Electroconductive biomaterials for cardiac tissue engineering

Myocardial infarction (MI) is still the leading cause of mortality worldwide. The success of cell-based therapies and tissue engineering strategies for treatment of injured myocardium have been notably hindered due to the limitations associated with the selection of a proper cell source, lack of engraftment of engineered tissues and biomaterials with the host myocardium, limited vascularity, as well as immaturity of the injected cells. The first-generation approaches in cardiac tissue engineering (cTE) have mainly relied on the use of desired cells (e.g., stem cells) along with non-conductive natural or synthetic biomaterials for in vitro construction and maturation of functional cardiac tissues, followed by testing the efficacy of the engineered tissues in vivo. However, to better recapitulate the native characteristics and conductivity of the cardiac muscle, recent approaches have utilized electroconductive biomaterials or nanomaterial components within engineered cardiac tissues. This review article will cover the recent advancements in the use of electrically conductive biomaterials in cTE. The specific emphasis will be placed on the use of different types of nanomaterials such as gold nanoparticles (GNPs), silicon-derived nanomaterials, carbon-based nanomaterials (CBNs), as well as electroconductive polymers (ECPs) for engineering of functional and electrically conductive cardiac tissues. We will also cover the recent progress in the use of engineered electroconductive tissues for in vivo cardiac regeneration applications. We will discuss the opportunities and challenges of each approach and provide our perspectives on potential avenues for enhanced cTE. Statement of significance: Myocardial infarction (MI) is still the primary cause of death worldwide. Over the past decade, electroconductive biomaterials have increasingly been applied in the field of cardiac tissue engineering. This review article provides the readers with the leading advances in the in vitro applications of electroconductive biomaterials for cTE along with an in-depth discussion of injectable/transplantable electroconductive biomaterials and their delivery methods for in vivo MI treatment. The article also discusses the knowledge gaps in the field and offers possible novel avenues for improved cardiac tissue engineering.