Immobilization of α-amylase and amyloglucosidase onto ion-exchange resin beads and hydrolysis of natural starch at high concentration.

α-Amylase was immobilized on Dowex MAC-3 with 88 % yield and amyloglucosidase on Amberlite IRA-400 ion-exchange resin beads with 54 % yield by adsorption process. Immobilized enzymes were characterized to measure the kinetic parameters and optimal operational parameters. Optimum substrate concentration and temperature were higher for immobilized enzymes. The thermal stability of the enzymes enhanced after the immobilization. Immobilized enzymes were used in the hydrolysis of the natural starch at high concentration (35 % w/v). The time required for liquefaction of starch to 10 dextrose equivalent (DE) and saccharification of liquefied starch to 96 DE increased. Immobilized enzymes showed the potential for use in starch hydrolysis as done in industry.

Studies on the properties and biodegradability of PVA/Trapa natans starch (N-st) composite films and PVA/N-st-g-poly (EMA) composite films.

The morphological modification of Trapa natans starch was done by grafting the methylmethacrylate (EMA) using ferrous ammonium sulphate­potassium persulphate as a redox initiator. Different reaction parameters such as reaction temperature, time, monomer concentration, pH and solvent were optimized to get maximum graft yield (56%). The graft copolymers thus formed were characterized by Fourier transform infrared, scanning electron microscopy, X-ray diffraction and TGA/DTA/DTG techniques. PVA/starch (N-st) composite films and PVA/N-Starch-grafted-poly (EMA) composite films were prepared separately by using glycerol as a plasticizer. The effect and content of grafted starch on the mechanical properties, water uptake (%), and biodegradability of the composite films were observed. Elongation at break % of PVA/starch-grafted-poly (EMA) (1:1) increased up to 38.9% of pure PVA/N-starch composites (1:1). With further increase in the ratio of grafted starch from (50% to 70%) Elongation at break, % increased to a great extent. There was 223.14% increased in PVA/starch-grafted-poly (EMA) (3:7) as compared to pure PVA/N-starch (3:7) composite films. The Max stress increased up to 100% in PVA/N-starch-grafted-poly (EMA) (3:7) composite film of pure PVA/N-starch composite films (3:7). There were 41.63% decreases in water uptake in PVA/N-starch-grafted-poly (EMA) (3:7) composite films as compared to PVA/N-starch composite films.

Effect of cross linking of PVA/starch and reinforcement of modified barley husk on the properties of composite films.

Barley husk (BH) was graft copolymerized by palmitic acid. The crystalline behavior of BH decreased after grafting. Poly vinyl alcohol (PVA)/starch (St) blend film, urea formaldehyde cross linked PVA/St films and composite films containing natural BH, grafted BH were prepared separately. The effect of urea/starch ratio, content of BH and grafted BH on the mechanical properties, water uptake (%), and biodegradability of the composite films was observed. With increase in urea: starch ratio from 0 to 0.5 in the blend, tensile strength of cross linked film increased by 40.23% compared to the PVA/St film. However, in grafted BH composite film, the tensile strength increased by 72.4% than PVA/St film. The degradation rate of natural BH composite film was faster than PVA/St film. Various films were characterized by SEM, FT-IR and thermal analysis.

Chitosan-assisted immobilization of serratiopeptidase on magnetic nanoparticles, characterization and its target delivery.

BACKGROUND: Magnetic nanoparticles (MNPs) gained attentions as universal carrier for drug delivery and for enzyme immobilization. PURPOSE: Target delivery of serratiopeptidase for treatment using this enzyme and applications in drug delivery. METHOD: Serratiopeptidase was immobilized on chitosan amino-functionalized MNPs by covalent bonding through glutaraldehyde. Targeting of MNPs with immobilized enzyme (EMNPs) was carried out in vitro in modified diffusion cell and in vivo in rats. RESULTS AND DISCUSSION: MNPs and EMNPs were 15.43 ± 5.22 and 18.43 ± 3.23 nm (transmission electron microscopy), crystallite size 16.89 and 21.05 nm (X-ray diffraction) and saturation magnetization 62 and 35.2 emug(-1), respectively. Maximum protein and enzyme loading on EMNPs were 264 mg g(-1) and 325 U g(-1), respectively. In the molecular level, maximum 52 enzyme molecules could bind to each particle showing residual activity 68%, little effect on KM and Vmax, good storage stability. Magnetic targeting of EMNPs increased the delivery (permeation) of drug through membrane in vitro and the enhanced anti-inflammatory effect on carrageenan-induced paw oedema in rats in vivo at much lower doses of enzyme than the doses required for treatment with free enzyme. CONCLUSIONS: The enzymatic preparation of MNPs showed enhanced effects (permeation enhancement and anti-inflammatory activity) at lower concentration with magnetic targeting.

Preparation, characterization and targeted delivery of serratiopeptidase immobilized on amino-functionalized magnetic nanoparticles.

Targeted delivery of serratiopeptidase enzyme immobilized on magnetic nanoparticles (MNPs) of Fe3O4 has been reported for the treatment using this enzyme. The enzyme was immobilized by covalent bonding through glutaraldehyde after amino functionalization of MNPs and parameters was studied. The enzyme bound MNPs (EMNPs) were characterized for size, crystallographic identity, phase purity, zeta potential and magnetic properties along with elemental and thermal analysis. The binding of enzyme had little effect on sizes (~10-17 nm) and on magnetic properties, but the zeta potential increased from -25 mV to +14.5 mV with surface amino groups up to 350 µmoles g(-1) MNPs, to stabilize its suspensions. In the molecular level, maximum of 17 molecules of enzyme could bind to each particle of MNPs that showed residual activity 67%, decreased KM and Vmax, good storage stability. Magnetic targeting of EMNPs increased the delivery (permeation) of drug through the membrane in in vitro study and enhanced the anti-inflammatory effect on carrageenan induced paw oedema in rats in in vivo study at much lower doses of enzyme than the doses required for treatment with free enzyme.