Multiresponsive polymers: nano-sized assemblies, stimuli-sensitive gels and smart surfaces

The complex function of living systems is dictated by their inherent cooperative response to multiple external stimuli which induce dynamic changes in their physicochemical properties. Advances in the areas of nano-and bio-technology demand for the development of "smart" synthetic materials that would resemble the living systems in their complex behaviour as a response to applied stimuli. This reversible response directs the formation of hierarchical self-assemblies or stimulates changes in the volume, the shape or the surface characteristics of the system. Progress in this rapidly expanding area can lead to the development of dynamically multiresponsive constructs in the form of polymers, particles, gels or surfaces, for potential use in a wide range of applications such as drug delivery, tissue engineering, self-healing materials, bioseparations, sensors and actuators. This review highlights the recent advances in polymer chemistry to design multiresponsive polymeric materials that recognize independently or synergistically more than one stimulus exhibiting collective responses. Emerging developments, challenges and future trends in this exciting field are also discussed.