Room: Exhibit Hall | Forum 8
Purpose: We are developing magnetic nanoparticle (NP) methods to characterize inflammation in vivo. Phagocytic activity is a primary function of inflammation and no methods of measuring it directly exit. We are developing NP methods to characterize phagocytic activity in vivo.
Methods: It has been shown that in vitro cell uptake of NPs can be measured remotely using the change in magnetic spectra produced by magnetic NPs in an alternating magnetic field. As the cell sequesters the NPs in vesicles, the rotational relaxation drops, i.e., the NPs cannot rotate in an external magnetic field as easily. We are extending the use of the method to in vivo phagocytic absorption of NPs to characterize inflammation. The phagocytic uptake and phagocytic clearance were characterized by changes in the relaxation time and changes in relaxation adjusted NP signal. The confounding factor that is not isolated from the other effects is the temperature of the mouse which presumably will increase with infection. A mouse model with peritoneal infection was compared to uninfected mice representing mice with and without inflammation. Two groups of three mice were studied. For each group, two infected female mice were compared to an uninfected female mouse.
Results: For infected mice (high inflammation) the relaxation time increased less slowly and the relaxation adjusted NP signal decreased less slowly than for the control mice with low inflammation.
Conclusion: The NP signal can be used to identify inflammation. More experiments are required to isolate the effects of phagocytic absorption, edema and temperature on the NP signal progression during inflammation.
Not Applicable / None Entered.