Platelet-rich plasma for tissue regeneration can be stored at room temperature for at least five days

Autologous platelet-rich plasma (PRP) is gaining increasing use as a wound healing promoter in a variety of clinical settings, including dentistry. Fresh PRP is often used, necessitating daily draws. The present study investigates the possibility of using stored PRP without having to freeze it by storing PRP under variable conditions and assessing growth factor release as a surrogate marker of continued viability.

Freshly drawn PRP was stored in oxygen permeable and non-oxygen permeable containers under conditions of constant agitation with or without added prostaglandin, intermittent agitation and no agitation, over an 8-day period. Serial platelet counts, mean platelet volume, platelet distribution width and platelet-large cell ratio, and collagen-induced aggregometry were undertaken. Once collagen-induced aggregation had gone to completion, the plasma was centrifuged to pellet platelet material and the supernatants separated and frozen for batched analysis of released platelet-derived growth factor-BB (PDGF-BB).

As would be anticipated, platelet counts, percentage aggregation and PDGF-BB levels all reduced over time. Platelet parameters suggested that platelets were more stable in the non-oxygen permeable containers, possibly due to pH drift and a degree of microaggregate formation in the oxygen permeable containers.

Although platelet integrity and PDGF-BB fell over time, the intermittently agitated non-oxygen permeable container appeared to retain better platelet integrity and function, and PDGF-BB release, than other storage conditions, with potential for clinical use for 5-8 days.