Search results for "Nanoparticles"

Apoferritin-encapsulated Ni and Co superparamagnetic nanoparticles

2006

Ni and Co nanoparticles (average diameters 3 and 3.5 nm) have been prepared within the apoferritin cavity. The protein shell prevents bulk aggregation of the metal particles, rendering them water soluble. X-Ray diffraction, transmission electronic microscopy and magnetization measurements have been used for characterizing the nanoparticles. The magnetic study of both nanoparticles confirmed the expected superparamagnetic behavior.

Ab Initio Structure Determination of Vaterite by Automated Electron Diffraction

2012

tion that is fundamental for understanding material properties. Still, a number of compounds have eluded such kinds of analysis because they are nanocrystalline, highly disordered, with strong pseudosymmetries or available only in small amounts in polyphasic or polymorphic systems. These materials are crystallographically intractable with conventional Xray or synchrotron radiation diffraction techniques. Single nanoparticles can be visualized by high-resolution transmission electron microscopy (HR-TEM) up to sub�ngstrom resolution, [2] but obtaining 3D information is still a difficult task, especially for highly beam-sensitive materials and crystal structures with long cell parameters. Elec…

Properties of the O2 diffusion process in amorphous SiO2 nanoparticles

2014

Synthesis and Spectroscopic Properties of Silica−Dye−Semiconductor Nanocrystal Hybrid Particles

2010

We prepared silica-dye-nanocrystal hybrid particles and studied the energy transfer from semiconductor nanocrystals (= donor) to organic dye molecules (= acceptor). Multishell CdSe/CdS/ZnS semiconductor nanocrystals were adsorbed onto monodisperse Stöber silica particles with an outer silica shell of thickness 2-23 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the energy transfer efficiency, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of nanocrystals with increasing dye amount. Our conclusions were underlined by…

Electrically Driven Magnetic Domain Wall Rotation in Multiferroic Heterostructures to Manipulate Suspended On-Chip Magnetic Particles

2015

In this work, we experimentally demonstrate deterministic electrically driven, strain-mediated domain wall (DW) rotation in ferromagnetic Ni rings fabricated on piezoelectric [Pb(Mg1/3Nb2/3)O3]0.66-[PbTiO3]0.34 (PMN-PT) substrates. While simultaneously imaging the Ni rings with X-ray magnetic circular dichroism photoemission electron microscopy, an electric field is applied across the PMN-PT substrate that induces strain in the ring structures, driving DW rotation around the ring toward the dominant PMN-PT strain axis by the inverse magnetostriction effect. The DW rotation we observe is analytically predicted using a fully coupled micromagnetic/elastodynamic multiphysics simulation, which v…

Electrochemical detection of dopamine with negligible interference from ascorbic and uric acid by means of reduced graphene oxide and metals-NPs base…

2021

Abstract Dopamine is an important neurotransmitter involved in many human biological processes as well as in different neurodegenerative diseases. Monitoring the concentration of dopamine in biological fluids, i.e., blood and urine is an effective way of accelerating the early diagnosis of these types of diseases. Electrochemical sensors are an ideal choice for real-time screening of dopamine as they can achieve fast, portable inexpensive and accurate measurements. In this work, we present electrochemical dopamine sensors based on reduced graphene oxide coupled with Au or Pt nanoparticles. Sensors were developed by co-electrodeposition onto a flexible substrate, and a systematic investigati…

Controlling the Stealth Effect of Nanocarriers through Understanding the Protein Corona

2016

The past decade has seen a significant increase in interest in the use of polymeric nanocarriers in medical applications. In particular, when used as drug vectors in targeted delivery, nanocarriers could overcome many obstacles for drug therapy. Nevertheless, their application is still impeded by the complex composition of the blood proteins covering the particle surface, termed the protein corona. The protein corona complicates any prediction of cell interactions, biodistribution, and toxicity. In particular, the unspecific uptake of nanocarriers is a major obstacle in clinical studies. This Minireview provides an overview of what we currently know about the characteristics of the protein …

Mesoporous inorganic nanoscale particles for drug adsorption and controlled release.

2018

The review provides an overview of the mesoporous inorganic particles employed as drug delivery systems for controlled and sustained release of drugs. We have classified promising nanomaterials for drug delivery on the basis of their natural or synthetic origin. Nanoclays are available in different morphologies (nanotubes, nanoplates and nanofibers) and they are typically available at low cost from natural resources. The surface chemistry of nanoclays is versatile for targeted modifications to control loading and release properties. Synthetic nanomaterials (imogolite, laponite and mesoporous silica) present the advantages of well-established purity and availability with size features that …

Amphiphilic HPMA-LMA copolymers increase the transport of Rhodamine 123 across a BBB model without harming its barrier integrity.

2012

Abstract The successful non-invasive treatment of diseases associated with the central nervous system (CNS) is generally limited by poor brain permeability of various developed drugs. The blood–brain barrier (BBB) prevents the passage of therapeutics to their site of action. Polymeric drug delivery systems are promising solutions to effectively transport drugs into the brain. We recently showed that amphiphilic random copolymers based on the hydrophilic p(N-(2-hydroxypropyl)-methacrylamide), pHPMA, possessing randomly distributed hydrophobic p(laurylmethacrylate), pLMA, are able to mediate delivery of domperidone into the brain of mice in vivo. To gain further insight into structure–propert…

Rapamycin-Loaded Polymeric Nanoparticles as an Advanced Formulation for Macrophage Targeting in Atherosclerosis

2021

Recently, rapamycin (Rapa) represents a potential drug treatment to induce regression of atherosclerotic plaques