Conductive PCL-graphene 3D scaffolds for functional cardiac tissue models

Abstract

The development of new interventions and devices for the treatment of cardiovascular disease is critically dependent on rigorous regulatory testing to ensure their safety and the efficacy for the patient. A central aspect of this testing is the use of in vivo animal models, in particular porcine, as a core element of the preclinical assessment regime. The provision of improved in vitro models that are closer to human physiology can significantly reduce this dependency on animal studies. Approaches that use a blend of the knowledge gained from tissue engineered constructs and lab-on-chip technologies to create a pseudo-tissue with suitable function are being developed whereby cardiac cells are combined with a smart 3D scaffold material. Such systems can be denoted as being ex vivo in that they offer a means to attain key physical, chemical mechanical, and electrical characteristics to replicate aspects of the native human myocardium.

The work presented in this thesis investigates the effects of using of graphene to impart electroactive properties to 3D printed a poly-e-caprolactone (PCL) scaffolds designed to act as a matrix for the study of functional cardiomyocytes. The chemical effects when Graphene is introduced into PCL inks have been determined using FTIR and Raman spectroscopy and the system is chemically stable up to 5% w/w which Graphene clearly distinguishable above 1% w/w. Mechanical and electrical conductivity testing has been used to further determine utility. These data indicate that the resulting 3D matrices have the physical and mechanical properties needed to fulfil the functions sought. The mechanical properties of PCL are sightly enhanced when Graphene is incorporated as determined through compression and tensile testing. Incorporating 3% w/w graphene into the PCL allows for the creation of electrically conductive constructs by 3D printing without loss of the resolution created with PCL alone. Moreover, these structures have a surface chemistry and topography that is not expected to cause an adverse myocardial cell response.

Date of Award	Jan 2022
Original language	English
Sponsors	Eastern Corridor for Medical Engineering (ECME)
Supervisor	Brian Meenan (Supervisor) & Adrian Boyd (Supervisor)