基于脂肪干细胞I型胶原凝胶PLGA-β-TCP支架的新型仿生骨组织工程复合体的构建及生物学性能

Fabrication and characterization of a novel bone tissue engineering construct using collagen I gel to suspend adipose-derived stem cells into a porous PLGA-β-TCP scaffold

目的:尝试构建基于脂肪干细胞、I型胶原凝胶以及PLGA-β-TCP支架的新型仿生骨组织工程复合体,并对其生物学性能进行研究.方法:取3 mo龄日本大耳白兔皮下脂肪,获得脂肪干细胞,经体外成骨诱导分化鉴定后使用I型胶原凝胶将其悬浮并与三维多孔支架PLGA-β-TCP复合,从而构建成脂肪干细胞-I型胶原凝胶/PLGA-β-TCP骨组织工程复合体,体外成骨诱导培养2 wk,实验以脂肪干细胞/PLGA-β-TCP材料复合体作为对照.扫描电镜观察复合情况,并对脂肪干细胞的增殖以及成骨诱导分化情况进行检测.结果:I型胶原凝胶将rADSCs均匀悬浮于材料孔隙中,碱性磷酸酶活性以及细胞外基质矿化程度检测显示I型胶原凝胶能显著促进rAD-SCs的成骨分化.结论:脂肪干细胞-I型胶原凝胶/PLGA-β-TCP复合体的构建成功为骨组织工程复合体的设计提供了一条新的思路.

AIM： To fabricate a novel bone tissue engineering construct using collagen Ⅰ gel to suspend adipose-derived stem cells （ADSCs） into a porous PLGA-β-TCP scaffold （rADSCs- COL/PLGA-β-TCP） and explore its potentiality for bone tissue engineering. METHODS： ADSCs were prepared by collagenase Ⅰ digestion of subcutaneous fat from the suprascapular site of Japa- nese white rabbit. Firstly, the osteogenic differentiation of rabbit ADSCs （rADSCs） was identified by yon Kossa staining after in vitro culture for 4 weeks under osteogenic medium. Then the rADSCs-COL/PLGA-β-TCP composite was fabricated using collagen Ⅰ gel to suspend rADSCs into PLGA-Iβ-TCP scaffold and cultured under osteogenic medium for 2 weeks. Meanwhile, the single combination of rADSCs and PLGA-β-TCP scaffold was also prepared as control. Morphological observations were carried out using scanning electron microscopy （SEM）. Cell proliferation, alkaline phosphatase activity and calcium deposit were also determined to fully evaluate the osteogenic differentiation of rADSCs in both composites. RESULTS- By presuspended in collagen Ⅰ gel, the rADSCs were evenly distributed in the pores of the PLGA-β-TCP scaffold. Furthermore, collagen Ⅰ gel remarkably promoted the osteogenic differentiation of rADSCs in PLGA-β-TCP scaffold. CONCLUSION： The successful fabrication of rADSCs-COL/PL- GA-β-TCP composite casts a new light on the construction of bone tissue engineering composites.