Ru(ii)-polypyridyl surface functionalised gold nanoparticles as DNA targeting supramolecular structures and luminescent cellular imaging agents

Abstract

The development of Ru(II) functionalized gold nanoparticles 1–3·AuNP is described. These systems were found to be mono-disperse with a hydrodynamic radius of ca. 15 nm in water but gave rise to the formation of higher order structures in buffered solution. The interaction of 1–3·AuNP with DNA was also studied by spectroscopic and microscopic methods and suggested the formation of large self-assembly structures in solution. The uptake of 1–3·AuNP by cancer cells was studied using both confocal fluorescence as well as transmission electron microscopy (TEM), with the aim of investigating their potential as tools for cellular biology. These systems displaying a non-toxic profile with favourable photophysical properties may have application across various biological fields including diagnostics and therapeutics.

Fluorescent ZnO–Au Nanocomposite as a Probe for Elucidating Specificity in DNA Interaction

“…The fluorescence spectral changes of this nature though small are sufficient for providing good binding analysis, as already demonstrated by earlier groups. 59 , 60 The base composition of DNA has been found to strongly influence the spectral nature of the nanocomposite emission by altering the relative intensity of the emission maximum at ∼520 nm with significant shifts in the peak position. The signature of the AT:GC composition of DNA on the shift in the emission band can be distinctly visualized from Figure 6 d. The inset of Figure 6 d typically displays the Commission Internationale de Ľeclairage (CIE) 1931 diagram exhibiting the shift in the emission wavelength as a function of DNA composition.…”

“…Besides these, through first-principles calculations, different groups reported the possible way of interaction of nanomaterials and DNA. 60 , 80 − 83 However, there are limited experimental research works pertaining to the interaction of nanomaterials and DNA mainly driven by direct binding study. To sum up, as shown in Table 3 , it is found that when nanomaterials interact with CT DNA the magnitude of binding constant ( K a ) was derived to be in the order of 10 4 –10 5 M –1 .…”

The development of ruthenium(ii) polypyridyl complexes and conjugates forin vitrocellular andin vivoapplications

“…44a and b for conjugates 107 and 111) with little or no toxicity towards cells after 24 hrs in the dark. 408,409 In the case of the larger diameter conjugates (15 nm), the individual particles could be visualised within cells using TEM, where they were observed within single membrane vesicles in the cytoplasm, which suggested the route of uptake to be endocytosis. In addition, these nanoparticles were shown to remain intact within these vesicles for up to 24 hrs, as demonstrated in Fig.…”

Nanoparticle Functionalization and Its Potentials for Molecular Imaging

“…Martínez‐Calvo et al showed that Ru(II) can bind to the DNA though groove binding which creates alterations in the photo properties. It can be captured by the confocal microscopy to analyze the induction of apoptosis in the cells because of binding DNA with Ru complexes 30. Tamborini et al showed the cellular uptake of PLGA NPs functionalized with chlorotoxin which specifically targets glioma cells and reported that it can be analyzed by doping optical CAs like Ag NPs 31…”