They are used for sensors and actuators such as artificial muscles, the production of hydrogels, biodegradable packaging, and to a great extent in biomedical engineering .
For example, Kubota et al designed and loaded ultrasound-responsive hydrogel microbeads with silica nanoparticles that were released under ultrasonic stimulation.
However, these weak responses, compounded hundreds or thousands of times, create a considerable force for driving biological processes.
Several homologous N-alkyl acrylamides also show LCST behavior, with the transition temperature depending on the length of the hydrophobic side chain.
Since the advent of timed-release pharmaceuticals, scientists have been faced with the problem of finding ways to deliver drugs to a particular site in the body without having them first degrade in the highly acidic stomach environment.
Researchers have devised ways to use smart polymers to control the release of drugs until the delivery system has reached the desired target.
Linear and matrix smart polymers exist with a variety of properties depending on reactive functional groups and side chains.
More recent developments have seen the formation of lattice-like matrices that hold the drug of interest integrated or entrapped between the polymer strands.
A combination of PAAc with another polymer that is less sensitive to changes at neutral pH might increase the residence time and slow the release of the drug, thus improving bioavailability and effectiveness.
Reversibly cross-linked polymer networks and hydrogels can be similarly applied to a biological system where the response and release of a drug are triggered by the target molecule itself.
Microscopic changes in the polymer structure are manifested as precipitate formation, which may be used to aid the separation of trapped proteins from solution.
This technique has been used to control ligand and cell binding activity, based on a variety of triggers including temperature and light.
The dressing design presents proprietary super-absorbent synthetic smart polymers immobilized in the 3-dimensional fiber matrix with added hydration functionality achieved by embedding hydrogel into the core of the material.
The dressing's mode of action relies on the ability of the polymers to sense and adapt to the changing humidity and fluid content in all areas of the wound simultaneously and to automatically and reversibly switch from absorption to hydration.
The smart polymer action ensures the active synchronized response of the dressing material to changes in and around the wound to support the optimal moist healing environment at all times.
It would be incredibly useful to have a system that turns on and off, and controls fertilizer concentrations, based on soil moisture, pH, and nutrient levels.
Many creative approaches to targeted drug delivery systems that self-regulate based on their unique cellular surroundings, are also under investigation.