Targeted polyrotaxane PEG-PCL nanoparticles with enhanced folate exposition

. In the present work, targeted self-assembly polyrotaxane PEG-PCL micelles were prepared from a mixture of pure PEG-PCL copolymer with a folate-bearing PEG-PCL polyrotaxane. Supramolecular structures consisting in macrocycles as cyclodextrins (CDs) threaded on a linear polymer are called polyrotaxanes. We prepared a Fol-PEG1.5k-PCL4k copolymer in which the PEG segment is threaded with ?CD. Our approach is based on the hypothesis that polyrotaxane copolymer will form brush-like NPs, favoring Fol surface exposition. The polyrotaxane copolymer was synthesized with an original methodology, using simultaneously two different end-capping reactions to prevent ?CD dethreating from PEG chain. At our knowledge, this is the first example of realization of a polyrotaxane bearing different end-terminal caps.