External stimuli triggered systems

In most cases, the as-obtained nanocarriers can release the loaded biomolecules in response to only one kind of external stimulus, such as light, pH, or temperature, and realize a monoresponsive nanochannel. However, the sensitivity of these nanocarriers is not very efficient. Even for NIR-triggered phototherapy, the effective penetration depth of NIR light is still limited to no more than 1 cm and its sensitivity and accuracy to treat tumors located deep inside the body is thus limited. Therefore, delivery systems triggered by at least two different inputs have recently been considered by researchers. Generally, in order to get dual-responsive nanocarriers, two kinds of smart materials or one material with two functional groups must be included in the same NP. For example, two kinds of responsive materials, such as PAA and PNIPAm, can be simultaneously employed in the a pH- and... 

Ultrarapid conjugation reactions that may be triggered by some external stimulus (such as the addition of a catalyst or exposure to UV light) are highly desirable as it allows for exquisite reaction control in complex, multicomponent systems. One such reaction is the photoinducible 1,3-dipolar cycloaddition between 2,5-diaryl tetrazoles and alkenes (Figure 2.16). 

Time-Triggered Actions. In addition to explicit stimulus from exemal actors, a system may need to respond on its own to the passage of time. Model this also as an external input to the system, driven by a clock of arbitrarily precise frequency. Pick a suitable name for this action e g. end of day, or tick. For clarity, separately define named effects to specify what happens at that time e.g. clear outdated reservations. As always, you can have multiple specifications for the action. 

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