The Role of Platelet Homeostasis in a Novel Topical PRP Formulation

Background: Topical platelet-rich plasma (PRP) must demonstrate stability to insure biologic activity in aesthetic medicine. Objective: The objective of this research was to evaluate the role of platelet homeostasis in a novel PRP topical cosmetic formulation to provide facial appearance improvement. Methods: The stability of the topical PRP formulation was evaluated in vitro followed by clinical in vivo testing. The in vitro evaluation examined platelet stability and morphology over a 90-day period within the preservative cosmetic base utilizing ELISA and light microscopy (LM)/scanning electron microscopy (SEM). The in vivo clinical study enrolled 20 subjects in a 120-day double blind split face study to evaluate the effect of 5-7x concentrated PRP compared to 2-3x concentrated PRP on facial photoaging. Cosmetic effect was evaluated by the subject and the dermatologist investigator on a 5-point ordinal scale at baseline, week 8, and week 16. Results: 90-day stability for the topical PRP formulation was verified via ELISA and LM/SEM. ELISA showed the PRP was more inactive than control conditions via analyte concentration curves (PDGF-AB, EGF, and P-Selectin). LM/SEM demonstrated the PRP had less aggregation/activation over time within the cosmetic base and that refrigeration is superior to room-temperature storage thus delaying full platelet degranulation. The in vivo clinical study demonstrated parity between 20ml and 60ml PRP in terms of clinical efficacy. Conclusion: Platelets remain viable for up to 90 days in a refrigerated cosmetic vehicle with demonstrated topical clinical PRP facial benefits. PRP kits of 20ml and 60ml volumes for topical PRP are equally efficacious.