Melt-based Compression Moulded Scaffolds from Chitosan-Polyester Blends and Composites: Morphology and Mechanical Properties

last updated: 2014-12-10
TitleMelt-based Compression Moulded Scaffolds from Chitosan-Polyester Blends and Composites: Morphology and Mechanical Properties
Publication TypePapers in Scientific Journals
Year of Publication2008
AuthorsCorrelo V. M., Boesel L. F., Pinho E. D., Costa-Pinto A. R., Alves da Silva, ML, Bhattacharya M., Mano J. F., Neves N. M., and Reis R. L.

Blends of chitosan and synthetic aliphatic poly- esters (polybutylene succinate, polybutylene succinate adi- pate, polycaprolactone, and polybutylene terepthalate adi- pate) were compounded with and without hydroxyapatite, a bioactive mineral filler known to enhance osteoconduc- tion. The blends and composites were compression molded with two different granulometric salt sizes (63–125 lm and 250–500 lm) having different levels of salt content (60, 70, and 80%) by weight. By leaching the salt particles, it was possible to produce porous scaffolds with distinct morphol- ogies. The relationship between scaffold morphology and mechanical properties was evaluated using scanning elec- tron microscopy, microcomputed tomography, compression testing, differential scanning calorimetry, small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering. The pro- duced scaffolds are characterized by having different mor- phologies depending on the average particle size and the amount of NaCl used. Specimens with higher porosity level have a less organized pore structure but increased intercon-

nectivity of the pores. The stress–strain curve under com- pression displayed a linear elasticity followed by a plateau whose characteristics depend on the scaffold polymer com- position. A decrease in the salt particle size used to create the porosity caused in general a decrease in the mechanical properties of the foams. Composites with hydroxyapatite had a sharp reduction in yield stress, modulus, and strain at break. The melting temperature decreased with increased chitosan content. SAXS results indicate no preferential crys- talline orientation in the scaffolds. Cytotoxicity evaluation were carried out using standard tests (accordingly to ISO/ EN 10993 part 5 guidelines), namely MTS test with a 24-h extraction period, revealing that L929 cells had comparable metabolic activities to that obtained for the negative control.

JournalJournal of Biomedical Materials Research: Part A.
Date Published2008-01-17
Keywordsbiodegradable blends, Chitosan, poly-esters, scaffolds, Tissue engineering
Peer reviewedyes

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