Stimulating the adhesion and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is crucial for the scaffold materials used in bone tissue engineering. In this study, a silk fibroin (SF)/nano-hydroxyapatite (nHAp) scaffold was prepared, embedded with SF microspheres containing bone morphogenetic protein-2 (BMP-2) and surface-modified through chemical conjugation with the type I collagen-mimetic peptide GFOGER. Surface-bound GFOGER and sustained BMP-2 release promoted the adhesion and osteogenic differentiation, respectively, of BMSCs. Our results indicated that this system released low doses of BMP-2 in a sustained manner, thereby avoiding cost and safety problems. The biological responses to this scaffold were investigated both in vitro and in vivo. Our results indicated that the synergistic effect of GFOGER and BMP-2 promoted the adhesion and osteogenic differentiation of BMSCs, thus leading to complete bone bridging of rat cranial defects after 12 weeks of implantation. This system might provide a powerful platform for treating bone defects and for bone tissue engineering.

中文翻译：

---

从骨胶原模拟肽修饰的丝素蛋白-纳米羟基磷灰石支架中受控释放BMP-2

刺激骨髓间充质干细胞（BMSCs）的粘附和成骨分化对于骨组织工程中使用的支架材料至关重要。在这项研究中，制备了丝素蛋白（SF）/纳米羟基磷灰石（nHAp）支架，将其嵌入含有骨形态发生蛋白2（BMP-2）的SF微球中，并通过化学偶联与I型胶原模拟物进行了表面修饰肽GFOGER。表面结合的GFOGER和持续的BMP-2释放分别促进了BMSC的粘附和成骨分化。我们的结果表明，该系统持续释放低剂量的BMP-2，从而避免了成本和安全性问题。在体外和体内研究了对该支架的生物学反应。我们的结果表明，GFOGER和BMP-2的协同作用促进了BMSCs的粘附和成骨分化，从而导致大鼠颅骨缺损在植入12周后完全桥接。该系统可能为治疗骨缺损和进行骨组织工程提供一个强大的平台。