Molecular nanoworm with PCL core and PEO shell as a non-spherical carrier for drug delivery

Core/shell wormlike polymer brushes with densely grafted poly(Ïμ-caprolactone)-b-poly(ethylene oxide) (PCL-b-PEO) are synthesized via grafting an alkynyl terminated PCL-b-PEO (ay-PCL₁₇-b-PEO ₁₁₃) onto a well-defined azido functionalized polymethacrylate (PGA₉₄₀) and are evaluated preliminarily as a single molecular cylindrical vehicle for drug delivery. Water soluble molecular worms of ca. 230 nm are obtained and then the anticancer drug doxorubicin (DOX) is loaded into its PCL core by hydrophobic interaction. Compared with spherical micelles from linear PCL₁₇-b-PEO₁₁₃, the brushes demonstrate a lower loading efficiency but a faster release rate of DOX. Confocal laser scanning microscopy measurements show that DOX-loaded cylindrical molecular brushes can easily enter into HeLa and HepG2 cells in 1 h. Poly(Ïμ-caprolactone)-b- poly(ethylene oxide)s are densely grafted along a polymer with a high degree of polymerization and water soluble molecular worms with a structure of PCL core and PEO shell are obtained. This well-defined molecular worm with an average length of 230 nm is evaluated as a vehicle to deliver doxorubicin.