Dexamethasone (DEX) is a glucocorticoid commonly used as an in vitro osteogenic inducer of mesenchymal stem/progenitor cells (abbreviated MSCs). However, several studies investigating the effects of glucocorticoids on bone regeneration through systemic injections have demonstrated negative impacts of the drugs at high concentration on the healing of hard tissues. These contrasting evidences suggest that application of glucocorticoids should be limited to low dosages but at the same time a long enough treatment period is preferred, which prompted us to evaluate the effects of different local release systems of DEX on MSC differentiation and bone repair. Two types of DEX‐loaded β‐cyclodextrin (CD) complexes, including CD/DEX and CD/AD‐DEX, were fabricated via host‐guest interactions and characterized by FTIR, 1H‐NMR, MS‐ESI, and UV–vis. The results demonstrated that these CD‐based assemblies released DEX in differentiated profiles, with CD/DEX releasing significantly faster than CD/AD‐DEX. Although CD/DEX were slightly more powerful than CD/AD‐DEX in inducing rat bone marrow MSCs (rBMSCs) into osteogenic lineage in vitro, CD/AD‐DEX was advantageous over CD/DEX in accelerating bone regeneration over a time period of 4 weeks in a rat tibia defect model. The results suggest that DEX‐loaded assemblies via host‐guest interactions are flexible in modulating DEX release patterns and have great potential in bone tissue engineering.

中文翻译：

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地塞米松负载β-环糊精用于间充质干/祖细胞的成骨诱导和骨再生

地塞米松 (DEX) 是一种糖皮质激素，通常用作间充质干/祖细胞（简称 MSCs）的体外成骨诱导剂。然而，几项通过全身注射研究糖皮质激素对骨再生影响的研究表明，高浓度药物对硬组织愈合有负面影响。这些对比证据表明，糖皮质激素的应用应限制在低剂量，但同时优选足够长的治疗期，这促使我们评估 DEX 的不同局部释放系统对 MSC 分化和骨修复的影响。两种类型的 DEX 负载 β-环糊精 (CD) 复合物，包括 CD/DEX 和 CD/AD-DEX，通过主客体相互作用，并通过 FTIR、1H-NMR、MS-ESI 和 UV-vis 表征。结果表明，这些基于 CD 的程序集以不同的配置文件释放 DEX，CD/DEX 的释放速度明显快于 CD/AD-DEX。尽管 CD/DEX在体外诱导大鼠骨髓间充质干细胞 (rBMSCs) 成骨谱系方面比 CD/AD-DEX 稍强，但在 4大鼠胫骨缺损模型中的几周。结果表明，通过主客体交互加载 DEX 的组件在调节 DEX 释放模式方面具有灵活性，并且在骨组织工程中具有巨大潜力。