Nanoparticles For Medical Applications Research Articles

Biodistribution of Nanostructured Lipid Carriers (NLCs) after intravenous administration to rats: Influence of technological factors

Nanoparticles for medical applications are frequently administered via parenteral administration. In this study, the tissue distribution of three lipid formulations based on Nanostructured Lipid Carriers (NLCs) after intravenous administration to rats was evaluated. NLCs were prepared by a high pressure homogenization method and varied in terms of particle size, surface charge, and surfactant content. The 99mTc radiolabeled NLCs were intravenously administered to rats, and radioactivity levels in blood and tissues were measured. Cmax, AUC0–24, and MRT0–24 were obtained from the radioactivity level versus time profiles. The radiolabeled nanocarriers exhibited a long circulation time since radioactivity was detected in blood even 24h post-injection. No differences on the MRT values in blood among the NLCs were observed, in spite of the different particle size and surface charge. The highest radioactivity levels were measured in the kidney, followed by the bone marrow, the liver, and the spleen. In the kidney, there was a higher accumulation of the positive nanoparticles, and in the liver, uptake of negative nanoparticles was higher than positive ones. NLCs with the largest particle size showed a higher uptake in the lung and lower accumulation in liver and bone marrow, in comparison with the smaller ones.

Internalization Pathways of Anisotropic Disc‐Shaped Zeolite L Nanocrystals with Different Surface Properties in HeLa Cancer Cells

Information about the mechanisms underlying the interactions of nanoparticles with living cells is crucial for their medical application and also provides indications of the putative toxicity of such materials. Here the uptake and intracellular delivery of disc-shaped zeolite L nanocrystals as porous aminosilicates with well-defined crystal structure, uncoated as well as with COOH-, NH2 -, polyethyleneglycol (PEG)- and polyallylamine hydrochloride (PAH) surface coatings are reported. HeLa cells are used as a model system to demonstrate the relation between these particles and cancer cells. Interactions are studied in terms of their fates under diverse in vitro cell culture conditions. Differently charged coatings demonstrated dissimilar behavior in terms of agglomeration in media, serum protein adsorption, nanoparticle cytotoxicity and cell internalization. It is also found that functionalized disc-shaped zeolite L particles enter the cancer cells via different, partly not yet characterized, pathways. These in vitro results provide additional insight about low-aspect ratio anisotropic nanoparticle interactions with cancer cells and demonstrate the possibility to manipulate the interactions of nanoparticles and cells by surface coating for the use of nanoparticles in medical applications.

Nanotoxicity: How the Body Develops A Way to Reduce the Toxicity of Carbon Nanotubes

The interaction of nanoparticles with cells and organisms are often the focus of biomedical, material, and environmental research. This article highlights a paper by Yuliang Zhao, Chunying Chen, Ruhong Zhou, and co-workers (Proc. Natl. Acad. Sci. USA 2011, 108, 16968), which brings a new aspect to the discussion about purpose and mechanisms underlying the reaction of an organism with nanoparticles. The interactions of carbon nanotubes with cells were investigated with regard to the defense mechanisms of the body against foreign materials developed during evolution. Such mechanisms are not only important for nanotoxicity research, but also for targeting nanoparticles in medical applications. The cited article thus gives a new focus to an important aspect of nanotechnology, which will determine the application aspects of this technology in future: the approach of biological systems to nanosized particles.

Potential of plant proteins for medical applications

Various natural and synthetic polymers are being explored to develop biomaterials for tissue engineering and drug delivery. Although proteins are preferable over carbohydrates and synthetic polymers, biomaterials developed from proteins lack the mechanical properties and/or biocompatibilities required for medical applications. Plant proteins are widely available, have low potential to be immunogenic and can be made into fibers, films, hydrogels and micro- and nano-particles for medical applications. Studies, mostly with zein, have demonstrated the potential of using plant proteins for tissue engineering and drug delivery. Although other plant proteins such as wheat gluten and soyproteins have also shown biocompatibility using in vitro studies, fabricating biomaterials such as nano-fibers and nano-particles from soy and wheat proteins offers considerable challenges.

Iron-included carbon nanocapsules coated with biocompatible poly(ethylene glycol) shells

Nanoparticles of iron carbides wrapped in multilayered graphitic sheets (carbon nanocapsules) were synthesized by electric plasma discharge in an ultrasonic cavitation field in liquid ethanol and purified by selective oxidation and magnetic separation. The particles had 100–200 nm in diameter after centrifuging for 10 min at 4000 rpm. Carbon nanocapsules were covered by wispy poly(ethylene glycol) PEG coating about 7–10 nm in thickness. The number of PEG chains coated on carbon nanocapsules could be estimated as 9.15%. The values of saturation magnetization Ms and coercivity Hc of purified carbon nanocapsules without PEG coating were 112 emu g −1 and 75 Oe respectively. Magnetically soft carbon nanocapsules with a poly(ethylene glycol) coating on the surface may possibly be used as biocompatible magnetic nanoparticles in medical applications.

A Decade of Nanoparticle Research in Australia and New Zealand

Nanoparticle research in Australia and New Zealand over the period 1998–2007 is reviewed. The topics covered include nanoparticles for medical applications, elemental nanoparticles (Au, Ag, Pt, and Ru), photocatalytic nanoparticles (TiO 2 and ZnO), lithium battery materials, MgB 2 superconductors, refractory and magnetic materials, properties and physics of nanoparticles, and heath and safety issues. Carbon and other nanotubes (BN, BC, aluminosilicate) and nanoparticle-polymer composites have mostly been excluded. While optical materials (CdSe, Se, Ge, Si, diamond, CdS, and PbS) are partially covered, arrays of these materials have generally been excluded.

Pharmacokinetic properties and tissue storage of FITC conjugated SA-MnMEIO nanoparticles in mice

Nowadays, attempts to use nanoparticles for medical applications are on the rise. However, the effect of nanoparticles in the body has not been clarified. In this study, we aimed to examine the pharmacokinetics of magnetized nanoparticles. FITC conjugated SA-MnMEIO nanoparticles were prepared for the purpose of tracing. Nanoparticles (15 nm diameter) were injected into the tail vein of BALB/c mice at a dose of 20 mg (Mn+Fe)/kg. A mouse was housed in a metabolic cage and sacrificed serially up to 14 days for the sampling of blood and tissues from various organs (i.e., heart, kidney, liver, and spleen). The concentration of nanoparticles was measured by detecting FITC using spectrofluorophotometer. Nanoparticles showed a half-life of 8.20 h. The fluorescence intensities of nanoparticles in tissues showed different time-dependent patterns among different organs. In the heart and the liver, the fluorescence intensities increased up to 2 weeks of observation, while those in the kidney and the spleen decreased. The results indicate that nanoparticles have unique pharmacokinetic characteristics and suggest that pharmacokinetic study is essential for the development of new nanoparticles for medical use.

Reactions of alkyl-radicals with gold and silver nanoparticles in aqueous solutions

Silver and gold nanoparticles are very efficient catalysts for the dimerization of methyl-radicals in aqueous solutions. The rate constants for the reaction of methyl-radicals with the gold and silver nanoparticles were measured and found to be 3.7 x 10(8) M(-1) s(-1) and 1.4 x 10(9) M(-1) s(-1), respectively. The results thus suggest that alkyl-radicals, also not reducing ones, are scavenged by these nanoparticles. This might explain the role, if such a role exists, of these nanoparticles in medical applications.