Multifunctional 3D-Printed Patches for Long-Term Drug Release Therapies after Myocardial Infarction

A biomaterial system incorporating nanocellulose, poly(glycerol sebacate), and polypyrrole is introduced for the treatment of myocardial infarction. Direct ink writing of the multicomponent aqueous suspensions allows multifunctional lattice structures that not only feature elasticity and electrical conductivity but enable cell growth. They are proposed as cardiac patches given their biocompatibility with H9c2 cardiomyoblasts, which attach extensively at the microstructural level, and induce their proliferation for 28 days. Two model drugs (3i-1000 and curcumin) are investigated for their integration in the patches, either by loading in the precursor suspension used for extrusion or by direct impregnation of the as-obtained, dry lattice. In studies of drug release conducted for five months, a slow in vitro degradation of the cardiac patches is observed, which prevents drug burst release and indicates their suitability for long-term therapy. The combination of biocompatibility, biodegradability, mechanical strength, flexibility, and electrical conductivity fulfills the requirement of the highly dynamic and functional electroresponsive cardiac tissue. Overall, the proposed cardiac patches are viable alternatives for the regeneration of myocardium after infarction through the effective integration of cardiac cells with the biomaterial.