Developing Injectable, 3D-printed, Vascularized Cardiac Patches

The only treatment currently available to patients suffering from the long-term damage caused by a myocardial infarction (or “heart attack”) is a full heart transplant. The field of tissue engineering and regenerative medicine aims to offer alternative treatments by fabricating replacement tissues without waiting for a matching cadaveric donor. However, these treatments still depend on open-chest surgery, a procedure which can injure the patient and lead to infection. Recently, technological innovations have allowed surgeons to provide minimally invasive alternatives that are designed to limit injury to the patient, minimize the risk of infection, and enable patients to recover much more quickly. Our lab has previously demonstrated the feasibility of printing fully autologous, vascularized, thick cardiac patches. However, the first generation of these patches demonstrated weak mechanical properties. In order to be of use in a minimally invasive procedure, the patch must be able to be administered by injection without macroscopic tearing, or damage at the cellular level. Recent work, therefore, has focused on developing a biocompatible technique for reinforcing fully-cellularized cardiac patches as a post-fabrication step to enable their use in minimally invasive procedures. In vitro results suggest that the technique significantly enhances the mechanical properties of the tissue while maintaining high levels of cell viability and functionality.