Random copolymer hydrogels of methacrylic acid (MAA) and JV-isopropylacrylamide (NIPAAm) were synthesized by free-radical polymerization in the presence of a cross-linking agent. The gels were characterized for their temperature-and pH-responsive behavior by equilibrium swelling experiments, differential scanning calorimetry, and thermal mechanical analysis. Depending upon composition, the gels showed sharp swelling transitions with small changes in temperature or pH, with initial time-dependent response reaching equilibrium on a time scale of hours.
This paper reviews the design and development of magnetothermally-triggered drug delivery systems, whereby magnetic nanoparticles are combined with thermally-activated materials. By combining superparamagnetic nanoparticles with lower critical solution temperature (LCST) polymers, an alternating current (AC) magnetic field can be used to trigger localized heating in vivo, which in turn causes a phase change in the host polymer to allow diffusion and release of drugs. The use of magnetic nanoparticles for biomedical applications is reviewed, as well as the design of thermally-activated polymeric systems. Current research on externally-triggered delivery is highlighted, with a focus on the design and challenges in developing magnetothermally-activated systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.