title: Denatured collagen as support for a FGF-2 delivery system: physicochemical characterizations and in vitro release kinetics and bioactivity.
abstract: Collagen-based materials have scaffold properties to support bioactive molecules such as growth factor (GF). Gelatin, a denatured collagen, may have also some potential to interact with GF. An alternative process to denature collagen using trifluoroacetic acid (TFA) was investigated. Physicochemical characterization (XPS, DSC, isoelectric point, water uptake) of TFA-denatured collagen was comparable to regular gelatin, except a significant hydrophilicity and a pH sensitivity. FGF-2 was mixed with either regular gelatin or TFA-denatured collagen, then incorporated to a collagen sponge. Autoradiography revealed a relatively homogenous distribution of radiolabeled FGF-2 within the sponge. In vitro release kinetic of radiolabeled FGF-2 was investigated as well as the bioactivity of FGF-2 towards endothelial cell growth. The mixture was also sorbed to hydrogels made of ethylene vinyl acetate co-polymer and poly(2-hydroxyethyl methacrylate), and to cell culture insert membranes as control. Release of FGF-2 from collagen was progressive in the presence of TFA-denatured collagen, and cell growth was stimulated (significant peak at 8 and 10 days) by TFA-denatured collagen and FGF-2 eluted particularly from collagen sponges. Whereas control hydrogels, and those with regular gelatin showed a early stimulation of cell growth (1-5 days). Thus, the combination of both FGF-2 and an acid-denatured collagen in collagen sponges allows to sustain in vitro endothelial cell activity.
authors.affiliation: Oncology and Molecular Endocrinology Research Center, CHUL's Research Center, CHUQ, 2705 bou. Laurier Quebec, Québec, G1V 4G2 Canada.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Côté
authors.forename: Gaetan
authors.initials: G
authors.lastname: Laroche
authors.forename: Edith
authors.initials: E
authors.lastname: Gagnon
authors.forename: Pascale
authors.initials: P
authors.lastname: Chevallier
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Doillon
mesh_terms: D000042:Absorption; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000008:administration & dosage* / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects*; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage* / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D016062:Porosity; D011489:Protein Denaturation; D014867:Water / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D014867:Water; D016222:Fibroblast Growth Factor 2; D003094:Collagen