Effect of enzyme and mechanical stirring on the degradation of polyaspartic acid hydro-gel

As a biodegradable polymer, polyaspartic acid (PASP) hydro-gel has been applied in various fields. Although the degradation mechanism of PASP was well studied, to our knowledge, limited research has been done on the degradation of PASP hydro-gel, whose main chain was cross-linked. This work mainly focused on the effects of enzyme and mechanical stirring on the structure of the PASP hydro-gel during its degradation. The change of the molecular weight and swelling ratio indicates that the simple mechanical stirring caused a break at the crosslink point of the PASP hydro-gel׳s spatial reticular structure with IR and SEM characterization, but has no significant effect on the degradation of the main chain. Changing the PH value of the degradation system also has little effect on the degradation of the main chain. However, the additions of enzyme both resulted in the break at the crosslink point and the degradation of the main chain, the significant decreases of both the molecular weight and swelling ratio of the PASP hydro-gel were observed.