Heart disease is the leading cause of death worldwide. Cardiac tissue engineering (CTE) aims to repair and replace heart tissue, offering a solution. Induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) could revolutionize CTE due to their theoretical ability to supply limitless patient-specific CMs. However, iPSC-CMs are electrophysiologically immature compared to functional adult CMs, and therefore incapable of sustaining a heartbeat.
Thus, a scaffold capable of electrophysiologically maturing iPSC-CMs is needed. My research increases the electroconductivity of electrospun (ES) scaffolds by incorporating carbon nanotubes (CNTs), which I hypothesize will mature iPSC-CMs seeded onto them due to their excellent electroconductive properties.
Morphological, biocompatibility, and electrical analyses have been performed on ES polycaprolactone (PCL) and gelatin scaffolds with CNTs incorporated via a ‘sandwich’ and dual deposition method in order to increase electroconductivity. Morphological analyses were performed via ImageJ on SEM images. Fiber diameter and pore size quantification confirmed the ability to exert morphological control by modifying solution properties and ES parameters, which is crucial to achieve biomimicry of the cardiac extracellular matrix. Live/dead assays and immunofluorescence revealed the CNT scaffolds offer high biocompatibility for NIH 3T3 fibroblasts, which attach, proliferate, and migrate well. Electrical analysis performed with a multimeter and two-probe resistance measurement confirms that inclusion of CNTs significantly increases scaffold conductivity, moreso for dual deposition scaffolds than ‘sandwich’ ones, and moreso parallel to the CNT arrays than orthogonally.
These results prove the feasibility of using such scaffolds as a method for
in vitro
electrophysiological iPSC-CM maturation. Next steps include optimization of scaffolds, analysis of iPSC-CM biocompatibility and response, and recapitulation and manipulation of the electrophysiology of cardiac tissue, including quantification of markers for cardiac function and maturity, and assessment of iPSC-CM + scaffold response to electrical pacing.
Recent progress in induced pluripotent stem cell-derived cardiac cell sheets for tissue engineering
