| 1. |
- Cabaleiro-Lago, Celia, et al.
(författare)
-
Dual Effect of Amino Modified Polystyrene Nanoparticles on Amyloid beta Protein Fibrillation
- 2010
-
Ingår i: ACS Chemical Neuroscience. - : American Chemical Society (ACS). - 1948-7193. ; 1:4, s. 279-287
-
Tidskriftsartikel (refereegranskat)abstract
- The fibrillation kinetics of the amyloid beta peptide is analyzed in presence of cationic polystyrene nanoparticles of different size. The results highlight the importance of the ratio between the peptide and particle concentration. Depending on the specific ratio, the kinetic effects vary from acceleration of the fibrillation process by reducing the lag phase at low particle surface area in solution to inhibition of the fibrillation process at high particle surface area. The kinetic behavior can be explained if we assume a balance between two different pathways: first fibrillation of free monomer in solution and second nucleation and fibrillation promoted at the particle surface. The overall rate of fibrillation will depend on the interplay between these two pathways, and the predominance of one mechanism over the other will be determined by the relative equilibrium and rate constants.
|
|
| 2. |
- Cabaleiro-Lago, Celia, et al.
(författare)
-
Dual effect of amino modified polystyrene nanoparticles on amyloid β protein fibrillation
- 2010
-
Ingår i: ACS Chemical Neuroscience. - 1948-7193 .- 1948-7193. ; 1:4, s. 279-87
-
Tidskriftsartikel (refereegranskat)abstract
- The fibrillation kinetics of the amyloid β peptide is analyzed in presence of cationic polystyrene nanoparticles of different size. The results highlight the importance of the ratio between the peptide and particle concentration. Depending on the specific ratio, the kinetic effects vary from acceleration of the fibrillation process by reducing the lag phase at low particle surface area in solution to inhibition of the fibrillation process at high particle surface area. The kinetic behavior can be explained if we assume a balance between two different pathways: first fibrillation of free monomer in solution and second nucleation and fibrillation promoted at the particle surface. The overall rate of fibrillation will depend on the interplay between these two pathways, and the predominance of one mechanism over the other will be determined by the relative equilibrium and rate constants.
|
|
| 3. |
- Cabaleiro-Lago, Celia, et al.
(författare)
-
Inhibition of Amyloid beta Protein Fibrillation by Polymeric Nanoparticles
- 2008
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 130:46, s. 15437-15443
-
Tidskriftsartikel (refereegranskat)abstract
- Copolymeric NiPAM:BAM nanoparticles of varying hydrophobicity were found to retard fibrillation of the Alzheimer's disease-associated amyloid beta protein (A beta). We found that these nanoparticles affect mainly the nucleation step of A beta fibrillation. The elongation step is largely unaffected by the particles, and once the M is nucleated, the fibrillation process occurs with the same rate as in the absence of nanoparticles. The extension of the lag phase for fibrillation of A beta is strongly dependent on both the amount and surface character of the nanoparticles. Surface plasmon resonance studies show that A beta binds to the nanoparticles and provide rate and equilibrium constants for the interaction. Numerical analysis of the kinetic data for fibrillation suggests that binding of monomeric A beta and prefibrillar oligomers to the nanoparticles prevents fibrillation. Moreover, we find that fibrillation of A beta initiated in the absence of nanoparticles can be reversed by addition of nanoparticles up to a particular time point before mature fibrils appear.
|
|
| 4. |
|
|
| 5. |
- Cedervall, Tommy, et al.
(författare)
-
Understanding the nanoparticle-protein corona using methods to quantify exchange rates and affinities of proteins for nanoparticles
- 2007
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 104:7, s. 2050-2055
-
Tidskriftsartikel (refereegranskat)abstract
- Due to their small size, nanoparticles have distinct properties compared with the bulk form of the same materials. These properties are rapidly revolutionizing many areas of medicine and technology. Despite the remarkable speed of development of nanoscience, relatively little is known about the interaction of nanoscale objects with living systems. In a biological fluid, proteins associate with nanoparticles, and the amount and presentation of the proteins on the surface of the particles leads to an in vivo response. Proteins compete for the nanoparticle "surface," leading to a protein "corona" that largely defines the biological identity of the particle. Thus, knowledge of rates, affinities, and stoichiometries of protein association with, and dissociation from, nanoparticles is important for understanding the nature of the particle surface seen by the functional machinery of cells. Here we develop approaches to study these parameters and apply them to plasma and simple model systems, albumin and fibrinogen. A series of copolymer nanoparticles are used with variation of size and composition (hydrophobicity). We show that isothermal titration calorimetry is suitable for studying the affinity and stoichiometry of protein binding to nanoparticles. We determine the rates of protein association and dissociation using surface plasmon resonance technology with nanoparticles that are thiol-linked to gold, and through size exclusion chromatography of protein-nanoparticle mixtures. This method is less perturbing than centrifugation, and is developed into a systematic methodology to isolate nanoparticle-associated proteins. The kinetic and equilibrium binding properties depend on protein identity as well as particle surface characteristics and size.
|
|
| 6. |
- Gallagher, William M., et al.
