Schuessele A, Mayr H, Tessmar J, Goepferich A
Department of Pharmaceutical Technology, University of Regensburg, Germany.
J Biomed Mater Res A. 2009 Sep 15;90(4):959-71. doi: 10.1002/jbm.a.31745.
The immobilization of biomolecules on biomaterial surfaces allows for the control of their localization and retention. In numerous studies, proteins have been simply adsorbed to enhance the biological performance of various materials in vivo. We investigated the potential of surface modification techniques on hydroxyapatite (HA) ceramic discs in an in vitro approach. A novel method for protein immobilization was evaluated using the aminobisphosphonates pamidronate and alendronate, which are strong Ca chelating agents, and was compared with the established silanization technique. Lysozyme and bone morphogenetic protein-2 (BMP-2) were used to assess the suitability of the two surface modification methods with regard to the enzymatic activity of lysozyme and to the capacity of BMP-2 to stimulate the osteoblastic differentiation of C2C12 mouse myoblasts. After immobilization, a 2.5-fold increase in enzymatic activity of lysozyme was observed compared with the control. The alkaline phosphatase activity per cell stimulated by immobilized BMP-2 was 2.5-fold higher [9 x 10(-6) I.U.] than the growth factor on unmodified surfaces [2-4 x 10(-6) I.U.]. With regard to the increase in protein activity, both procedures lead to equivalent results. Thus, the bisphosphonate-based surface modification represents a safe and easy alternative for the attachment of proteins to HA surfaces.
生物分子固定在生物材料表面能够控制其定位和保留。在众多研究中，蛋白质已被简单吸附以增强各种材料在体内的生物学性能。我们采用体外方法研究了羟基磷灰石（HA）陶瓷盘表面改性技术的潜力。使用氨基双膦酸盐帕米膦酸盐和阿仑膦酸盐（它们是强钙螯合剂）评估了一种新型蛋白质固定方法，并与已确立的硅烷化技术进行了比较。使用溶菌酶和骨形态发生蛋白-2（BMP-2）评估这两种表面改性方法在溶菌酶酶活性以及BMP-2刺激C2C12小鼠成肌细胞成骨细胞分化能力方面的适用性。固定后，观察到溶菌酶的酶活性与对照相比增加了2.5倍。固定化BMP-2刺激的每细胞碱性磷酸酶活性[9×10（-6）国际单位]比未改性表面上的生长因子[2 - 4×10（-6）国际单位]高2.5倍。就蛋白质活性的增加而言，两种方法都产生了等效结果。因此，基于双膦酸盐的表面改性是将蛋白质附着到HA表面的一种安全且简便的替代方法。
