Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization

Abstract

Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m 2 / g), specific volumes (from 0.755 to 1.191 cm 3 /g) and particle sizes (<100 lm-630 lm) were synthesized via suspension polymerization. Modifications of poly(GMA-co-EGDMA) with various diamines (1,2diaminoethane, 1,4-diaminobutane, 1,6-diaminohexane and 1,8-diaminooctane), 2-fluoroethylamine, glutaraldehyde and cyanuric chloride were carried out. The influence of the interaction between Candida antarctica lipase B (Cal-B) and various carriers during immobilization on the loading and hydrolytic activity (hydrolysis of para-nitrophenyl acetate) of the immobilized Cal-B were studied. Immobilization of Cal-B was performed at different temperatures and pH values. Cal-B immobilized at 30°C and pH 6.8 was leading to increased activities. Purely physical adsorption between enzyme and copolymer was observed on carriers in which amine or fluorine groups were introduced into the carrier structure by modification with various diamines or 2-fluoroethylamine. As a consequence enzyme loading and activity decreases. In contrary, modification of the poly(GMA-co-EGDMA) with glutaraldehyde and cyanuric chloride results in a covalent connection between enzyme and carrier. The obtained results show a significant increase in Cal-B activity. The influence of the amount of glutaraldehyde and cyanuric chloride used for modification was screened. Increasing the amount of glutaraldehyde or cyanuric chloride used for modification resulted in an increase of the enzyme loading. Consequently, higher amount of glutaraldehyde used led to a higher fraction of the enzyme molecules that are covalently connected on to the carrier. As the amount of glutaraldehyde or cyanuric chloride used for modifications increases, activity of immobilized C. antarctica lipase B primarily increases, showing the highest value for 0.66% and 0.050% w/w, respectively, and subsequently decreases. We could show that Cal-B immobilized on epoxy-containing copolymer modified with glutaraldehyde and cyanuric chloride performs higher activity than free enzyme powder.

Thermal properties of TRIM–GMA copolymers with pendant amine groups

“…The presence of epoxy groups allows a number of chemical modifications on the initial polymer to suit a variety of applications. Consequently, preparation of GMA-based copolymers and their modifications is the subject of numerous papers [10][11][12][13][14][15][16][17][18][19][20][21][22]. The conducted studies had indicated that an amine group is one of the most efficient functional groups for heavy metal ion removal.…”

Synergistic Effect of Adsorption and Enzymatic Conversion in the Bisphenol-A Removal by Laccase Immobilized on Poly(glycidyl methacrylate-co-ethyleneglycol dimethacrylate)

“…were added in a three-necked round bottom reactor flask and then slowly stirred at 50 °C for 24 h. Microbeads were washed with deionized water until the washing water turned neutral and dried at 40 °C for 72 h. Ammonia-modified resin was dispersed in phosphate buffered saline (pH 8.0) containing 5% v/v glutaraldehyde (20 cm 3 ). After reaction, the microspheres were washed with deionized water and dried at 40 °C for 72 h. 15 The glutaraldehyde-activated and ammonia-modified resin was designated AMINO-GLUT.…”

Polymer materials for enzyme immobilization and their application in bioreactors

“…Similarly, in the study by Miletic et al, crosslinked macroporous hydrophilic poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) (poly(GMA-co-EGDMA)) were synthesized via suspension polymerization and then went through glutaraldehyde and cyanuric chloride modification process. It was shown that as the amount of glutaraldehyde or cyanuric chloride increased, the activity of immobilized CALB primary increased at first and then decreased (20,21).…”