Human Platelet Lysate (PL) is an hemoderivate enriched of soluble mediators employed in several regenerative-based clinical applications. We have patented an optimized PL preparation (Mesengen®, N. WO/2013/042095) with a standardized concentration of growth factors/cytokines and with reduced interference of residual proteins, providing higher in vitro performance combined to decreased immunogenic/inflammatory potential. Many studies demonstrated that human platelets source a wide range of circulating miRNAs and extracellular vesicles (EV) by which active biological molecules are transported. Although platelet-derived extracellular vesicles (P-EV) are known to regulate homeostasis, inflammation and angiogenesis, they have not yet well characterized in PL-derived preparations. The understanding of their content and role in PL preparations would be of high significant to exploit the benefits of platelets in absence of their adverse effects and responsiveness upon cardiovascular insult.
In this study we aim to unravel the regenerative potential of human PL to mediate cardiac/endothelial regenerative properties. Our preliminary data already highlight that PL contains EVs displaying subpopulations of different size (0.8/0.45/ 022 um) exhibiting a different degree in inducing in vitro angiogenesis of endothelial cells (HUVEC).RTPCR analysis shows that PL is enriched of miRNA 126, coherently to its abundant derivation from platelets.
This study supports the proficiency of PL and in particular of P-EV in enhancement of angiogenic capacity in endothelial cells.
Free Cell Therapies may be the new future of tissue repair as well as in the cardiovascular field because they exploit the paracrine effects. PL has the characteristics of a standard product in terms of cytokines and growth factors and the presence of EVs in the PL can be a strength to exploit the beneficial potential of the biologically active molecules that are contained in the EVs.
For these reasons it is necessary to investigate in depth the characteristics of the P-EV and which biologically active molecules contain to understand the mechanisms at the base of their potentiality.
In particular it would be interesting to know the total miRNA expressed with miRNoma profiler on PL.