title: Simultaneous mechanical loading and confocal reflection microscopy for three-dimensional microbiomechanical analysis of biomaterials and tissue constructs.
abstract: At present, mechanisms by which specific structural and mechanical properties of the three-dimensional extracellular matrix microenvironment influence cell behavior are not known. Lack of such knowledge precludes formulation of engineered scaffolds or tissue constructs that would deliver specific growth-inductive signals required for improved tissue restoration. This article describes a new mechanical loading-imaging technique that allows investigations of structural-mechanical properties of biomaterials as well as the structural-mechanical basis of cell-scaffold interactions at a microscopic level and in three dimensions. The technique is based upon the integration of a modified, miniature mechanical loading instrument with a confocal microscope. Confocal microscopy is conducted in a reflection and/or fluorescence mode for selective visualization of load-induced changes to the scaffold and any resident cells, while maintaining each specimen in a "live," fully hydrated state. This innovative technique offers several advantages over current biomechanics methodologies, including simultaneous visualization of scaffold and/or cell microstructure in three dimensions during mechanical loading; quantification of macroscopic mechanical parameters including true stress and strain; and the ability to perform multiple analyses on the same specimen. This technique was used to determine the structural-mechanical properties of three very different biological materials: a reconstituted collagen matrix, a tissue-derived biomaterial, and a tissue construct representing cells and matrix.
authors.affiliation: Department of Basic Medical Sciences, Purdue University, 1515 Hansen Hall, West Lafayette, IN 47907-1515, USA. voytik@ecn.purdue.edu
authors.forename: Sherry L
authors.initials: SL
authors.lastname: Voytik-Harbin
authors.forename: Blayne A
authors.initials: BA
authors.lastname: Roeder
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Sturgis
authors.forename: Klod
authors.initials: K
authors.lastname: Kokini
authors.forename: J Paul
authors.initials: JP
authors.lastname: Robinson
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002417:Cattle; D003094:Collagen / Q000502:physiology; D005109:Extracellular Matrix / Q000502:physiology; D007413:Intestinal Mucosa / Q000502:physiology; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D018613:Microscopy, Confocal / Q000295:instrumentation / Q000379:methods*; D034421:Sus scrofa; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D003094:Collagen