Sorption of lysozyme by HEMA copolymer hydrogels

• Published in: Journal of applied polymer science Vol. 60; no. 2; pp. 225 - 234
• Main Authors: Sassi, Alexander P., Lee, Sang-Hoon, Park, Yong H., Blanch, Harvey W., Prausnitz, John M.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 11.04.1996; Wiley
• Subjects: Applied sciences; Exact sciences and technology; Miscellaneous; Organic polymers; Physicochemistry of polymers; Properties and characterization; Acrylic acid copolymer; pH gradient; Swelling; Enzyme; Contact lens; Liquid absorption; Composition effect; Hydroxyethyl methacrylate copolymer; Experimental study; Colloidal gel; Solid state; Glycosidases; Hydrolases; Biomaterial; Kinetics; Methacrylate copolymer; O-Glycosidases; Lysozyme
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/(SICI)1097-4628(19960411)60:2<225::AID-APP10>3.0.CO;2-4

Sorption of lysozyme by 2‐hydroxyethyl methacrylate (HEMA) copolymer hydrogels was studied as a function of pH and gel composition. Three types of HEMA gels were synthesized: neutral (HEMA), acidic (HEMA + acrylic acid), and basic (HEMA + dimethylaminoethyl methacrylate). Each gel was synthesized at four initial volume fractions to obtain different equilibrium swelling ratios and microstructures. Sorption as a function of time was measured for each gel at pH 7, 7.5, and 8. The rate of uptake by the acidic gels was more rapid than that by the neutral gels: To sorb 90% of the protein required only 1 h for the acidic gels but 15 days for neutral gels. Lysozyme did not adsorb or partition into the basic gels. The fractional approach to equilibrium was most rapid for the more swollen gels, and the effect of pH was small. The results reported here may be useful for rational design of new biomaterials where it is desirable to know the relative magnitude of the effects of composition, synthesis, and pH on protein sorption. © 1996 John Wiley & Sons, Inc.