title: Drug release from enzyme-mediated in situ-forming hydrogel based on gum tragacanth-tyramine conjugate.
abstract: In the present study, injectable hydrogels based on gum tragacanth-tyramine conjugate were prepared by enzymatic oxidation of tyramine radicals in the presence of hydrogen peroxide. Then, in vitro release of bovine serum albumin and insulin as model protein drugs from this polymeric network was investigated. Also, to improve the properties of this hydrogel, a blended hydrogel composed of tyramine-conjugated gelatin and tyramine-conjugated tragacanth was prepared. Experimental results showed that the gelation time ranged from 3 to 28 s depending on the polymer and enzyme concentrations. Results of morphological investigation of hydrogels indicated that the average pore size of hydrogels varied from 120 to 160 µm. Swelling degree of hydrogels and the rate of drug release decreased by increasing of hydrogen peroxide and polymer concentrations. The release profile of drug from hydrogels followed Higuchi and Fickian diffusion mechanism. Finally, it was shown that the swelling characteristics and drug release behavior of this polymeric network could be improved by blending it with tyramine-conjugated gelatin.
authors.affiliation: Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, I.R. Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Dehghan-Niri
authors.affiliation: Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, I.R. Iran.
authors.forename: Moslem
authors.initials: M
authors.lastname: Tavakol
authors.affiliation: Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, I.R. Iran evf@modares.ac.ir.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Vasheghani-Farahani
authors.affiliation: Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, I.R. Iran.
authors.forename: Fariba
authors.initials: F
authors.lastname: Ganji
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000737:chemistry; D002417:Cattle; D004338:Drug Combinations; D016503:Drug Delivery Systems; D065546:Drug Liberation; D020100:Hydrogels / Q000008:administration & dosage / Q000737:chemistry; D066298:In Vitro Techniques; D007328:Insulin / Q000008:administration & dosage; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D012710:Serum Albumin, Bovine / Q000008:administration & dosage; D014144:Tragacanth / Q000008:administration & dosage* / Q000737:chemistry*; D014439:Tyramine / Q000008:administration & dosage* / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004338:Drug Combinations; D020100:Hydrogels; D007328:Insulin; D012710:Serum Albumin, Bovine; D014144:Tragacanth; D014439:Tyramine
keywords: Injectable hydrogels; bovine serum albumin; enzymatic gelation; gelatin; gum tragacanth; insulin; protein delivery