title: Fabrication of porous polysaccharide-based scaffolds using a combined freeze-drying/cross-linking process.
abstract: Biocompatible three-dimensional (3-D) porous scaffolds are of great interest for tissue engineering applications. We here present a novel combined freeze-drying/cross-linking process to prepare porous polysaccharide-based scaffolds. This process does not require an organic solvent or porogen agent. We unexpectedly found that cross-linking of biomacromolecules such as pullulan and dextran with sodium trimetaphosphate could be performed during freeze-drying. We have demonstrated that the freeze-drying pressure modulates the degree of porosity. High freeze-drying pressure scaffolds presented pores with a mean diameter of 55 +/- 4 microm and a porosity of 33 +/- 12%, whereas low freeze-drying pressure scaffolds contained larger pores with a mean diameter of 243 +/- 14 microm and a porosity of 68 +/- 3%. Porous scaffolds of the desired shape could be easily obtained and were stable in culture medium for weeks. In vitro viable mesenchymal stem cells were found associated with porous scaffolds in higher proportions than with non-porous scaffolds. Moreover, cells penetrated deeper into scaffolds with larger pores. This novel combined freeze-drying/cross-linking processing of polysaccharides enabled the fabrication of biocompatible scaffolds with controlled porosity and architectures suitable for 3-D in vitro culture and biomedical applications.
authors.affiliation: INSERM, U698, Bio-ingénierie Cardiovasculaire, Hôpital Bichat, 46 Rue H. Huchard, F-75877 Paris Cedex 18, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Autissier
authors.forename: Catherine
authors.initials: C
authors.lastname: Le Visage
authors.forename: Cécile
authors.initials: C
authors.lastname: Pouzet
authors.forename: Frédéric
authors.initials: F
authors.lastname: Chaubet
authors.forename: Didier
authors.initials: D
authors.lastname: Letourneur
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005612:Freeze Drying / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D011134:Polysaccharides / Q000494:pharmacology*; D016062:Porosity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D054457:Tissue Scaffolds / Q000737:chemistry*; D014618:Vacuum; D014867:Water / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D005456:Fluorescent Dyes; D011134:Polysaccharides; D014867:Water; D016650:Fluorescein-5-isothiocyanate