Investigation of the synergistic effect of platelet-rich plasma and polychromatic light on human dermal fibroblasts seeded chitosan/gelatin scaffolds for wound healing.

Conventional wound healing treatments are insufficient for chronic wounds caused by factors such as senescence of fibroblasts, reduced growth factor synthesis, and poor angiogenesis. Recently, tissue engineering approaches have been investigated to develop effective therapies. In this study, a biochemical/biophysical stimulant-based 3D system was developed for the healing of chronic wounds. In this direction, genipin crosslinked chitosan (CHT)/gelatin (GEL) scaffolds were fabricated by freeze-drying and loaded with platelet-rich plasma (PRP). The scaffolds were seeded with human dermal fibroblasts and then, polychromatic light in near infrared region (NIR) was applied to the scaffolds for activating the platelets and stimulating the fibroblasts (photoactivation, PAC). Thus, fibroblasts were stimulated both chemically and physically by PRP and light, respectively. Cell migration, proliferation, morphology, gene expressions and reactive oxygen species (ROS) activity were evaluated in-vitro. Laminin and collagen 4 expressions that are important for extracellular matrix (ECM) formation, and PDGF (Platelet-derived growth factor) and VEGF (Vascular endothelial growth factor) expressions that are important for vascularization significantly increased in the presence of both PRP and light. Besides, PRP and light improved cell migration in 3D core-and shell model synergistically. Hydrogen peroxide content decreased in both PRP and light, indicating inhibition of ROS production. It was concluded that the stimulation of platelets with light in the NIR has a great potential to use for both platelets activation and stimulation of fibroblasts. As a result, an effective therapy can be developed for chronic wounds by using scaffold-based 3D systems together with PRP and photostimulation.