Bone morphogenetic protein sustained-release microspheres combined with platelet-rich gel contribute to the proliferation and differentiation of bone marrow stromal stem cells

Lu Xiao-lang; Zheng Yi-jing; Cheng Tao; Ye Chao; Hong Jian-jun

doi:10.3969/j.issn.2095-4344.2016.47.009

Abstract：BACKGROUND:Various growth factors together participate in the different stages of bone healing, but the current tissue-engineered materials limited on single type and concentration cannot obtain satisfactory outcomes. There is stil a lack of study on the novel tissue-engineered material releasing two or more growth factors in order. OBJECTIVE:To observe the effect of platelet-rich gel (PRG) combined with poly(lactide-glycolide acid) (PLGA) microspheres encapsulating bone morphogenetic protein-2 (BMP-2) on the proliferation and osteoblastic differentiation of bone marrow stromal stem cel s. METHODS:PLGA microspheres loading BMP-2 were prepared by multiple emulsion method, and the encapsulation rate, morphology and volume of microspheres as wel as in vitro releasing rate of BMP-2 were measured. The eligible microspheres combined with the activated PRG were co-cultured with human bone marrow stromal stem cel s on the PLGA three-dimensional scaffold. Additional y, bone marrow stromal stem cel s were divided into six groups including platelet poor gel, PRG, BMP-2/platelet poor gel, BMP-2/PRG, BMP-2 microspheres/platelet poor gel and BMP-2 microspheres/PRG groups, and the preprocessed PLGA scaffold was added into each group. The DNA content, alkaline phosphatase activity and mRNA expression levels of osteopontin and osteocalcin were observed. RESULTS AND CONCLUSION:The DNA content of bone marrow stromal stem cel s was higher in al PRG scaffolds compared with the platelet poor gel scaffolds. The alkaline phosphatase activity and mRNA expression levels of osteopontin and osteocalcin in the BMP-2 microspheres/platelet poor gel and BMP-2 microspheres/PRG groups were markedly higher than those in the other four groups. These results suggest that the BMP-2 sustained-release microspheres combined with PRG are able to enhance the proliferation and differentiation of bone marrow stromal stem cel s.