94 research outputs found
The impact of species and cell type on the nanosafety profile of iron oxide nanoparticles in neural cells
Background: While nanotechnology is advancing rapidly, nanosafety tends to lag behind since general mechanistic insights into cell-nanoparticle (NP) interactions remain rare. To tackle this issue, standardization of nanosafety assessment is imperative. In this regard, we believe that the cell type selection should not be overlooked since the applicability of cell lines could be questioned given their altered phenotype. Hence, we evaluated the impact of the cell type on in vitro nanosafety evaluations in a human and murine neuroblastoma cell line, neural progenitor cell line and in neural stem cells. Acute toxicity was evaluated for gold, silver and iron oxide (IO) NPs, and the latter were additionally subjected to a multiparametric analysis to assess sublethal effects.
Results: The stem cells and murine neuroblastoma cell line respectively showed most and least acute cytotoxicity. Using high content imaging, we observed cell type-and species-specific responses to the IONPs on the level of reactive oxygen species production, calcium homeostasis, mitochondrial integrity and cell morphology, indicating that cellular homeostasis is impaired in distinct ways.
Conclusions: Our data reveal cell type-specific toxicity profiles and demonstrate that a single cell line or toxicity end point will not provide sufficient information on in vitro nanosafety. We propose to identify a set of standard cell lines for screening purposes and to select cell types for detailed nanosafety studies based on the intended application and/or expected exposure
Effective macrospin model for nanoparticles: decreasing the anisotropy by Co-doping?
-doping of magnetic nanoparticles is an effective way to
tailor their magnetic properties. When considering the two extreme cases of the
series, i.e. the and values, one finds that
the system evolves from a negative cubic-anisotropy energy constant,
. Thus, what happens for
intermediate -compositions? In this work we present a very simple
phenomenological model for the anisotropy, under the \textit{macrospin}
approximation, in which the resultant anisotropy is just directly proportional
to the amount of . First, we perform a detailed analysis on a rather ideal
system in which the extreme values have the same magnitude (i.e.
) and then we focus on the real
system, for which . Remarkably, the approach
reproduces rather well the experimental values of the heating performance of
nanoparticles, suggesting that our simple approach may in
fact be a good representation of the real situation. This gives rise to an
intriguing related possibility arises: a -doping composition should exist
for which the effective anisotropy tends to zero, estimated here as 0.05.Comment: 6 pages, 7 figure
Biomimetic cell-derived nanocarriers in cancer research
Nanoparticles have now long demonstrated capabilities that make them attractive to use in biology and medicine. Some of them, such as lipid nanoparticles (SARS-CoV-2 vaccines) or metallic nanoparticles (contrast agents) are already approved for their use in the clinic. However, considering the constantly growing body of different formulations and the huge research around nanomaterials the number of candidates reaching clinical trials or being commercialized is minimal. The reasons behind being related to the âsyntheticâ and âforeignâ character of their surface. Typically, nanomaterials aiming to develop a function or deliver a cargo locally, fail by showing strong off-target accumulation and generation of adverse responses, which is connected to their strong recognition by immune phagocytes primarily. Therefore, rendering in negligible numbers of nanoparticles developing their intended function. While a wide range of coatings has been applied to avoid certain interactions with the surrounding milieu, the issues remained. Taking advantage of the natural cell membranes, in an approach that resembles a cell transfer, the use of cell-derived surfaces has risen as an alternative to artificial coatings or encapsulation methods. Biomimetic technologies are based on the use of isolated natural components to provide autologous properties to the nanoparticle or cargo being encapsulated, thus, improving their therapeutic behavior. The main goal is to replicate the (bio)-physical properties and functionalities of the source cell and tissue, not only providing a stealthy character to the core but also taking advantage of homotypic properties, that could prove relevant for targeted strategies. Such biomimetic formulations have the potential to overcome the main issues of approaches to provide specific features and identities synthetically. In this review, we provide insight into the challenges of nano-biointerfaces for drug delivery; and the main applications of biomimetic materials derived from specific cell types, focusing on the unique strengths of the fabrication of novel nanotherapeutics in cancer therapyThe authors thank the financial support of the European Research Council (starting grant #950421), the European Union (INTERREG V-A SpainâPortugal #0624_2IQBIONEURO_6_E, NextGenerationEU/PRTR and ERDF), the MCIN/AEI (PID2020-119206RB-I00, PID2020-119479RA-I00, PID2019-111218RB-I00, RYC-2017-23457 and RYC-2019-028238-I), and the Xunta de Galicia (ED431F 2021/02, 2021-CP090, ED431C 2022/018, and Centro Singular De InvestigaciĂłn de Galicia Accreditation 2019â2022 #ED431G 2019/03)S
Antireflection self-reference method based on ultrathin metallic nanofilms for improving terahertz reflection spectroscopy
We present the potential of an antireflection self-reference method based on ultrathin tantalum nitride (TaN) nanofilms for improving terahertz (THz) reflection spectroscopy.
