快速降解水凝胶以支持软骨微组织的生物制造和三维生物打印。
Rapidly Degrading Hydrogels to Support Biofabrication and 3D Bioprinting Using Cartilage Microtissues.
机构信息
Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin D02 R590, Ireland.
Department of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin D02 R590, Ireland.
出版信息
ACS Biomater Sci Eng. 2024 Oct 14;10(10):6441-6450. doi: 10.1021/acsbiomaterials.4c00819. Epub 2024 Sep 6.
In recent years, there has been increased interest in the use of cellular spheroids, microtissues, and organoids as biological building blocks to engineer functional tissues and organs. Such microtissues are typically formed by the self-assembly of cellular aggregates and the subsequent deposition of a tissue-specific extracellular matrix (ECM). Biofabrication and 3D bioprinting strategies using microtissues may require the development of supporting hydrogels and bioinks to spatially localize such biological building blocks in 3D space and hence enable the engineering of geometrically defined tissues. Therefore, the aim of this work was to engineer scaled-up, geometrically defined cartilage grafts by combining multiple cartilage microtissues within a rapidly degrading oxidized alginate (OA) supporting hydrogel and maintaining these constructs in dynamic culture conditions. To this end, cartilage microtissues were first independently matured for either 2 or 4 days and then combined in the presence or absence of a supporting OA hydrogel. Over 6 weeks in static culture, constructs engineered using microtissues that were matured independently for 2 days generated higher amounts of glycosaminoglycans (GAGs) compared to those matured for 4 days. Histological analysis revealed intense staining for GAGs and negative staining for calcium deposits in constructs generated by using the supporting OA hydrogel. Less physical contraction was also observed in constructs generated in the presence of the supporting gel; however, the remnants of individual microtissues were more observable, suggesting that even the presence of a rapidly degrading hydrogel may delay the fusion and/or the remodeling of the individual microtissues. Dynamic culture conditions were found to modulate ECM synthesis following the OA hydrogel encapsulation. We also assessed the feasibility of 3D bioprinting of cartilage microtissues within OA based bioinks. It was observed that the microtissues remained viable after extrusion-based bioprinting and were able to fuse after 48 h, particularly when high microtissue densities were used, ultimately generating a cartilage tissue that was rich in GAGs and negative for calcium deposits. Therefore, this work supports the use of OA as a supporting hydrogel/bioink when using microtissues as biological building blocks in diverse biofabrication and 3D bioprinting platforms.
近年来,人们对使用细胞球体、微组织和类器官作为生物构建块来构建功能性组织和器官越来越感兴趣。这种微组织通常是通过细胞聚集体的自组装和随后沉积组织特异性细胞外基质 (ECM) 形成的。使用微组织的生物制造和 3D 生物打印策略可能需要开发支持水凝胶和生物墨水,以在 3D 空间中对这些生物构建块进行空间定位,并因此能够构建具有几何定义的组织。因此,本工作的目的是通过在快速降解的氧化海藻酸钠 (OA) 支撑水凝胶中组合多个软骨微组织,并在动态培养条件下维持这些构建体,来构建规模化的、具有几何定义的软骨移植物。为此,首先将软骨微组织分别培养 2 天或 4 天,然后在有或没有支撑 OA 水凝胶的情况下进行组合。在静态培养 6 周后,与培养 4 天的微组织构建体相比,培养 2 天的微组织构建体生成的糖胺聚糖 (GAG) 量更高。组织学分析显示,使用支撑 OA 水凝胶生成的构建体中 GAG 染色强烈,钙沉积染色阴性。在存在支撑凝胶的情况下,构建体的物理收缩也较少;然而,单个微组织的残留物更容易观察到,这表明即使存在快速降解的水凝胶,也可能延迟单个微组织的融合和/或重塑。动态培养条件被发现可以调节 OA 水凝胶包封后的 ECM 合成。我们还评估了在基于 OA 的生物墨水中 3D 生物打印软骨微组织的可行性。观察到挤出式生物打印后微组织仍然存活,并在 48 小时后能够融合,特别是当使用高微组织密度时,最终生成富含 GAG 且无钙沉积的软骨组织。因此,这项工作支持在使用微组织作为生物构建块的各种生物制造和 3D 生物打印平台中使用 OA 作为支撑水凝胶/生物墨水。