可注射矿化胶原水凝胶修复大鼠颅骨临界性骨缺损的研究

目的 基于矿化胶原（MC）与海藻酸盐（ALG），制备一种新型可注射矿化胶原水凝胶（MCA），研究MCA对颅骨临界性骨缺损的修复作用。方法 将MC粉末以200 mg/mL的比例加入到ALG（C_ALG=15 mg/mL）中制备出矿化胶原水凝胶（MCA）。采用扫描电子显微镜对MCA的交联状态和元素分析情况进行观察。采用L929细胞增殖实验评估MCA的生物安全性，体内降解实验观察MCA降解性和生物相容性。通过大鼠颅骨临界骨缺损模型来验证MCA的骨修复效果。结果 MCA水凝胶经过扫描电子显微镜（SEM）观察后发现水凝胶表面粗糙，其内部Ca/P信号均匀且密集。为了评估MCA的生物安全性，使用MCA浸提液与L929细胞共同孵育后，发现200 mg/mL浸提液实验组的L929细胞增值率为99.95%，毒性评级为1级。同时，将MCA水凝胶注射至大鼠皮下，术后60 d注射部位仍见残留的MCA植入物，而在MCA水凝胶注射到颅骨缺损处的第60天时，MCA则全部降解。最后，观察MCA在颅骨临界骨缺损动物模型中的骨缺损修复效果，实验结果表明MCA水凝胶组的颅骨缺损修复效果优于ALG水凝胶组和对照组。结论 MCA水凝胶具有良好的生物安全性，降解性和促进骨再生的能力，是一种安全可靠的骨修复材料。

Preparation of an injectable mineralized collagen hydrogel and its application in the treatment of the rat cranial critical bone defect

Objective To prepare an injectable mineralized collagen hydrogel (MCA) and to investigate the repair effect of MCA on the cranial critical bone defect.Methods Mineralized collagen hydrogel (MCA) was prepared by adding MC powder at a ratio of 200 mg/mL to ALG hydrogel (C_ALG=15 mg/mL). Cross-linked morphology and elemental analysis of MCA were conducted with a scanning electron microscope to observe the diffusion of MC in the MCA. L929 cell proliferation assay was used to evaluate the biocompatibility of MCA, and in vivo biodegradation assay was used to observe the biodegradability and biosafety of MCA. The effect of MCA bone defect repair was evaluated using a rat cranial critical bone defect model.Results The results from scanning electron microscopy (SEM) showed that the surface of MCA hydrogels was rough and the Ca/P signal was uniform and dense. In order to evaluate the biosafety of MCA, it was found that the proliferation rate of L929 cells in the 200 mg/mL concentration of extract group was 99.95%, and the toxicity rating was grade 1. In addition, on the 60th day after the MCA hydrogel was injected subcutaneously into the rat, the MCA implant remained at the injection site, while the MCA hydrogel was injected into the skull defect at the same time, the MCA was completely degraded. Besides, the repair effect of MCA in the cranial critical bone defect models was better than that in the ALG group and the control group.Conclusion MCA hydrogel has good biosafety, degradability and ability to promote bone regeneration, and is a safe and reliable bone repair material.