Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering , Southwest Jiaotong University , Chengdu , Sichuan 610031 , China.
National Engineering Research Center for Biomaterials , Research Center for Materials Genome Engineering , Chengdu , Sichuan 610064 , China.
Nano Lett. 2019 Dec 11;19(12):8343-8356. doi: 10.1021/acs.nanolett.9b00363. Epub 2019 Nov 5.
Anisotropic hydrogels with a hierarchical structure can mimic biological tissues, such as neurons or muscles that show directional functions, which are important factors for signal transduction and cell guidance. Here, we report a mussel-inspired approach to fabricate an anisotropic hydrogel based on a conductive ferrofluid. First, polydopamine (PDA) was used to mediate the formation of PDA-chelated carbon nanotube-FeO (PFeCNT) nanohybrids and also used as a dispersion medium to stabilize the nanohybrids to form a conductive ferrofluid. The ferrofluid can respond to an orientated magnetic field and be programed to form aligned structures, which were then frozen in a hydrogel network formed via free-radical polymerization and gelation. The resulted hydrogel shows directional conductive and mechanical properties, mimicking an oriented biological tissue. Under external electrical stimulation, the orientated PFeCNT nanohybrids can be sensed by the myoblasts cultured on the hydrogel, resulting in the oriented growth of cells. In summary, the mussel-inspired anisotropic hydrogel with its aligned structural complexity and anisotropic properties together with the cell affinity and tissue adhesiveness is a potent multifunctional biomaterial for mimicking oriented tissues to guide cell proliferation and tissue regeneration.
具有分级结构的各向异性水凝胶可以模拟具有定向功能的生物组织，如神经元或肌肉，这是信号转导和细胞导向的重要因素。在这里，我们报告了一种基于导电铁磁流体的贻贝启发式方法来制造各向异性水凝胶。首先，聚多巴胺（PDA）被用于介导 PDA 螯合碳纳米管-FeO（PFeCNT）纳米杂化物的形成，并且还被用作分散介质以稳定纳米杂化物以形成导电铁磁流体。该铁磁流体可以响应定向磁场并被编程以形成取向结构，然后将其冷冻在通过自由基聚合和胶凝形成的水凝胶网络中。所得水凝胶表现出定向导电性和机械性能，模拟定向生物组织。在外部电刺激下，培养在水凝胶上的成肌细胞可以感应到取向的 PFeCNT 纳米杂化物，从而导致细胞的定向生长。总之，具有各向异性结构复杂性和各向异性特性以及细胞亲和性和组织粘附性的贻贝启发式各向异性水凝胶是一种很有前途的多功能生物材料，可用于模拟定向组织以指导细胞增殖和组织再生。
