, high energy density (HIGH)-PBMT, and HIGH-PBMT + Arg 2%. First, we generated an ischemic and delayed healing wound model in each rat. We examined wound strength, stereological parameters, and gene expressions of basic fibroblast growth factor (bFGF), vascular endothelial growth factor A (VEGF-A), and stromal cell-derived factor 1 (SDF-1) by quantitative real-time polymerase chain reaction (qRT-PCR). PBMT alone and PBMT + Arg 2% considerably increased wound strength compared to the control and Arg 2% groups during the inflammatory and proliferative steps of wound healing (p < 0.05). In these steps, PBMT alone significantly induced an anti-inflammatory effect and increased fibroblast counts; Arg 2% alone induced an inflammatory response (p < 0.05). Concurrently, PBMT and PBMT + Arg 2% significantly increased keratinocyte counts and volume of the new dermis (p < 0.05). At the remodeling step, the Arg 2% groups had significantly better wound strength than the other groups (p < 0.05). In this step, PBMT and PBMT + Arg 2% significantly decreased inflammation, and increased fibroblast counts, vascular length, and the volume of new epidermis and dermis compared to the control and Arg 2% groups (p < 0.05). In all cases of gene analysis, there were statistically better results in the PBMT and PBMT + Arg 2% groups compared with the Arg 2% and control groups (p < 0.05). The anti-inflammatory and repairing effects of PBMT on an ischemic and delayed healing wound model in rats were shown by significant improvements in wound strength, stereological parameters, and gene expressions of bFGF, VEGF-A, and SDF-1α.