Enzyme-triggered drug delivery system

This drug design is already pointing to an enzyme-triggered drug delivery system. 

Enzyme-triggered release of bioactive molecules from a polymer based material is possibly the most intensely researched application for enzyme-responsive polymers. Such delivery systems typically employ vehicles such as micelles, solid particles and capsules to contain and protect a drug and deliver it to the site of action either by injection directly into the diseased tissue or by circulation through the blood stream. At the site of action, the enzyme will degrade the polymer, cause disassembly of the micelle or swell the particle and thus cause release of the drug into the environment. 

Dual-responsive polymer-based drug delivery vehicles offer even more versatility. Both temperature and enzyme-responsive micelles were formed from block polymers. While the thermoresponsive properties of the material allow it to be injected and subsequently form a reservoir in the body from where micelles enter the blood stream, the enzyme-responsive component allows triggered degradation of the micelles and release of the drug at the location of the diseased tissue (Garripelli et fl/.,2011). A doubly enzyme-responsive system can be obtained, for example, by designing polymer capsules with a shell that contains two layers. The two layers are degraded by different enzymes thus, proteins entrapped in the outer layer itself can be released upon exposure to the first enzyme, whereas the second enzyme destroys the capsule completely and liberates the proteins entrapped in the cavity of the vehicle (Itoh et al, 2008). 

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