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1.
Arch Virol ; 166(10): 2673-2682, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34297222

RESUMEN

Traditional veterinary virus vaccines, such as inactivated and live-attenuated vaccines, have achieved tremendous success in controlling many viral diseases of livestock and chickens worldwide. However, many recent viral outbreaks caused by different emerging and re-emerging viruses continue to be reported annually worldwide. It is therefore necessary to develop new control regimens. Nanoparticle research has received considerable attention in the last two decades as a promising platform with significant success in veterinary medicine, replacing traditional viral vector vaccines. However, the field of nanoparticle applications is still in its initial phase of growth. Here, we discuss various preparation methods, characteristics, physical properties, antiviral effects, and pharmacokinetics of well-developed nanoparticles and the potential of nanoparticles or nano-vaccines as a promising antiviral platform for veterinary medicine.


Asunto(s)
Antivirales/uso terapéutico , Nanopartículas/uso terapéutico , Medicina Veterinaria , Virosis/veterinaria , Animales , Antivirales/química , Antivirales/clasificación , Pollos , Ganado , Nanopartículas/química , Nanopartículas/clasificación , Preparaciones Farmacéuticas , Vacunas Virales/química , Vacunas Virales/clasificación , Vacunas Virales/uso terapéutico , Virosis/tratamiento farmacológico , Virosis/prevención & control , Virus/efectos de los fármacos , Virus/inmunología
2.
Exp Parasitol ; 218: 108008, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32979343

RESUMEN

Acanthamoeba sp. is a free living amoeba that causes severe, painful and fatal infections, viz. Acanthamoeba keratitis and granulomatous amoebic encephalitis among humans. Antimicrobial chemotherapy used against Acanthamoeba is toxic to human cells and show side effects as well. Infections due to Acanthamoeba also pose challenges towards currently used antimicrobial treatment including resistance and transformation of trophozoites to resistant cyst forms that can lead to recurrence of infection. Therapeutic agents targeting central nervous system infections caused by Acanthamoeba should be able to cross blood-brain barrier. Nanoparticles based drug delivery put forth an effective therapeutic method to overcome the limitations of currently used antimicrobial chemotherapy. In recent years, various researchers investigated the effectiveness of nanoparticles conjugated drug and/or naturally occurring plant compounds against both trophozoites and cyst form of Acanthamoeba. In the current review, a reasonable effort has been made to provide a comprehensive overview of various nanoparticles tested for their efficacy against Acanthamoeba. This review summarizes the noteworthy details of research performed to elucidate the effect of nanoparticles conjugated drugs against Acanthamoeba.


Asunto(s)
Acanthamoeba/efectos de los fármacos , Amebicidas/administración & dosificación , Nanopartículas/administración & dosificación , Acanthamoeba/crecimiento & desarrollo , Queratitis por Acanthamoeba/tratamiento farmacológico , Queratitis por Acanthamoeba/parasitología , Amebiasis/tratamiento farmacológico , Amebiasis/mortalidad , Amebiasis/parasitología , Amebicidas/farmacología , Amebicidas/uso terapéutico , Biguanidas/administración & dosificación , Biguanidas/farmacología , Biguanidas/uso terapéutico , Infecciones Protozoarias del Sistema Nervioso Central/tratamiento farmacológico , Infecciones Protozoarias del Sistema Nervioso Central/mortalidad , Infecciones Protozoarias del Sistema Nervioso Central/parasitología , Clorhexidina/administración & dosificación , Clorhexidina/farmacología , Clorhexidina/uso terapéutico , Sistemas de Liberación de Medicamentos , Inmunocompetencia , Huésped Inmunocomprometido , Encefalitis Infecciosa/tratamiento farmacológico , Encefalitis Infecciosa/mortalidad , Encefalitis Infecciosa/parasitología , Nanopartículas/clasificación , Nanopartículas/uso terapéutico , Trofozoítos/efectos de los fármacos
3.
Int J Mol Sci ; 19(7)2018 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-29996469

