Efficacy and Safety of a Defined Two‐Dose Protocol of Autologous Platelet‐Rich Plasma (PRP) Injection for Refractory Chronic Non‐Healing Wounds: A Prospective Clinical Study

ABSTRACT

Chronic non-healing wounds represent a major global public health challenge. Their persistence is frequently attributed to localized biological deficits that cause them unresponsive to conventional therapeutic modalities. While Platelet-Rich Plasma (PRP) has demonstrated promising results as an adjunctive treatment by delivering highly concentrated growth factors, its clinical application is currently impeded by a lack of clinical standardization, particularly optimal injection frequency, interval, and dosage. The aim of this study is to rigorously evaluate the efficacy and safety of a specific, non-intensive two-dose PRP injection protocol for accelerating the reduction of wound area in patients with various types of refractory chronic wounds. We conducted a prospective, single-arm, pretest-posttest study enrolling 18 patients with refractory non-healing wounds, defined as lesions persisting for a minimum period of 4 weeks which had failed to achieve definitive closure under optimized standard care. Autologous high-concentration PRP was injected intradermally around the wound margin at baseline (Day 0) and again 3 weeks later (Day 21). Wound area was digitally measured at baseline and subsequently at 7, 11 and 15 weeks. The primary outcome was the mean reduction in wound area (cm²) at the 15-week follow-up, assessed using a Paired Samples t-test. The mean patient age was 57.89 ± 15.64 years, and wounds had a mean chronicity of 15.83 ± 19.05 months. The PRP preparation achieved a mean platelet concentration 8.5 times greater than the peripheral blood threshold (first injection) and 7.0 times greater than the threshold (second injection), confirming high therapeutic quality. Analysis of the total cohort demonstrated a statistically significant reduction in mean wound area from baseline 27.41 ± 70.38 cm² to 15 weeks 21.5 ± 68.96 cm². Three patients (16.67%) achieved complete epithelialization. Subgroup trends suggested diabetic and venous ulcers responded more favourably than radiation-induced ulcers. The protocol was safe, with no systemic or severe localized adverse events observed among participants. The defined two-dose PRP injection protocol provides a clinically effective and safe adjunctive therapy that significantly promotes wound area reduction in challenging chronic non-healing wounds. This reproducible, low-frequency protocol offers a rationale for standardization in advanced wound care, warranting validation through future large-scale Randomized Controlled Trials (RCTs).