The antibacterial action of silver is utilized in numerous consumer products and medical devices. Metallic silver, silver salts, and also silver nanoparticles are used for this purpose. The state of research on the effect of silver on bacteria, cells, and higher organisms is summarized. It can be concluded that the therapeutic window for silver is narrower than often assumed. However, the risks for humans and the environment are probably limited.

Silver as Antibacterial Agent: Ion, Nanoparticle, and Metal

In vivo imaging, which enables us to peer deeply within living subjects, is producing tremendous opportunities both for clinical diagnostics and as a research tool. Contrast material is often required to clearly visualize the functional architecture of physiological structures. Recent advances in nanomaterials are becoming pivotal to generate the high-resolution, high-contrast images needed for accurate, precision diagnostics. Nanomaterials are playing major roles in imaging by delivering large imaging payloads, yielding improved sensitivity, multiplexing capacity, and modularity of design. Indeed, for several imaging modalities, nanomaterials are now not simply ancillary contrast entities, but are instead the original and sole source of image signal that make possible the modality’s existence. We address the physicochemical makeup/design of nanomaterials through the lens of the physical properties that produce contrast signal for the cognate imaging modality—we stratify nanomaterials on the basis of thei...

Nanomaterials for In Vivo Imaging

Stimuli-responsive magnetic particles for biomedical applications.

The detection techniques used in biosensors can be broadly classified into label-based and label-free. Label-based detection relies on the specific properties of labels for detecting a particular target. In contrast, label-free detection is suitable for the target molecules that are not labeled or the screening of analytes which are not easy to tag. Also, more types of label-free biosensors have emerged with developments in biotechnology. The latest developed techniques in label-free biosensors, such as field-effect transistors-based biosensors including carbon nanotube field-effect transistor biosensors, graphene field-effect transistor biosensors and silicon nanowire field-effect transistor biosensors, magnetoelastic biosensors, optical-based biosensors, surface stress-based biosensors and other type of biosensors based on the nanotechnology are discussed. The sensing principles, configurations, sensing performance, applications, advantages and restriction of different label-free based biosensor...

Progress of new label-free techniques for biosensors: a review.

ConspectusPositron emission tomography (PET) is a radionuclide imaging technology that plays an important role in preclinical and clinical research. With administration of a small amount of radiotracer, PET imaging can provide a noninvasive, highly sensitive, and quantitative readout of its organ/tissue targeting efficiency and pharmacokinetics. Various radiotracers have been designed to target specific molecular events. Compared with antibodies, proteins, peptides, and other biologically relevant molecules, nanoparticles represent a new frontier in molecular imaging probe design, enabling the attachment of different imaging modalities, targeting ligands, and therapeutic payloads in a single vector.We introduce the radiolabeled nanoparticle platforms that we and others have developed. Due to the fundamental differences in the various nanoparticles and radioisotopes, most radiolabeling methods are designed case-by-case. We focus on some general rules about selecting appropriate isotopes for given types of ...

Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

We present in this article an outline of some cyclotron-based irradiation techniques that can be used to directly radiolabel industrially manufactured nanoparticles, as well as two techniques for synthesis of labelled nanoparticles using cyclotron-generated radioactive precursor materials. These radiolabelled nanoparticles are suitable for a range of different in vitro and in vivo tracing studies of relevance to the field of nanotoxicology. A basic overview is given of the relevant physics of nuclear reactions regarding both ion-beam and neutron production of radioisotopes. The various issues that determine the practicality and usefulness of the different methods are discussed, including radioisotope yield, nuclear reaction kinetics, radiation and thermal damage, and radiolabel stability. Experimental details are presented regarding several techniques applied in our laboratories, including direct light-ion activation of dry nanoparticle samples, neutron activation of nanoparticles and suspensions using an ion-beam driven activator, spark-ignition generation of nanoparticle aerosols using activated electrode materials, and radiochemical synthesis of nanoparticles using cyclotron-produced isotopes. The application of these techniques is illustrated through short descriptions of some selected results thus far achieved. It is shown that these cyclotron-based methods offer a very useful range of options for nanoparticle radiolabelling despite some experimental difficulties associated with their application. For direct nanoparticle radiolabelling, if care is taken in choosing the experimental conditions applied, useful activity levels can be achieved in a wide range of nanoparticle types, without causing substantial thermal or radiation damage to the nanoparticle structure. Nanoparticle synthesis using radioactive precursors presents a different set of issues and offers a complementary and equally valid approach when laboratory generation of the nanoparticles is acceptable for the proposed studies, and where an appropriate radiolabel can be incorporated into the nanoparticles during synthesis.

