Li Pengfei, Jia Zhanrong, Wang Qun, Tang Pengfei, Wang Menghao, Wang Kefeng, Fang Ju, Zhao Cancan, Ren Fuzeng, Ge Xiang, Lu Xiong
Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China.
J Mater Chem B. 2018 Dec 7;6(45):7427-7438. doi: 10.1039/c8tb01672k. Epub 2018 Oct 22.
Cryogels from natural biopolymers, especially chitosan (CS) and silk fibroin (SF), have attracted significant attention for bone tissue engineering due to their good biocompatibility and tissue affinity. However, they are still not widely applied in clinics because of their poor mechanical properties, and lack of osteoinductivity and antibacterial properties. Here, by integrating a physico-chemical hybrid-crosslinking strategy and a freeze-drying method, the authors have prepared a resilient and flexible chitosan/silk cryogel with Ag and Sr co-doped hydroxyapatite (AgSrHA). The cryogel exhibits super resilience and flexibility, which guarantees the mechanical strength required for bone repair. Furthermore, the cryogel possesses long-term effective antibacterial properties and osteoinductivity due to the slow release of Ag and Sr ions. The physico-chemical hybrid-crosslinking points were introduced into a CS/SF network by treating with a mixture of alkaline and polyethylene glycol glycidyl ether (PEGDE) at 60 °C, which endowed the cryogel with super resilience and flexibility. Nanoscale AgSrHA was incorporated into the CS/SF network to further enhance the mechanical properties of the cryogel. In addition, Ag and Sr were doped into the HA crystal lattice, which not only prevents cytotoxicity by avoiding the ion burst release behavior, but also can achieve antibacterial and osteoinductive properties for a long period of time. In short, the AgSrHA/CS/SF cryogel with excellent mechanical properties and long-term effective dual-biofunction of antibacterial properties and osteoinductivity would be an ideal candidate for successful bone repair in clinics.
天然生物聚合物制成的冷冻凝胶，尤其是壳聚糖（CS）和丝素蛋白（SF），因其良好的生物相容性和组织亲和性，在骨组织工程领域备受关注。然而，由于其机械性能较差，且缺乏骨诱导性和抗菌性能，它们仍未在临床上得到广泛应用。在此，作者通过整合物理化学混合交联策略和冷冻干燥方法，制备了一种含有银和锶共掺杂羟基磷灰石（AgSrHA）的具有弹性和柔韧性的壳聚糖/丝素冷冻凝胶。该冷冻凝胶具有超强的弹性和柔韧性，可确保骨修复所需的机械强度。此外，由于银和锶离子的缓慢释放特性，该冷冻凝胶具有长期有效的抗菌性能和骨诱导性。通过在60°C下用碱和聚乙二醇缩水甘油醚（PEGDE）的混合物处理，将物理化学混合交联点引入CS/SF网络中，赋予了冷冻凝胶超强的弹性和柔韧性。将纳米级AgSrHA纳入CS/SF网络，进一步增强了冷冻凝胶的机械性能。此外，银和锶被掺杂到HA晶格中，这不仅通过避免离子的突然释放行为来防止细胞毒性，而且还能长期实现抗菌和骨诱导性能。简而言之，具有优异机械性能以及长期有效抗菌和骨诱导双重生物功能的AgSrHA/CS/SF冷冻凝胶将是临床上成功进行骨修复的理想候选材料。
