Poly(acrylamide)-co-poly(hydroxyethyl)methacrylate-co-poly(cyclohexyl methacrylate) hydrogel platform for stability, storage and biocatalytic applications of urease.

In our present work, an explicit crosslinked thermo-responsive hydrogel platform has been developed, by using polyacrylamide (PAAm), poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(cyclohexyl methacrylate) (PCHMA), and then coupled with urease to yield bioconjugates (BCs). Synergic effect of these polymer units provides thermoresponsive nature, optimum crosslinking with desired swelling behaviour, and stability and improved catalytic to Urease in the resultant BCs. Synthesis of the terpolymer has been achieved by employing HEMA (monomer as well as crosslinker), instead of using the conventional crosslinkers, through free radical solution polymerization technique. Various grades of TRPUBs have been fabricated by varying HEMA and CHMA contents while keeping fixed amounts of AAm. Further, the structural analysis of BCs has been done by fourier transform infra-red spectroscopic study and their thermal stabilities have been studied by thermogravimetric analysis. Urea present in TRPUBs has beenanalysed for its hydrolysis atdifferent temperatures viz., 25 °C, 45 °C and 70 °C. Further, the effect of crosslinking, temperature and reaction time on catalytic activities of TRPUBs has been studied. TRPUBs grades have showna maximum swelling capacity up to 5200 %; excellent catalytic activity even at 70 °C; and 85 % activity retention after 18 days storage in buffer medium.

Solution and microwave assisted synthesis of ß-Cyclodextrin grafted polyacrylamide: Water treatment and In-vitro drug release study.

The present article reports the application of ß-cyclodextrin grafted polyacrylamides synthesized through solution and microwave assisted polymerization techniques as flocculants and then the employment of partially hydrolyzed products of best grade of each technique in-vitro drug release study of diclofenac sodium. Five different grades of ß-cyclodextrin grafted polyacrylamides by each of solution and microwave assisted polymerization techniques have been synthesized, by varying the monomer concentration. The synthesized polymers have been well characterized and their flocculation performances have been evaluated in kaolin suspension through settling and jar test methods Then the best performing grades of both the techniques have been partially hydrolyzed to prepare three different grades each technique by varying the concentration aqueous NaOH solution. Flocculation efficiencies of these polymers have been investigated in kaolin suspension. Thus best grades of partially hydrolyzed grafted polymers of each technique have been chosen for further study of drug delivery. In-vitro drug release study has been done using diclofenac sodium loaded microbeads prepared by ionic gelation method with two partially hydrolyzed grafted polymers (one from each technique) in phosphate buffer solution (PBS) at 37±0.5 ○C and pH 7.4. The drug load and release have been analyzed by UV-vis spectroscopy.

Trimerization of ß-cyclodextrin through the click reaction.

Triprop-2-ynyl benzene-1,3,5-tricarboxylate (A) is synthesized by the reaction of 1,3,5-benzenetricarbonyl trichloride with propargyl alcohol and (A) is clicked with mono-6-deoxy-6-azido-ß-cyclodextrin (N3-ß-CD) in the presence of copper(I) bromide catalyst. N3-ß-CD has been prepared from ß-cyclodextrin (ß-CD) on treatment with toluenesulfonyl chloride (TsCl) and then with sodium azide (NaN3) in two consecutive steps. Further trimer of ß-CD is characterized by (1)H NMR and FTIR studies. Solubility of ß-cyclodextrin (ß-CD) in water can be increased by increasing the number of alcoholic OH functionalities and hydrophobic cavities in a molecule by the trimerization of ß-CD.