Modulating in vivo degradation rate of injectable extracellular matrix hydrogels

Extracellular matrix (ECM) derived hydrogels are increasingly used as scaffolds to stimulate endogenous repair. However, few studies have examined how altering the degradation rates of these materials affect cellular interaction in vivo. This study sought to examine how crosslinking or matrix metalloproteinase (MMP) inhibition by doxycycline could be employed to modulate the degradation rate of an injectable hydrogel derived from decellularized porcine ventricular myocardium. While both approaches were effective in reducing degradation in vitro, only doxycycline significantly prolonged hydrogel degradation in vivo without affecting material biocompatibility. In addition, unlike crosslinking, incorporation of doxycycline into the hydrogel did not affect mechanical properties. Lastly, the results of this study highlighted the need for development of novel crosslinkers for in situ modification of injectable ECM-derived hydrogels, as none of the crosslinking agents investigated in this study were both biocompatible and effective.