MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Biomater Sci. 2021 Feb 9;9(3):960-972. doi: 10.1039/d0bm01840f.
Numerous efforts have been made to prepare hydrogels with injectability, adhesivity and osteogenic activity for bone regeneration. However, current hydrogels with these characteristics have limited application in clinical translation due to their complex chemical compositions, which causes difficulty in batch production. In this study, a multifunctional hydrogel with a binary component is prepared for bone regeneration. Dopamine (DA) is first grafted to alginate (Alg) by amidation reaction to give Alg-DA. Then an injectable hydrogel is facilely prepared by mixing strontium ions with the Alg-DA aqueous solution, utilizing the dynamic ionic bonds between the strontium ions and carboxyl groups of Alg-DA. Under the simulated oxidation conditions in vivo, the injectable hydrogel can form stable chemical crosslinkages owing to the presence of catechol groups on Alg-DA. In addition, the catechol groups endow the hydrogel with significant tissue adhesivity. More importantly, the strontium ions endow the hydrogel with osteogenic activity. As indicated by animal experiments, the strontium containing hydrogel scaffolds help to treat rat bone defects within 8 weeks compared to hydrogels without strontium and control groups. This simple hydrogel constructed by using a binary component has achieved several necessary functions, and is expected to be used as a scaffold for bone tissue engineering in clinical applications.
人们已经做出了许多努力来制备具有可注射性、黏附性和成骨活性的水凝胶，以用于骨再生。然而，由于当前具有这些特性的水凝胶具有复杂的化学成分，导致批量生产困难，因此其在临床转化中的应用受到限制。在本研究中，制备了一种具有双组分的多功能水凝胶用于骨再生。首先通过酰胺反应将多巴胺（DA）接枝到海藻酸钠（Alg）上，得到 Alg-DA。然后通过将锶离子与 Alg-DA 水溶液混合，利用锶离子与 Alg-DA 中的羧基之间的动态离子键，简便地制备出可注射水凝胶。在体内模拟氧化条件下，由于 Alg-DA 上存在儿茶酚基团，可形成稳定的化学交联。此外，儿茶酚基团赋予水凝胶显著的组织黏附性。更重要的是，锶离子赋予水凝胶成骨活性。动物实验表明，与不含锶的水凝胶和对照组相比，含锶的水凝胶支架在 8 周内有助于治疗大鼠骨缺损。这种由二元成分构建的简单水凝胶实现了多种必要的功能，有望用作临床应用中的骨组织工程支架。
