Advances in studies on self-assembled nanoparticles and its application in drug carriers Synthesis of glycyrrhetinic acid-modified chitosan cligosaccharide-stearic acid drug carrier and its micellar properties Synthesis of glycyrrhetinic acid-modified chitosan oligosaccharide-stearic acid drug carrier and its micellar properties Application of functionalized graphene materials in biomedicine Application of functionalized graphene materials in biomedicine Application of polymer nanoparticles to antitumor drug delivery system