Embodiments of the invention can include or be used in conjunction with implantable medical devices and various in vitro applications. In an embodiment, an implantable medical device is included herein. The device can include a frame having an inner lumen the frame comprising a copolymer formed from monomers comprising N-isopropylacrylamide or a thermally responsive derivative thereof and a second monomeric species including one or more of a heteroatom or a charged moiety. In an embodiment, a method of isolating a component of a mixture is included herein. The method can include mixing a sample with a copolymer formed from monomers comprising N-isopropylacrylamide or a thermally responsive derivative thereof and a second monomeric species including one or more of a heteroatom or a charged moiety to form a reagent mixture, the copolymer further comprising a moiety exhibiting affinity for an analyte in the sample. The method can further include raising the temperature of the reagent mixture to high enough for the copolymer to form a hydrogel. Other embodiments are also included herein.
