Biodegradable and thermo-sensitive chitosan-g-poly(N-vinylcaprolactam) nanoparticles as a 5-fluorouracil carrier

We developed a nanoformulation of 5-FU (5-fluorouracil) with biodegradable thermo-responsive chitosan-g-poly(N-vinylcaprolactam) biopolymer composite for its delivery to cancer cells. The novel thermo-responsive graft co-polymeric nanoparticles (TRC-NPs) were prepared by ionic cross-linking method, which showed a lower critical solution temperature (LCST) at 38 °C. The 5-FU drug was incorporated into the carrier using cross-linking reaction. The in vitro drug release showed prominent release above LCST. Cytotoxicity assay showed TRC-NPs in the concentration range of 100–1000 μg/ml are non-toxic to an array of cell lines. The drug-loaded nanoparticles showed comparatively higher toxicity to cancer cells while they are less toxic to normal cells. The cell uptake of the 5-FU loaded thermo-responsive graft co-polymeric nanoparticles (5-FU–TRC-NPs) was confirmed from green fluorescence inside cells by rhodamine-123 conjugation. The apoptosis assay showed increased apoptosis of cancer cells when treated with 5-FU compared to the normal cells. These results indicated that novel 5-FU–TRC-NPs could be a promising candidate for cancer drug delivery.