RESUMEN

Nanoparticles (NPs) have attracted unequivocal attention in recent years due to their potential applications in therapeutics, bio-imaging and material sciences. For drug delivery, NP-based carrier systems offer several advantages over conventional methods. When conjugated with ligands and drugs (or other therapeutic molecules), administrated NPs are able to deliver cargo to targeted sites through ligand-receptor recognition. Such targeted delivery is especially important in cancer therapy. Through this targeted cancer nanotherapy, cancer cells are killed with higher specificity, while the healthy cells are spared. Furthermore, NP drug delivery leads to improved drug load, enhanced drug solubility and stability, and controlled drug release. G protein-coupled receptors (GPCRs) are a superfamily of cell transmembrane receptors. They regulate a plethora of physiological processes through ligand-receptor-binding-induced signaling transduction. With recent evidence unveiling their roles in cancer, GPCR agonists and antagonists have quickly become new targets in cancer therapy. This review focuses on the application of some notable nanomaterials, such as dendrimers, quantum dots, gold nanoparticles, and magnetic nanoparticles, in GPCR-related cancers.


Asunto(s)
Antineoplásicos/administración & dosificación , Nanopartículas/administración & dosificación , Neoplasias/tratamiento farmacológico , Receptores Acoplados a Proteínas G/metabolismo , Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Ensayos Clínicos como Asunto , Portadores de Fármacos , Oro/química , Humanos , Nanopartículas/química , Nanopartículas/clasificación , Neoplasias/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inhibidores
4.
Int J Mol Sci ; 18(5)2017 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-28471401

RESUMEN

In recent years, the influence of the tumor microenvironment (TME) on cancer progression has been better understood. Macrophages, one of the most important cell types in the TME, exist in different subtypes, each of which has a different function. While classically activated M1 macrophages are involved in inflammatory and malignant processes, activated M2 macrophages are more involved in the wound-healing processes occurring in tumors. Tumor-associated macrophages (TAM) display M2 macrophage characteristics and support tumor growth and metastasis by matrix remodeling, neo-angiogenesis, and suppressing local immunity. Due to their detrimental role in tumor growth and metastasis, selective targeting of TAM for the treatment of cancer may prove to be beneficial in the treatment of cancer. Due to the plastic nature of macrophages, their activities may be altered to inhibit tumor growth. In this review, we will discuss the therapeutic options for the modulation and targeting of TAM. Different therapeutic strategies to deplete, inhibit recruitment of, or re-educate TAM will be discussed. Current strategies for the targeting of TAM using nanomedicine are reviewed. Passive targeting using different nanoparticle systems is described. Since TAM display a number of upregulated surface proteins compared to non-TAM, specific targeting using targeting ligands coupled to nanoparticles is discussed in detail.


Asunto(s)
Macrófagos/inmunología , Nanomedicina/métodos , Neoplasias/terapia , Animales , Humanos , Activación de Macrófagos , Nanopartículas/química , Nanopartículas/clasificación , Nanopartículas/uso terapéutico
5.
Int J Mol Sci ; 18(5)2017 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-28531102

RESUMEN

Prostate and breast cancer are the second most and most commonly diagnosed cancer in men and women worldwide, respectively. The American Cancer Society estimates that during 2016 in the USA around 430,000 individuals were diagnosed with one of these two types of cancers, and approximately 15% of them will die from the disease. In Europe, the rate of incidences and deaths are similar to those in the USA. Several different more or less successful diagnostic and therapeutic approaches have been developed and evaluated in order to tackle this issue and thereby decrease the death rates. By using nanoparticles as vehicles carrying both diagnostic and therapeutic molecular entities, individualized targeted theranostic nanomedicine has emerged as a promising option to increase the sensitivity and the specificity during diagnosis, as well as the likelihood of survival or prolonged survival after therapy. This article presents and discusses important and promising different kinds of nanoparticles, as well as imaging and therapy options, suitable for theranostic applications. The presentation of different nanoparticles and theranostic applications is quite general, but there is a special focus on prostate cancer. Some references and aspects regarding breast cancer are however also presented and discussed. Finally, the prostate cancer case is presented in more detail regarding diagnosis, staging, recurrence, metastases, and treatment options available today, followed by possible ways to move forward applying theranostics for both prostate and breast cancer based on promising experiments performed until today.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Nanopartículas/química , Vehículos Farmacéuticos/química , Neoplasias de la Próstata/tratamiento farmacológico , Nanomedicina Teranóstica/métodos , Femenino , Humanos , Masculino , Nanopartículas/clasificación , Vehículos Farmacéuticos/clasificación , Neoplasias de la Próstata/diagnóstico por imagen
6.
Biochim Biophys Acta ; 1848(1 Pt A): 67-75, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25285435

