Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
Small. 2022 Sep;18(37):e2202390. doi: 10.1002/smll.202202390. Epub 2022 Aug 3.
3D bioprinting of granular hydrogels comprising discrete hydrogel microparticles (microgels) may overcome the intrinsic structural limitations of bulk (nanoporous) hydrogel bioinks, enabling the fabrication of modular thick tissue constructs. The additive manufacturing of granular scaffolds has predominantly relied on highly jammed microgels to render the particulate suspensions shear yielding and extrudable. This inevitably compromises void spaces between microgels (microporosity), defeating rapid cell penetration, facile metabolite and oxygen transfer, and cell viability. Here, this persistent bottleneck is overcome by programming microgels with reversible interfacial nanoparticle self-assembly, enabling the fabrication of nanoengineered granular bioinks (NGB) with well-preserved microporosity, enhanced printability, and shape fidelity. The microporous architecture of bioprinted NGB constructs permits immediate post-printing 3D cell seeding, which may expand the library of bioinks via circumventing the necessity of bioorthogonality for cell-laden scaffold formation. This work opens new opportunities for the 3D bioprinting of tissue engineering microporous scaffolds beyond the traditional biofabrication window.
包含离散水凝胶微球（微凝胶）的 3D 生物打印可能克服块状（纳米多孔）水凝胶生物墨水的固有结构限制，从而能够制造模块化的厚组织构建体。颗粒状支架的添加剂制造主要依赖于高度堵塞的微凝胶，以使颗粒悬浮液具有剪切屈服性和可挤压性。这不可避免地损害了微凝胶之间的空隙（微孔率），从而妨碍了细胞的快速渗透、代谢物和氧气的轻松转移以及细胞活力。在这里，通过用可逆界面纳米颗粒自组装对微凝胶进行编程，克服了这一持续存在的瓶颈，从而能够制造出具有良好保留的微孔率、增强的可打印性和形状保真度的纳米工程化颗粒状生物墨水（NGB）。生物打印的 NGB 结构的微孔结构允许在打印后立即进行 3D 细胞播种，这可以通过避免用于细胞负载支架形成的生物正交性来扩展生物墨水库。这项工作为超越传统生物制造窗口的组织工程微孔支架的 3D 生物打印开辟了新的机会。
