TY - JOUR
T1 - Oligomers modulate interfibril branching and mass transport properties of collagen matrices
AU - Whittington, Catherine F.
AU - Brandner, Eric
AU - Teo, Ka Yaw
AU - Han, Bumsoo
AU - Nauman, Eric
AU - Voytik-Harbin, Sherry L.
PY - 2013/10
Y1 - 2013/10
N2 - 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.
AB - 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.
KW - collagen matrix
KW - diffusivity
KW - mass transport
KW - monomer
KW - oligomer
KW - permeability
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U2 - 10.1017/S1431927613001931
DO - 10.1017/S1431927613001931
M3 - Article
C2 - 23842082
AN - SCOPUS:84884544650
SN - 1431-9276
VL - 19
SP - 1323
EP - 1333
JO - Microscopy and Microanalysis
JF - Microscopy and Microanalysis
IS - 5
ER -