Synthetic polymers offer the possibility to introduce biologically active moieties and to design tailor-made macromolecules with well-defined architectures and properties. The design of glycopolymeric materials with tailored properties has become a very important topic of interest in current chemistry, biology, and medicine.
The main reason behind this significance lies within their structure. A glycopolymer, by definition, consists of a synthetic polymeric backbone with covalently-linked, pendant carbohydrate moieties. The backbone may be composed of various monomeric units, in different arrangements. As a consequence, it provides the possibility to adjust the physical properties, such as water solubility of the final material.
The second building block of a glycopolymer consists of pendant sugar moieties which act as ligands for a broad spectrum of protein receptors that play an important role in different cell-surface interactions. Therefore, the structure of synthetic glycopolymers allows the precise modification of their material and biological features for special biomedical purposes.
Now, the research group around Ulrich Schubert (University of Jena) have demonstrated that poly(pentafluorostyrene)-based glycopolymers also possess the above-mentioned properties. By the introduction of hydrophobic polystyrene block into the backbone they can modify the water solubility of the system and obtain amphiphilic glycopolymers. These materials do not dissolve in aqueous environments. Under appropriate conditions they form nanoparticles with carbohydrates on the surface. By the introduction of glucose or galactose the recognition and uptake of these polymers by liver cancer cells is modified.
Fluorescence microscopy and flow cytometry show that nanoparticles are taken up by these cells to a higher degree than respective water soluble polymers, and that internalization of galactosylated materials is enhanced. These glycopolymers can find a multitude of potential applications in, for example, liver tumor-targeted chemotherapy, imaging, and as extracellular matrices for hepatocytes.