Magneto-rheologiacal Fluid (MRF), suspensions of polarizable micron size particles, is synthesized from suspensions of iron particles (micron and nano size) in phosphate buffered saline (PBS). The iron particles have been surface coated using atom transfer radical polymerization (ATRP) with various polymers, such as poly(N-isopropylacrylamide) (poly(NIPAAm)), and poly(acrylamide) (poly(AAm)). The surface grafted polymer has been characterized using differential scanning calorimetry (DSC), and properties of resulting fluid have been measured using a rheometer.
A mathematical model is developed to explore the force induced by the particles on the neighboring tissue under externally applied magnetic field. This force results in the damage of the tumor cell lines and trigger the immune system response.
The effect of MRF on primary and metastasized tumor growth were evaluated by using an orthotopic murine breast cancer model (4T1). Tumors were evaluated by growth measurements and histological changes following injection of MRF or carrier fluid alone into the tumor and the effects of subsequent application of a magnetic field to the site. Results indicate slowed tumor growth and increased dendritic cell activation with this therapy and they are encouraging.