John B. Weaver1, Adam M. Rauwerdink2
1Radiology, Dartmouth-Hitchcock Medical
Center, Lebanon, NH, United States; 2Thayer School of Engineering,
Dartmouth College, Hanover, NH, United States
The
microscopic stiffness of cellular cytoskeleton and the extracellular matrix
have been very important in understanding metastasis and angiogenesis but no
methods capable of in vivo measurement exist.
We show that a new method related to magnetic particle imaging (MPI)
called magnetic spectroscopy of nanoparticle Brownian motion (MSB) is
sensitive to the stiffness of the microscopic environment surrounding the
binding sites of the streptavidin functionalized nanoparticles. The matrix consisted of gels made with
mixtures of gelatin and biotinated BSA.
Gel stiffness was changed by varying the concentration of
gelatin. MSB showed significant
differences between each of the gels.