Biocompatible, electrically conductive microfibers with superior mechanical properties have received a great attention due to their potential applications in various biomedical applications such as implantable medical devices, biosensors, artificial muscles, and microactuators. Here, we developed an electrically conductive and mechanically stable carbon nanotube-based microactuator with a low degradability that makes it usable for an implantable device in the body or biological environments. The microfiber was composed of hyaluronic acid (HA) hydrogel and single-wall carbon nanotubes (SWCNTs) (HA/SWCNT). HA hydrogel acts as biosurfactant and ion-conducting binder to improve the dispersion of SWCNTs resulting in enhanced electrical and mechanical properties of the hybrid microfiber. In addition, HA was crosslinked to prevent the leaking of the nanotubes from the composite. Crosslinking of HA hydrogel significantly enhances Young's modulus, the failure strain, the toughness, the stability of the electrical conductivity, and the resistance to biodegradation and creep of hybrid microfibers. The obtained crosslinked HA/SWCNT hybrid microfibers show an excellent capacitance and actuation behavior under mechanical loading with a low potential of ±1 V in a biological environment. Furthermore, the HA/SWCNT microfibers exhibit an excellent in vitro viability. Finally, the biocompatibility is shown through the resolution of an early inflammatory response in less than 3 weeks after the implantation of the microfibers in the subcutaneous tissue of mice.
Bibliographical noteFunding Information:
The authors gratefully acknowledge funding from the National Institutes of Health (NIH) (EB024403, AR074234, EB026824) and the Department of Defense, ARMI (Biofabusa). The research was partially supported by a micro grant from Brigham Research Institute and Center for Faculty Development and Diversity’sOffice for Research Careers at Brigham and Women’s Hospital. S.R.S. would like to recognize and thank Brigham and Women’s Hospital President Betsy Nabel, MD, and the Reny family, for the Stepping Strong Innovator Award through their generous funding. T.Z. acknowledges the China Scholarship Council (No. 201506120155) and Harbin Institute of Technology for the financial support. P.P.S.S.A. was supported by NIH grant 5T32EB016652-02, American Heart Association grant 17SDG33660925, and an American Fellowship from American Association of University Women. This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF award no. 1541959. CNS is part of Harvard University.
All Science Journal Classification (ASJC) codes
- Materials Science(all)