Development of a novel surgical procedure for large osteochondral defects using platelet rich plasma(PRP)

本研究的目的是开发一种新的关节内骨软骨缺损的手术技术，使用多孔羟基磷灰石(HA)，包括富血小板血浆(PRP)来源的纤维蛋白凝胶和由藻酸盐回收软骨细胞法(ARC法)产生的无支架软骨组织。首先，我们检测了PRP来源的纤维蛋白凝胶对培养的兔软骨细胞代谢的影响。此外，还研究了多孔HA块上ARC组织的体内成熟过程。在此基础上，我们将含有PRP(或血小板贫乏血浆，PPP)的HA块和ARC组织植入大型骨软骨缺损区，并检测该方法对骨和软骨组织修复的影响。将关节软骨细胞(包埋于藻酸盐珠中)在PRP纤维蛋白凝胶上进行三维培养，可促进软骨细胞的增殖和海藻酸微珠中总蛋白多糖(PG)的含量，而PRP凝胶显著降低海藻酸微珠中PG含量(与DNA含量归一化)。将ARC组织放置在多孔HA块上并植入裸鼠皮下口袋，组织与Hablock表面结合良好。在此条件下，ARC组织在8周内成熟。将含有PRP凝胶的HA-ARC组织构建物植入骨软骨缺损区，可促进软骨修复和骨形成。这些结果表明PRP凝胶联合HA-ARC植入是修复大型骨软骨病变的一种有效方法。

The purpose of this study was to develop a new surgical technique for intra-articular osteochondral defects using porous hydroxyapatite (HA) including platelet rich plasma (PRP)-derived fibrin gel and scaffold-free cartilage tissue produced by the alginate-recovered-chondrocyte method (ARC method). First of all, we examined the effects of PRP-derived fibrin gel on the metabolism of cultured rabbit chondrocytes. The maturation process of the ARC tissue on porous HA block in vivo was also investigated. On the basis of these results, we implanted HA blocks with PRP (or platelet poor plasma, PPP) and the ARC tissue into the large osteochondral defects, and examined the effects of this procedure on bone and cartilage tissue repair. Three-dimensional cultivation of articular chondrocytes (embedded in alginate beads) on PRP-derived fibrin gel promoted their proliferation and total proteoglycan (PG) content in alginate bead, while PG content normalized with DNA content in alginate bead was significantly decreased by PRP gel When the ARC tissue was placed on porous HA block and implanted into subcutaneous pocket of athyrnir nude mice, the tissue was well integrated with the surface of Hablock. Maturation of the ARC tissue was observed in this condition within 8 weeks. Implantation of the HA-ARC tissue constructs with PRP gel into osteochondral defects enhanced cartilage repair and bone formation. These results suggest that combination of PRP gel with HA-ARC implantation can be a useful procedure for the repair of large osteochondral lesions.