南方医科大学学报

南方医科大学学报 ›› 2024, Vol. 44 ›› Issue (2): 370-380.doi: 10.12122/j.issn.1673-4254.2024.02.20

• • 上一篇    下一篇

聚乳酸/羟基磷灰石/磷钙锌石复合支架促进大鼠骨质疏松性骨缺损愈合

罗彩珠，陈金香，张 群，于学钊，张书勤   

  1. 南方医科大学第三附属医院//广东省骨与关节退行性疾病重点实验室，广东 广州 510630；药学院//国家药监局药物代谢研究与评价重点实验室，广东 广州 510515
  • 发布日期:2024-03-14

A polylactic acid/hydroxyapatite/scholzite composite scaffold for promoting healing of osteoporotic bone defects in rats

LUO Caizhu, CHEN Jinxiang, ZHANG Qun, YU Xuezhao, ZHANG Shuqin   

  1. Third Affiliated Hospital of Southern Medical University//Guangdong Key Laboratory of Bone and Joint Degenerative Diseases, Guangzhou 510630, China; School of Pharmacy, Southern Medical University//NMPA Key Laboratory of Drug Metabolism Research and Evaluation, Guangzhou 510515, China
  • Published:2024-03-14

RichHTML

1

PDF

37

摘要： 目的 探究将纳米磷钙锌石（nZCP）载入聚乳酸/羟基磷灰石（PLA/HA）制成复合支架（PHZ）后Zn2+的释放动力学及最佳nZCP含量。方法 通过动态光散射（DLS）对nZCP的粒径大小进行测定，采用粉末X射线衍射（PXRD）、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）分别对PLA/HA、PHZ复合支架以及nZCP的PXRD图谱、形貌、FTIR图谱进行了表征，此外用X射线能谱分析（EDS）对支架进行了元素分析，并测定支架压缩强度，电感耦合等离子体质谱（ICP-MS）探究支架的离子释放过程；在体外实验中将PLA/HA、PHZ-1、PHZ-2、PHZ-3制备的浸提液处理rBMSCs细胞不同时间，CCK-8活性检测、死-活染色评价材料的生物相容性，用碱性磷酸酶（ALP）染色和活性分析、茜素红染色、实时荧光定量PCR（qPCR）及Western blot探究材料的促成骨性能；体内实验采用双侧卵巢切除合并股骨髁骨缺损模型，分组为PLA/HA、PHZ-1、PHZ-2、PHZ-3，术后6周和12周分别进行μCT扫描以及组织学染色评价骨修复情况。 结果 nZCP的DLS、PXRD、SEM、FTIR结果表明粒径10 nm ZCP的成功合成，支架PXRD、FTIR、EDS结果表明nZCP的成功负载，SEM显示支架呈现三维多孔结构，其内部有直径为40 μm孔洞分布，nHA和nZCP均匀分布在支架中，PHZ-2（P<0.0001）和PHZ-3（P<0.0005）两组的压缩强度高于PLA/HA，ICP-MS离子释放实验结果表明PHZ-1、PHZ-2、PHZ-3所释放的Zn2+都在有效的促成骨浓度内。在体外细胞实验中，CCK-8和死-活染色实验结果表明，4组实验组都具有良好的生物相容性，含有不同质量nZCP的支架不同程度地增加了ALP活性（P<0.05）和细胞外基质矿化，并增加了ALP、RUNX 相关转录因子2和骨钙素基因的转录和翻译（P<0.05）。在体内实验中，6周数据表明nZCP的掺入提高了材料的骨整合度，12周的数据观察到PHZ-2和PHZ-3相较于剩余两组骨缺损内有较多的新骨生成（P<0.05）。结论 PHZ支架能够稳定释放Zn2+，促进骨质疏松性骨缺损愈合，PHZ-2和PHZ-3两组的成骨活性较好，此时的nZCP质量分数为4.5%~7.5%。

关键词: 聚乳酸；磷钙锌石；羟基磷灰石；骨质疏松；骨再生

Abstract: Objective To investigate the release kinetics of Zn2 + from nZCP-loaded polylactic acid/hydroxyapatite (PLA/HA) composite scaffold (PHZ) and determine the optimal nZCP content in the scaffold. Methods The particle size of nZCP was measured by DLS measurement, and PXRD, FTIR, and SEM were used to characterize the scaffolds and nZCP distribution; EDS was used to analyze element composition of the scaffold. Compression strength of the scaffold was determined, and ion release profile was investigated using ICP-MS. The biocompatibility of the materials was evaluated by CCK-8 assay and dead/alive staining of rat bone marrow stem cells (BMSCs) incubated with their aqueous extracts. ALP staining, alizarin red staining, RT-qPCR, and Western blotting were used to assess the osteogenic potential of the treated cells. In a rat model of bilateral ovariectomy (OVX) with femoral condylar bone defect, PHZ-1, PHZ- 2, PHZ-3 or PLA/HA scaffold was implanted into the bone defect, and bone repair was observed using a microCT scanner and histological staining at 6 and 12 weeks. Results DLS, PXRD, SEM, FTIR, and EDS confirmed successful synthesis of 10-nm ZCP and efficient nZCP loading in the scaffold. PHZ-2 and PHZ-3 had significantly greater compression strength than PLA/HA. ICP-MS showed that Zn2+ release from PHZ-1, PHZ-2 and PHZ-3 were all optimal for promoting osteogenesis. In rat BMSCs, all the 4 scaffolds showed good biocompatibility, and their extracts enhanced ALP activity and extracellular matrix mineralization and promoted expressions of ALP, RUNX2, and OCN in the cells. In the rat models, nZCP in the implants improved bone graft integration at 6 weeks, and PHZ-2 and PHZ-3 more effectively induced new bone formation at 12 weeks (P<0.05). Conclusion PHZ scaffold is capable of stable Zn2+ release to promote osteoporotic bone defect healing, and PHZ-2 and PHZ-3 scaffolds with nZCP mass fraction of 4.5%-7.5% have better osteogenic activity.

Key words: polylactic acid; scholzite; hydroxyapatite; osteoporosis; bone regeneration