Uptake of bright fluorophore core-silica shell nanoparticles by biological systems

Abstract

Nanoparticles are used in a variety of consumer applications. Silica nanoparticles in particular are common, including as a component of foods. There are concerns that ingested nano-silica particles can cross the intestinal epithelium, enter the circulation, and accumulate in tissues and organs. Thus, tracking these particles is of interest, and fluorescence spectroscopic methods are well-suited for this purpose. However, nanosilica is not fluorescent. In this article, we focus on core-silica shell nanoparticles, using fluorescent Rhodamine 6G, Rhodamine 800, or CdSe/CdS/ZnS quantum dots as the core. These stable fluorophore/silica nanoparticles had surface characteristics similar to those of commercial silica particles. Thus, they were used as model particles to examine internalization by cultured cells, including an epithelial cell line relevant to the gastrointestinal tract. Finally, these particles were administered to mice by gavage, and their presence in various organs, including stomach, small intestine, cecum, colon, kidney, lung, brain, and spleen, was examined. By combining confocal fluorescence microscopy with inductively coupled plasma mass spectrometry, the presence of nanoparticles, rather than their dissolved form, was established in liver tissues.

Doped Graphene Quantum Dots for Intracellular Multicolor Imaging and Cancer Detection

“…GQDs are simple and inexpensive in preparation as opposed to many nanoscale therapeutic delivery systems that require elaborate multistep synthesis . High quantum yield (greater than 60% for N-GQDs) intrinsic fluorescence of GQDs allows for imaging without the attachment of additional fluorophores, often used to track many other nanoparticles , and adding to their toxicity profile. GQDs show substantial biodegradability within 36 h that sets them ahead of all nonbiodegradable nanoscale platforms, accumulation of which in the cells and tissues may hinder their long-term use. ,, In addition, GQDs offer multicolor visible and visible and near-IR imaging capabilities for both in vitro and in vivo detection unlike the majority of nanoscale drug delivery platforms, or even other graphene quantum dots, , which offer imaging only in the visible.…”

“…GQDs are simple and inexpensive in preparation as opposed to many nanoscale therapeutic delivery systems that require elaborate multistep synthesis. 18 High quantum yield (greater than 60% for N-GQDs 52 ) intrinsic fluorescence of GQDs allows for imaging without the attachment of additional fluorophores, often used to track many other nanoparticles 69,70 and adding to their toxicity profile. GQDs show substantial biodegradability within 36 h that sets them ahead of all nonbiodegradable nanoscale platforms, accumulation of which in the cells and tissues may hinder their long-term use.…”

Nanotechnology-Assisted Cell Tracking

“…References miRNA [68,69] siRNA [78,187] Drugs (doxorubicin, dexamethasone, betamethasone, methotrexate, caspase inhibitors, ceramide, oleanoic acid, emodin, heparin, aspirin, curcumin and sulforaphane) [66,67,79,95,103,132,147,167,189] Gene [164] The surface modifications for NP delivery, diagnostic imaging and tracking of therapeutic effects are summarized in Figure 4.…”

A review of hepatic nanotoxicology – summation of recent findings and considerations for the next generation of study designs

“…Although, of course, not all of this initial dose will remain as free NMs on reaching the liver. It is also evident that NMs translocate to secondary organs following inhalation and oral administration (Smulders et al 2014;Zane et al 2015). Several investigators suggested that the extent of uptake of insoluble NMs from the GIT and airways is in the order of approximately 1-5% of the total applied dose (summarized in Kermanizadeh et al 2015), detectable in the liver as early as 24 hr post exposure (Gosens et al 2015;Thakur et al 2014).…”