Cytotoxicity of CdSe and CdSe/ZnS nanoparticles has been investigated for different surface modifications such as coating with mercaptopropionic acid, silanization, and polymer coating. For all cases, quantitative values for the onset of cytotoxic effects in serum-free culture media are given. These values are correlated with microscope images in which the uptake of the particles by the cells has been investigated. Our data suggest that in addition to the release of toxic Cd 2+ ions from the particles also their surface chemistry, in particular their stability toward aggregation, plays an important role for cytotoxic effects. Additional patch clamp experiments investigate effects of the particles on currents through ion channels.

Cytotoxicity of colloidal CdSe and CdSe/ZnS nanoparticles.

Macrophages are one of the principal immune effector cells that play essential roles as secretory, phagocytic, and antigen-presenting cells in the immune system. In this study, we address the issue of cytotoxicity and immunogenic effects of gold nanoparticles on RAW264.7 macrophage cells. The cytotoxicity of gold nanoparticles has been correlated with a detailed study of their endocytotic uptake using various microscopy tools such as atomic force microscopy (AFM), confocal-laser-scanning microscopy (CFLSM), and transmission electron microscopy (TEM). Our findings suggest that Au(0) nanoparticles are not cytotoxic, reduce the production of reactive oxygen and nitrite species, and do not elicit secretion of proinflammatory cytokines TNF-α and IL1-β, making them suitable candidates for nanomedicine. AFM measurements suggest that gold nanoparticles are internalized inside the cell via a mechanism involving pinocytosis, while CFLSM and TEM studies indicate their internalization in lysosomal bodies arranged in ...

Biocompatibility of gold nanoparticles and their endocytotic fate inside the cellular compartment: a microscopic overview.

"Nanoantibiotics": a new paradigm for treating infectious diseases using nanomaterials in the antibiotics resistant era.

There have been major advances in the design and fabrication of structured delivery systems for the encapsulation of nutraceutical and functional food components. A wide variety of delivery systems is now available, each with its own advantages and disadvantages for particular applications. This review begins by discussing some of the major nutraceutical and functional food components that need to be delivered and highlights the main limitations to their current utilization within the food industry. It then discusses the principles underpinning the rational design of structured delivery systems: the structural characteristics of the building blocks; the nature of the forces holding these building blocks together; and, the different ways of assembling these building blocks into structured delivery systems. Finally, we review the major types of structured delivery systems that are currently available to food scientists: lipid-based (simple, multiple, multilayer, and solid lipid particle emulsions); surfactant-based (simple micelles, mixed micelles, vesicles, and microemulsions) and biopolymer-based (soluble complexes, coacervates, hydrogel droplets, and particles). For each type of delivery system we describe its preparation, properties, advantages, and limitations.

Structural design principles for delivery of bioactive components in nutraceuticals and functional foods.

Solid lipid nanoparticles as a drug delivery system for peptides and proteins.

Lymphatic drainage plays an important role in the uptake of particulates in the respiratory system, being also associated to the spreading of lung cancer through metastasis development. In recent years solid lipid nanoparticles (SLN) have been proposed as carriers of anti-tumoural drugs, for their low toxicity and surface characteristics make them suitable for either imaging (gamma-scintigraphy) or therapy upon encapsulation of cytotoxic drugs. Assessment of inhaled radiolabelled SLN biodistribution is described in the present work. Methods : Nanoparticles (200 nm) were radiolabelled with 99m Tc using the lipophilic chelator d, l -hexamehylpropyleneamine oxime (HMPAO). Biodistribution studies were carried out following aerosolisation and administration of a 99m Tc-HMPAO-SLN suspension to a group of adult male Wistar rats. A 60 min dynamic image acquisition was performed in a gamma-camera, followed by static image collection at 30 min intervals up to 4 h postinhalation. Radiation counting was performed in ...

Lymphatic Uptake of Pulmonary Delivered Radiolabelled Solid Lipid Nanoparticles

Synthesis, characterization, and biodistribution of oxo complexes of technetium-99m with biguanide and N1-substituted ligands.

Visualising deep lung lymphatic drainage with radioliposomes.

The purpose of this review is not to present a comprehensive description of all the mathematical tools used in nuclear medicine, but to emphasize the importance of the mathematical method in nuclear medicine and to elucidate some of the mathematical concepts currently used. We can distinguish three different areas in which mathematical support has been offered to nuclear medicine: physiology, methodology and data processing. Nevertheless, the boundaries between these areas can be indistinct. It is impossible in a single article to give even an idea of the extent and complexity of the procedures currently used in nuclear medicine, such as image processing, reconstruction from projections and artificial intelligence. These disciplines do not belong to nuclear medicine: they are already branches of engineering, and my interest will reside simply in revealing a little of the elegance and the fantastic potential of these new “allies” of nuclear medicine. In this review the mathematics of physiological interpretation and methodology are considered together in the same section. General aspects of data-processing methods, including image processing and artificial intelligence, are briefly analysed. The mathematical tools that are most often used to assist the interpretation of biological phenomena in nuclear medicine are considered; these include convolution and deconvolution methods, Fourier analysis, factorial analysis and neural networking.

Nuclear medicine and mathematics

The authors present here a registration solution and a 3D integrated representation of the fused modalities, CT and SPECT. The registration process is based on the inertial moments determination. The visualization process uses a raycaster philosophy with multiple objects in volume. Functional data is represented with pseudo colour on orthogonal clipping planes, anatomical information is displayed using a raycaster approach with a grey shade look up table. The registration process is evaluated with a phantom derived from a genuine clinical volume. A case study is presented. >

J. J. Pedroso de Lima

Papers

Lymphatic Uptake of Pulmonary Delivered Radiolabelled Solid Lipid Nanoparticles

Synthesis, characterization, and biodistribution of oxo complexes of technetium-99m with biguanide and N1-substituted ligands.

Visualising deep lung lymphatic drainage with radioliposomes.

Nuclear medicine and mathematics

3D registration and integrated visualization of multimodal clinical data