Optimizing Platelet and Leucocyte-Rich Plasma as Biomaterials for Ophthalmic Applications: Impact of Centrifugation Speed

Abstract

Purpose: To assess the impact of varying centrifugation speeds on platelet and leucocyte-rich plasma (L-PRP) in liquid and gel form cellularity and growth factor concentrations for potential use against ocular surface disorders.

Patients and methods: L-PRP was collected from 16 healthy subjects using three different centrifugation speeds: 580, 1000, and 2000 g, each for 8 min at 25°C. Platelet and leukocyte counts were automatically evaluated. The concentrations of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and transforming growth factor beta 1 (TGF-B1) were measured using enzyme-linked immunosorbent assays. L-PRP gel cellularity was assessed through hematoxylin-eosin and Masson's trichrome staining, categorized as moderate or abundant, and statistically analyzed. L-PRP gel membrane's chemical composition was analyzed using Fourier-transform infrared spectroscopy (FTIR), crystallization was investigated with X-ray diffraction (XRD), and ultrastructure was assessed using surface electron microscopy (SEM). Additionally, membrane degradation was evaluated over a 7-day period.

Results: No significant differences in cellularity and growth factor concentrations among centrifugation speeds (p > 0.05) were found. Moderate cellularity predominated at 580 g and 2000 g, while abundant cellularity was observed at 1000 g. No significant differences were found techniques (p = 0.16). Masson's trichrome staining suggested the existence of abundant fibrin at 1000 g but without significant differences (p = 0.07). FTIR analysis exhibited the characteristic fibrin bands at all speeds, and XRD indicated a keratin-like pattern. SEM revealed greater porosity at 580 g and fibrin membrane degradation was lower at this speed (p = 0.0001).

Conclusion: Centrifugation speed did not significantly affect growth factor concentration or cellularity in both liquid and gel L-PRP. Further studies should explore the impact of different separation techniques for L-PRP used in ophthalmic applications.

Keywords: centrifugation; growth factors; leucocytes; platelet.