(författare)
-
Molecular basis of cell-biomaterial interaction: Insights gained from transcriptomic and proteomic studies
- 2006
-
Ingår i: Biomaterials. - : Elsevier BV. - 1878-5905 .- 0142-9612. ; 27:35, s. 5871-5882
-
Forskningsöversikt (refereegranskat)abstract
- With the growing interest in clinical interventions that involve medical devices, the role for new biomaterials in modern medicine is currently expanding at a phenomenal rate. Failure of most implant materials stems from an inability to predict and control biological phenomena, such as protein adsorption and cell interaction, resulting in an inappropriate host response to the materials. Contemporary advances in biological investigation are starting to shift focus in the biomaterials field, in particular with the advent of high-throughput methodologies for gene and protein expression profiling. Here, we examine the role that emerging transcriptomic and proteomic technologies could play in relation to biomaterial development and usage. Moreover, a number of studies are highlighted which have utilized such approaches in order to try to create a deeper understanding of cell-biomaterial interactions and, hence, improve our ability to predict and control the biocompatibility of new materials. (c) 2006 Elsevier Ltd. All rights reserved.
|
|
| 7. |
|
|
| 8. |
- Hellstrand, Erik, et al.
(författare)
-
Complete high-density lipoproteins in nanoparticle corona.
- 2009
-
Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 276:12, s. 3372-3381
-
Tidskriftsartikel (refereegranskat)abstract
- In a biological environment, nanoparticles immediately become covered by an evolving corona of biomolecules, which gives a biological identity to the nanoparticle and determines its biological impact and fate. Previous efforts at describing the corona have concerned only its protein content. Here, for the first time, we show, using size exclusion chromatography, NMR, and pull-down experiments, that copolymer nanoparticles bind cholesterol, triglycerides and phospholipids from human plasma, and that the binding reaches saturation. The lipid and protein binding patterns correspond closely with the composition of high-density lipoprotein (HDL). By using fractionated lipoproteins, we show that HDL binds to copolymer nanoparticles with much higher specificity than other lipoproteins, probably mediated by apolipoprotein A-I. Together with the previously identified protein binding patterns in the corona, our results imply that copolymer nanoparticles bind complete HDL complexes, and may be recognized by living systems as HDL complexes, opening up these transport pathways to nanoparticles. Apolipoproteins have been identified as binding to many other nanoparticles, suggesting that lipid and lipoprotein binding is a general feature of nanoparticles under physiological conditions.
|
|
| 9. |
- Kookana, Rai, et al.
(författare)
-
Nanopesticides: Guiding principles for regulatory evaluation of environmental risks
- 2014
-
Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 62:19, s. 4227-4240
-
Tidskriftsartikel (refereegranskat)abstract
- Nanopesticides or nano plant protection products represent an emerging technological development that, in relation to pesticide use, could offer a range of benefits including increased efficacy, durability, and a reduction in the amounts of active ingredients that need to be used. A number of formulation types have been suggested including emulsions (e.g., nanoemulsions), nanocapsules (e.g., with polymers), and products containing pristine engineered nanoparticles, such as metals, metal oxides, and nanoclays. The increasing interest in the use of nanopesticides raises questions as to how to assess the environmental risk of these materials for regulatory purposes. Here, the current approaches for environmental risk assessment of pesticides are reviewed and the question of whether these approaches are fit for purpose for use on nanopesticides is addressed. Potential adaptations to existing environmental risk assessment tests and procedures for use with nanopesticides are discussed, addressing aspects such as analysis and characterization, environmental fate and exposure assessment, uptake by biota, ecotoxicity, and risk assessment of nanopesticides in aquatic and terrestrial ecosystems. Throughout, the main focus is on assessing whether the presence of the nanoformulation introduces potential differences relative to the conventional active ingredients. The proposed changes in the test methodology, research priorities, and recommendations would facilitate the development of regulatory approaches and a regulatory framework for nanopesticides.
|
|
| 10. |
- Lindman, Stina, et al.
(författare)
-
Systematic investigation of the thermodynamics of HSA adsorption to N-iso-propylacrylamide/N-tert-butylacrylamide copolymer nanoparticles. Effects of particle size and hydrophobicity
- 2007
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 7:4, s. 914-920
-
Tidskriftsartikel (refereegranskat)abstract
- Nanoparticles in biological fluids almost invariably become coated with proteins that may confer nanomedical and nanotoxicological effects. Understanding these effects requires quantitative measurements using simple systems. Adsorption of HSA to copolymer nanoparticles of varying hydrophobicity and curvature was studied using ITC, yielding stoichiometry, affinity, and enthalpy changes upon binding. The hydrophobicity was controlled via the co-monomer ratio, N-iso-propylacrylamide/N-tert-butylacrylamide. The most hydrophobic particles become fully covered with a single layer of protein, except at high curvature.
|
|
