Bandyopadhyay Ashutosh, Mandal Biman B, Bhardwaj Nandana
Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India.
Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, India.
J Biomed Mater Res A. 2022 Apr;110(4):884-898. doi: 10.1002/jbm.a.37336. Epub 2021 Dec 16.
Articular cartilage damage poses huge burden on healthcare sector globally due to its extremely weak inherent regenerative ability. Three-dimensional (3D) bioprinting for development of cartilage mimic constructs using composite bioinks serves as an emerging perspective. However, difficulty in development of suitable bioink and chemical crosslinking associated inherent toxicity hamper widespread adoption of this technique. To circumvent this, a photo-polymerizable hydrogel-based bioink which helps in recapitulation of the complex cartilage microenvironment is pertinent. Herein, a photo-crosslinkable bioink containing different concentrations of silk methacrylate (SilMA) and polyethylene glycol diacrylate (PEGDA) was mixed with chondrocytes for biofabrication of 3D bioprinted cartilage constructs. The rheological properties, printability of bioink and physico-chemical characterization of printed hydrogel constructs were examined along with cartilaginous tissue formation. The printed SilMA-PEGDA hydrogel constructs possessed proper internal porous structure and demonstrated most reliable rheological properties, printability along with good mechanical, and degradation properties suitable for cartilage regeneration. Live/dead staining showed cytocompatibility of the 3D-bioprinted SilMA-PEGDA constructs. Moreover, a marked increase in cell number and DNA content was observed within the cartilaginous tissue as indicated by cell viability and DNA content quantitation. Biochemical evaluation confirmed the neocartilage formation within SilMA-PEGDA bioprinted constructs as revealed by enhanced deposition of cartilage specific extracellular matrix-sulphated GAG (sGAG) and collagen type II (>2-fold increase, p < 0.001) with time. Finally, immunohistochemical analysis indicated expression of collagen type II and aggrecan which corroborated with cartilaginous tissue formation. Taken together, we conclude that SilMA-PEGDA bioink could be suitable candidate for bioprinting chondrocytes to support cartilage tissue repair and regeneration.
由于关节软骨固有的再生能力极其微弱，其损伤给全球医疗保健部门带来了巨大负担。利用复合生物墨水开发模仿软骨结构的三维（3D）生物打印技术成为一个新的研究方向。然而，合适生物墨水的开发困难以及化学交联相关的固有毒性阻碍了该技术的广泛应用。为了克服这一问题，一种基于光聚合水凝胶的生物墨水应运而生，它有助于重现复杂的软骨微环境。在此，将含有不同浓度甲基丙烯酸丝素（SilMA）和聚乙二醇二丙烯酸酯（PEGDA）的可光交联生物墨水与软骨细胞混合，用于3D生物打印软骨结构的生物制造。研究了生物墨水的流变学特性、可打印性以及打印水凝胶结构的物理化学特性，同时观察了软骨组织的形成情况。打印的SilMA-PEGDA水凝胶结构具有合适的内部多孔结构，并表现出最可靠的流变学特性、可打印性以及良好的机械性能和降解性能，适合软骨再生。活/死染色显示3D生物打印的SilMA-PEGDA结构具有细胞相容性。此外，细胞活力和DNA含量定量结果表明，软骨组织内的细胞数量和DNA含量显著增加。生化评估证实，随着时间的推移，SilMA-PEGDA生物打印结构内形成了新软骨，软骨特异性细胞外基质硫酸化糖胺聚糖（sGAG）和II型胶原蛋白的沉积增加（增加了2倍以上，p < 0.001）。最后，免疫组织化学分析表明II型胶原蛋白和聚集蛋白聚糖的表达，这与软骨组织的形成情况相符。综上所述，我们得出结论，SilMA-PEGDA生物墨水可能是用于生物打印软骨细胞以支持软骨组织修复和再生的合适候选材料。
