Department of Bioengineering, Rice University, Houston, TX, USA; NIH/NIBIB Center for Engineering Complex Tissues, USA.
Department of Bioengineering, Rice University, Houston, TX, USA; NIH/NIBIB Center for Engineering Complex Tissues, USA.
Biomaterials. 2021 Jul;274:120871. doi: 10.1016/j.biomaterials.2021.120871. Epub 2021 May 12.
Biomaterials-based strategies have shown great promise for tissue regeneration. 3D printing technologies can deliver unprecedented control over architecture and properties of biomaterial constructs when combined with innovative material design strategies. Colloidal gels made of polymeric nanoparticles are attractive injectable and self-healing systems, but their use as bio-inks for extrusion-based printing is largely unexplored. Here, we report 3D printing of novel biomaterial constructs with shape memory behavior using photo-reactive gelatin nanoparticles as colloidal building blocks. These nanoparticles are stabilized with intraparticle covalent crosslinks, and also contain pendant methacryloyl groups as photo-reactive moieties. While non-covalent interactions between nanoparticles enable formation of colloidal gel inks that are printable at room temperature, UV-induced covalent interparticle crosslinks based on methacryloyl moieties significantly enhance mechanical properties of printed constructs. Additionally, the UV crosslinking modality enables remarkable control over swelling, degradation, and biomolecule release behavior of 3D constructs. Finally, by exploiting the mechanical properties of colloidal biomaterials after UV crosslinking, 3D constructs can be designed with shape memory properties, returning to their original programmed geometry upon re-hydration. Accordingly, these novel colloidal inks exhibit great potential to serve as bio-inks for 3D printing of biomaterials with shape-morphing features for a wide range of tissue engineering and regenerative medicine applications.
基于生物材料的策略在组织再生方面显示出巨大的潜力。3D 打印技术与创新材料设计策略相结合，可以对生物材料结构的形态和性能进行前所未有的控制。由聚合物纳米粒子制成的胶体凝胶是一种有吸引力的可注射和自修复系统，但它们作为用于挤出式打印的生物墨水的用途在很大程度上尚未得到探索。在这里，我们报告了使用光反应性明胶纳米粒子作为胶体构建块 3D 打印具有形状记忆行为的新型生物材料结构。这些纳米粒子通过粒子内共价交联稳定，并且还包含作为光反应性部分的侧基甲基丙烯酰基。虽然纳米粒子之间的非共价相互作用能够形成可在室温下打印的胶体凝胶墨水，但基于甲基丙烯酰基部分的 UV 诱导的粒子间共价交联显著增强了打印结构的机械性能。此外，UV 交联方式可以显著控制 3D 结构的溶胀、降解和生物分子释放行为。最后，通过利用胶体生物材料在 UV 交联后的机械性能，可以设计具有形状记忆特性的 3D 结构，在重新水合时恢复到其原始编程几何形状。因此，这些新型胶体墨水具有很大的潜力，可作为用于 3D 打印具有形状变形特征的生物材料的生物墨水，适用于广泛的组织工程和再生医学应用。
