title: In vitro assessment of three dimensional dense chitosan-based structures to be used as bioabsorbable implants.
abstract: Chitosan biocompatibility and biodegradability properties make this biopolymer promising for the development of advanced internal fixation devices for orthopedic applications. This work presents a detailed study on the production and characterization of three dimensional (3D) dense, non-porous, chitosan-based structures, with the ability to be processed in different shapes, and also with high strength and stiffness. Such features are crucial for the application of such 3D structures as bioabsorbable implantable devices. The influence of chitosan's molecular weight and the addition of one plasticizer (glycerol) on 3D dense chitosan-based products' biomechanical properties were explored. Several specimens were produced and in vitro studies were performed in order to assess the cytotoxicity of these specimens and their physical behavior throughout the enzymatic degradation experiments. The results point out that glycerol does not impact on cytotoxicity and has a high impact in improving mechanical properties, both elasticity and compressive strength. In addition, human mesenchymal stem/stromal cells (MSC) were used as an ex-vivo model to study cell adhesion and proliferation on these structures, showing promising results with fold increase values in total cell number similar to the ones obtained in standard cell culture flasks.
authors.affiliation: ICEMS, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Altakitin S.A., Rua José Gomes Ferreira, Arm. D, 2660-360 São Julião do Tojal, Lisboa, Portugal; MIT Portugal Program, IST-Tagus Park, Av. Professor Cavaco Silva, 2744-016 Porto Salvo, Portugal. Electronic address: nguitian@mit.edu.
authors.forename: Nuno
authors.initials: N
authors.lastname: Guitian Oliveira
authors.affiliation: Department of Bioengineering and IBB-Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Sirgado
authors.affiliation: ICEMS, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Reis
authors.affiliation: Altakitin S.A., Rua José Gomes Ferreira, Arm. D, 2660-360 São Julião do Tojal, Lisboa, Portugal; CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia FCT, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal.
authors.forename: Luís F V
authors.initials: LFV
authors.lastname: Pinto
authors.affiliation: MIT Portugal Program, IST-Tagus Park, Av. Professor Cavaco Silva, 2744-016 Porto Salvo, Portugal; Department of Bioengineering and IBB-Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors.forename: Cláudia Lobato
authors.initials: CL
authors.lastname: da Silva
authors.affiliation: MIT Portugal Program, IST-Tagus Park, Av. Professor Cavaco Silva, 2744-016 Porto Salvo, Portugal; Department of Bioengineering and IBB-Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors.forename: Frederico Castelo
authors.initials: FC
authors.lastname: Ferreira
authors.affiliation: ICEMS, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; GI-MOSM, Instituto Superior de Engenharia de Lisboa, ISEL, Rua Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rodrigues
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry*; D002448:Cell Adhesion; D049109:Cell Proliferation; D048271:Chitosan / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D048271:Chitosan
keywords: Bioabsorbable implants; Chitosan; Cytotoxicity; Enzymatic degradation; Glycerol; Mechanical properties