Search results for "nanoparticle"
showing 10 items of 2198 documents
Thermodynamics and Biophysics of Biomedical Nanosystems Applications and Practical Considerations
2019
This book highlights the recent advances of thermodynamics and biophysics in drug delivery nanosystems and in biomedical nanodevices. The up-to-date book provides an in-depth knowledge of bio-inspired nanotechnological systems for pharmaceutical applications. Biophysics and thermodynamics, supported by mathematics, are the locomotive by which the drug transportation and the targeting processes will be achieved under the light of the modern pharmacotherapy. They are considered as scientific tools that promote the understanding of physicochemical and thermotropic functionality and behavior of artificial cell membranes and structures like nanoparticulate systems. Therefore, this book focusses …
Nanodevices by DNA based gold nanostructures
2017
In this thesis DNA based structures were utilized to create gold nanostructures for nanosensing and nanoelectronic applications. In the past, both of these fields have been dominated by the conventional lithography methods, e.g., electron beam lithography and UV-lithography, but more recently scaling down the components by these techniques has become increasingly more complex and costly. Especially in the micro- and nanoelectronics, the increase in the component density and thus computational power would require fabrication of sub-10-nm components, which is challenging for the top-down approaches. Aforementioned developments have led researchers to seek alternative methods to fabricate these…
In vitro evaluation of glycol chitosan based formulations as oral delivery systems for efflux pump inhibition.
2017
Recently, we have reported that glycol chitosan (GCS) was able to reverse the P- glycoprotein (P-gp) efflux pump. The objective of the present study was to evaluate the potential of two GCS-based dosage forms (aqueous solution or nanoparticle suspension) for oral administration of the P-gp substrate Rho-123. A further aim of the present study was to assess the effect of the glycol chitosan-4-thiobutylamidine thiomer (GCS-TBA) on P-gp activity considering that the corresponding thiomer of chitosan series is a well-known P-gp inhibitor. Pre-treatment of Caco-2 cell monolayer with a GCS solution or GCS-based nanoparticles increased the absorptive transport of Rho-123 across the monolayer of 1.…
Preservation of the soft protein corona in distinct flow allows identification of weakly bound proteins.
2018
Abstract Nanocarriers that are used for targeted drug delivery come in contact with biological liquids and subsequently proteins will adsorb to the nanocarriers’ surface to form the so called ‘protein corona’. The protein corona defines the biological identity and determines the biological response towards the nanocarriers in the body. To make nanomedicine safe and reliable it is required to get a better insight into this protein corona and, therefore, the adsorbed proteins have to be characterized. Currently, centrifugation is the common method to isolate the protein corona for further investigations. However, with this method it is only possible to investigate the strongly bound proteins,…
Carbohydrate-Based Nanocarriers Exhibiting Specific Cell Targeting with Minimum Influence from the Protein Corona.
2015
Whenever nanoparticles encounter biological fluids like blood, proteins adsorb on their surface and form a so-called protein corona. Although its importance is widely accepted, information on the influence of surface functionalization of nanocarriers on the protein corona is still sparse, especially concerning how the functionalization of PEGylated nanocarriers with targeting agents will affect protein corona formation and how the protein corona may in turn influence the targeting effect. Herein, hydroxyethyl starch nanocarriers (HES-NCs) were prepared, PEGylated, and modified on the outer PEG layer with mannose to target dendritic cells (DCs). Their interaction with human plasma was then s…
A plasma protein corona enhances the biocompatibility of Au@Fe3O4 Janus particles
2015
AbstractAu@Fe3O4 Janus particles (JPs) are heteroparticles with discrete domains defined by different materials. Their tunable composition and morphology confer multimodal and versatile capabilities for use as contrast agents and drug carriers in future medicine. Au@Fe3O4 JPs have colloidal properties and surface characteristics leading to interactions with proteins in biological fluids. The resulting protein adsorption layer (“protein corona”) critically affects their interaction with living matter. Although Au@Fe3O4 JPs displayed good biocompatibility in a standardized in vitro situation, an in-depth characterization of the protein corona is of prime importance to unravel underlying mecha…
Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.
2012
Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs expe…
Reconfigurable DNA Origami Nanocapsule for pH-Controlled Encapsulation and Display of Cargo
2019
DNA nanotechnology provides a toolbox for creating custom and precise nanostructures with nanometer-level accuracy. These nano-objects are often static by nature and serve as versatile templates for assembling various molecular components in a user-defined way. In addition to the static structures, the intrinsic programmability of DNA nanostructures allows the design of dynamic devices that can perform predefined tasks when triggered with external stimuli, such as drug delivery vehicles whose cargo display or release can be triggered with a specified physical or chemical cue in the biological environment. Here, we present a DNA origami nanocapsule that can be loaded with cargo and reversibl…
Synthesis of Monodisperse Spherical Nanocrystals
2016
Nanoparticles, small units of matter with dimensions in the range 1-100 nm, exhibit many advantageous size-dependent magnetic, electrical, chemical and optical prop- erties, which are not observed at the microscale or bulk. These properties are extremely sensitive to particle size, and thus the ability to produce monodisperse particles is critical. Due to its ease of use and flexibility, precipitation of nanoparticles from solution is one of the most widely used synthesis methods. The main disadvantage of this method is that the relationship between particle growth and system conditions is not fully understood. In practice, the optimal reaction conditions are usually ascertained empirically…
Reversible Strong Coupling in Silver Nanoparticle Arrays Using Photochromic Molecules
2012
International audience; In this Letter, we demonstrate a reversible strong coupling regime between a dipolar surface plasmon resonance and a molecular excited state. This reversible state is experimentally observed on silver nanoparticle arrays embedded in a polymer film containing photochromic molecules. Extinction measurements reveal a clear Rabi splitting of 294 meV, corresponding to ∼13% of the molecular transition energy. We derived an analytical model to confirm our observations, and we emphasize the importance of spectrally matching the polymer absorption with the plasmonic resonance to observe coupled states. Finally, the reversibility of this coupling is illustrated by cycling the …