Department of Chemistry , Royal College of Surgeons in Ireland (RCSI) , 123 St. Stephens Green , Dublin 2 , Ireland.
Drug Delivery & Advanced Materials Team, School of Pharmacy & Tissue Engineering Research Group, Department of Anatomy , Royal College of Surgeons in Ireland (RCSI) , 123 St. Stephens Green , Dublin 2 , Ireland.
Biomacromolecules. 2018 Jul 9;19(7):2691-2699. doi: 10.1021/acs.biomac.8b00299. Epub 2018 Apr 24.
We present a star copolypeptide-based hydrogel ink capable of structural microfabrication using 3D extrusion printing. The material comprises an amphiphilic block copolymer structure of poly(benzyl-l-glutamate)- b-oligo(l-valine), which spontaneously forms hydrogels through hydrophobic interactions. The chemical design allows the bulk phase of the hydrogel to remain intact after application of shear due to its self-recovery behavior. It is demonstrated that the composition of the materials is ideally suited for 3D printing with scaffolds capable of maintaining structural cohesion after extrusion. Post extrusion UV-triggered fixation of the printed structures is carried out, resulting in stable hydrogel constructs. The constructs were found to be degradable, exhibited favorable release of encapsulated molecular cargo, and do not appear to affect the metabolic health of the commonly used fibroblastic cell line Balb/3T3 in the absence of the reactive diluent N, N'-methylenebis(acrylamide). The star copolypeptide inks allow for rapid prototyping enabling the fabrication of defined intricate microstructures, providing a platform for complex scaffold development that would otherwise be unattainable with other processing techniques such as molding or casting.
我们提出了一种基于星形共聚多肽的水凝胶墨水，可通过 3D 挤出打印进行结构微制造。该材料由聚（苄基-L-谷氨酸）-b-低聚（L-缬氨酸）的两亲嵌段共聚物结构组成，通过疏水相互作用自发形成水凝胶。化学设计允许水凝胶的本体相在应用剪切后保持完整，因为它具有自恢复行为。结果表明，该材料的组成非常适合 3D 打印，打印的支架在挤出后能够保持结构内聚性。在挤出后进行 UV 触发的打印结构固定，得到稳定的水凝胶结构。研究发现，这些结构可降解，包封的分子货物能够有效释放，并且在没有反应性稀释剂 N, N'-亚甲基双（丙烯酰胺）的情况下，似乎不会影响常用成纤维细胞系 Balb/3T3 的代谢健康。星形共聚多肽墨水可实现快速原型制作，从而能够制造出定义明确的复杂微结构，为复杂支架的开发提供了一个平台，而其他加工技术（如模塑或铸造）则无法实现。