RESUMEN

Molecular interactions between engineered nanomaterials (ENM) and biomembranes are not well understood. This study investigated the effects of particle size and surface functional group on polystyrene nanoparticles' (PNPs) potency for biomembrane disruption. Electrochemical impedance spectroscopy was used to measure changes in the electrical resistance (Rm) of a tethered bilayer lipid membrane BLM (tBLM) composed of 1,2-dioleoyl-sn-glycero-phosphocholine (DOPC) following PNP exposure. All PNPs tested triggered a decline in the Rm that could be described using an exponential-decay model. Statistical hierarchical clustering analysis of two model parameters (exponential rate constant and fractional loss of Rm) could distinguish between the PNPs based on both size and surface functional group. For COOH modified nanoparticles, 20nm PNPs were more potent in reducing Rm than 100nm PNP. However, for amidine modified nanoparticles, 120nm PNPs were more potent in reducing Rm than 23nm PNP. The COOH modified PNPs were more potent in reducing Rm than amidine modified PNP, which tended to aggregate following exposure to a tBLM. Ultra performance liquid chromatography-mass spectroscopy analysis suggested that the aggregation may have been triggered by DOPC that was removed from the tBLM by the amidine PNP.


Asunto(s)
Membrana Dobles de Lípidos/química , Nanopartículas/química , Fosfatidilcolinas/química , Poliestirenos/química , Cromatografía Liquida/métodos , Análisis por Conglomerados , Espectroscopía Dieléctrica/métodos , Impedancia Eléctrica , Nanopartículas/clasificación , Tamaño de la Partícula , Espectrometría de Masa por Ionización de Electrospray
7.
Crit Rev Microbiol ; 42(2): 209-21, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25430521

RESUMEN

Nanotechnology is gaining tremendous attention in the present century due to its expected impact on many important areas such as medicine, energy, electronics, and space industries. In this context, actinobacterial biosynthesis of nanoparticles is a reliable, eco-friendly, and important aspect of green chemistry approach that interconnects microbial biotechnology and nanobiotechnology. Antibiotics produced by actinobacteria are popular in almost all the therapeutic measures and it is known that these microbes are also helpful in the biosynthesis of nanoparticles with good surface and size characteristics. In fact, actinobacteria are efficient producers of nanoparticles that show a range of biological properties, namely, antibacterial, antifungal, anticancer, anti-biofouling, anti-malarial, anti-parasitic, antioxidant, etc. This review describes the potential use of the actinobacteria as the novel sources for the biosynthesis of nanoparticles with improved biomedical applications.


Asunto(s)
Actinobacteria/fisiología , Biotecnología , Nanopartículas/metabolismo , Nanotecnología , Antiinfecciosos/química , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacología , Espacio Extracelular/metabolismo , Humanos , Espacio Intracelular/metabolismo , Nanopartículas/química , Nanopartículas/clasificación , Nanopartículas/ultraestructura
8.
Nanomedicine ; 11(2): 457-65, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25072377

RESUMEN

The shape of nanoparticles and nanomaterials is a fundamental characteristic that has been shown to influence a number of their properties and effects, particularly for nanomedical applications. The information related with this feature of nanoparticles and nanomaterials is, therefore, crucial to exploit and foster in existing and future research in this area. We have found that descriptions of morphological and spatial properties are consistently reported in the nanotechnology literature, and in general, these morphological properties can be observed and measured using various microscopy techniques. In this paper, we outline a taxonomy of nanoparticle shapes constructed according to nanotechnologists' descriptions and formal geometric concepts that can be used to address the problem of nanomaterial categorization. We employ an image segmentation technique, belonging to the mathematical morphology field, which is capable of identifying shapes in images that can be used to (semi-) automatically annotate nanoparticle images. FROM THE CLINICAL EDITOR: This team of authors outlines a taxonomy of nanoparticle shapes constructed according to nanotechnologists' descriptions and formal geometric concepts enabling nanomaterial categorization. They also employ a mathematical morphology-based image segmentation system, capable of identifying shapes and can be utilized in semi-automated annotation of nanoparticle images.