Radiolabelling of engineered nanoparticles for in vitro and in vivo tracing applications using cyclotron accelerators

Cancer often remains an incurable disease, despite significant progresses in diagnosis and treatment that have been made. Specifically, the use of nuclear medicine in oncology is greatly contributing to both imaging and therapy aspects. Targeted therapies are a major field of interest since it increases efficiency and reduces side effects. Brachytherapy is among the most valuable of recent developments for treating localized tumours resulting in improvements in improved quality of life. This is primarily because it irradiates cancerous cells most exclusively while barely effecting healthy tissue. The use of radiochemicals implies specific management for production, transport and handling that have limited the development of this technique. This review article describes brachytherapy and their latest developments. Furthermore, alternative activation methods for the production of radioisotopes and a novel delivery system for targeted multi-therapy by using PLA-ferrite nanospheres are described.

Brachytherapy: state of the art and possible improvements.

In the framework of the EC funded INBARCA project (Innovative Nanosphere Brachytherapy with Adiabatic Resonance Crossing using Accelerators) a compact, accelerator driven neutron activator has been designed and constructed, with the aim of efficiently utilising ion-beam generated neutrons for the production of radioactive nanoparticles for brachytherapy. The design is based on a modified version of the Adiabatic Resonance Crossing concept, first proposed by C. Rubbia of CERN. The neutron activator has been tested in two experimental configurations, with and without a central lead block. The activation performance on different materials was quantified by γ-spectrometry. Monte Carlo simulations accompanied all experimental runs, and neutron unfolding techniques were used to derive the experimental neutron spectrum. This paper compares the simulated and the unfolded neutron spectra thus obtained, as well as the experimental and simulated activation results for pure Au, Ag, Mo, Ni, Ho and Re foils as well as for Re and Ho nanoparticles.

Experimental Results of an Accelerator-Driven Neutron Activator for Medical Radioisotope Production

Medical radioisotopes activation in the JRC cyclotron-driven INBARCA neutron activator

A compact, accelerator-driven, neutron activator based on the Adiabatic Resonance Crossing (ARC) method has been developed in the frame of the INBARCA project, funded under the EUREKA programme. It has been assembled and tested at the Scanditronix MC40 Cyclotron of the Joint Research Centre (JRC Ispra, Italy) with the aim of efficiently utilising ion-beam generated neutrons for the production of radioactive nanoparticles for brachytherapy. Monte Carlo and Computational Fluid Dynamics simulations were carried out to optimise the design of the activator, which is based on a hybrid approach, coupling a lead buffer and a graphite reflector. The activator has been tested under various experimental conditions, and the neutron fluxes at the different irradiation positions of the system were calculated. Experimental results on the activation of pure Au, Al, Mo, Ho and Re foils are presented and show a good agreement with calculations. The results obtained are compared to previously reported work. The next experimental stage will be the activation of Ho/Re PolyLactic Acid nanoparticles for brachytherapy applications.

L. Maciocco

Papers

Radiolabelling of engineered nanoparticles for in vitro and in vivo tracing applications using cyclotron accelerators

Brachytherapy: state of the art and possible improvements.

Experimental Results of an Accelerator-Driven Neutron Activator for Medical Radioisotope Production

Medical radioisotopes activation in the JRC cyclotron-driven INBARCA neutron activator

Design and Test of an Accelerator Driven Neutron Activator at the JRC Cyclotron of the European Commission