Cartilage regeneration after injury is still a great challenge in clinics, which suffers from its avascularity and poor proliferative ability. Herein we designed a novel biocompatible cellulose nanocrystal/GelMA (gelatin-methacrylate anhydride)/HAMA (hyaluronic acid-methacrylate anhydride)-blended hydrogel scaffold system, loaded with synthetic melanin nanoparticles (SMNP) and a bioactive drug kartogenin (KGN) for theranostic purpose. We found that the SMNP-KGN/Gel showed favorable mechanical property, thermal stability, and distinct magnetic resonance imaging (MRI) contrast enhancement. Meanwhile, the sustained release of KGN could recruit bone-derived mesenchymal stem cells to proliferate and differentiate into chondrocytes, which promoted cartilage regeneration in vitro and in vivo. The hydrogel degradation and cartilage restoration were simultaneously monitored by multiparametric MRI for 12 weeks, and further confirmed by histological analysis. Together, these results validated the multifunctional hydrogel as a promising tissue engineering platform for noninvasive imaging-guided precision therapy in cartilage regenerative medicine.

中文翻译：

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Kartogenin (KGN)/合成黑色素纳米粒子 (SMNP) 加载的治疗诊断水凝胶支架系统用于多参数磁共振成像引导软骨再生


由于软骨缺乏血管、增殖能力差，损伤后的软骨再生仍然是临床上的一大挑战。在此，我们设计了一种新型生物相容性纤维素纳米晶体/GelMA（明胶-甲基丙烯酸酐）/HAMA（透明质酸-甲基丙烯酸酐）混合水凝胶支架系统，负载合成黑色素纳米颗粒（SMNP）和用于治疗目的的生物活性药物卡托肾素（KGN） 。我们发现 SMNP-KGN/Gel 显示出良好的机械性能、热稳定性和明显的磁共振成像 (MRI) 对比度增强功能。同时，KGN的持续释放可以招募骨源间充质干细胞增殖并分化为软骨细胞，从而促进体外和体内的软骨再生。通过多参数 MRI 同时监测水凝胶降解和软骨恢复 12 周，并通过组织学分析进一步证实。总之，这些结果验证了多功能水凝胶作为软骨再生医学中非侵入性成像引导精准治疗的有前途的组织工程平台。