Abstract

A nano-hydroxyapatite/chitosan (n-HA/CS) scaffold loading with CS microspheres was developed in this study. First, CS microspheres with an average diameter of ∼57 μm were prepared by cross-linking, and a three-dimensional (3D) printing technology was used to fabricate n-HA/CS porous scaffolds with an average pore size and porosity of 454 ± 51 μm and 60.71%, respectively. Then, the n-HA/CS scaffolds were immersed in a solution of CS microspheres and cross-linked by vanillin. The structure, porosity, composition, and cellular behavior of the CS-microsphere-loaded scaffolds were investigated. In vitro cell experiments showed that the CS microspheres on the scaffolds could effectively promote the adhesion and growth of cells on the scaffolds, suggesting that the CS microspheres and the scaffolds have good cytocompatibility. The composite scaffolds were implanted in the back muscles of rabbits for 3, 6, and 9 weeks, and the results of subsequent SEM and H&E staining analyses demonstrated that both the n-HA/CS scaffolds and the loaded CS microspheres had good biocompatibility and gradually degraded over time, where the microspheres were gradually released from the scaffolds. The strategy developed in this study for loading microspheres on scaffolds has promising prospects for future clinical applications of enhancing bone defect repair or implant integration.

摘要

本研究开发了一种载有 CS 微球的纳米羟基磷灰石/壳聚糖 (n-HA/CS) 支架。首先，通过交联制备平均直径为~57 μm的CS微球，并采用三维（3D）打印技术制备了n-HA/CS多孔支架，平均孔径和孔隙率为454 ±分别为 51 μm 和 60.71%。然后，将 n-HA/CS 支架浸入 CS 微球溶液中并通过香草醛交联。研究了负载 CS 微球的支架的结构、孔隙率、组成和细胞行为。体外细胞实验表明，支架上的CS微球能有效促进细胞在支架上的粘附和生长，表明CS微球与支架具有良好的细胞相容性。将复合支架植入家兔背部肌肉3、6、9周，随后的SEM和H&E染色分析结果表明，n-HA/CS支架和负载的CS微球均具有良好的生物相容性，并逐渐随着时间的推移降解，微球逐渐从支架中释放出来。本研究中开发的用于在支架上加载微球的策略对于增强骨缺损修复或植入​​物整合的未来临床应用具有广阔的前景。