Delicate control on core-shell structure of trypsin-based polymeric bioreactors enables efficient mass transport

A novel intelligent polymeric bioreactor was designed through the switch of core-shell structure, which exhibited the controllable shell permeability and enrichment effect, leading to an improvement in the hydrolysis activity. During the preparation process, the polymeric micelles generated a large amount of accessible binding sites on the soluble shell for trypsin immobilization. Subsequently, a core-shell exchange created a rigid protective cavity to stabilize the immobilized trypsin. The immobilization capacity reached 352 mg/g within 60 min (81 % immobilization efficiency), which was 7.6 times that of UCST-type polymers (PMAAc). 86 %, 82 %, 66 % of its original activity was maintained under strong acid (pH = 3), alkali (pH = 8), high temperature (55 °C) for 120 min, respectively. Furthermore, the controllable shell permeability and enrichment effect of the polymeric bioreactors facilitated the diffusion and enrichment of large molecule substrates into active sites for catalysis, giving 16 % increase in the degree of hydrolysis and 10 % improvement in antioxidant activity of almond protein.