We developed an injectable gelatin/hyaluronic acid hydrogel with slow degradability, which consisted of carbohydrazide-modified gelatin (Gel-CDH) and hyaluronic acid monoaldehyde (HA-mCHO). Gel-CDH/HA-mCHO hydrogels were degraded much more slowly in phosphate-buffered saline than the other Schiff’s base cross-linked gelatin/hyaluronic acid hydrogels that were comprised of native gelatin, adipic acid dihydrazide-modified gelatin, or hyaluronic acid dialdehyde because of stable Schiff’s base formation between aldehyde and carbohydrazide groups, and suppression of ring-opening oxidation by monoaldehyde modification. This prolonged degradation would be suitable for inducing angiogenesis. Therefore, the Gel-CDH/HA-mCHO hydrogels were sufficiently stable during the angiogenesis process. In addition, the hydrogel had a pore size of 15–55 μm and a shear storage modulus of 0.1–1 kPa, which were appropriate for scaffold application. Ex vivo rat aortic-ring assay demonstrated the concentration dependency of microvascular extension in the Gel-CDH/HA-mCHO hydrogel. These results demonstrated the potential usefulness of Gel-CDH/HA-mCHO hydrogel for tissue-engineering scaffolds.

中文翻译：

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由希夫碱形成的明胶和透明质酸交联的慢速降解注射用水凝胶

我们开发了一种降解速度较慢的可注射明胶/透明质酸水凝胶，该凝胶由碳酰肼改性的明胶（Gel-CDH）和透明质酸单醛（HA-mCHO）组成。与其他由天然明胶，己二酸二酰肼改性的明胶或透明质酸二醛组成的席夫氏碱交联明胶/透明质酸水凝胶相比，凝胶-CDH / HA-mCHO水凝胶在磷酸盐缓冲液中的降解要慢得多。醛和碳酰肼基之间稳定的席夫碱形成，以及通过单醛修饰抑制开环氧化。这种延长的降解将适于诱导血管生成。因此，Gel-CDH / HA-mCHO水凝胶在血管生成过程中足够稳定。此外，离体大鼠主动脉环测定证明了凝胶-CDH / HA-mCHO水凝胶中微血管延伸的浓度依赖性。这些结果证明了Gel-CDH / HA-mCHO水凝胶在组织工程支架中的潜在用途。