Recently, polymeric nanoparticles have attracted tremendous interests as a useful tool to encapsulate therapeutic drugs, genes, and proteins for their controlled and sustained delivery. Among them, polymeric hydrogel nanoparticles with thermal and/or pH responsiveness have attracted particular attention [1]. Trehalose, a non-reducing disaccharide of glucose, has been demonstrated to be a potent, nontoxic bioprotectant for stabilizing lipids, proteins, viruses, and blood cells at cryogenic and particularly, ambient temperatures (i.e., cryo and lyopreservation) [2]. However, intracellular delivery of trehalose into small eukaryotic mammalian cells in a large quantity for biostabilization purpose has not been very successful so far [2]. In this study, a thermally responsive polymeric nanocapsule was synthesized and characterized with the aim to encapsulate trehalose for its intracellular delivery.