Mohammad Eskandari Fard

Xylanase improves poultry nutrition by degrading xylan in the cell walls of feed grains and release the entrapped nutrients. However, the application of xylanase as a feed supplement is restricted to its low stability in the environment and gastrointestinal (GI) tract of poultry. To overcome these obstacles, Zeozyme NPs as a smart pH-responsive nanosystem was designed based on xylanase immobilization on zeolitic nanoporous as the major cornerstone that was modified with L-lysine. The immobilized xylanase was followed by encapsulating with a cross-linked CMC-based polymer. Zeozyme NPs was structurally characterized using TEM, SEM, AFM, DLS, TGA and nitrogen adsorption/desorption isotherms at liquid nitrogen temperature. The stability of Zeozyme NPs was evaluated at different temperatures, pH, and in the presence of proteases. Additionally, the release pattern of xylanase was investigated at a digestion model mimicking the GI tract. Xylanase was released selectively at the duodenum an...

ABSTRACT Ferrogels with well-dispersed single-domain magnetic nanoparticles (NPs) were obtained by the infusion of iron salts in physically cross-linked poly(vinyl alcohol) (PVA) hydrogels followed by coprecipitation. Freeze–thaw (F–T) cycling was used as a cryogenic technique to form mechanically strong and highly swellable hydrogels. The networked structure of the final material was used as a constrained environment for the precipitation of iron oxide NPs and formation of the magnetic gel. A homogeneous, single-domain ensemble of more than 15 wt % iron oxide NPs (in only one cycle of absorption) could be obtained through this easy technique. Moreover, the capacity of these magnetic ferrogels to absorb high amounts of ethanol/water solutions allows impregnation of these materials with ibuprofen and subsequent release of the drug at physiological pH. The biocompatibility of the components and the use of the nontoxic PVA cross-linking strategy (F–T cycling) make these materials promising for drug-delivery applications.

ABSTRACT Ferrogels with well-dispersed single-domain magnetic nanoparticles (NPs) were obtained by the infusion of iron salts in physically cross-linked poly(vinyl alcohol) (PVA) hydrogels followed by coprecipitation. Freeze–thaw (F–T) cycling was used as a cryogenic technique to form mechanically strong and highly swellable hydrogels. The networked structure of the final material was used as a constrained environment for the precipitation of iron oxide NPs and formation of the magnetic gel. A homogeneous, single-domain ensemble of more than 15 wt % iron oxide NPs (in only one cycle of absorption) could be obtained through this easy technique. Moreover, the capacity of these magnetic ferrogels to absorb high amounts of ethanol/water solutions allows impregnation of these materials with ibuprofen and subsequent release of the drug at physiological pH. The biocompatibility of the components and the use of the nontoxic PVA cross-linking strategy (F–T cycling) make these materials promising for drug-delivery applications.