In recent years, advances in nanotechnology have made it possible to develop nanomedicines for biomedical applications. Nanomedicine, an offshoot of nanotechnology, refers to highly specific, molecular-scale medical intervention for treating diseases or repairing damaged tissues. In our research group, much effort has been devoted to developing a novel type of polymeric nanomedicine for therapy and diagnosis of obstinate diseases such as cancer, rheumatoid arthritis, diabetes, and atherosclerosis. Also, we are trying to prepare biocompatible polymers that can be used as the constituent of the biomedical devices. In an attempt to obtain the synergistic effects, our group is currently collaborating with many world-famous research groups regarding biomaterials, drug delivery system, and molecular imaging. In recent years, our research interests have been focused on stimuli-responsive nanomedicine, Immunotherapeutic nanomedicine, engineered exosomes, and living biotherapeutics.