Novel water soluble phosphonium chitosan derivatives: synthesis, characterization and cytotoxicity studies

Novel water soluble phosphonium chitosan derivatives (WSPCSs) with two different degrees of substitution (3.6% and 4.2%) of quaternary phosphonium were synthesized in a homogeneous system at 25°C. The chemical structures of the WSPCS were characterized by (31)P NMR (nuclear magnetic resonance), (1)H NMR, FT-IR (Fourier-transformed infrared) spectroscopy and WAXD (wide-angle X-ray diffraction). Their solubility in water and several organic solvents and cytotoxicity to L929 cells were also evaluated. The degree of substitution (DS) of WSPCS was calculated by (1)H NMR. WAXD analysis showed that the derivatives had low crystallinity. The derivatives could be easily dissolved in water. MTT (methyl thiazolyl tetrazolium) assay indicated that they had low cytotoxicity to L929 cells.