Nowadays, engineering‐based cardiac patches aim to accelerate cardiac regeneration in myocardial infarcted tissues. Considering the fundamental role of cardiac electrophysiology in myocardial function, this study aims to investigate graphene oxide (GO) incorporation in the polyethylene terephthalate (PET) nanofibrous scaffold, as a conductive cardiac patch. The PET/GO nanocomposites are prepared using the uniaxial nozzle and coaxial nozzle electrospinning processes and comprehensively evaluated. The morphological observation indicates a uniform beaded free morphology with an average diameter of 147 ± 38 and 253 ± 67 nm for solid and core–shell nanocomposite fibers, respectively. Addition of GO to the PET nanofibers in a concentration of 0.05 wt% remarkably increases the Young modulus of mats from 30 ± 0.03 to 60 ± 0.02 and 69 ± 0.08 MPa for solid and core–shell nanofibers, respectively. Also, the electroconductivity is improved from 0.7 × 10−6 to 1.175 × 10−6 and 1.3 × 10−6 S cm−1 for solid and core–shell nanofibers, which are in the range of cardiac electroactivity values. PET/GO substrate interestingly supports human umbilical vein endothelial cells’ spreading morphology and cardiomyocyte elongated morphology, mainly where the GO nanosheets are distributed near the surface of nanofibers. In conclusion, the core–shell electrospun PET/GO nanocomposite fibers are suggested as a potential electroactive cardiac patch to improve cardiac cell attachment and proliferation.

Islet transplantation provides a promising strategy in treating type 1 diabetes as an autoimmune disease, in which damaged β-cells are replaced with new islets in a minimally invasive procedure. Although islet transplantation avoids the complications associated with whole pancreas transplantations, its clinical applications maintain significant drawbacks, including long-term immunosuppression, a lack of compatible donors, and blood-mediated inflammatory responses. Biomaterial-assisted islet transplantation is an emerging technology that embeds desired cells into biomaterials, which are then directly transplanted into the patient, overcoming the aforementioned challenges. Among various biomaterials, hydrogels are the preferred biomaterial of choice in these transplants due to their ECM-like structure and tunable properties. This review aims to present a comprehensive overview of hydrogel-based biomaterials that are engineered for encapsulation of insulin-secreting cells, focusing on new hydrogel design and modification strategies to improve β-cell viability, decrease inflammatory responses, and enhance insulin secretion. We will discuss the current status of clinical studies using therapeutic bioengineering hydrogels in insulin release and prospective approaches.