The Study Of Standardized Preparation Of The Allogeneic Platelet-rich Plasma

A variety of growth factors were rich in the platelet-rich plasma. Currently, a largenumber of literature has reported that these growth factors could significantly promote thedefect repair of bone and the proliferation and differentiation of bone marrow stromal cellsin vitro.However, some scholars believed that the platelet-rich plasma could not promotebone regeneration in animal experiments, and the effect of platelet-rich plasmacompositing bone graft materials to repair bone defects is unobvious in clinicalapplications. The main reason is that the standard of preparation platelet-rich plasma bythe researchers and practitioners is inconsistent. In addition, the researchers and clinicaldoctors mostly use the patients’ own blood nowadays, which would undoubtedly makesecondary injury to patients. Due to the individual differences among patients, the quality of platelet-rich plasma prepared would be inconsistent, which would consequently affectthe study results and clinical efficacy. This article is studied on comparing the differenteffects between autologous and allogeneic platelet rich plasma，to investigate whetherautologous PRP could be replaced by allogeneic PRP, this would provide some reliabletheoretical basis to the standardization of allogeneic platelet-rich plasma preparation in thefuture, which makes the allogeneic platelet-rich plasma prepared by the unified methodvery broad application prospects both in research and clinical field.【Objective】 To compare the different effects between autologous and allogeneicplatelet rich plasma on the proliferation and differentiation of bone marrow stromal stemcells in vitro，and to find an optimal concentration.To compare the different effects between autologous and allogeneic platelet-rich gelon bone defect repair in vivo，to investigate whether autologous PRP could be replaced byallogeneic PRP, This would provide some reliable theoretical basis to the standardizationof allogeneic platelet-rich plasma preparation in the future.【Methods】 The rabbit BMSCs were cultured routinely and divided into four groups:autograft group, allograft group, positive control group and negative control group. In theintervention of4,8,12,16,20,24,28day, MTT, alkaline phosphatase (ALP) activity andcell apoptosis rate were tested respectively and alkaline phosphatase staining and calciumnodule staining, the different effects of the four groups on the proliferation, differentiationand apoptosis of BMSCs were compared.Healthy New Zealand rabbits were randomly divided into3groups of autologous,allogeneic and control. To establish dual forelimb bone defect model, autologous groupwere transplantated by the "scaffold+BMSCs+autologous platelet-rich gel", allogeneicgroup were transplantated by the " scaffold+BMSCs+allogeneic platelet-rich gel" controlgroup were transplantated by the " scaffold+BMSCs ". To observe the gross specimen,X-ray film, Micro-CT, biomechanical testing, and HE staining of tissue morphology on1,2,3month after operation. different groups of material degradation and new boneformation were compared. 【Results】 On the20th day, there were significant differences regarding to OD valuerespectively between each concentration groups of allograft, positive control group andnegative control group(P<0.05), and the concentration of30%was used as the optimal one.The expressions of ALP activity at the optimal concentration on20th day wererespectively0.418±0.017,0.421±0.014,0.532±0.022and0.578±0.015. there weresignificant differences regarding to the expression levels respectively between autograftgroup, allograft group and positive control group and negative control group (P<0.05). Atthe same time point, there were mostly no significant differences between autograft groupand allograft group with same concentration regarding to the effects on the proliferationand differentiation of BMSCs (P>0.05).Gross specimen and X-ray showed that the trabecular bone formation, continuouscortical bone and medullary cavity recanalization of group A and group B earlier than thatof group C, Micro-CT reconstruction of Group A and Group B showed that the materialdegradation rate, the rate of new bone formation and completely shaping time faster thanthe group C, But the trabecular thickness between three groups were not statisticallysignificant (P>0.05).Maximum compression load pairwise comparison between3groupswere not statistically significance (P>0.05). The tissue morphology HE staining showedthat the new blood vessels form of group A and group B earlier than that of group C,and microscopic chondrocytes, osteoblasts and osteoclasts earlier and more than group C.【Conclusion】 Autologous PRP could be replaced by allogeneic PRP for both in vitroculture of BMSCs and animal bone defect repair.