使用细胞外基质模拟物磷酸/硫酸修饰的糖胺聚糖-琼脂糖凝胶修复骨软骨缺损及定量显微CT评估
Osteochondral Defects Healing Using Extracellular Matrix Mimetic Phosphate/Sulfate Decorated GAGs-Agarose Gel and Quantitative Micro-CT Evaluation.
作者信息
Kapat Kausik, Rameshbabu Arun Prabhu, Maity Priti Prasanna, Mandal Abhisek, Bankoti Kamakshi, Dutta Joy, Das Deb Kumar, Dey Goutam, Mandal Mahitosh, Dhara Santanu
机构信息
Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur 711103, India.
出版信息
ACS Biomater Sci Eng. 2019 Jan 14;5(1):149-164. doi: 10.1021/acsbiomaterials.8b00253. Epub 2018 May 31.
Tissue engineering has a major emphasis in creating tissue specific extracellular ambiance by altering chemical functionalities of scaffold materials. Heterogeneity of osteochondral tissue necessitates tailorable bone and cartilage specific extracellular environment. Carboxylate- and sulfate-functionalized glycosaminoglycans (GAGs) in cartilage extracellular matrix (ECM) create an acidic ambience to support chondrogenic activity, whereas phosphate-rich environment in bone enables chelation of calcium leading to the formation of mineralized matrix along with an alkaline environment to support osteogenesis. In this study, chitosan, a naturally occurring GAGs, was functionalized with phosphate/sulfate groups analogous to bone/cartilage ECM and incorporated in thermogelling agarose hydrogel for delivery to osteochondral defects. In vitro studies revealed significantly higher adhesion and proliferation of adipose derived mesenchymal stem cells (ADMSCs) with blended hydrogels as compared to that of native agarose. Cell differentiation and RT-PCR studies of the phosphorylated hydrogels revealed higher osteogenic potential, while sulfated hydrogels demonstrated enhanced chondrogenic activity in comparison to agarose. Recovery of osteochondral defects after delivery of the thermoresponsive agarose-based hydrogels decorated with phosphorylated derivatives showed significantly higher bone formation. On the other hand, cartilage formation was significant with chitosan sulfate decorated hydrogels. The study highlights the role of chitosan derivatives in osteochondral defect healing, especially phosphorylated ones as bone promoter, whereas sulfated ones act as cartilage enhancer, which was quantitatively distinguished through micro-CT-based noninvasive imaging and analysis.
组织工程学主要致力于通过改变支架材料的化学功能来营造组织特异性的细胞外环境。骨软骨组织的异质性需要可定制的骨和软骨特异性细胞外环境。软骨细胞外基质(ECM)中的羧酸盐和硫酸盐功能化糖胺聚糖(GAGs)营造出酸性环境以支持软骨生成活性,而骨中富含磷酸盐的环境能够螯合钙,从而导致矿化基质的形成,同时还有碱性环境来支持骨生成。在本研究中,天然存在的GAGs壳聚糖用类似于骨/软骨ECM的磷酸盐/硫酸盐基团进行功能化,并掺入热凝胶化琼脂糖水凝胶中,用于递送至骨软骨缺损处。体外研究表明,与天然琼脂糖相比,混合水凝胶能使脂肪来源的间充质干细胞(ADMSCs)的黏附与增殖显著增加。对磷酸化水凝胶的细胞分化和逆转录聚合酶链反应(RT-PCR)研究表明,其具有更高的成骨潜力,而硫酸化水凝胶与琼脂糖相比则表现出增强的软骨生成活性。递送装饰有磷酸化衍生物的热响应性琼脂糖基水凝胶后,骨软骨缺损的修复显示出显著更高的骨形成。另一方面,用壳聚糖硫酸盐装饰的水凝胶有显著的软骨形成。该研究突出了壳聚糖衍生物在骨软骨缺损愈合中的作用,尤其是磷酸化的壳聚糖作为骨促进剂,而硫酸化的壳聚糖则作为软骨增强剂,这通过基于微计算机断层扫描(micro-CT)的非侵入性成像和分析进行了定量区分。