Application Research On Platelet-rich Plasma In Bone Tissue Engineering

Objectives:1.Conventional static seeding method is not efficient in establishing 3D cell/scaffold composites,so fibrinogen and other hydrogels are used to increase seeding efficiency.Platelet-rich plasma(PRP) is derived from autologous whole blood and rich in fibrinogen and piatelets which release multiple active factors in response to thrombin. Therefore,we think using platelet-rich plasma(PRP) as seeding intermedium instead of fibrinogen and other hydrogels can improve current static seeding technology.2.In PRP clinical or research studies,the anticoagulant application does not draw enough attentions though anticoagulants might influence the quality and then biological effect of PRP.This study conducted a comparative study to investigate the effect of the anticoagulants on PRP quality wishing to clarify the appropriate anticoagulant used in PRP production.Methods:To test our hypothesis,this study evaluated seeding efficiency,proliferation and differentiation of BMSCs seeded into PLGA porous scaffolds via PRP,autologous fibrinogen,and DMEM respectively.Additionally,BMSCs/PLGA constructs established by above three intermediums were implanted in goat calvarial defects to evaluate the capability of PRP in enhancing bone regeneration by radiological and histological assay. 2.The microstructure change of platelets collected via heparin,citrate,acid citrate dextrose(ACD) and citrate-theophylline-adenosine-dipyridamole(CTAD) was observed by TEM following time course.The extent of spontaneous activation of platelets in four groups was detected by measuring sP-selectin in plasma.The TGF-β1 release amount of activated PRP of four groups was measured and the biological effect of PRP on cell proliferation was also studied.Results:1.PRP not only could increase BMSCs seeding efficiency like fibrinogen,but also could significantly stimulate BMSCs proliferation without inhibition BMSCs differentiation in vitro and obviously enhance bone regeneration in vivo compared with DMEM and fibrinogen.2.CTAD is superior to other anticoagulants in maintaining the integrity of platelet structures for a long time and preventing platelet spontaneous activation.ACD slightly surpassed heparin and citrate in above two aspects.ACD-PRP and CTAD-PRP released significantly more TGF-β1 and significantly enhanced hBMSCs proliferation compared with heparin and citrate.Conclusion:1.Therefore,PRP seeding strategy is both valuable and convenient for application in bone tissue engineering and this new seeding method will hopefully enhance the clinical utility of engineered bone.2.The PRP quality and biological effects were strongly associated with the type of Anticoagulants.ACD and CTAD are optimal anticoagulants in PRP production for they can maintain platelet viability at a high level.