The effects of platelet rich plasma and zinc oxide nanoparticle on skin wound healing in dogs.

Wound healing is a complicated process, so it's critical to identify efficient ways to hasten recovery. Platelet-rich plasma (PRP) and zinc oxide nanoparticles (ZnO NPs) have demonstrated potential in improving cutaneous wound healing in a variety of species. But little is known about their combined effects, especially in dogs. Therefore, this study determined how topical infiltration of PRP and ZnO NPs ointment, both separately and in combination, affect the healing of dogs' cutaneous wounds. Thirty-six full skin wounds were induced in the chest of six adult mongrel dogs. These wounds were randomly divided into six equal groups (6 wounds each) according to treatment protocol: group 1 served as a control and the wounds were dressed daily with normal saline only, group 2: the wounds were dressed daily with lanolin only, group 3: the wounds were infiltrated once with PRP, group 4: the wounds were treated with PRP single infiltration combined with lanolin ointment daily dressing, group 5: the wounds were dressed daily with ZnO NPs ointment, and group 6: the wounds were infiltrated once with PRP and daily dressed with ZnO NPs ointment. Wound healing progress was monitored; epithelialization, wound contraction, and overall healing were assessed. Total antioxidant capacity (TAC), malondialdehyde (MDA) and the concentration of platelets derived growth factor beta (PDGFβ) were measured on wound fluid. Gene expression of matrix extracellular phosphoglycoprotien (MEPE), transforming growth factor beta (TGF-β) and tumor necrosis factor alpha (TNF-α) were also evaluated on skin biopsies at day 0, 5, 10 and 20. Histopathology, immunohistochemistry and staining of collagen bundles were performed on skin biopsies at 5, 10 and 20 days of wound induction. All data were statistically analyzed. There was a significant interaction between the group and time across all parameters (P < 0.001). The PRP-ZnO NPs group consistently has a great effect on wound size reduction, contraction, healing, epithelialization, and antioxidant activity, along with higher MEPE and PDGFβ expression and arranged parallel collagen bundles, indicating enhanced regeneration. While PRP alone showed the strongest TGF-β increase and anti-inflammatory effect (lowest TNF-α). PRP-ZnO NPs provided the best overall balance between regeneration and inflammation control. All treatments surpassed the control and lanolin groups, which showed minimal improvement. PRP-Lanolin and ZnO NPs offered moderate benefits but were less effective than PRP-ZnO NPs or PRP. ZnO NPs and PRP work together to improve skin wound healing in dogs; PRP promotes regenerative signaling, while ZnO NPs reduce oxidative stress and microbial load.