The development of sensitive molecular nanostructures with well-defined particle architecture is of interest in biomedical applications as drug delivery, pH-sensors and imaging agents. Special interest has been devoted to nanogels (NGs) which are water soluble high molecular weight cross-linked polymers particles in the useful size range between 20 and 350 nm.
Stimuli-sensitive NGs are polymeric particles that can respond to local environmental conditions. They can shrink or swell rapidly by expelling or absorbing water in response to external stimuli such as temperature, pH, electrical and magnetic fields.
In this work, precipitation polymerization was used as a convenient synthetic methodology to yield thermosensitive NGs based on poly (N-isopropylacrylamide) (PNIPAm) and hyperbranched polyglycerol (HPG). HPG was incorporated to enhance the water solubility and biocompatibility of the NGs as well as to tune the thermoresponsive profile as a function of the NG size in the solution.