title: Characterization and evaluation of silk protein hydrogels for drug delivery.
abstract: The objective of this study was to characterize and evaluate the physicochemical properties and drug release profiles of hydrogels composed of silk protein (SP) polymers. SPs with a low MW (SPL, ca. 18 kDa) and a high MW (SPH, ca. 76 kDa) were used for preparing hydrogels. Both the random coil form and beta-sheet conformation simultaneously existed in the hydrogels according to Fourier-transformed IR determination. Morphologically, the hydrogels showed a sponge-like cross-linked structure produced by physical entanglement as well as chemical hydrogen and covalent bindings. The in vitro buprenorphine delivery from SPH hydrogels showed a slow-release effect, and a zero-order rate was obtained for all preparations. Drug release could be controlled by varying the SPH concentrations or incorporation of SPL into the systems. SP hydrogels showed a stronger barrier property for hydrophilic solutes than for hydrophobic solutes. The incorporation of SPH into Pluronic F-127 (PF-127) hydrogels changed the gel structure from amorphous micelles to a regularly interconnected texture with pores. Furthermore, SPH as an adjuvant polymer in PF-127 and chitosan hydrogels lowered and controlled the amount of drug released from those systems.
authors.affiliation: Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Jia-You
authors.initials: JY
authors.lastname: Fang
authors.forename: Jyh-Ping
authors.initials: JP
authors.lastname: Chen
authors.forename: Yann-Lii
authors.initials: YL
authors.lastname: Leu
authors.forename: Hsin-Yuan
authors.initials: HY
authors.lastname: Wang
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D002627:Chemistry, Physical; D048271:Chitosan; D016503:Drug Delivery Systems; D005079:Excipients; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D020100:Hydrogels / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D009266:Nalbuphine / Q000008:administration & dosage; D020442:Poloxamer / Q000737:chemistry; D011355:Prodrugs; D047011:Silk / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014783:Viscosity
chemical_list: D000701:Analgesics, Opioid; D005079:Excipients; D005456:Fluorescent Dyes; D020100:Hydrogels; D011355:Prodrugs; D047011:Silk; D020442:Poloxamer; D048271:Chitosan; D016650:Fluorescein-5-isothiocyanate; D009266:Nalbuphine