Biofunctionalized calcium phosphate cement to enhance the attachment and osteodifferentiation of stem cells released from fast-degradable alginate-fibrin microbeads.
Biofunctionalized calcium phosphate cement to enhance the attachment and osteodifferentiation of stem cells released from fast-degradable alginate-fibrin microbeads.
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DOI：
10.1089/ten.tea.2011.0604
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发表时间：
2012-05
影响因子：
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通讯作者：
Hongzhi Zhou;Wenchuan Chen;M. Weir;H. Xu
中科院分区：
文献类型：
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作者：
Hongzhi Zhou;Wenchuan Chen;M. Weir;H. Xu
包封干细胞的微珠可以混合成糊状物，如磷酸钙水泥（CPC），其中微珠可以保护细胞免受混合和注射力的影响。放置后，微珠可以快速降解，在整个支架中释放细胞，同时产生大孔。本研究的目的是（1）构建包埋人脐带间充质干细胞（hUCMSCs）的藻酸盐纤维蛋白微珠包埋在新型生物功能化CPC表面;（2）研究微珠在CPC上的降解、细胞释放和成骨分化。制备水凝胶微珠，其以1×10（6）个细胞/mL包封hUCMSC。以纤维连接蛋白（Fn）和精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp，RGD）对CPC进行功能化修饰。测试了四种支架：CPC对照、CPC与Fn混合、CPC与RGD混合以及CPC与RGD接枝。可降解微珠在第7天释放hUCMSCs，并附着于CPC上。加入Fn或RGD的CPC大大提高了细胞的附着。移植有RGD的CPC表现出最快的细胞增殖，细胞密度是CPC对照的9倍。释放的hUCMSCs进行骨分化。碱性磷酸酶，骨钙素，胶原蛋白1，和runt相关转录因子2（Runx 2）基因表达增加了10至30倍，在7-21天，与第1天相比。CPC上释放的细胞合成骨矿物质，21天的矿化量比7天高两个数量级。总之，包埋在CPC表面的海藻酸纤维蛋白微珠能够快速释放附着在生物功能化CPC上的hUCMSCs。将Fn和RGD接枝到CPC中，可显著改善细胞功能，且接枝有RGD的CPC细胞增殖最快。CPC上释放的细胞分化为成骨细胞并合成骨矿物质。具有hUCMSC包封微珠的新型生物功能化CPC有希望用于骨再生应用。
Stem cell-encapsulating microbeads could be mixed into a paste such as calcium phosphate cement (CPC), where the microbeads could protect the cells from the mixing and injection forces. After being placed, the microbeads could quickly degrade to release the cells throughout the scaffold, while creating macropores. The objectives of this study were to (1) construct alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs) embedded in the surface of novel biofunctionalized CPC and (2) investigate microbead degradation, cell release, and osteodifferentiation on CPC. Hydrogel microbeads were fabricated that encapsulated hUCMSCs at 1×10(6) cells/mL. CPC was biofunctionalized with fibronectin (Fn) and Arg-Gly-Asp (RGD). Four scaffolds were tested: CPC control, CPC mixed with Fn, CPC mixed with RGD, and CPC grafted with RGD. The degradable microbeads released hUCMSCs at 7 days, which attached to CPC. Adding Fn or RGD to CPC greatly improved cell attachment. CPC grafted with RGD showed the fastest cell proliferation, with cell density being ninefold that on CPC control. The released hUCMSCs underwent osteodifferentiation. Alkaline phosphatase, osteocalcin, collagen 1, and runt-related transcription factor 2 (Runx2) gene expression increased by 10 to 30 fold at 7-21 days, compared with day 1. The released cells on CPC synthesized bone minerals, with the mineralization amount at 21 days being two orders of magnitude higher than that at 7 days. In conclusion, alginate-fibrin microbeads embedded in CPC surface were able to quickly release the hUCMSCs that attached to biofunctionalized CPC. Incorporating Fn and RGD into CPC greatly improved cell function, and CPC grafted with RGD had the fastest cell proliferation. The released cells on CPC differentiated into the osteogenic lineage and synthesized bone minerals. The new biofunctionalized CPC with hUCMSC-encapsulating microbeads is promising for bone regeneration applications.