Hydrogel nanocomposites, involving the incorporation of nanoparticles into hydrogel matrices, have been recently investigated owing to their ability to improve the properties of conventional hydrogels. These improvements may include increased mechanical strength, the ability to be remotely-controlled via external stimuli such as light or magnetic fields, or more finely tunable swelling characteristics. These improved hydrogel systems can provide the necessary characteristics to allow them to be utilized in a wide variety of biomedical applications such as bone tissue engineering, drug delivery, hyperthermia treatment, and biosensors. In this work, the systems studied involved a temperature-responsive hydrogel of N-isopropylacrylamide crosslinked with tetra(ethylene glycol) dimethacrylate both with iron oxide magnetic nanoparticles incorporated into the hydrogel matrices. The addition of iron oxide nanoparticles allows for the nanocomposite temperature to be controlled through the heating of the superparamagnetic nanoparticles via an alternating magnetic field. An important step in utilizing hydrogel nanocomposites in biomedical applications is ensuring the biocompatibility of the materials. Cytocompatibility analysis has been performed on magnetic hydrogel nanocomposites and they have the potential to be used for implant applications. Specifically, they have minimal effect on murine fibroblasts when in direct and indirect contact with the cells. In addition to these results, swelling and heat studies have been performed.