Antibacterial and Cytotoxic Activities of Copper-Functionalized Silsesquioxane 3-n-Propylpyridinium Chloride

Abstract

Abstract Silsesquioxane 3-n-propylpyridinium chloride (SiPy+Cl-) is a water-soluble polymer that can be used as a promising material with remarkable biological effects. SiPy+Cl- can form thin films on substrate surfaces and shows suitable adhesiveness. Besides, it has high affinity for metal ions. Considering this effect as exchanger polymer and the well-known antimicrobial and cytotoxic features of copper, the aim of this study was to perform the copper functionalization of silsesquioxane 3-n-propylpyridinium chloride Cu-SiPy+Cl-. The SiPy+Cl- was obtained by the sol-gel processing method and the incorporation of copper (II) chloride was carried out by immobilization. Its characterization was performed by spectroscopic methods of Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The FTIR spectrum of SiPy+Cl- showed symmetric and asymmetric stretching of Si-O-Si group and also exhibited vibrational bands of pyridinium ring. The FTIR spectrum of Cu-SiPy+Cl- assigned typical bands displacements of the metal coordination to nitrogen atoms. Spectroscopic data recorded by 13C and 29S NMR confirmed the chemical structures of SiPy+Cl- and Cu-SiPy+Cl-. Concerning to the in vitro susceptibility assay, the antimicrobial activity against Staphylococcus aureus, Escherichia coli and Streptococus mutans was achieved by the agar-well diffusion method. Cu-SiPy+Cl- showed similar cytotoxicity than SiPy+Cl- against Calu-3 and 3T3 cell lines by the MTT colorimetric assay. Further studies are required to investigate the use of Cu-SiPy+Cl- as a novel dental material.

Keywords

• antimicrobial activity
• cell viability
• copper functionalization
• novel dental materials.