Asunto(s)
Nanomedicina , Nanopartículas/química , Nanoestructuras/química , Humanos , Nanopartículas/clasificación , Nanopartículas/uso terapéutico , Nanoestructuras/clasificación , Nanoestructuras/uso terapéutico
9.
Water Sci Technol ; 72(12): 2318-24, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26676021

RESUMEN

The understanding of nano-sized particle separation processes has been limited by difficulties of nanoparticle characterization. In this study, nanoparticle tracking analysis (NTA) was deployed to evaluate the absolute particle size distributions in laboratory scale flocculation and filtration experiments with silver nanoparticles. The results from NTA were consistent with standard theories of particle destabilization and transport. Direct observations of changes in absolute particle size distributions from NTA enhance both qualitative and quantitative understanding of particle separation processes of nano-sized particles.


Asunto(s)
Nanopartículas/química , Benzopiranos , Compuestos de Calcio/química , Ácido Cítrico/química , Filtración , Floculación , Sustancias Húmicas , Concentración de Iones de Hidrógeno , Compuestos de Magnesio/química , Nanopartículas del Metal/química , Nanopartículas del Metal/clasificación , Nanopartículas/análisis , Nanopartículas/clasificación , Nitratos/química , Concentración Osmolar , Tamaño de la Partícula , Povidona/química , Plata
10.
Acc Chem Res ; 45(11): 1916-26, 2012 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-22449243

RESUMEN

Although nanoparticle (NP) assemblies are at the beginning of their development, their unique geometrical shapes and media-responsive optical, electronic, and magnetic properties have attracted significant interest. Nanoscale assembly bridges multiple levels of hierarchy of materials: individual nanoparticles, discrete molecule-like or virus-like nanoscale agglomerates, microscale devices, and macroscale materials. The capacity to self-assemble can greatly facilitate the integration of nanotechnology with other technologies and, in particular, with microscale fabrication. In this Account, we describe developments in the emerging field of dynamic NP assemblies, which are spontaneously form superstructures containing more than two inorganic nanoscale particles that display the ability to change their geometrical, physical, chemical, and other attributes. In many ways, dynamic assemblies can represent a bottleneck in the "bottom-up" fabrication of NP-based devices because they can produce a much greater variety of assemblies, but they also provide a convenient tool for variation of geometries and dimensions of nanoparticle assemblies. Superstructures of NPs (and those held together by similar intrinsic forces)are classified into two groups: Class 1 where media and external fields can alter shape, conformation, and order of stable super structures with a nearly constant number of NPs or Class 2 where the total number of NPs changes, while the organizational motif in the final superstructure remains the same. The future development of successful dynamic assemblies requires understanding the equilibrium in dynamic NP systems. The dynamic nature of Class 1 assemblies is associated with the equilibrium between different conformations of a superstructure and is comparable to the isomerization in classical chemistry. Class 2 assemblies involve the formation or breakage of linkages between the NPs, which is analogous to the classical chemical equilibrium for the formation of a molecule from atoms. Finer classification of NP assemblies in accord with established conventions in the field may include different size dimensionalities: discrete assemblies (artificial molecules) and one-dimensional (spaced chains), two-dimensional (sheets), and three-dimensional (superlattices, twisted structures) assemblies. Notably, these dimensional attributes must be regarded as primarily topological in nature because all of these superstructures can acquire complex three-dimensional shapes. We discuss three primary strategies used to prepare NP superstructures: (1) anisotropy-based assemblies utilizing either intrinsic force field anisotropy around NPs or external anisotropy associated with templates or applied fields, (2) assembly methods utilizing uniform NPs with isotropic interactions, and (3) methods based on mutual recognition of biomolecules, such as DNA and antigen-antibody interactions. We consider optical, electronic, and magnetic properties of dynamic superstructures, focusing primarily on multiparticle effects in NP superstructures as represented by surface plasmon resonance, NP-NP charge transport, and multibody magnetization. Unique properties of NP superstructures are being applied to biosensing, drug delivery, and nanoelectronics. For both Class 1 and Class 2 dynamic assemblies, biosensing is the most dominant and well-developed area of dynamic nanostructures being successfully transitioned into practice. We can foresee the rapid development of dynamic NP assemblies toward applications in harvesting of dissipated energy, photonics, and electronics. The final part of this Account is devoted to the fundamental questions facing dynamic assemblies of NPs in the future.


