Ambient temperature synthesis of citrate stabilized and biofunctionalized, fluorescent calcium fluoridenanocrystals for targeted labeling of cancer cells

Abstract

Targeted biological contrast agents are emerging as promising candidates in the field of cancer theragnostics. Herein, we report an ambient temperature synthesis of a nanosized, antibody functionalized lanthanide doped CaF 2 biolabel and demonstrate in vitro its potential for cancer cell targeting efficacy and specificity. Monodispersed citrate stabilized lanthanide (Eu 3+ ) doped CaF 2 nanoparticles with size ∼25 nm, exhibiting strong fluorescent emission at 612 nm, were prepared using an aqueous wet chemical route at room temperature. Biofunctionalization of the fluorescent nanoparticles using an anti-EGFR antibody through EDC-NHS coupling chemistry enabled targeting of EGFR over-expressing cells. The nanobioconjugates showed preferential binding to EGFR +ve oral epithelial carcinoma cells (KB) and human epidermoid carcinoma cells (A431) with no accumulation onto EGFR −ve non-cancerous NIH 3T3 cells. The fluorescence was maintained after the bioconjugation as well as after attachment to the cancer cells, demonstrating their potential as targeted biolabels. Cytotoxicity evaluation with several cancerous (A431, KB) and non-cancerous (NIH 3T3, L929) cell lines revealed no toxicity at concentrations up to 1 mM. Thus, the fluorescence characteristics and biocompatibility, coupled with the molecular receptor targeting capability, suggest the potential use of CaF 2 in the field of bioimaging.

Enhanced stability of superparamagnetic iron oxide nanoparticles in biological media using a pH adjusted-BSA adsorption protocol

“…2A-c), indicating the existence of TMAOH on T-SPIONs. Peaks at 1570 cm -1 and 1450 cm -1 ( Fig. 2B-a) are characteristic of the RCO 2 symmetric and asymmetric stretches (Sasidharan et al 2013), though both peaks show a slight shift from 1579 cm -1 and 1415 cm -1 (Fig 2B-c), respectively, suggesting citrate ligand is present on the SPIONs surface. …”

Energy transfer in color-tunable water-dispersible Tb–Eu codoped CaF2 nanocrystals

“…9,10 The latter anion was also used by Sasidharan et al for downconverting CaF2:Eu 3+ nanoparticels, through a simple aqueous wet chemical route at room temperature. 11 More recently, Song et al obtained down-converting CaF2 nanoparticles (Ln 3+ = Eu, Tb, Ce/Tb) using PVP as a coating ligand, which also demonstrated to act as a sensitizer for the Tb 3+ ion. 12 Finally, Zhao et al used micro-wave assisted solvothermal synthesis using adenosine 5'-triphosphate disodium salt (ATP) as a functionalization agent to obtain up-converting CaF2:Yb 3+ /Er 3+ nanocrystals.…”

Apigenin mediated gold nanoparticle synthesis and their anti-cancer effect on human epidermoid carcinoma (A431) cells

“…[2][3][4] Therefore, there is a need to develop novel therapeutic agents which preferably target cancer cells leaving normal cells unaffected. [11][12][13] Applications in biomedicine are however limited when the capping and stabilizing agents used have toxic effects in biological systems. [5][6][7][8][9][10] AuNPs have been synthesized by reducing Au 3+ ions employing chemical reductants such as citrate, CTAB, etc., and the shape and size of the particles are tunable by adjusting the conditions employed.…”