Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland; Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland.
Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland; Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland; Advanced Materials and Bioengineering Research Centre (AMBER), Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland.
Acta Biomater. 2021 Jul 1;128:130-142. doi: 10.1016/j.actbio.2021.04.016. Epub 2021 Apr 15.
3D bioprinting has emerged as a promising technology in the field of tissue engineering and regenerative medicine due to its ability to create anatomically complex tissue substitutes. However, it still remains challenging to develop bioactive bioinks that provide appropriate and permissive environments to instruct and guide the regenerative process in vitro and in vivo. In this study alginate sulfate, a sulfated glycosaminoglycan (sGAG) mimic, was used to functionalize an alginate-gelatin methacryloyl (GelMA) interpenetrating network (IPN) bioink to enable the bioprinting of cartilaginous tissues. The inclusion of alginate sulfate had a limited influence on the viscosity, shear-thinning and thixotropic properties of the IPN bioink, enabling high-fidelity bioprinting and supporting mesenchymal stem cell (MSC) viability post-printing. The stiffness of printed IPN constructs greatly exceeded that achieved by printing alginate or GelMA alone, while maintaining resilience and toughness. Furthermore, given the high affinity of alginate sulfate to heparin-binding growth factors, the sulfated IPN bioink supported the sustained release of transforming growth factor-β3 (TGF-β3), providing an environment that supported robust chondrogenesis in vitro, with little evidence of hypertrophy or mineralization over extended culture periods. Such bioprinted constructs also supported chondrogenesis in vivo, with the controlled release of TGF-β3 promoting significantly higher levels of cartilage-specific extracellular matrix deposition. Altogether, these results demonstrate the potential of bioprinting sulfated bioinks as part of a 'single-stage' or 'point-of-care' strategy for regenerating cartilaginous tissues. STATEMENT OF SIGNIFICANCE: This study highlights the potential of using sulfated interpenetrating network (IPN) bioink to support the regeneration of phenotypically stable articular cartilage. Construction of interpenetrating networks in the bioink enables unique high-fidelity bioprinting and provides synergistic increases in mechanical properties. The presence of alginate sulfate enables the capacity of high affinity-binding of TGF-β3, which promoted robust chondrogenesis in vitro and in vivo.
3D 生物打印技术在组织工程和再生医学领域中已经崭露头角，因为它能够制造出具有复杂解剖结构的组织替代品。然而，开发具有生物活性的生物墨水仍然具有挑战性，因为这些生物墨水需要提供适当且允许的环境，以在体外和体内指导和引导再生过程。在这项研究中，硫酸化藻酸盐，一种硫酸化糖胺聚糖（sGAG）模拟物，被用于功能化藻酸盐-明胶甲基丙烯酰（GelMA）互穿网络（IPN）生物墨水，以实现软骨组织的生物打印。硫酸化藻酸盐的加入对 IPN 生物墨水的粘度、剪切变稀和触变性能的影响有限，使高精度生物打印和打印后间充质干细胞（MSC）的活力得以支持。打印的 IPN 结构的硬度大大超过了单独打印藻酸盐或 GelMA 时的硬度，同时保持了弹性和韧性。此外，由于硫酸化藻酸盐与肝素结合生长因子具有高亲和力，因此磺化 IPN 生物墨水支持转化生长因子-β3（TGF-β3）的持续释放，为体外强大的软骨生成提供了支持，在延长的培养期间几乎没有肥大或矿化的证据。这种生物打印的构建物也支持体内软骨生成，TGF-β3 的控制释放促进了软骨特异性细胞外基质沉积的显著提高。总的来说，这些结果表明，生物打印磺化生物墨水作为再生软骨组织的“单阶段”或“就地”策略的一部分具有潜力。
