Extraction of platelet-rich plasma retaining physiological-concentration erythrocytes and enriched leukocytes...

Conventional platelet-rich plasma (PRP) typically requires erythrocyte removal in clinical practice. However, emerging evidence suggests that erythrocytes and leukocytes play key roles in tissue repair. This study investigated whether PRP retaining physiological concentrations of erythrocytes and enriched leukocytes (PRP-RE&EL) affects its functional capabilities. An automatic hematology analyzer and enzyme-linked immunosorbent assay were used to detect differences in component composition and cytokine levels between PRP-RE&EL and conventional PRP. The CCK-8 assay, vascular capillary network formation assay, and Western blot analysis were employed to evaluate their performance differences. The regenerative repair effects of PRP-RE&EL versus conventional PRP on fresh articular osteochondral injuries were compared in vivo. Compared with conventional PRP, PRP-RE&EL contained higher cytokine concentrations. In vitro, it more effectively promoted cell proliferation and facilitated capillary network formation. PRP-RE&EL also significantly influenced the abundance of HIF1-α and VEGF proteins in related cells and the differentiation of bone marrow mesenchymal stem cells. In vivo, PRP-RE&EL was more effective than conventional PRP in treating fresh articular osteochondral injuries. Thus, PRP-RE&EL significantly increases cytokine concentrations, thereby enhancing its ability to promote the regenerative repair of articular osteochondral injuries and holding potential for clinical application.