Review article Oligoaniline-based conductive biomaterials for tissue engineering Payam Zarrintaj a , Behnaz Bakhshandeh b , Mohammad Reza Saeb c,⇑ , Farshid Sefat d,e , Iraj Rezaeian a , Mohammad Reza Ganjali f , Seeram Ramakrishna g,h , Masoud Mozafari i,j,k,⇑ a School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran b Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran c Departments of Resin and Additives, Institute for Color Science and Technology, P.O. Box 16765-654, Tehran, Iran d School of Engineering, Design and Technology-Medical Engineering, University of Bradford, Bradford, West Yorkshire, UK e Tissue Engineering Group, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA f Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran g Guangdong-Hongkong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou, China h Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore (NUS), Singapore 117576, Singapore i Bioengineering Research Group, Nanotechnology and Advanced Materials Department, Materials and Energy Research Center (MERC), Tehran, Iran j Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran k Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran article info Article history: Received 21 November 2017 Received in revised form 23 February 2018 Accepted 27 March 2018 Available online xxxx Keywords: Aniline oligomer Conductive polymer Biomaterials Tissue engineering Regenerative medicine abstract The science and engineering of biomaterials have improved the human life expectancy. Tissue engineering is one of the nascent strategies with an aim to fulfill this target. Tissue engineering scaffolds are one of the most significant aspects of the recent tissue repair strategies; hence, it is imperative to design biomimetic substrates with suitable features. Conductive substrates can ameliorate the cellular activity through enhancement of cellular signaling. Biocompatible polymers with conductivity can mimic the cells’ niche in an appropriate manner. Bioconductive polymers based on aniline oligomers can potentially actualize this purpose because of their unique and tailoring properties. The aniline oligomers can be positioned within the molecular structure of other polymers, thus painter acting with the side groups of the main polymer or acting as a comonomer in their backbone. The conductivity of oligoaniline-based conductive biomaterials can be tailored to mimic the electrical and mechanical properties of targeted tissues/organs. These bioconductive substrates can be designed with high mechanical strength for hard tissues such as the bone and with high elasticity to be used for the cardiac tissue or can be synthesized in the form of inject- able hydrogels, particles, and nanofibers for noninvasive implantation; these structures can be used for applications such as drug/gene delivery and extracellular biomimetic structures. It is expected that with progress in the fields of biomaterials and tissue engineering, more innovative constructs will be proposed in the near future. This review discusses the recent advancements in the use of oligoaniline-based conduc- tive biomaterials for tissue engineering and regenerative medicine applications. Statement of Significance The tissue engineering applications of aniline oligomers and their derivatives have recently attracted an increasing interest due to their electroactive and biodegradable properties. However, no reports have sys- tematically reviewed the critical role of oligoaniline-based conductive biomaterials in tissue engineering. Research on aniline oligomers is growing today opening new scenarios that expand the potential of these biomaterials from ‘‘traditional” treatments to a new era of tissue engineering. The conductivity of this class of biomaterials can be tailored similar to that of tissues/organs. To the best of our knowledge, this is the first review article in which such issue is systematically reviewed and critically discussed in the light of the existing literature. Undoubtedly, investigations on the use of oligoaniline-based conductive biomaterials in tissue engineering need further advancement and a lot of critical questions are yet to be answered. In this review, we introduce the salient features, the hurdles that must be overcome, the hopes, and practical constraints for further development. Ó 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. https://doi.org/10.1016/j.actbio.2018.03.042 1742-7061/Ó 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. ⇑ Corresponding authors at: Bioengineering Research Group, Nanotechnology and Advanced Materials Department, Materials and Energy Research Center (MERC), Tehran, Iran (M. Mozafari) & Departments of Resin and Additives, Institute for Color Science and Technology, P.O. Box 16765-654, Tehran, Iran (M.R. Saeb). E-mail addresses: saeb-mr@icrc.ac.ir (M.R. Saeb), mozafari.masoud@gmail.com (M. Mozafari). Acta Biomaterialia xxx (2018) xxx–xxx Contents lists available at ScienceDirect Acta Biomaterialia journal homepage: www.elsevier.com/locate/actabiomat Please cite this article in press as: P. Zarrintaj et al., Oligoaniline-based conductive biomaterials for tissue engineering, Acta Biomater. (2018), https://doi. org/10.1016/j.actbio.2018.03.042