Differential effects of amino acid surface decoration on the anticancer efficacy of selenium nanoparticles

Abstract

The use of selenium for anticancer therapy has been heavily explored during the last decade. Amino acids (AAs) play central roles both as building blocks of proteins and intermediates in metabolism. In the present study, AAs-modified selenium nanoparticles (SeNPs@AAs) have been successfully synthesized in a simple redox system. Typical neutral (valine), acidic (aspartic acid) and basic (lysine) amino acids were used to decorate SeNPs, and the stable and homodisperse nanoparticles were characterized by zeta potential and transmission electron microscope. The result of X-ray photoelectron spectra (XPS) showed that the interaction of -NH3(+) groups of the amino acids with negative-charged SeNPs could be a driving force for dispersion of the nanoparticles. The screening of in vitro anticancer activities demonstrated that SeNPs@AAs exhibited differential growth inhibitory effects on various human cancer cell lines. Among them, SeNPs decorated by Lys displayed higher anticancer efficacy than those of valine and aspartic acid. The studies on the in vitro cellular uptake mechanisms revealed that SeNPs@AAs were internalized by cancer cells through endocytosis. Flow cytometric analysis and the determination of caspase activity indicated that treatment of the MCF-7 breast adenocarcinoma cells with SeNPs@AAs led to a dose-dependent increase in apoptosis. Moreover, it was found that SeNPs@AAs-induced ROS overproduction could be the upstream signal of caspase activation and mitochondrial dysfunction in cancer cells. Taken together, our results suggest that these amino acid biocompatible nanoparticles might have potential application as chemopreventive and chemotherapeutic agents for human cancers.

Preparation and antioxidant properties of selenium nanoparticles-loaded chitosan microspheres

“…15,25,39 It was why the fresh CTS-SeNPs were able to remain very stable. However, the zeta potential decreased from 40.8 mV at the initial day to 18.4 mV at the 28th day ( Figure 2F), indicating that CTS-SeNPs become more unstable during storage.…”

“…This was consistent with some previous studies reporting that two chemical states of nitrogen could be observed by N 1s XPS. 25 Finally, XRD was conducted to analyze the amorphous/ crystalline nature of SeNPs. Typical XRD peaks of crystal Se were found in the XRD patterns of SeNPs-M, while Blank-M were amorphous ( Figure 3H).…”

“…Over the past decade, much effort had been devoted to synthesize and stabilize SeNPs with the use of polysaccharides, 15,[18][19][20] monosaccharides, 21 proteins, 3,[22][23][24] amino acids, 25 polyphenols, [26][27][28] melatonin, 29 ATP, 30 complex plant extract 10,31 and even microorganism culture. 8 Among them, polysaccharide is regarded as an appropriate template for fabricating SeNPs when considering energy efficiency and eco-friendliness, according to Zhang et al 15 However, the SeNPs prepared using polysaccharides were found to be unstable, due to enlargement of size and decrease of zeta potential during storage in aqueous environment.…”

Anticancer activity of biostabilized selenium nanorods synthesized by Streptomyces bikiniensis strain Ess_amA-1

“…However, a few recent studies have reported lower toxicity and selectivity of SNMs toward normal cells. 1,20 The mechanism involved in the selectivity of the SNMs remains unexplained. Therefore, we tried to explain the plausible mechanism of SNMs for selective killing of cancer cells.…”

“…[19][20][21] Biogenic methods are a renewable, clean, nontoxic, and environmentally friendly procedure for the synthesis of these types of nanomaterials. 7,22,23 Recently, biogenic methods have been utilized for the synthesis of a variety of SNMs at ambient conditions.…”