title: Oligomers modulate interfibril branching and mass transport properties of collagen matrices.
abstract: Mass transport within collagen-based matrices is critical to tissue development, repair, and pathogenesis, as well as the design of next-generation tissue engineering strategies. This work shows how collagen precursors, specified by intermolecular cross-link composition, provide independent control of collagen matrix mechanical and transport properties. Collagen matrices were prepared from tissue-extracted monomers or oligomers. Viscoelastic behavior was measured in oscillatory shear and unconfined compression. Matrix permeability and diffusivity were measured using gravity-driven permeametry and integrated optical imaging, respectively. Both collagen types showed an increase in stiffness and permeability hindrance with increasing collagen concentration (fibril density); however, different physical property–concentration relationships were noted. Diffusivity was not affected by concentration for either collagen type over the range tested. In general, oligomer matrices exhibited a substantial increase in stiffness and only a modest decrease in transport properties when compared with monomer matrices prepared at the same concentration. The observed differences in viscoelastic and transport properties were largely attributed to increased levels of interfibril branching within oligomer matrices. The ability to relate physical properties to relevant microstructure parameters, including fibril density and interfibril branching, is expected to advance the understanding of cell–matrix signaling, as well as facilitate model-based prediction and design of matrix-based therapeutic strategies.
authors.affiliation: Weldon School of Biomedical Engineering, College of Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Catherine F
authors.initials: CF
authors.lastname: Whittington
authors.forename: Eric
authors.initials: E
authors.lastname: Brandner
authors.forename: Ka Yaw
authors.initials: KY
authors.lastname: Teo
authors.forename: Bumsoo
authors.initials: B
authors.lastname: Han
authors.forename: Eric
authors.initials: E
authors.lastname: Nauman
authors.forename: Sherry L
authors.initials: SL
authors.lastname: Voytik-Harbin
mesh_terms: D000818:Animals; D001692:Biological Transport; D055598:Chemical Phenomena; D024042:Collagen Type I / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D004548:Elasticity; D010539:Permeability; D013552:Swine; D014783:Viscosity
chemical_list: D024042:Collagen Type I