Supramolecular assembly is attracting a lot of attention as multifunctional nanoparticles can be prepared by using different constituents.In this study,a pH-sensitive supramolecular nanoparticle formed by host-guest interaction between cyclodextrin (CD) and a diblock hydrophilic copolymer mPEG-b-PCL-Ad (Fig.1).In order to achieve site-specific drug release,doxorubicin (DO)X) was modified by cell-penetrating peptide (RKKRRQRRRGD) and conjugated to β-CD via the acid-labile hydrazone bond [1].In accordance to the geometric compatibility,modified DOX could be encapsulated in the core of supramolecular assemblies by host-guest interaction between β-CD and terminal adamantyl group of PCL segment [2].Confocal microscopy studies confirmed efficient internalization of self-assemblies by tumor cells and release of DOX inside the tumor cells,indicating that these self-assemblies could be used as a promising drug carrier with cell targeting function.