title: Mathematical modeling of uniaxial mechanical properties of collagen gel scaffolds for vascular tissue engineering.
abstract: Small diameter tissue-engineered arteries improve their mechanical and functional properties when they are mechanically stimulated. Applying a suitable stress and/or strain with or without a cycle to the scaffolds and cells during the culturing process resides in our ability to generate a suitable mechanical model. Collagen gel is one of the most used scaffolds in vascular tissue engineering, mainly because it is the principal constituent of the extracellular matrix for vascular cells in human. The mechanical modeling of such a material is not a trivial task, mainly for its viscoelastic nature. Computational and experimental methods for developing a suitable model for collagen gels are of primary importance for the field. In this research, we focused on mechanical properties of collagen gels under unconfined compression. First, mechanical viscoelastic models are discussed and framed in the control system theory. Second, models are fitted using system identification. Several models are evaluated and two nonlinear models are proposed: Mooney-Rivlin inspired and Hammerstein models. The results suggest that Mooney-Rivlin and Hammerstein models succeed in describing the mechanical behavior of collagen gels for cyclic tests on scaffolds (with best fitting parameters 58.3% and 75.8%, resp.). When Akaike criterion is used, the best is the Mooney-Rivlin inspired model.
authors.affiliation: Instituto de Física de Líquidos y Sistemas Biológicos, CONICET-CCT La Plata, B1900BTE La Plata, Buenos Aires, Argentina ; Instituto de Ingeniería y Agronomía, Universidad Nacional Arturo Jauretche, 1888 Florencio Varela, Buenos Aires, Argentina.
authors.forename: Ramiro M
authors.initials: RM
authors.lastname: Irastorza
authors.affiliation: Laboratory for Biomaterials and Bioengineering, Canada Research Chair I, Laval University, Quebec City, QC, Canada G1V 0A6.
authors.forename: Bernard
authors.initials: B
authors.lastname: Drouin
authors.affiliation: Laboratorio de Biomecánica, Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Buenos Aires, C1063ACV Buenos Aires, Argentina.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Blangino
authors.affiliation: Laboratory for Biomaterials and Bioengineering, Canada Research Chair I, Laval University, Quebec City, QC, Canada G1V 0A6.
authors.forename: Diego
authors.initials: D
authors.lastname: Mantovani
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000166:cytology*; D003094:Collagen / Q000737:chemistry*; D005782:Gels; D008962:Models, Theoretical; D051381:Rats; D023822:Tissue Engineering
chemical_list: D005782:Gels; D003094:Collagen
references.citation: Crit Rev Biomed Eng. 2001;29(3):279-301
references.pmid: 11730097
references.citation: Med Eng Phys. 2012 Apr;34(3):269-78
references.pmid: 22133487
references.citation: Ann Biomed Eng. 2003 Nov;31(10):1287-96
references.pmid: 14649502
references.citation: Proc Natl Acad Sci U S A. 2010 Feb 23;107(8):3335-9
references.pmid: 19955446
references.citation: J Biomech Eng. 2004 Apr;126(2):152-66
references.pmid: 15179845
references.citation: Acta Biomater. 2014 Apr;10(4):1488-501
references.pmid: 24012608
references.citation: J Biomech Eng. 2009 Oct;131(10):101016
references.pmid: 19831486
references.citation: Nat Protoc. 2006;1(6):2753-8
references.pmid: 17406532
references.citation: J Biomech. 2007;40(14):3070-8
references.pmid: 17499254
references.citation: Int J Biomater. 2012;2012:319290
references.pmid: 22844285
references.citation: J Biomed Mater Res B Appl Biomater. 2004 Nov 15;71(2):343-54
references.pmid: 15386396