Asunto(s)
Nanopartículas/química , Nanotecnología/métodos , Anisotropía , Técnicas Biosensibles , Sistemas de Liberación de Medicamentos , Electrónica , Magnetismo , Nanopartículas/clasificación , Fenómenos Ópticos
11.
J Am Chem Soc ; 134(49): 19977-80, 2012 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-23190283

RESUMEN

III-V nanocrystals displaying high crystallinity and low size dispersity are difficult to access by direct synthesis from molecular precursors. Here, we demonstrate that cation exchange of cadmium pnictide nanocrystals with group 13 ions yields monodisperse, crystalline III-V nanocrystals, including GaAs, InAs, GaP, and InP. This report highlights the versatility of cation exchange for accessing nanocrystals with covalent lattices.


Asunto(s)
Arsenicales/síntesis química , Galio/química , Indio/química , Nanopartículas/química , Fósforo/química , Arsenicales/química , Cadmio/química , Iones/química , Nanopartículas/clasificación
12.
Nanomedicine ; 8(2): 147-66, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21703993

RESUMEN

Drug delivery is an interdisciplinary and independent field of research and is gaining the attention of pharmaceutical researchers, medical doctors and industry. A safe and targeted drug delivery could improve the performance of some classic medicines already on the market, and moreover, will have implications for the development and success of new therapeutic strategies such as anticancer drug delivery, peptide and protein delivery and gene therapy. In the last decade, several drug-delivery technologies have emerged and a fascinating part of this field is the development of nanoscale drug delivery devices. Nanoparticles (NPs) have been developed as an important strategy to deliver conventional drugs, recombinant proteins, vaccines and more recently, nucleotides. NPs and other colloidal drug-delivery systems modify the kinetics, body distribution and drug release of an associated drug. This review article focuses on the potential of nanotechnology in medicine and discusses different nanoparticulate drug-delivery systems including polymeric NPs, ceramic NPs, magnetic NPs, polymeric micelles and dendrimers as well as their applications in therapeutics, diagnostics and imaging. FROM THE CLINICAL EDITOR: This comprehensive review focuses on different nanoparticulate drug-delivery systems including polymeric NPs, ceramic NPs, magnetic NPs, polymeric micelles and dendrimers as well as their applications in therapeutics, diagnostics and imaging.


Asunto(s)
Diagnóstico por Imagen/métodos , Sistemas de Liberación de Medicamentos , Terapia Genética/métodos , Nanopartículas/uso terapéutico , Dendrímeros/uso terapéutico , Humanos , Micelas , Nanopartículas/clasificación , Nucleótidos/uso terapéutico , Péptidos/uso terapéutico , Proteínas Recombinantes/uso terapéutico , Vacunas/uso terapéutico
13.
J Microencapsul ; 29(7): 636-49, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22494033

RESUMEN

This review highlights the materials, mechanisms and applications of microencapsulation by interfacial polycondensation in different areas. This technology entraps active ingredients inside microcapsules/microspheres, having an average diameter ranging from nanosize to several 100 µ. Polycondensation reactions take place at the boundary of two phases to form the shells of microcapsules or matrix microspheres. The emulsion can be classified into three types: water-in-oil, oil-in-water and oil-in-oil. According to the hydrophilic-lipophilic property of core phase, different active substances, such as proteins, enzymes, insecticides, herbicides, vitamins, catalysts, drugs, essential oils, dyes and phase change materials, have been successfully incorporated into different microcapsules/microspheres. Based on the shell-forming materials, this technology is capable of preparing polyamine, polyurea, polyurethane, polythiourea, polyester, polyepoxide, polyacrylamide and polysiloxane microcapsules. Over the past two decades, microcapsules prepared by interfacial polycondensation have been widely used in carbonless paper, cosmetics, pharmacy, agriculture, energy storage/transfer, thermal insulation/regulation and information and magnetic recording.


Asunto(s)
Cápsulas/química , Microesferas , Nanopartículas/química , Polímeros/química , Polímeros/síntesis química , Animales , Cápsulas/clasificación , Humanos , Nanopartículas/clasificación
14.
Yao Xue Xue Bao ; 47(7): 856-62, 2012 Jul.
Artículo en Zh | MEDLINE | ID: mdl-22993848

RESUMEN

As nanomedicines are developing fast in both academic and market areas, building up suitable methods for nanomedicine analysis with proper techniques is an important subject, requiring further research. The techniques, which could be employed for grain size analysis of nanomedicines, were reviewed. Several key techniques were discussed with their principles, scope of applications, advantages and defects. Their applications to nanomedine analysis were discussed according to the properties of different nanomedicines, with the purpose of providing some suggestions for the control and administration of nanomedicines.


