New Insight into the Synthesis and Biological Activity of the Polymeric Materials Consisting of Folic Acid and β-Cyclodextrin.

This work presents a very new look at folate targeting and is focused on synthesizing and assessing the biological activity of folic acid-targeted drug delivery materials based on β-cyclodextrin. Both folic acid and β-cyclodextrin have been covalently conjugated to branched polyethylenimine as the polymeric vector. Host-guest inclusion of folic acid into a β-cyclodextrin cavity, demonstrated by means of the spectroscopic methods (2-D NMR, IR, UV-Vis), is found to be of crucial importance for biological activity of nanotherapeutics. This paper describes the very first example of the versatile synthetic approach to create the polymeric biosystems, where folic acid activity is not limited by the inclusion phenomenon. Cytotoxicity of the obtained polymeric materials against Lewis lung carcinoma cells is determined by neutral red uptake assay. Folate receptor-binding studies reveal that the developed synthetic approach enables full exploitation of the potential of folic acid as a targeting ligand.