Chondroitin sulfate-g-poly(ϵ-caprolactone) co-polymer aggregates as potential targeting drug carriers

The aim of this study is to delineate the effect of various amounts of hydrophobic polycaprolactone (PCL) grafted onto three different degrees of methacrylated chondroitin sulfate (CSMA) on chemical-physical properties. The co-polymers were prepared by reacting the modified PCL and the hydrophilic CSMA via a radical reaction (CSMA-PCL). The effect of degree of methacrylation of CSMA and feed ratio between CSMA and PCL on compositions and critical micelle concentrations was systematically studied. The PCL composition of the CSMA-PCL was characterized by (1)H-NMR and FT-IR. The hydrodynamic diameters and morphologies of CSMA-PCL micelles were studied by DLS and TEM. Critical micelle concentrations were determined using pyrene as a probe. Taking one of the CSMA-PCL micelles as an example, a cancer-mediated ligand, folic acid, was linked to the surface. The cellular uptake of the folic acid-linked CSMA-PCL in folate-receptor-overexpressing KB cells was studied by confocal laser scanning microscopy and flow cytometry.