Differential Therapeutic Efficacy of Autologous Platelet-Rich Plasma at Varying Concentrations in the Treatment of Deep Second-Degree Burn and Its Underlying Molecular Mechanisms.

BACKGROUND

Platelet-rich plasma (PRP) shows promise in burn management, yet optimal platelet concentrations, timing, and standardized protocols remain unclear, leading to inconsistent clinical outcomes.

AIMS: To compare the therapeutic efficacy of PRP at different platelet concentrations in deep second-degree burns and to explore associated molecular mechanisms.

PATIENTS/

METHODS

Twenty-eight patients with small-area deep second-degree burns were randomly assigned to four groups: Group A (PRP 600-1000 × 109/L), Group B (normal saline control), Group C (PRP 1000-1400 × 109/L), and Group D (PRP 1400-1800 × 109/L). Outcomes included wound healing time, wound coverage rates at 2 and 3 weeks, bacterial culture positivity, and 3-month scar scores. Full-thickness biopsies were collected on days 5, 9, and 16 for histopathology, immunohistochemistry, and growth factor quantification.

RESULTS

All PRP groups showed faster healing and lower infection rates compared with controls. Group C achieved the shortest healing time (p < 0.05). Growth factor concentrations rose with increasing platelet levels, but M2 macrophage polarization was highest in Group C. Elevated transforming growth factor-β (TGF-β) in Group D appeared to trigger negative feedback, limiting M2 accumulation and diminishing added benefit. Scar scores did not differ significantly among PRP groups.

CONCLUSIONS

PRP accelerates wound healing and reduces infection risk in deep second-degree burns. A platelet concentration of 1000-1400 × 109/L provides the best therapeutic balance. Excessively high concentrations may impair repair through TGF-β-mediated inhibitory effects. Future research should explore controlled-release strategies to optimize PRP-derived growth factor activity.