A Study On The Effect Of Platelet-rich Plasma, Activated By Different Concentrations Of Thrombin, On The Repair Of Cranial Defects

Objective: This study is to evaluate the effect of platelet-rich plasma (PRP), activated by different concentrations of thrombin, on the proliferation of bone marrow stromal cells (BMSCs) and the repair of cranial defects. Method: 1. PRP was obtained from a New Zealand rabbit. The PRP was divided into 7 groups, added in different concentrations of calcium chloride and thrombin at the following concentrations: 20U/ml, 40U/ml, 60U/ml, 80U/ml, 100U/ml, 500U/ml and 1000U/ml, in proportion as 1ml thrombin to 9 ml PRP, so that the autologous multiple growth factors were released from PRP. BMSCs were isolated from the same rabbit, and then cultured in vitro. 1×104cells/well were incubated in a 96-well plate at the third passage. 3 wells/group were added in DMEM contained the prepared growth factors and 10% fetal bovine serum(FBS), DMEM contained 10% FBS and DMEM alone. Cell proliferation was assessed utilizing MTT assay, and the best dose of thrombin was gained. 2. Four equal 8 mm diameter cranial bone defects were created in 16 New Zealand rabbits and randomly grafted with (a):β-TCP and PRP, activated by 1000U/ml dose of thrombin, (b):β-TCP and PRP, activated by A dose of thrombin, (c):β-TCP and PRP, and (d):β-TCP alone. The rabbits was sacrificed at 1 and 3 months postsurgery for histologic and histometric analysis. Result: 1. Cell proliferation was enhanced by all the experimental groups contained PRP. PRP, activated by calcium chloride and thrombin at the dose of 20U/ml, 40U/ml, 60U/ml, promoted BMSCs growth in a dose-dependant manner, and 60U/ml was the best dose. 2. The result of animal experimental showed that the groups grafted with PRP presented with significantly greater bone formation thanβ-TCP alone group at both 1 and 3...