Scaffolds with osteogenic differentiation function play an important role in the healing process of bone defects. Here, we designed a high strength Poly(ethyleneglycol) diacrylate/Hydroxyapatite (PEGDA/HA) mineralized hydrogel loaded with Exendin4 for inducing osteogenic differentiation. In this study, PEGDA hydrogel was prepared by photo initiating method. PEGDA/HA mineralized hydrogel was prepared by in-situ precipitation method, and Exendin4 was loaded by gel adsorption. The effects of different calcium and phosphorus concentrations on the strength and Exendin4 release of PEGDA/HA hydrogels were investigated. Rat models of bone defect were made and randomly divided into 5 groups. The experimental group was implanted with PEGDA hydrogel, Exendin4-PEGDA hydrogel, PEGDA/HA mineralized hydrogel, Exendin4-PEGDA/HA mineralized hydrogel, and no materials were implanted in the blank control group. Computed tomography (CT) and histology were observed 4 and 8 weeks after operation. Our results revealed that the PEGDA/HA mineralized hydrogel had porous structure, high mechanical strength and good biocompatibility. In vitro release test showed that the mineralized hydrogel exhibited good sustained release profile within 20 d. The animal experiments showed that the mineralized hydrogel accelerated the formation of new bone after 4 and 8 weeks, and formed a seamless union on the defected bone area after 8 weeks. In conclusions, The Exendin4-PEGDA/HA mineralized hydrogel can effectively repair bone defects in rats, and it is expected to be used as a biomaterial for human bone tissue repair.

具有成骨分化功能的支架在骨缺损的愈合过程中发挥着重要作用。在这里，我们设计了一种负载有 Exendin4 的高强度聚（乙二醇）二丙烯酸酯/羟基磷灰石（PEGDA/HA）矿化水凝胶，用于诱导成骨分化。本研究采用光引发法制备PEGDA水凝胶。采用原位沉淀法制备PEGDA/HA矿化水凝胶，凝胶吸附加载Exendin4。研究了不同钙和磷浓度对 PEGDA/HA 水凝胶强度和 Exendin4 释放的影响。制作骨缺损大鼠模型，随机分为5组。实验组植入PEGDA水凝胶、Exendin4-PEGDA水凝胶、PEGDA/HA矿化水凝胶、Exendin4-PEGDA/HA矿化水凝胶，空白对照组不植入任何材料。术后 4 周和 8 周进行计算机断层扫描 (CT) 和组织学观察。结果表明，PEGDA/HA矿化水凝胶具有多孔结构、高机械强度和良好的生物相容性。体外释放试验表明，矿化水凝胶在 20 d 内表现出良好的缓释曲线。动物实验表明，矿化水凝胶在4周和8周后加速了新骨的形成，8周后在缺损骨区形成了无缝结合。综上所述，Exendin4-PEGDA/HA矿化水凝胶可有效修复大鼠骨缺损，有望作为人体骨组织修复的生物材料。