Science for Life Laboratory, Division of Nanobiotechnology, Department of Protein Science, KTH Royal Institute of Technology, 17165 Solna, Sweden.
Biopromic AB, 17165 Solna, Sweden.
Biosensors (Basel). 2022 Jul 13;12(7):521. doi: 10.3390/bios12070521.
Bioprinting is an acclaimed technique that allows the scaling of 3D architectures in an organized pattern but suffers from a scarcity of appropriate bioinks. Decellularized extracellular matrix (dECM) from xenogeneic species has garnered support as a biomaterial to promote tissue-specific regeneration and repair. The prospect of developing dECM-based 3D artificial tissue is impeded by its inherent low mechanical properties. In recent years, 3D bioprinting of dECM-based bioinks modified with additional scaffolds has advanced the development of load-bearing constructs. However, previous attempts using dECM were limited to low-temperature bioprinting, which is not favorable for a longer print duration with cells. Here, we report the development of a multi-material decellularized liver matrix (dLM) bioink reinforced with gelatin and polyethylene glycol to improve rheology, extrudability, and mechanical stability. This shear-thinning bioink facilitated extrusion-based bioprinting at 37 °C with HepG2 cells into a 3D grid structure with a further enhancement for long-term applications by enzymatic crosslinking with mushroom tyrosinase. The heavily crosslinked structure showed a 16-fold increase in viscosity (2.73 Pa s) and a 32-fold increase in storage modulus from the non-crosslinked dLM while retaining high cell viability (85-93%) and liver-specific functions. Our results show that the cytocompatible crosslinking of dLM bioink at physiological temperatures has promising applications for extended 3D-printing procedures.
生物打印是一种备受推崇的技术,可按组织模式对 3D 架构进行缩放,但存在生物墨水不足的问题。异种去细胞细胞外基质(dECM)作为一种生物材料,已被广泛用于促进组织特异性再生和修复。基于 dECM 的 3D 人工组织的开发前景受到其固有低机械性能的阻碍。近年来,通过添加额外支架对基于 dECM 的生物墨水进行 3D 生物打印,推动了承重结构的发展。然而,以前使用 dECM 的尝试仅限于低温生物打印,这不利于细胞的长时间打印。在这里,我们报告了一种多材料去细胞化肝脏基质(dLM)生物墨水的开发,该生物墨水通过添加明胶和聚乙二醇来改善流变学、可挤出性和机械稳定性。这种剪切稀化生物墨水可在 37°C 下进行基于挤出的生物打印,将 HepG2 细胞打印成 3D 网格结构,进一步通过蘑菇酪氨酸酶的酶交联进行长期应用增强。交联后的结构的粘度增加了 16 倍(2.73 Pa·s),储能模量增加了 32 倍,而非交联的 dLM 则保留了较高的细胞活力(85-93%)和肝脏特异性功能。我们的结果表明,在生理温度下对 dLM 生物墨水进行细胞相容的交联具有在扩展 3D 打印过程中的应用潜力。