7Be-recoil radiolabelling of industrially manufactured silica nanoparticles

Radiolabelling of industrially manufactured nanoparticles is useful for nanoparticle dosimetry in biodistribution or cellular uptake studies for hazard and risk assessment. Ideally for such purposes any chemical processing post production should be avoided as it may change the physico-chemical characteristics of the industrially manufactured species. In many cases proton irradiation of nanoparticles allows radiolabelling by transmutation of a tiny fraction of their constituent atoms into radionuclides. However, not all types of nanoparticles offer nuclear reactions leading to radionuclides with adequate radiotracer properties. We describe here a process whereby in such cases nanoparticles can be labelled with 7Be, which exhibits a physical halflife of 53.29 days and emits γ-rays of 478 keV energy and is suitable for most radiotracer studies. 7Be is produced via the proton-induced nuclear reaction 7Li(p,n)7Be in a fine-grained lithium compound with which the nanoparticles are mixed. The high recoil energy of 7Be-atoms gives them a range that allows the 7Be-recoils to be transferred from the lithium compound into the nanoparticles by recoil implantation. The nanoparticles can be recovered from the mixture by dissolving the lithium compound and subsequent filtration or centrifugation. The method has been applied to radiolabel industrially manufactured SiO2 nanoparticles. The process can be controlled in such a way that no alterations of the 7Be-labelled nanoparticles are detectable by dynamic light scattering, X-ray diffraction and electron microscopy. Moreover, cyclotrons with maximum proton energies of 17 to 18 MeV that are available in most medical research centres could be used for this purpose.JRC.I.4-Nanobioscience

Nano-Aptamer for Breast Cancer Imaging: Initial Considerations.

The application of aptamers especially in the use of drug delivery systems (DDSs) has the potential to develop in vivo nanoparticles for theranosis (therapy+diagnosis). With the advent of medical imaging and radiotherapeutics, this area of research developing the next era of radiopharmaceuticals is both attractive and promising. Overall, nano-radiopharmaceuticals have the potential to solve several problems regarding the in vivo stability of aptamers. This paper discusses a study in the development and proof-of-concept of nano-aptamers and supporting its use as a nano-radiopharmaceutical for the treatment of breast cancer and other potentially related disease states

Towards a consistent mechanism of emulsion polymerization—new experimental details

The application of atypical experimental methods such as conductivity measurements, optical microscopy, and nonstirred polymerizations to investigations of the ‘classical’ batch ab initio emulsion polymerization of styrene revealed astonishing facts. The most important result is the discovery of spontaneous emulsification leading to monomer droplets even in the quiescent styrene in water system. These monomer droplets with a size between a few and some hundreds of nanometers, which are formed by spontaneous emulsification as soon as styrene and water are brought into contact, have a strong influence on the particle nucleation, the particle morphology, and the swelling of the particles. Experimental results confirm that micelles of low-molecular-weight surfactants are not a major locus of particle nucleation. Brownian dynamics simulations show that the capture of matter by the particles strongly depends on the polymer volume fraction and the size of the captured species (primary free radicals, oligomers, single monomer molecules, or clusters)

A novel method for n.c.a. 64Cu production by the 64Zn(d, 2p)64Cu reaction and dual ion-exchange column chromatography,”

Summary. A novel production method for n.c.a. 64 Cu based on deuteron irradiation of 64 Zn is presented. The production takes place through the 64 Zn(d, 2 p) 64 Cu reaction using a deuteron beam of 19.5 MeV energy on highly enriched 64 Zn disks. An average yield over three irradiations of 31 MBq/µA h (850 µCi/µA h) and saturation yield of 575 MBq/µA (15.5 mCi/µA) at the end of the beam (EOB) was measured by γ -ray spectrometry. Two of the three runs, of low irradiation charge, were used for radiochemistry. The copper isotopes were separated from other radionuclidic impurities by the combination of cation and anion exchange chromatography. An average radiochemical yield of 90% was estimated for the two runs performed in this study, and the specific activity as determined using flame atomic absorption spectrometry was about 4 MBq/µg, 2 hours after EOB. An extrapolation of the present results to production conditions (50 µA, 10 h) indicates approximately 8 GBq/µg (220 mCi/µg) of specific activity. The overall uncertainty in these values is estimated to 15%