Highly efficient functionalization of hydroxypropyl cellulose with glucuronic acid through click chemistry under microwave irradiation as potential biomaterial with therapeutic properties

Abstract

A straightforward and effective method to chemically conjugate hydroxypropyl cellulose (HPC) to GlcA is described via microwave assisted copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC) between the azide functionalized HPC and the alkynyl functionalized GlcA, reducing reaction times from 24 h to 2 h. Two types of HPC azide derivatives, including an ester (ES) or a carbamate (CB) functional group, were synthesized and characterized by FT-IR and NMR spectroscopy that revealed the efficiency in the incorporation of the azide moieties in the cellulose backbone. These compounds were then conjugated with the alkynyl GlcA by CuAAC, affording the desired glycopolymers, HPA-ES-GlcA and HPA-CB-GlcA in excellent yields. The whole process involved rapid and effective reactions as well as easy purification techniques, using mostly non-toxic solvents, contributing to the sustainability of the synthesis These glycopolymers were characterized by FT-IR, NMR, TGA, DTA and SEM. Furthermore, the cytotoxicity, anti-inflammatory and antibacterial properties of the new glycopolymers were tested and it was found that these new HPC-GlcA conjugates presented low cytotoxicity, good anti-inflammatory and antibacterial properties. Overall, our results showed that HPC-GlcA polymers are suitable as potential GAG mimics for biomedical applications, therefore further investigations will be carried out.