Chitosan conjugation: a facile approach to enhance the cell viability of LaF3:Yb,Er upconverting nanotransducers in human breast cancer cells.

In this study, chitosan functionalized LaF3:Yb,Er upconverting nanotransducers (UCNTs) with controlled size and shape have been successfully synthesized by a facile one pot precipitation method. The chitosan encapsulated UCNTs show bright upconversion fluorescence upon excitation with 974 nm NIR region. The average crystallite size of UCNTs about 7.6 nm was achieved using chitosan mediated synthesis. The FTIR result confirms the chitosan coating over the LaF3:Yb,Er nanoparticles. Due to the surface modification using natural biopolymer chitosan, the as-prepared nanocrystals show excellent biocompatibility even at high dose at 200 µg/ml. To the best of our knowledge the presented work is the first report on in vitro analysis of chitosan conjugated LaF3:Yb,Er upconverting nanocrystals in human breast (MCF-7) cancer cells. These nanotransducers can be used as luminescent probes for bioimaging and deep tissue cancer therapeutic applications.

Synthesis of YF3: Yb, Er upconverting nanofluorophores using chitosan and their cytotoxicity in MCF-7 cells.

In this work, we described one pot hydrothermal synthesis of surface modified water soluble YF3: Yb, Er upconverting nanofluorophores (UCNFs) using natural biopolymer chitosan. The obtained nanocrystals have undergone X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) studies. The nanoparticles possess uniform particle size distribution with average size about 27 nm. The cytotoxicity results revealed that the chitosan capped nanoparticles exhibit excellent biocompatibility in human breast cancer cells. In conclusion, the water soluble chitosan capped YF3: Yb, Er nanoparticles could be used as a potential candidate in bio-imaging and therapeutic applications.