IJMS, Vol. 21, Pages 1399: Interpenetrating Hydrogel Networks Enhance Mechanical Stability, Rheological Properties, Release Behavior and Adhesiveness of Platelet-Rich Plasma (International Journal of Molecular Sciences)

Platelet-rich plasma (PRP) has attracted much attention for the treatment of articular cartilagedefects or wounds due to its intrinsic content of growth factors relevant for tissue repair. However, the shortresidence time of PRP in vivo, due to the action of lytic enzymes, its weak mechanical properties and theconsequent short-term release of bioactive factors has restricted its application and efficacy. The present workaimed at designing new formulation strategies for PRP, based on the use of platelet concentrate (PC)-loadedhydrogels or interpenetrating polymer networks, directed at improving mechanical stability and sustainingthe release of bioactive growth factors over a prolonged time-span. The interpenetrating hydrogels comprisedtwo polymer networks interlaced on a molecular scale: (a) a first covalent network of thermosensitive andbiodegradable vinyl sulfone bearing p(hydroxypropyl methacrylamide-lacate)-polyethylene glycol triblockcopolymers, tandem cross-linked by thermal gelation and Michael addition when combined with thiolatedhyaluronic acid, and (b) a second network composed of cross-linked fibrin. The PC-loaded hydrogels, instead,was formed only by network (a). All the designed and successfully synthesized formulations greatlyincreased the stability of PRP in vitro, leading to significant increase in degradation time and storagemodulus of PRP gel. The resulting viscoelastic networks showed the ability to controllably release plateletderived growth factor and transforming growth factr β1, and to improve the tissue adhesiveness of PRP. Thenewly developed hydrogels show great potential for application in the field of wound healing, cartilagerepair and beyond.