Histopathological and Immunohistochemical Evaluation of Nanofat versus Platelet Rich Plasma in Promoting the Healing Process for Donor Site in Split Thickness Graft

Background: Scar of donor site after Split-thickness skin graft (STSG) remains a challenge in reconstructive surgery. Nanofat is composed of small fat particles (less than 0.1 mm in diameter) containing a high concentration of stem cells and growth factors that helps in tissue regeneration. PRP positively impacts skin quality, texture and hyperpigmentation due to the presence of platelet derived growth factors (PDGF), Transforming growth factor-beta (TGF-β), vascular endothelial growth (VEGF), Epidermal Growth Factor (EGF). Objectives: This study aimed to compare the effect of adjuvant nanofat grafting versus PRP injection on STSG donor sites healing (Epidermal thickness, re-epithelization), scar quality by Vancouver score and postoperative complications. Patients and Methods: This comparative self-controlled multi-center clinical trial was carried out in Plastic surgery unit of General Surgery Department at Benha University hospital and Plastic surgery Department of Benha Teaching hospital from February 2024 to September 2025. This study included 50 patients who had raw areas that necessitated skin reconstruction by STSG to evaluate the effect of adding nanofat grafts and platelet rich plasma injection to donor sites of STSG. The donor site was divided into 2 halves.1 half was treated with nanofat and the other half was treated with PRP combined with Vaseline gauze. Results: Nanofat-treated sites demonstrated significantly superior healing characteristics. At one month, nanofat achieved a significantly greater mean epidermal thickness (259.5 ± 12.3 µm vs. 198 ± 38 µm, P < 0.001) and larger re-epithelialization area (85.1 ± 11.5% vs. 78.74 ± 10.2%, P=0.004). At three months, nanofat sites showed better VSS scores, with significantly less firm pliability (0% vs. 36%, P < 0.001) and fewer red (hyperemic) areas (4% vs. 20%, P=0.028) compared to PRP. No hypertrophic scar formation was observed in either the nanofat-treated or PRP-treated donor sites during the follow-up period. Conclusion: Nanofat grafting provides a regenerative advantage over PRP, leading to accelerated and more stable healing, superior pliability, and significantly better scar quality at STSG donor sites.