Bottlebrush Bridge between Soft Gels and Firm Tissues
Bottlebrush Bridge between Soft Gels and Firm Tissues
复制标题
DOI：
10.1021/acscentsci.9b01216
复制
发表时间：
2020-03-25
影响因子：
18.2
通讯作者：
Sheiko, Sergei S.
中科院分区：
文献类型：
--
作者：
Keith, Andrew N.;Vatankhah-Varnosfaderani, Mohammad;Sheiko, Sergei S.
柔软性和坚固性似乎是不相容的特征，它们协同作用，创造出软机器人、可穿戴电子产品和整形外科所追求的活组织独特的柔软而坚固的触感。这种二分法在组织中特别明显，例如已知既超软又超硬的脂肪。然而，合成地复制这种机械响应仍然是难以捉摸的，因为普遍采用的软凝胶不能同时再现组织硬度。我们已经解决了组织的挑战，通过自组装成热塑性弹性体的线性瓶刷线性（LBL）嵌段共聚物。这种混合分子结构提供了一个层次网络组织与级联的变形机制负责最初的低模量，然后强烈的应变硬化。通过弥合凝胶和组织之间的硬度差距，我们复制了脂肪，胎膜，脊髓和脑组织的力学。这些无溶剂、不可沥滤和组织模拟弹性体还显示出增强的生物相容性，如细胞增殖研究所示，所有这些对于未来生物医学器械的安全性和寿命至关重要。
Softness and firmness are seemingly incompatible traits that synergize to create the unique soft-yet-firm tactility of living tissues pursued in soft robotics, wearable electronics, and plastic surgery. This dichotomy is particularly pronounced in tissues such as fat that are known to be both ultrasoft and ultrafirm. However, synthetically replicating this mechanical response remains elusive since ubiquitously employed soft gels are unable to concurrently reproduce tissue firmness. We have addressed the tissue challenge through the self-assembly of linear-bottlebrush-linear (LBL) block copolymers into thermoplastic elastomers. This hybrid molecular architecture delivers a hierarchical network organization with a cascade of deformation mechanisms responsible for initially low moduli followed by intense strain-stiffening. By bridging the firmness gap between gels and tissues, we have replicated the mechanics of fat, fetal membrane, spinal cord, and brain tissues. These solvent-free, nonleachable, and tissue-mimetic elastomers also show enhanced biocompatibility as demonstrated by cell proliferation studies, all of which are vital for the safety and longevity of future biomedical devices.