地塞米松负载双相磷酸钙纳米粒/胶原多孔骨组织工程支架的制备

虽然骨是再生的，但其再生能力是有限的。对于超过临界尺寸的骨缺损，需要进一步的干预。骨组织工程作为一种具有吸引力的修复方法，在修复骨缺损方面得到了广泛的研究。然而，快速、有效地修复大骨不连的缺损仍然是一个巨大的挑战。具有骨诱导性和骨传导性的多功能支架是加快功能性骨组织再生的理想材料。

本研究中，日本材料科学研究所陈国平教授采用搭载可控释放地塞米松（DEX）的双相磷酸钙纳米颗粒（BCPNP）结合胶原制备的多孔仿生复合骨组织工程支架。在BCPNP的制备过程中引入DEX，并与胶原支架杂交结合。用预制备的冰粒作为制孔剂去制备多孔材料的空隙结构。复合支架具有良好的控制和互连的孔结构，高机械强度和缓释的DEX的性质。复合支架材料具有良好的生物相容性，在三维培养骨髓间充质干细胞（hMSCs）时，促进其向成骨细胞分化。在裸鼠的皮下植入复合支架，证明了该支架对异位骨组织的再生有促进作用。结果表明，DEX负载的BCPNP/胶原复合支架具有很高的骨再生潜能。

Although bone is regenerative, its regeneration capacity is limited. For bone defects beyond a critical size, further intervention is required. As an attractive strategy, bone tissue engineering (bone TE) has been widely investigated to repair bone defects. However, the rapid and effective bone regeneration of large non-healing defects is still a great challenge. Multifunctional scaffolds having osteoinductivity and osteoconductivity are desirable to fasten functional bone tissue regeneration.

In the present study, biomimetic composite scaffolds of collagen and biphasic calcium phosphate nanoparticles (BCP NPs) with a controlled release of dexamethasone (DEX) and the controlled pore structures were prepared for bone TE. DEX was introduced in the BCP NPs during preparation of the BCP NPs and hybridized with collagen scaffolds, which pore structures were controlled by using pre-prepared ice particulates as a porogen material. The composite scaffolds had well controlled and interconnected pore structures, high mechanical strength and a sustained release of DEX. The composite scaffolds showed good biocompatibility and promoted osteogenic differentiation of hMSCs when used for three-dimensional culture of human bone marrow-derived mesenchymal stem cells. Subcutaneous implantation of the composite scaffolds at the dorsa of athymic nude mice demonstrated that they facilitated the ectopic bone tissue regeneration. The results indicated the DEX-loaded BCP NPs/collagen composite scaffolds had high potential for bone TE.

（朱宇航）

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