Yuan Fu-Zhen, Wang Hu-Fei, Guan Jian, Fu Jiang-Nan, Yang Meng, Zhang Ji-Ying, Chen You-Rong, Wang Xing, Yu Jia-Kuo
Department of Sports Medicine, Peking University Third Hospital, Beijing 100083, China.
Beijing Key Laboratory of Sports Injuries, Institute of Sports Medicine of Peking University, Beijing 100191, China.
Pharmaceutics. 2021 Sep 16;13(9):1487. doi: 10.3390/pharmaceutics13091487.
Ultrasound-responsive microspheres (MPs) derived from natural polysaccharides and injectable hydrogels have been widely investigated as a biocompatible, biodegradable, and controllable drug delivery system and cell scaffolds for tissue engineering. In this study, kartogenin (KGN) loaded poly (lactide--glycolic acid) (PLGA) MPs (MPs@KGN) were fabricated by premix membrane emulsification (PME) method which were sonicated by an ultrasound transducer. Furthermore, carboxymethyl chitosan-oxidized chondroitin sulfate (CMC-OCS) hydrogel were prepared via the Schiff' base reaction-embedded MPs to produce a CMC-OCS/MPs scaffold. In the current work, morphology, mechanical property, porosity determination, swelling property, in vitro degradation, KGN release from scaffolds, cytotoxicity, and cell bioactivity were investigated. The results showed that MPs presented an obvious collapse after ultrasound treatment. The embedded PLGA MPs could enhance the compressive elastic modulus of soft CMC-OCS hydrogel. The cumulative release KGN from MPs exhibited a slow rate which would display an appropriate collapse after ultrasound, allowing KGN to maintain a continuous concentration for at least 28 days. Moreover, the composite CMC-OCS@MPs scaffolds exhibited faster gelation, lower swelling ratio, and lower in vitro degradation. CCK-8 and LIVE/DEAD staining showed these scaffolds did not influence rabbit bone marrow mesenchymal stem cells (rBMMSCs) proliferation. Then these scaffolds were cultured with rBMMSCs for 2 weeks, and the immunofluorescent staining of collagen II (COL-2) showed that CMC-OCS hydrogel embedded with MPs@KGN (CMC-OCS@MPs@KGN) with ultrasound had the ability to increase the COL-2 synthesis. Overall, due to the improved mechanical property and the ability of sustained KGN release, this injectable hydrogel with ultrasound-responsive property is a promising system for cartilage tissue engineering.
源自天然多糖和可注射水凝胶的超声响应性微球（MPs）作为一种生物相容性、可生物降解且可控的药物递送系统以及用于组织工程的细胞支架，已得到广泛研究。在本研究中，通过预混膜乳化（PME）法制备了负载软骨生成素（KGN）的聚（丙交酯-乙交酯）（PLGA）微球（MPs@KGN），并使用超声换能器对其进行超声处理。此外，通过席夫碱反应将MPs包埋于羧甲基壳聚糖-氧化硫酸软骨素（CMC-OCS）水凝胶中，以制备CMC-OCS/MPs支架。在当前工作中，对其形态、力学性能、孔隙率测定、溶胀性能、体外降解、KGN从支架中的释放、细胞毒性和细胞生物活性进行了研究。结果表明，MPs在超声处理后出现明显塌陷。包埋的PLGA MPs可提高柔软的CMC-OCS水凝胶的压缩弹性模量。MPs中KGN的累积释放速率缓慢，在超声处理后会出现适当塌陷，使KGN至少在28天内维持持续浓度。此外，复合CMC-OCS@MPs支架表现出更快的凝胶化、更低的溶胀率和更低的体外降解率。CCK-8和活/死染色表明这些支架不影响兔骨髓间充质干细胞（rBMMSCs）的增殖。然后将这些支架与rBMMSCs培养2周，Ⅱ型胶原（COL-2）的免疫荧光染色表明，经超声处理的包埋有MPs@KGN的CMC-OCS水凝胶（CMC-OCS@MPs@KGN）具有增加COL-2合成的能力。总体而言，由于力学性能的改善和持续释放KGN的能力，这种具有超声响应特性的可注射水凝胶是软骨组织工程的一个有前景的系统。
