Neuhäusler A, Rogg K, Schröder S, Spiehl D, Zora H, Arefaine E, Schettler J, Hartmann H, Blaeser A
Technical University of Darmstadt, Institute for BioMedical Printing Technology, Magdalenenstr. 2, 64289 Darmstadt, Germany.
Technical University of Darmstadt, Institute of Printing Science and Technology, Magdalenenstr. 2, 64289 Darmstadt, Germany.
Biofabrication. 2024 Dec 27;17(1). doi: 10.1088/1758-5090/ad9d7a.
3D-bioprinting is a promising technique to mimic the complex anatomy of natural tissues, as it comprises a precise and gentle way of placing bioinks containing cells and hydrogel. Although hydrogels expose an ideal growth environment due to their extracellular matrix (ECM)-like properties, high water amount and tissue like microstructure, they lack mechanical strength and possess a diffusion limit of a couple of hundred micrometers. Integration of electrospun fibers could hereby benefit in multiple ways, for instance by controlling mechanical characteristics, cell orientation, direction of diffusion and anisotropic swelling behavior. The aim of this study was to create an advanced ECM-biomimicking scaffold material for tissue engineering, which offers enhanced diffusion properties. PCL bulk membranes were successfully electrospun and fragmented using a cryo cutting technique. Subsequently, these short single fibers (<400m in length and ∼5-10m in diameter) were embedded in an agarose-based hydrogel after hydrophilization of the short single fibers by Oplasma treatment. Fiber-filled bioinks exhibit significantly improved biomolecule diffusion (>500m), swelling properties (20%-60% of control), and higher mechanical strength, while its viscosity (5-30 mPas*s) and gelation kinetics (28 °C) remained almost unaffected. The diffusion tests indicate a high level of size selectivity, which can be utilized for targeted biomolecule transport in the future. Finally, applying 3D-bioprinting technology (drop-on-demand vs. microextrusion) a print setting dependent post-dispensing orientation of the fibers could be induced, which ultimately paves way for the fabrication of metamaterials with anisotropic material properties. As expected, the fiber-filled bioink was found to be non-cytotoxic in cell culture trials using HUVECs and HepG2 (>80% viability). In summary, microfiber integration holds great promise for 3D-bioprinting of tissue percursors with advanced metamaterial properties and thus offers high applicability in various fields of research, such astissue models, tissue engineered implants or cultivated meat.
3D生物打印是一种很有前景的技术，可用于模拟天然组织的复杂解剖结构，因为它提供了一种精确且温和的方式来放置含有细胞和水凝胶的生物墨水。尽管水凝胶因其类似细胞外基质（ECM）的特性、高含水量和类似组织的微观结构而提供了理想的生长环境，但它们缺乏机械强度，并且存在几百微米的扩散极限。在此，电纺纤维的整合可以在多个方面带来益处，例如通过控制机械特性、细胞取向、扩散方向和各向异性膨胀行为。本研究的目的是创建一种用于组织工程的先进的ECM仿生支架材料，该材料具有增强的扩散特性。聚己内酯（PCL）块状膜通过冷冻切割技术成功地进行了电纺和破碎。随后，在通过常压等离子体处理使短单纤维亲水化后，将这些短单纤维（长度<400μm，直径约5-10μm）嵌入基于琼脂糖的水凝胶中。纤维填充的生物墨水在生物分子扩散（>500μm）、膨胀特性（对照的20%-60%）和更高的机械强度方面表现出显著改善，而其粘度（5-30mPas·s）和凝胶化动力学（28℃）几乎不受影响。扩散测试表明具有高水平的尺寸选择性，这在未来可用于靶向生物分子运输。最后，应用3D生物打印技术（按需滴注与微挤压），可以诱导纤维在滴注后的取向依赖于打印设置，这最终为制造具有各向异性材料特性的超材料铺平了道路。正如预期的那样，在使用人脐静脉内皮细胞（HUVECs）和人肝癌细胞（HepG2）的细胞培养试验中，发现纤维填充的生物墨水无细胞毒性（活力>80%）。总之，微纤维整合对于具有先进超材料特性的组织前体的3D生物打印具有很大的前景，因此在各种研究领域，如组织模型、组织工程植入物或人造肉中具有很高的适用性。
