Stimuli-triggered drug release

Ultrasound is an important local stimulus for triggering drug release at the target tissue. Ultrasound-responsive drug delivery systems have become an important research focus in targeted therapy. 

Bio-responsive release the system modulates drug release in response to a biological stimulus (e.g. blood glucose levels triggering the release of insulin from a dmg delivery device). 

Apart from these properties, the release kinetics can be manipulated in such a way that drug release occurs due to a trigger from an environmental stimulus like pH, temperature, etc. [88]. The thermoresponsive graft co-polymeric 5-FU-loaded nanoparticles made from chitosan-g-poly(A -vinylcaprolactam), prepared by an ionic crosslinking method, showed a lower critical solution temperature (LCST) at 38 C, with a prominent in vitro drug release above LCST [89]. Camptothecin-loaded polyfiV-isopropylacrylamide) (PNIPAAm)/chitosan nanoparticles were... 

Wong, A. D., Dewit, M. A. and Gillies, E. R. (2012). Amplified release through the stimulus triggered degradation of self-immolative oligomers, dendrimers, and linear polymers. Advanced Drug Delivery Reviews, 64,1031-1045. 

Figure 8.10 Redox and pH stimulus-based nanovehicles based on PU were reported. Doxorubicin was used as the anticancer drug triggered to be released near the tumor environment by acidic pH and GSH.

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