title: Incorporation of proteins within alginate fibre-based scaffolds using a post-fabrication entrapment method.
abstract: In this study, a physical entrapment process was explored for the incorporation of proteins within preformed fibrous alginates and the release profile was tuned by varying the processing parameters. The entrapment process was carried out in a series of aqueous solutions at room temperature and involved pre-swelling of the fibrous alginate within a Na(+)-rich solution, followed by exposure to the protein of choice and entrapping it by re-establishing cross-links of alginate with BaCl2. Entrapment and release of fluorescein isothiocyanate-labelled bovine serum albumin (FITC-BSA), a model protein, was studied. It was found that a sustained release of the incorporated protein in cell culture medium for about 6 days was achieved. The main factors determining the release profile included the NaCl/CaCl2 ratio in the pre-swelling solution, protein concentration, and the exposure time. To retard protein release, alginate fibres with entrapped FITC-BSA were processed together with poly(D, L-lactide) (PDLLA) into porous alginate fibre/PDLLA composites using supercritical CO2. In this manner, release of the protein for up to 3 months was achieved.
authors.affiliation: Division of Drug Delivery and Tissue Engineering, School of Pharmacy, The University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
authors.forename: Qingpu
authors.initials: Q
authors.lastname: Hou
authors.forename: Maria C
authors.initials: MC
authors.lastname: Walsh
authors.forename: Richard
authors.initials: R
authors.lastname: Freeman
authors.forename: John J A
authors.initials: JJ
authors.lastname: Barry
authors.forename: Steven M
authors.initials: SM
authors.lastname: Howdle
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Shakesheff
mesh_terms: D016475:3T3 Cells; D000464:Alginates / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D005347:Fibroblasts / Q000187:drug effects; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D051379:Mice; D016062:Porosity; D012259:Ribonuclease, Pancreatic / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D005456:Fluorescent Dyes; D012710:Serum Albumin, Bovine; D012259:Ribonuclease, Pancreatic; D016650:Fluorescein-5-isothiocyanate