Dependence of protein recognition of temperature-sensitive imprinted hydrogels on preparation temperature.

Temperature-sensitive imprinted and non-imprinted hydrogels composed of N-isopropylacrylamide (NIPA) and 2-acrylamido-2-methyl-propanosulfonic acid (AMPS) have been prepared by free-radical crosslinking copolymerization in aqueous solution at three different temperatures: 10 degrees C (below the lower critical solution temperature, LCST), 33 degrees C (at the LCST), and 40 degrees C (above the LCST). Myoglobin (Mb, MW 17 kDa) is used as the template biomolecule. The effects of the initial concentration and adsorption time over the Mb adsorption capacity of the hydrogels have been analyzed and found to be strongly dependent on the preparation temperature (T(prep)). The maximum Mb adsorption for the imprinted hydrogel prepared at 10 degrees C is 97.40 +/- 2.35 mg Mb x g(-1) dry gel in 0.32 mg x mL(-1) Mb solution at 22 degrees C. Moreover, batch adsorption equilibrium and selectivity studies have been performed using a reference molecule, hemoglobin (Hb, MW 65 kDa). The imprinted hydrogels have a 2.8-3.3 times higher adsorption capacity for Mb than the non-imprinted hydrogels prepared at the same T(prep)s, and also have a 1.8-2.7 times higher selectivity for the imprinted molecule.

pH/temperature - sensitive imprinted ionic poly(N-tert-butylacrylamide-co-acrylamide/maleic acid) hydrogels for bovine serum albumin.

In this study, we have prepared pH/temperature-sensitive imprinted ionic poly(N-tert-butylacrylamide-co-acrylamide/maleic acid) [P(TBA-co-AAm/MA)] hydrogels for bovine serum albumin (BSA) by using molecular imprinting method. BSA adsorption from aqueous BSA solutions was investigated with two types of hydrogel systems prepared by non-imprinted and imprinted methods. Hydrogels imprinted with BSA showed higher adsorption capacity and specificity for BSA than hydrogels prepared by the usual procedure. At all studied conditions, the highest BSA adsorption was observed in the hydrogel imprinted with 8.63 wt.-% BSA. In addition, the imprinted hydrogels exhibited both for good selectivity BSA and high adsorption rate depending on the number of BSA-sized cavities. Adsorption studies showed that other stimuli, such as pH, temperature and initial BSA concentration also influenced the BSA adsorption capacity of both non-imprinted and imprinted hydrogels.