title: Mutually reinforced multicomponent polysaccharide networks.
abstract: Networks made from chitosan and alginate have been utilized as prospective tissue engineering scaffolds due to material biocompatibility and degradability. Calcium (Ca(2+) ) is often added to these networks as a modifier for mechanical strength enhancement. In this work, we examined changes in the bulk material properties of different concentrations of chitosan/alginate mixtures (2, 3, or 5% w/w) upon adding another modifier, chondroitin. We further examined how material properties depend on the order the modifiers, Ca(2+) and chondroitin, were added. It was found that the addition of chondroitin significantly increased the mechanical strength of chitosan/alginate networks. Highest elastic moduli were obtained from samples made with mass fractions of 5% chitosan and alginate, modified by chondroitin first and then Ca(2+) . The elastic moduli in dry and hydrated states were (4.41 ± 0.52) MPa and (0.11 ± 0.01) MPa, respectively. Network porosity and density were slightly dependent on total polysaccharide concentration. Average pore size was slightly larger in samples modified by Ca(2+) first and then chondroitin and in samples made with 3% starting mass fractions. Here, small-angle neutron scattering (SANS) was utilized to examine mesh size of the fibrous networks, mass-fractal parameters and average dimensions of the fiber cross-sections prior to freeze-drying. These studies revealed that addition of Ca(2+) and chondroitin modifiers increased fiber compactness and thickness, respectively. Together these findings are consistent with improved network mechanical properties of the freeze-dried materials.
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Hyland
authors.forename: Marc B
authors.initials: MB
authors.lastname: Taraban
authors.forename: Boualem
authors.initials: B
authors.lastname: Hammouda
authors.forename: Y
authors.initials: Y
authors.lastname: Bruce Yu
mesh_terms: D000464:Alginates / Q000737:chemistry; D001672:Biocompatible Materials; D002118:Calcium / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D002807:Chondroitin / Q000737:chemistry; D019245:Compressive Strength; D004548:Elasticity; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D015233:Models, Statistical; D011134:Polysaccharides / Q000737:chemistry*; D016062:Porosity; D011312:Pressure; D053838:Scattering, Small Angle; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D006603:Hexuronic Acids; D011134:Polysaccharides; D020723:Glucuronic Acid; D002807:Chondroitin; D048271:Chitosan; D002118:Calcium