Introduction: Hyaluronan (HA), a natural polysaccharide, is produced in large amounts by the human body. Since its receptor CD44 is highly expressed in many types of cancers, HA is a promising ligand for cancer-targeting nanoparticles (NPs). Since the enhanced permeability and retention (EPR) effect-based strategy faces difficulties in terms of efficiency in clinical studies, studies focusing on HA-modified NPs that can actively target cancer cells should be prominent for further progress in NP-based cancer treatment. Areas covered: Various materials combined with HA composed of lipid nanoparticles and polymers as well as iron, gold and other metals have been examined. In addition, their cargos have been quite diverse and include small molecule drugs, imaging agents, proteins and nucleic acids. We summarize recent studies on varieties of NPs and describe the properties of HA as a ligand of CD44. Expert opinion: In spite of a number of studies on HA-based NPs, there is few examples of HA-based NPs in clinical. In order to make a progress in clinical study, an evaluation methodology of HA-NPs should be unified and normalized.
Keywords: CD44; Nanoparticles; hyaluronan; inorganic; lipid nanoparticles; polymer.