TY - GEN
T1 - A multi-phasic, continuum damage mechanics model of mechanically induced increased permeability in tissues
AU - O'Neill, Brian E.
AU - Quinn, Timothy P.
AU - Frenkel, Victor
AU - Li, King C.P.
PY - 2005
Y1 - 2005
N2 - Recently, we have reported enhanced permeability of tissues due to in vivo treatment with pulsed high intensity focused ultrasound (pHIFU). This new therapy has shown promise as a way of increasing the penetration of large drug molecules, both out of the vasculature and through the tissue. To date, no clear physical model of tissue exists that can account for these effects. A new model is proposed that clearly establishes the link between tissue structure and fluid flow properties on one hand, and the history of applied mechanical forces on the other. The model draws inspiration from two different theoretical fields of materials science, multi-phase theory and continuum damage mechanics. The theory differs from the traditional bi-phasic solid-fluid model of tissues in that the fluid part here is broken into trapped (moving with the solid) and free (moving through the solid) parts. A damage-like variable links the effective elasticity of the tissue to the ratio of the trapped to free fluids. As the damage increases, the tissue becomes, in effect, less stiff and more permeable. Release of elastic energy drives the process. A distribution of energy barriers opposes the process and governs how the fluid is released as damage increases.
AB - Recently, we have reported enhanced permeability of tissues due to in vivo treatment with pulsed high intensity focused ultrasound (pHIFU). This new therapy has shown promise as a way of increasing the penetration of large drug molecules, both out of the vasculature and through the tissue. To date, no clear physical model of tissue exists that can account for these effects. A new model is proposed that clearly establishes the link between tissue structure and fluid flow properties on one hand, and the history of applied mechanical forces on the other. The model draws inspiration from two different theoretical fields of materials science, multi-phase theory and continuum damage mechanics. The theory differs from the traditional bi-phasic solid-fluid model of tissues in that the fluid part here is broken into trapped (moving with the solid) and free (moving through the solid) parts. A damage-like variable links the effective elasticity of the tissue to the ratio of the trapped to free fluids. As the damage increases, the tissue becomes, in effect, less stiff and more permeable. Release of elastic energy drives the process. A distribution of energy barriers opposes the process and governs how the fluid is released as damage increases.
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U2 - 10.1557/proc-0898-l02-05
DO - 10.1557/proc-0898-l02-05
M3 - Conference contribution
AN - SCOPUS:34250010004
SN - 1558998535
SN - 9781558998537
T3 - Materials Research Society Symposium Proceedings
SP - 13
EP - 18
BT - Mechanical Behavior of Biological and Biomimetic Materials
PB - Materials Research Society
T2 - 2005 MRS Fall Meeting
Y2 - 28 November 2005 through 2 December 2005
ER -