PC 29


R. Hobzováa,b, N.M. Zhunusbekovac, J. Micháleka,b, M. Přádnýa,b

aDepartment of Hydrogels for Medical and Technical Practice, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague (hobzova@imc.cas.cz)

b Centre for Cell Therapy and Tissue Repair, Charles University, Prague, Czech Republic

c Laboratory of Physical Chemistry, A.B. Bekturov Institute of Chemical Sciences, Valikhanov Str. 106, Almaty, 050010, Kazakhstan, (znazym@mail.ru)

A model protein (avidin from chicken egg white) was covalently attached to copolymers based on 2-hydroxyethyl methacrylate (HEMA). HEMA polymers were chosen due to their known good biocompatibility and other properties suitable for biomedical applications. We have prepared HEMA copolymers with methacrylic acid derivatives - glycidyl methacrylate (GMA) and N-succinimidyl methacrylate (NHSMA). The hydrogels contain appropriate functional epoxy or activated carboxylic groups. To incorporate more carboxylic groups, we carried out hydrolysis of HEMA polymers with aqueous NaOH of various concentrations at 60 °C, 90 °C and 130 °C. Subsequently, carboxylic groups formed on the polymer surface were activated by the reaction with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide. The conditions (temperature, time) of polymer surface treatment and its influence on immobilization of avidin were studied. The adsorption capacity of hydrogel was determined by the Bradford spectrophotometric method. The absorption maximum for an acidic solution of Coomassie Brilliant Blue G‑250 shifts from 465 nm to 595 nm when binding to protein occurs and the color intensity is proportional to protein amount. The modified materials were characterized by infrared spectroscopy, elemental analysis and swelling properties. The amount of water was determined by weighing dry and swollen samples and, independently, by measurement of refractive index.