Deo Kaivalya A, Jaiswal Manish K, Abasi Sara, Lokhande Giriraj, Bhunia Sukanya, Nguyen Thuy-Uyen, Namkoong Myeong, Darvesh Kamran, Guiseppi-Elie Anthony, Tian Limei, Gaharwar Akhilesh K
Houston Methodist Institute for Academic Medicine and Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, Texas 77030, United States.
ACS Nano. 2022 Jun 28;16(6):8798-8811. doi: 10.1021/acsnano.1c09386. Epub 2022 Jun 8.
Flexible electronics require elastomeric and conductive biointerfaces with native tissue-like mechanical properties. The conventional approaches to engineer such a biointerface often utilize conductive nanomaterials in combination with polymeric hydrogels that are cross-linked using toxic photoinitiators. Moreover, these systems frequently demonstrate poor biocompatibility and face trade-offs between conductivity and mechanical stiffness under physiological conditions. To address these challenges, we developed a class of shear-thinning hydrogels as biomaterial inks for 3D printing flexible bioelectronics. These hydrogels are engineered through a facile vacancy-driven gelation of MoS nanoassemblies with naturally derived polymer-thiolated gelatin. Due to shear-thinning properties, these nanoengineered hydrogels can be printed into complex shapes that can respond to mechanical deformation. The chemically cross-linked nanoengineered hydrogels demonstrate a 20-fold rise in compressive moduli and can withstand up to 80% strain without permanent deformation, meeting human anatomical flexibility. The nanoengineered network exhibits high conductivity, compressive modulus, pseudocapacitance, and biocompatibility. The 3D-printed cross-linked structure demonstrates excellent strain sensitivity and can be used as wearable electronics to detect various motion dynamics. Overall, the results suggest that these nanoengineered hydrogels offer improved mechanical, electronic, and biological characteristics for various emerging biomedical applications including 3D-printed flexible biosensors, actuators, optoelectronics, and therapeutic delivery devices.
柔性电子器件需要具有类似天然组织机械性能的弹性体和导电生物界面。设计这种生物界面的传统方法通常利用导电纳米材料与使用有毒光引发剂交联的聚合物水凝胶相结合。此外，这些系统常常表现出较差的生物相容性，并且在生理条件下在导电性和机械刚度之间面临权衡。为了应对这些挑战，我们开发了一类剪切变稀水凝胶作为用于3D打印柔性生物电子器件的生物材料墨水。这些水凝胶是通过二硫化钼纳米组装体与天然衍生的聚合物硫醇化明胶的简便空位驱动凝胶化来设计的。由于具有剪切变稀特性，这些纳米工程水凝胶可以被打印成能够响应机械变形的复杂形状。化学交联的纳米工程水凝胶的压缩模量提高了20倍，并且能够承受高达80%的应变而不发生永久变形，符合人体解剖学的柔韧性。纳米工程网络具有高导电性、压缩模量、赝电容和生物相容性。3D打印的交联结构表现出优异的应变敏感性，可作为可穿戴电子器件用于检测各种运动动态。总体而言，结果表明，这些纳米工程水凝胶为包括3D打印柔性生物传感器、致动器、光电器件和治疗递送装置在内的各种新兴生物医学应用提供了改进的机械、电子和生物学特性。
