Functional Polymer Materials, Chair for Advanced Materials Synthesis, Institute for Functional Materials and Biofabrication, Department of Chemistry and Pharmacy, Julius-Maximilians-University Würzburg, Röntgenring 11, Würzburg 97070, Germany.
Institute of Biomaterials, Friedrich Alexander University of Erlangen-Nürnberg, Cauerstr. 6, Erlangen 91058, Germany.
Biomacromolecules. 2021 Jul 12;22(7):3017-3027. doi: 10.1021/acs.biomac.1c00427. Epub 2021 Jun 8.
Hydrogels are key components in several biomedical research areas such as drug delivery, tissue engineering, and biofabrication. Here, a novel ABA-type triblock copolymer comprising poly(2-methyl-2-oxazoline) as the hydrophilic A blocks and poly(2-phenethyl-2-oxazoline) as the aromatic and hydrophobic B block is introduced. Above the critical micelle concentration, the polymer self-assembles into small spherical polymer micelles with a hydrodynamic radius of approx 8-8.5 nm. Interestingly, this specific combination of hydrophilic and hydrophobic aromatic moieties leads to rapid thermoresponsive inverse gelation at polymer concentrations above a critical gelation concentration (20 wt %) into a macroporous hydrogel of densely packed micelles. This hydrogel exhibited pronounced viscoelastic solid-like properties, as well as extensive shear-thinning, rapid structure recovery, and good strain resistance properties. Excellent 3D-printability of the hydrogel at lower temperature opens a wide range of different applications, for example, in the field of biofabrication. In preliminary bioprinting experiments using NIH 3T3 cells, excellent cell viabilities of more than 95% were achieved. The particularly interesting feature of this novel material is that it can be used as a printing support in hybrid bioink systems and sacrificial bioink due to rapid dissolution at physiological conditions.
水凝胶是药物输送、组织工程和生物制造等多个生物医学研究领域的关键组成部分。在这里，我们介绍了一种新型的 ABA 型三嵌段共聚物，由亲水性 A 嵌段聚（2-甲基-2-恶唑啉）和疏水性芳香族 B 嵌段聚（2-苯乙基-2-恶唑啉）组成。在临界胶束浓度以上，聚合物自组装成具有约 8-8.5nm 水动力半径的小的球形聚合物胶束。有趣的是，这种特定的亲水和疏水性芳香族部分的组合导致在聚合物浓度高于临界凝胶浓度（20wt%）时快速热响应反向胶凝，形成具有密集排列的胶束的大孔水凝胶。这种水凝胶表现出明显的粘弹性固体样性质，以及广泛的剪切稀化、快速结构恢复和良好的应变抗性。水凝胶在较低温度下出色的 3D 打印性能为各种不同的应用开辟了广泛的应用前景，例如在生物制造领域。在使用 NIH 3T3 细胞的初步生物打印实验中，实现了超过 95%的优异细胞活力。这种新型材料的特别有趣的特点是，由于在生理条件下快速溶解，它可以用作混合生物墨水系统和牺牲性生物墨水中的打印支撑。
