Evaluation of Stimuli-Sensitive Nanoparticles in vitro

Nanoparticles are advantageous systems due to unique properties they present when they are used as drug delivery systems. One of the most intriguing approaches to obtain a desirable in vivo fate for nanoparticles is designing stimuli-responsive nanoparticles. Stimuli-responsive behavior can be obtained by using stimuli-responsive materials for forming of nanoparticles. Nanocarriers lead to some adverse effects, including uncontrollable drug release and biodistribution, because of some intracellular and extracellular barriers. In clinical use controlled-release nanosized drug delivery systems are present, but many of these controlled-release systems offer either constant or decreasing drug release and they are not sensitive to changes in the body that occur due to pathologies or external stimuli. Local abundance of enzymes at the tumor site is thought to provide drug release at the desired site, while in normal tissues low expression of enzymes is considered insufficient to cause drug release.