Comparison of Resuspension Techniques on the Cellular and Cytokine Characteristics of Platelet Rich Plasma: A Pilot Study

Abstract

Background: Platelet Rich Plasma (PRP) is increasingly used for a variety of musculoskeletal ailments such as tendinopathy and arthritis. There are numerous protocols for preparing PRP, but to our knowledge there have been no studies to assess the impact that re-suspension techniques may have on the cellular characteristics and growth factor expression of the final PRP product. Hypothesis: The type of re-suspension technique used will alter the platelet characteristics and growth factor expression of PRP. Study Design: Descriptive laboratory study. Methods: Blood was collected from nine healthy volunteer donors between ages 26-60. Informed consent and ethics approval was obtained. A double spin technique was used resulting in a concentrated PRP product. Three commonly employed re-suspension techniques were utilized to re-suspend the final PRP product and the cellular characteristics and growth factor expression were analyzed using a reproducible protocol. This study was completed over a single day. Results: All three re-suspension techniques resulted in a 4.6-5.2-fold increase in platelet concentration with no difference between groups (p=0.31). This is consistent with the recommended PRP concentration in published literature. Each re-suspension technique also demonstrated in increase in concentration of PDGF and VEGF with no difference between groups (p=0.81 and p=0.97). Conclusion: This pilot study suggests that the re-suspension techniques may be equivalent and do not result in altered cellular or growth factor characteristics within the study limitations. Clinical Relevance: The mixing method can be labor and time intensive and prolong patient wait times. The vortex method can shorten the overall patient encounter time while still providing an optimal PRP product. Previously, there were only theoretical assumptions regarding how the re-suspension techniques may modify PRP characteristics.