骨组织具有自身的再生能力来修复畸形；然而，其修复严重骨折、肿瘤切除、骨质疏松症、关节置换术和外科再斟酌所致缺陷的能力可能受到阻碍。为了解决这个限制，骨组织工程技术已经成为一种有前景的骨修复和再生方法，特别适用于大规模骨缺陷。在本研究中，通过自由基聚合和反溶剂蒸发技术合成了一种基于κ-卡拉胶-共-N-异丙基丙烯酰胺（κC-co-NIPAAM）的可注射水凝胶。通过傅里叶变换红外光谱（FTIR）和核磁共振（1H NMR）确认了κC-co-NIPAAM水凝胶的交联结构。通过热重分析（TGA）和扫描电子显微镜（SEM），分别评估了水凝胶的热稳定性和形态行为。在不同pH和温度下进行了水胀和体外药物释放研究，结果表明在低pH（1.2）和25°C时水胀和释放最小，而在pH 7.4和37°C时水胀和释放最大。细胞相容性分析表明，κC-co-NIPAAM水凝胶是生物相容的，血红木和伊红染色（H&E染色）显示相比其他实验组，其具有组织再生和增强骨修复的潜力。值得注意的是，使用体内骨缺陷模型进行的数字X射线检查显示，κC-co-NIPAAM水凝胶显著改善了骨再生，使其成为一种有前途的骨缺陷候选材料。版权所有 © 2023 Elsevier B.V. 发布。

Bone tissue possesses intrinsic regenerative capabilities to address deformities; however, its ability to repair defects caused by severe fractures, tumor resections, osteoporosis, joint arthroplasties, and surgical reconsiderations can be hindered. To address this limitation, bone tissue engineering has emerged as a promising approach for bone repair and regeneration, particularly for large-scale bone defects. In this study, an injectable hydrogel based on kappa-carrageenan-co-N-isopropyl acrylamide (κC-co-NIPAAM) was synthesized using free radical polymerization and the antisolvent evaporation technique. The κC-co-NIPAAM hydrogel's cross-linked structure was confirmed using Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance (1H NMR). The hydrogel's thermal stability and morphological behavior were assessed using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. Swelling and in vitro drug release studies were conducted at varying pH and temperatures, with minimal swelling and release observed at low pH (1.2) and 25 °C, while maximum swelling and release occurred at pH 7.4 and 37oC. Cytocompatibility analysis revealed that the κC-co-NIPAAM hydrogels were biocompatible, and hematoxylin and eosin (H&E) staining demonstrated their potential for tissue regeneration and enhanced bone repair compared to other experimental groups. Notably, digital x-ray examination using an in vivo bone defect model showed that the κC-co-NIPAAM hydrogel significantly improved bone regeneration, making it a promising candidate for bone defects.Copyright © 2023. Published by Elsevier B.V.