Platelet rich plasma enhances osteoconductive properties of a hydroxyapatite-β-tricalcium phosphate scaffold (Skelite™) for late healing of critical size rabbit calvarial defects

11siThe use of platelet rich plasma (PRP) in bone repair remains highly controversial. In this work, we evaluated the effect of lyophilized PRP on bone regeneration when associated with a silicon stabilized hydroxyapatite tricalcium phosphate scaffold in a rabbit calvarial defect (Skelite™). Critical defects were created in the calvaria of twenty-four rabbits. The periosteum was removed and the defects were either left empty or filled with allogeneic PRP gel; Skelite particles; Skelite and PRP gel. Four animals were killed after 4 weeks, 10 animals after 8 and 10 after 16 weeks. Specimens were processed for X-ray microtomography (μCT) and for resin embedded histology. μCT analysis revealed significant osteoid-like matrix and new bone deposition in PRP + Skelite group at both 8 and 16 weeks in respect to Skelite alone. Histologically, PRP + Skelite defects were highly cellular with more abundant osteoid deposition and more regular collagen fibres. Moreover, in vitro migration assays confirmed the chemotactic effect of PRP to endothelial and osteoprogenitor cells. We conclude that the addition of PRP influenced the local tissue microenvironment by providing key cryptic factors for regeneration, thereby enhancing progenitor cell recruitment, collagen and bone matrix deposition, and by creating a bridging interface between the scaffold and bone.nonenoneEl Backly, Rania M.; Zaky, Samer H.; Canciani, Barbara; Saad, Manal M.; Eweida, Ahmed M.; Brun, Francesco; Tromba, Giuliana; Komlev, Vladimir S.; Mastrogiacomo, Maddalena; Marei, Mona K.; Cancedda, RanieriEl Backly, Rania M.; Zaky, Samer H.; Canciani, Barbara; Saad, Manal M.; Eweida, Ahmed M.; Brun, Francesco; Tromba, Giuliana; Komlev, Vladimir S.; Mastrogiacomo, Maddalena; Marei, Mona K.; Cancedda, Ranier

The current state of scaffolds for musculoskeletal regenerative applications

Musculoskeletal disease and injury are highly prevalent conditions that lead to many surgical procedures. Autologous tissue transfer, allograft transplantation and nontissue prosthetics are currently used for the surgical treatment of critical-sized defects. However, the field of tissue engineering is actively investigating tissue-replacement solutions, many of which involve 3D scaffolds. Scaffolds must provide a balance of shape, biomechanical function and biocompatibility in order to achieve tissue replacement success. Different tissues can have different requirements for success, which has led to the development of various materials with unique characteristics. Articular cartilage scaffolds have the most robust clinical experience, with many scaffolds, mostly constructed of natural materials, showing promise, but levels of success vary. Tendon scaffolds also have proven clinical applications, with human-dermis-derived scaffolds showing the most potential. Synthetic and naturally derived meniscus scaffolds have been investigated in few clinical studies, but the results are encouraging. Bone scaffolds are limited to amorphous pastes and putties, owing to difficulties achieving adequate vascularization and biomechanical optimization. The complex physiological function and vascular demands of skeletal muscle have limited the widespread clinical use of scaffolds for engineering this tissue. Continued progress in preclinical study, not only of scaffolds, but also of other facets of tissue engineering, should enable the successful translation of musculoskeletal tissue engineering solutions to the clinic