Enzymatic degradation of graphene/polycaprolactone materials for tissue engineering

Graphene/polycaprolactone composites have proven to be promising substrates for biodegradable tissue engineering scaffolds for electro-responsive tissue types. The degradation behaviour of these materials will be critical to any future application. To that end, the effect of chemically converted reduced graphene oxide (CCG) on the enzymatic degradation of graphene/polycaprolactone composites in phosphate buffered saline was examined. Two types of graphene/polycaprolactone composites were tested; a simple blend and our previously developed covalently-linked composites. A number of graphene concentrations of each type were tested. Covalently linked graphene/polycaprolactone (cPCl-CCG) showed a consistent degradation profile maintaining the graphene:PCL ratio throughout the degradation process. However, the mixed blended sample (mixPCl-CCG) showed inconsistent graphene loss indicative of non-homogeneous dispersion throughout the polymer matrix. Increasing the graphene concentration up to 1 wt% did not change the rate of degradation but at higher concentrations degradation was slowed. The degradation products were also shown to be non-toxic to the proliferating cells.