title: Biodegradable hydrogels for time-controlled release of tethered peptides or proteins.
abstract: Tethering drug substances to a gel network is an effective way of controlling the release kinetics of hydrogel-based drug delivery systems. Here, we report on in situ forming, biodegradable hydrogels that allow for the covalent attachment of peptides or proteins. Hydrogels were prepared by step-growth polymerization of branched poly(ethylene glycol). The gel strength ranged from 1075 to 2435 Pa; the degradation time varied between 24 and 120 h. Fluorescence recovery after photobleaching showed that fluorescently labeled bovine serum albumin (FITC-BSA) was successfully bound to the gel network during gel formation. Within 168 h, the mobility of the tethered molecules gradually increased due to polymer degradation. Using FITC-BSA and lysozyme as model proteins, we showed the potential of the developed hydrogels for time-controlled release. The obtained release profiles had a sigmoidal shape and matched the degradation profile very well; protein release was complete after 96 h.
authors.affiliation: Department of Pharmaceutical Technology, University of Regensburg, Germany.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Brandl
authors.forename: Nadine
authors.initials: N
authors.lastname: Hammer
authors.forename: Torsten
authors.initials: T
authors.lastname: Blunk
authors.forename: Joerg
authors.initials: J
authors.lastname: Tessmar
authors.forename: Achim
authors.initials: A
authors.lastname: Goepferich
mesh_terms: D000818:Animals; D001711:Biotransformation; D002417:Cattle; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D020100:Hydrogels / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009113:Muramidase / Q000008:administration & dosage / Q000493:pharmacokinetics; D010455:Peptides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011506:Proteins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012710:Serum Albumin, Bovine / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D003692:Delayed-Action Preparations; D020100:Hydrogels; D010455:Peptides; D011506:Proteins; C039217:fluorescein isothiocyanate bovine serum albumin; D012710:Serum Albumin, Bovine; D009113:Muramidase; D016650:Fluorescein-5-isothiocyanate