ABSTRACT
The field of drug delivery has focused on the use of polymers for controlling release and targeting of therapeutics. For years, research endeavors have concentrated mainly on the development of new degradable polymers for delivering proteins/peptides, DNA, and higher generation chemical drugs in an efficient and safe manner. Recent interest in biomaterials that show sharp changes in properties to small or modest changes in the environment have opened new methods to trigger the release of drugs and localize the therapeutic within a particular site. These novel polymers, usually termed “smart” or “intelligent,” are stimuli-responsive materials and could potentially elicit a therapeutically effective dose without adverse side effects. Smart polymers responding to different stimuli, such as pH, light, temperature, salt concentration, ultrasound, magnetism, or biomolecules, have been investigated. However, the possible environmental conditions, most applicable or limited to the biomedical application for drug delivery are pH and temperature, which makes these stimuli important among others. This entry describes “smart” drug delivery systems based on polymers or polymer combinations sensitive to either temperature or pH or both.