Asunto(s)
Sistemas de Liberación de Medicamentos , Nanopartículas/análisis , Luz , Microscopía Electrónica/métodos , Microscopía de Sonda de Barrido/métodos , Nanopartículas/química , Nanopartículas/clasificación , Tamaño de la Partícula , Dispersión de Radiación , Dispersión del Ángulo Pequeño , Espectrometría Raman/métodos , Difracción de Rayos X/métodos
15.
Compend Contin Educ Dent ; 33(1): 42-5, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22432175

RESUMEN

Introduced more than some 50 years ago, composite resin technology has simplified the manner in which clinicians practice restorative dentistry, offering greater predictability and improved physical properties. Decades of material science and laboratory development along with clinical trials in human subjects have culminated in composite resin being validated as a reliable, multifunctional restorative material. With a wide range of composite resins available today, clinicians can benefit from knowing the infrastructure of a given material in order to determine which type will work best in a particular clinical situation.


Asunto(s)
Resinas Compuestas/química , Materiales Dentales/química , Restauración Dental Permanente/métodos , Fenómenos Químicos , Resinas Compuestas/clasificación , Materiales Dentales/clasificación , Diseño de Prótesis Dental , Reparación de Prótesis Dental , Humanos , Nanocompuestos/química , Nanocompuestos/clasificación , Nanopartículas/química , Nanopartículas/clasificación
16.
Acc Chem Res ; 43(5): 621-30, 2010 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-20214405

RESUMEN

The ability to engineer the band gap energy of semiconductor nanocrystals has led to the development of nanomaterials with many new exciting properties and applications. Band gap engineering has thus proven to be an effective tool in the design of new nanocrystal-based semiconductor devices. As reported in numerous publications over the last three decades, tuning the size of nanocrystalline semiconductors is one way of adjusting the band gap energy. On the other hand, research on band gap engineering via control of nanocrystal composition, which is achieved by adjusting the constituent stoichiometries of alloyed semiconductors, is still in its infancy. In this Account, we summarize recent research on colloidal alloyed semiconductor nanocrystals that exhibit novel composition-tunable properties. Alloying of two semiconductors at the nanometer scale produces materials that display properties distinct not only from the properties of their bulk counterparts but also from those of their parent semiconductors. As a result, alloyed nanocrystals possess additional properties that are composition-dependent aside from the properties that emerge due to quantum confinement effects. For example, although the size-dependent emission wavelength of the widely studied CdSe nanocrystals can be continuously tuned to cover almost the entire visible spectrum, the near-infrared (NIR) region is far outside its spectral range. By contrast, certain alloy compositions of nanocrystalline CdSe(x)Te(1-x), an alloy of CdSe and CdTe, can efficiently emit light in the NIR spectral window. These NIR-emitting nanocrystals are potentially useful in several biomedical applications. In addition, highly stable nanocrystals formed by alloying CdSe with ZnSe (i.e., Zn(x)Cd(1-x)Se) emit blue light with excellent efficiency, a property seldom achieved by the parent binary systems. As a result, these materials can be used in short-wavelength optoelectronic devices. In the future, we foresee new discoveries related to these interesting nanoalloys. In particular, colloidal semiconductor nanoalloys that exhibit composition-dependent magnetic properties have yet to be reported. Further studies of the alloying mechanism are also needed to develop improved synthetic strategies for the preparation of these alloyed nanomaterials.


Asunto(s)
Aleaciones/química , Nanopartículas/química , Semiconductores , Técnicas de Química Analítica , Fuentes Generadoras de Energía , Nanopartículas/clasificación , Fenómenos Ópticos , Semiconductores/clasificación
17.
Analyst ; 136(5): 872-7, 2011 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-21258678

RESUMEN

Sensitive detection and efficient removal of an increasing number of persistent and emerging environmental pollutants are major challenges in our industrialized world. Now these challenges can be better answered by utilizing the advantages of nanotechnology in addition to traditional methods. Due to unique features of nanomaterials, such as size, surface area, adsorptivity, photoelectronic, and photocatalytic properties, they have emerged to be important materials in the analytical detection and remediation of environmental pollutants.


