Nanotoxicity and Spectroscopy Studies of Silver Nanoparticle: Calf Thymus DNA and K562 as Targets

Abstract

The interaction between silver nanoparticle and calf thymus DNA was studied by UV−visible, fluorescence, and far UV circular dichroism (CD) spectroscopies at a physiologic temperature of 37 °C. By the analysis of UV−visible titration and thermal denaturation studies of DNA, it was found that silver nanoparticle can form a new complex with double-helical DNA and increase the T m value of DNA. This kind of binding may cause a slight change of the conformation of DNA. The fluorescence emission spectra of intercalated ethidium bromide (EB) with increasing concentration of silver nanoparticle at 37 °C represented a significant reduction of the ethidium intensity and quenching of EB fluorescence. Also, CD results suggested that silver nanoparticle can significantly change the helicity conformation of DNA and then induce the alteration of nonplanar and tilted orientations of DNA bases, resulting in the changes of DNA base stacking, and act as an intercalator. Spectroscopic results represented that binding of silver nanoparticle to DNA resulted in significant changes in the structure and conformation of DNA in a concentration dependent manner and act as an intercalator via increasing stability of DNA by increasing T m, quenching of EB fluorescence intensity, and alteration of CD spectra. Also, the antitumor property of silver nanoparticle was studied by testing it on human tumor cell line K562. The 50% cytotoxic concentration (Cc50) of silver nanoparticle was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay after a 24 h incubation time. Results of the present study may provide useful information to design better anticancer compounds using metal nanoparticles with lower side effects in the future.

Self-Assembly of Calcium Carbonate Nanoparticles in Water and Hydrophobic Solvents

“…Sperling and Parak demonstrated that the chemical nature of the solvent affects the extent of aggregation of the micelle into colloidal nanostructures. 9 Calcium carbonate, CaCO 3 , is found in nature in many morphological forms, and sea life has proved particularly adept at growing it into a variety of shapes. Recent laboratory-based studies have revealed that carbonates can be grown into different structures (e.g.…”

“…22 Experiments on alkyl sulfonate and alkyl phenate stabilized nanoparticles predict a predominantly amorphous core, 22-24 a conclusion supported by classical Molecular Dynamics (MD) simulations of Quigley and Rodger. 25 Kobylyansky found that CaCO 3 nanoparticles stabilized by sulfonate-based surfactants display faster neutralization properties than the corresponding phenate and salicylate systems. 21 There is widespread interest in establishing chemical architecture-property relationships for these nanoparticles.…”

Binding of DNA by a dinitro-diester calix[4]arene: Denaturation and condensation of DNA

“…In general, the interaction of a fluorescence compound with DNA provokes changes in its emission spectrum [45].…”

Synthesis and multi-spectroscopic DNA binding study of 1,3,4-oxadiazole and 1,3,4-thiadiazole derivatives of fatty acid

“…Generally, hypochromism and red shift are associated with the intercalative binding mode between molecules and DNA [11] whereas hyperchromism is correlated with groove binding between host and guest [12]. Since the compounds 3a and 6a showed the band in the UV-range under identical experimental conditions, here we just discuss the apparent changing of UV bands of 3a and 6a when interacted with CT-DNA.…”