Acoustic radiation enhanced drug delivery

Abstract

Drug development is one of the main concerns in cancer research. In recent years, lots of new drugs have been discovered in order to increase the e ciency of cancer treatment and enhance the quality of patient's life. However, anti-cancer drugs, which are e ective in laboratory experiments, may not give positive results when they are injected to humans. Because of the abnormal vasculature in tumor microenvironment, drug particles face with several physiological barriers preventing the transport of therapeutic agents homogeneously from the region of administration to the cells in solid tumors. Recent studies have revealed that drug response of a tumor cell is determined by its biological characteristics and its microenvironment regulation. The abnormalities in tumor vasculature result in uneven drug distribution and blood ow within solid tumors. Moreover, the leaky, tortuous and highly permeable tumor vessels and the lack of functional lymphatic vessels lead to the elevated interstitial uid pressure (IFP). The use of radiation force is for the enhancement of drug delivery is an emerging method. Experimental studies have shown that radiation force can manipulate delivery vehicles in the vasculature by changing their velocities and positions. In the light of these experiments, a mathematical model which associates the e ect of acoustic radiation force for the convective transport and the drug distribution in tumors is constructed. Governing equations in the model involve the principles for transvascular and interstitial drug transport as well as conservation laws.