Asunto(s)
Contaminantes Ambientales/análisis , Restauración y Remediación Ambiental , Nanopartículas/análisis , Adsorción , Contaminantes Ambientales/aislamiento & purificación , Industrias , Nanopartículas/clasificación , Nanopartículas/toxicidad
18.
Ann Occup Hyg ; 55(1): 1-5, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21233257

RESUMEN

In 2010, the European Commission held a short consultation on a proposed definition for nanomaterials, to be used in European Union legislation and programmes. This was in response to a European Parliament resolution, and the definition followed a proposal by one of the Commission's scientific committees. The definition has three parts: on size distribution, size of internal structural elements, and surface area; a material caught by any of these parts meets the definition. There are a number of problems. The definition seems to be written with engineered nanomaterials in mind but as written applies to non-supplied materials, such as smokes. The structural element component seems to capture items such as sunscreen and tennis rackets, which include nanomaterials. Use of the definition will require some international standards, which have yet to be written and which will involve some difficult decisions. It is understandable why there are both size and surface area requirements, but they are not wholly consistent. The Commission plans a further consultation in 2012, but it might be better to delay this until after the standardisation work.


Asunto(s)
Nanopartículas , Terminología como Asunto , Unión Europea , Nanopartículas/clasificación
19.
Life Sci ; 285: 119969, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34547339

RESUMEN

Inflammatory lung diseases related morbidity and mortality impose a significant financial burden. Inflammation is a hallmark of many diseases of the respiratory system which is directly or indirectly linked to adverse health conditions, air pollution, rapid lifestyle changes, and regular outbreaks of microbial infections. The unique anatomical and physiological features of the lungs make them an ideal target organ in the treatment of inflammatory respiratory disease and with the help of inhaled therapy lungs can be targeted directly. The principal objective of this review is to present the comprehensive role of inhaled nano-based therapeutics such as liposomes, niosomes, nanoparticles, nanoemulsion, nanosuspension, and exosomes in the treatment and management of inflammatory respiratory diseases. Inhaled nanomedicines provide targeted diagnosis and treatment, improved drug solubility and distribution, prevent first-pass hepatic metabolism, improved patient compliance, and reduced drug side effects. They overcome several biological barriers in the human body and provide immediate, and quick-onset of action. Future research should be focused on improving the therapeutic efficiency of inhaled nanocarriers and to carry out in-depth mechanistic studies to translate current scientific knowledge for the efficient management of inflammatory lung diseases with minimal or no toxicity.


Asunto(s)
Nanopartículas/administración & dosificación , Neumonía/tratamiento farmacológico , Administración por Inhalación , Animales , Ensayos Clínicos como Asunto , Sistemas de Liberación de Medicamentos , Humanos , Liposomas , Ratones , Nanomedicina/tendencias , Nanopartículas/clasificación
20.
Carbohydr Polym ; 254: 117271, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357852

RESUMEN

Dispersion of cellulose nanocrystals (CNCs) is of utmost importance to guarantee their reliable application. Nevertheless, there is still no consensual method to characterize CNC aggregation. The hypothesis of this paper is that dispersion could be quantified through the classification of aggregates detected in transmission electron microscopy images. k-Means was used to classify image particulate elements of five CNC samples into groups according to their geometric features. Particles were classified into five groups according to their maximum Feret diameter, elongation, circularity and area. Two groups encompassed the most application-critical aggregates: one integrated aggregates of high complexity and low compactness while the other included elongated aggregates. In addition, the characterization of CNC dispersion after different levels of sonication was achieved by assessing the change in the number of elements belonging to each cluster after sonication. This approach could be used as a standard for the characterization of the aggregation state of CNCs.


Asunto(s)
Celulosa/química , Nanopartículas/química , Nanopartículas/ultraestructura , Materiales Biocompatibles/química , Celulosa/clasificación , Fractales , Procesamiento de Imagen Asistido por Computador , Microscopía Electrónica de Transmisión , Nanopartículas/clasificación , Tamaño de la Partícula , Sonicación , Aprendizaje Automático no Supervisado
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