A new approach for the synthesis of hydrogel films with thermo-sensitive enzymatic activity is reported.Pepsin (PEP) was covalently immobilized on thermo-responsive hydrogels by radical polymerization inthe presence of N-isopropylacrylamide and poly-(ethylene glycol) dimethacrylate 750, acting asfunctional monomer and crosslinking agent, respectively. Hydrogels showing lower critical solutiontemperatures between 32.9 and 36.1 C were synthesized by UV-irradiation of reaction batches differingin the PEP/monomers ratio. The derivatization degree of the hydrogels was expressed as mg of PEP pergram of matrix and found to be in the range of 6 to 11% as assessed by Lowry method. Scanning electronmicroscopy analysis and water affinity evaluation allowed to highlight the porous morphology andthermo-responsivity of hydrogels as a function of temperature. Using bovine serum albumin as asubstrate, kinetics parameters were determined by Lineweaver–Burk plots and the catalyst efficiencyevaluated. The influence of temperature on enzyme activity, as well as the thermal stability and reusabilityof devices, were also investigated.
Enzyme immobilization on smart polymers: Catalysis on demand
Spizzirri U. G.;Iemma F.
2014-01-01
Abstract
A new approach for the synthesis of hydrogel films with thermo-sensitive enzymatic activity is reported.Pepsin (PEP) was covalently immobilized on thermo-responsive hydrogels by radical polymerization inthe presence of N-isopropylacrylamide and poly-(ethylene glycol) dimethacrylate 750, acting asfunctional monomer and crosslinking agent, respectively. Hydrogels showing lower critical solutiontemperatures between 32.9 and 36.1 C were synthesized by UV-irradiation of reaction batches differingin the PEP/monomers ratio. The derivatization degree of the hydrogels was expressed as mg of PEP pergram of matrix and found to be in the range of 6 to 11% as assessed by Lowry method. Scanning electronmicroscopy analysis and water affinity evaluation allowed to highlight the porous morphology andthermo-responsivity of hydrogels as a function of temperature. Using bovine serum albumin as asubstrate, kinetics parameters were determined by Lineweaver–Burk plots and the catalyst efficiencyevaluated. The influence of temperature on enzyme activity, as well as the thermal stability and reusabilityof devices, were also investigated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