The antireflection self-reference method is proposed to eliminate mutual interference caused
by unwanted reflections, which significantly interferes with the important reflection from the
actual sample in THz reflection measurement. The antireflection self-reference model was
investigated using a wave-impedance matching approach, and the theoretical model was
verified in experimental studies. We experimentally demonstrated this antireflection selfreference method can completely eliminate the effect of mutual interference, accurately
recover the actual sampleâs reflection and improve THz reflection spectroscopy. Our method
paves the way to implement a straightforward, accurate and efficient approach to investigate
THz properties of the liquids and biological samplesThe Fund from Hefei University of Technology (407-0371000019); Sichuan Province
Science and Technology Support Program (No. 2016GZ0250); the Fundamental Research
Funds for the Central Universities (Grant No. JD2017JGPY0006); National Natural Science
Foundation of China (Grant No.51607050); MINECO (MAT2015â74381-JIN to B.P., RYC2014â16962 and CTQ2017-89588-R to P.dP.); Xunta de Galicia (Centro singular de
investigaciĂłn de Galicia accreditation 2016â2019, ED431G/09); European Union (European Regional Development Fund â ERDF)S
Comparison of the in Vitro Uptake and Toxicity of Collagen- and Synthetic Polymer-Coated Gold Nanoparticles
We studied the physico-chemical properties (size, shape, zeta-potential),cellular internalization and toxicity of gold nanoparticles (NPs) stabilized with the most abundant mammalian protein, collagen. The properties of these gold NPs were compared to the same sized gold NPs coated with synthetic poly(isobutylene-alt-maleic anhydride) (PMA). Intracellular uptake and cytotoxicity were assessed in two cell lines (cervical carcinoma and lung adenocarcinoma cells) by employing inductively-coupled plasma-mass spectrometry (ICP-MS) analysis and a cell viability assay based on 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT),respectively. We found that the collagen-coated gold NPs exhibit lower cytotoxicity, but higher uptake levels than PMA-coated gold NPs. These results demonstrate that the surface coating of Au NPs plays a decisive role in their biocompatibility
Enhanced Terahertz Radiation Generation of Photoconductive Antennas Based on Manganese Ferrite Nanoparticles
This paper presents a significant effect of manganese ferrite nanoparticles (MnFe2O4 NPs) on the increase of the surface photoconductivity of semiconductors. Herein, the optical characterization of photo-excited carriers of silicon coated with MnFe2O4 NPs was studied by using THz time-domain spectroscopy (THz-TDs). We observed that silicon coated with MnFe2O4 NPs provided a significantly enhanced attenuation of THz radiation in comparison with bare silicon substrates under laser irradiation. The experimental results were assessed in the context of a surface band structure model of semiconductors. In addition, photoconductive antennas coated with MnFe2O4 NPs significantly improved the efficiency of THz radiation generation and signal to noise ratio of the THz signal. This work demonstrates that coating with MnFe2O4 NPs could improve the overall performance of THz systems, and MnFe2O4 NPs could be further used for the implementation of novel optical devicesQ.Z. acknowledges a fellowship from the Chinese Scholarship Council. Part of the project was funded by the European Commission (grant Future NanoNeeds to WJP). Financial support from MINECO (MAT2015â74381-JIN to B.P., RYC-2014â16962 to P.dP.), the ConsellerĂa de Cultura, EducaciĂłn e OrdenaciĂłn Universitaria (Centro singular de investigaciĂłn de Galicia accreditation 2016â2019, ED431G/09), and the European Regional Development Fund (ERDF) is gratefully acknowledgedS
Direct protein quantification in complex sample solutions by surface-engineered nanorod probes
Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essenceThis research was supported by the European Commission FP7 NAMDIATREAM project (EU NMP4-LA-2010â246479), and the German Research Foundation (DFG grant PA 794/25-1)S
Biosensor comprising metal nanoparticles
[ES] La presente invenciĂłn se refiere a un biosensor
donde la detecciĂłn del analito se realiza de forma
visual por el cambio de color en las zonas del soporte
en que el analito esté presente producido por las
nanopartĂculas al ser irradiadas con una fuente de luz
externa[EN] The present invention discloses a biosensor for visual detection of an analyte, based on the light to heat conversion properties of metal nanoparticles: the analyte is visually detected by the colour change in the support areas (where the analyte is present), produced as a result of the heat generated by the metal nanoparticles where they are irradiated with an external light source. Use of said biosensor in a method for the detection of analytes is also claimed.Peer reviewedUniversidad de Zaragoza, FundaciĂłn Agencia Aragonesa para la InvestigaciĂłn y el Desarrollo, Consejo Superior de Investigaciones CientĂficas (España)B1 Patente sin examen previ
Nanosized metalâorganic frameworks as unique platforms for bioapplications
Metalâorganic frameworks (MOFs) are extremely versatile materials, which serve to create platforms with exceptional porosity and specific reactivities. The production of MOFs at the nanoscale (NMOFs) offers the possibility of creating innovative materials for bioapplications as long as they maintain the properties of their larger counterparts. Due to their inherent chemical versatility, synthetic methods to produce them at the nanoscale can be combined with inorganic nanoparticles (NPs) to create nanocomposites (NCs) with one-of-a-kind features. These systems can be remotely controlled and can catalyze abiotic reactions in living cells, which have the potential to stimulate further research on these nanocomposites as tools for advanced therapiesS
Homogeneous Biosensing Based on Magnetic Particle Labels
The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation
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