基于陕速成型技术的可控结构多孔硅酸钙支架的制备及体外研究

目的 利用快速成型技术制备可控结构多孔硅酸钙(rapid pfototyping-calcium silicate,RP-CS)支架,并评价其特性和体外生物学表现.方法 利用间接快速成型技术,结合固态自由成型和凝胶铸模的优点.制备町控结构RP-CS支架.与采用间法制备的多孔磷酸钙(RP-tricalcium phosphate,RP-TCP)支架相对照,将其置人体外模拟体液(simulated body fluid,SBF)、体外骨髓细胞共培养进行研究.结果 所制备RP-CS支架具有相互连通的孔道结构,平均孔隙率为71%,平均轴向压缩强度为28MPa.平均孔道直径为(555.82±29.77)μm.体外SBF浸置试验发现RP-CS支架上有羟基磷灰石的沉积,说明此支架具有体外生物活性.体外细胞共培养试验表明,兔骨髓细胞可以在此支架表面贴附并分化.MTT表明共培养7 d、14 d,细胞增殖RP-CS组均明显高于RP-TCP组(P<0.05).共培养7 d时,碱性磷酸酶活性RP-CS组明显高于RP-TCP组(P<0.05),提示CS可能具有促进骨髓细胞向成骨细胞分化的能力.结论 利用快速成型技术制备的可控结构RP-CS具有良好的生物相容性,在骨组织工程领域具有广泛应用前景.

Fabrication and in vitro evaluation of a novel calcium silicate scaffold with controlled architecture by rapid prototyping

Objective To fabricate porous calcium silicate (CS) scaffolds with controlled architecture by rapid prototyping and to evaluate the characterization of scaffolds and cell proliferation and differentiation on the prepared scaffolds. Methods The porous calcium silicate scaffolds with controlled architecture was fabricated by indirect rapid prototyping (RP-CS) which has the combined advantages of indirect solid freeform fabrication and gel-casting. Compared with the porous tricalcium phosphate scaffolds fabricated with the same method (RP-TCP), the obtained RP-CS scaffolds were investigated by simulated body fluid (SBF) immersing test and in vitro incubation with bone marrow cells. Results An average compressive strength of 28 MPa for the RP-CS scaffold with the average total porosity of 71% was achieved. The scaffolds with mean channel diameter of about (555.82±29.77)μm have interconnected macroporous architecture. The SBF test showed that hydroxyapatite could be found on the surface of RP-CS scaffold indicating its in vitro bioactivity. The in vitro study showed that the rabbit bone marrow cells attached and proliferated on the surface of the RP-CS scaffolds. MTF tests demonstrated that the cell proliferation was significantly higher on RP-CS scaffolds than on RP-TCP scaffolds at 7 and 14 days (P<0.05). Moreover, the alkaline phosphatase (ALP) activities of cells on RP-CS scaffolds were increased as compared to the control at 7 days (P<0.05), indicating the capacity in promoting bone marrow cells differentiation into osteogenic cells. Conclusion The obtained RP-CS scaffold in this study is biocompatible, and has promising future for bone tissue engineering.