In vitro release kinetics of bovine serum albumin from highly swellable dextran hydrogels

Abstract

Hydrogels synthesized from a polysaccharide-based polymer, dextran, in the presence of two crosslinking agents, N,N 0 -methylenebisacrylamide and epichlorohydrin, were evaluated for the oral colon-specific delivery of polypeptide drugs. These novel dextran hydrogels had significantly greater swelling ratios than recently developed dextran hydrogels. A model protein, bovine serum albumin, was loaded into 50% (by weight) crosslinker-containing dextran hydrogels in two ways: during the crosslinking reaction and by a soaking method. The loading capacity was varied between 22 and 25 mg/g of dry gel, depending on the loading procedure. In vitro release experiments were performed with a simulated gastrointestinal system in the presence and absence of dextranase. The diffusion exponents were calculated by means of a semiempirical power-law equation for the release of protein from swellable hydrogel discs. Bovine serum albumin was mainly released by Fickian diffusion, and this indicated that its hydrodynamic diameter (7.7 nm) was smaller than the hydrogel mesh size ($19 nm). The release of bovine serum albumin from both hydrogel types was substantially higher than expected, especially in the presence of dextranase, and this was attributed to the high swellability of the hydrogels.

Enhanced pH-responsive carrier system based on alginate and chemically modified carboxymethyl chitosan for oral delivery of protein drugs: Preparation and in-vitro assessment

“…Also, the short half-life of protein drugs and their limited transit time in the gastrointestinal tract represent major challenges (El-Sherbiny, Abdel-Bary, & Harding, 2010;Ramadas, Paul, Dileep, Anitha, & Sharma, 2000). To date, several trials have been reported to overcome these shortcomings and to formulate peptide and protein drugs with maximum oral bioavailability (Dolatabadi-Farahani, Vasheghani-Farahani, & Mirzadeh, 2006;El-Sherbiny et al, 2010;Heller et al, 2002;Imren, Gumusderelioglu, & Guner, 2010;Liu, Jiao, & Zhang, 2007;Mi et al, 2005;Rekha & Sharma, 2008).…”

Dual stimuli responsive glycidyl methacrylate chitosan‐quaternary ammonium hybrid hydrogel and its bovine serum albumin release

“…For example, the dextran hydrogel crosslinked by epichlorohydrin, phosphorus oxychloride, and N,N ′ ‐methylenebisacrylamide is only suitable for protein postloading method, because the epoxy group of epichlorohydrin is also able to react with the amine or hydroxyl groups of protein, which can change the protein chemistry structure and lead to a unpredictable release dynamics . A postloading method can also lead to nonhomogeneous and nonuniform drug distribution within the hydrogel matrix as most of the postloaded drugs stay near the surface of the hydrogels.…”

Newly designed polyacrylamide/dextran gels for electrophoresis protein separation: synthesis and characterization

“…The work presented is a contribution along these lines based on newly designed PAAm/dextran gels. The properties of dextran gels were examined recently by Imren et al seeking highly swellable hydrogels 16. However, in our case, the best gels must have the opposite property in order to preserve as much as possible their original size in various media used in proteomics for staining gels.…”