Magnetic nanoparticle (MNP)-mediated hyperthermia (MH) coupled with radiation therapy (RT) is a novel approach that has the potential to overcome various practical difficulties encountered in cancer treatment. In this work, we present recommendations for the in vitro and in vivo testing and application of the two treatment techniques. These recommendations were developed by the members of Working Group 3 of COST Action TD 1402: Multifunctional Nanoparticles for Magnetic Hyperthermia and Indirect Radiation Therapy (“Radiomag”). The purpose of the recommendations is not to provide definitive answers and directions but, rather, to outline those tests and considerations that a researcher must address in order to perform in vitro and in vivo studies. The recommendations are divided into 5 parts: (a) in vitro evaluation of MNPs; (b) in vitro evaluation of MNP-cell interactions; (c) in vivo evaluation of the MNPs; (d) MH combined with RT; and (e) pharmacokinetic studies of MNPs. Synthesis and characterization of the MNPs, as well as RT protocols, are beyond the scope of this work.

Microbial contamination of food and alimentary toxoinfection/intoxication in humans are commonly caused by bacteria such as Salmonella spp., Escherichia coli, Yersinia spp., Campylobacter spp., Listeria monocytogenes, and fungi (Aspergillus, Fusarium). The addition of probiotic cultures (bacterial strains Lactobacillus and Bifidobacterium and the yeast Saccharomyces cerevisiae var. boulardii) to food contributes primarily to food enrichment and obtaining a functional product, but also to food preservation. Reducing the number of viable pathogenic microorganisms and eliminating or neutralizing their toxins in food is achieved by probiotic-produced antimicrobial substances such as organic acids (lactic acid, acetic acid, propionic acid, phenylacetic acid, and phenyllactic acid), fatty acids (linoleic acid, butyric acid, caproic acid, and caprylic acid), aromatic compounds (diacetyl, acetaldehyde, reuterin), hydrogen peroxide, cyclic dipeptides, bacteriocins, and salivabactin. This review summarizes the basic facts on microbial contamination and preservation of food and the potential of different probiotic strains and their metabolites (postbiotics), including the mechanisms of their antimicrobial action against various foodborne pathogens. Literature data on this topic over the last three decades was searched in the PubMed, Scopus, and Google Scholar databases, systematically presented, and critically discussed, with particular attention to the advantages and disadvantages of using probiotics and postbiotics as food biopreservatives.

The present study describes for the first time a procedure for the radiolabeling of fullerene (C(60)) nanocrystals (nanoC(60)) with Na (125)I, as well as the biodistribution of radiolabeled nanoC(60) ((125)I-nanoC(60)). The solvent exchange method with tetrahydrofuran was used to make colloidal water suspensions of radiolabeled nanoC(60) particles. The radiolabeling procedure with the addition of Na (125)I to tetrahydrofuran during dissolution of C(60) gave a higher radiochemical yield of radiolabeled nanoC(60) particles in comparison to the second option, in which Na (125)I was added after C(60) was dissolved. Using photon correlation spectroscopy and transmission electron microscopy, (125)I-nanoC(60) particles were found to have a crystalline structure and a mean diameter of 200-250 nm. The (125)I-nanoC(60) had a particularly high affinity for human serum albumin, displaying 95% binding efficiency after 1 h. Biodistribution studies of (125)I-nanoC(60) in rats indicated significant differences in tissue accumulation of (125)I-nanoC(60) and the radioactive tracer Na (125)I. The higher accumulation of radiolabeled nanoC(60) was observed in liver and spleen, while accumulation in thyroid, stomach, lungs and intestines was significantly lower in comparison to Na (125)I. In addition to being useful for testing the biological distribution of nanoC(60), the described radiolabeling procedure might have possible applications in cancer radiotherapy.

In this study, we have investigated the synthesis of nanoparticles of hydroxyapatite (HAp) and hydroxyapatite coated with chitosan (HAp/Ch) and the chitosan-poly-d,l-lactide-co-glycolide polymer blend (HAp/Ch-PLGA) as an organ-targeting system. We have examined and defined the final destination, as well as the dynamics and the pathways of the synthesized particles following intravenous administration in vivo. The XRD, ZP, FT-IR and SEM analyses have confirmed that the hydroxyapatite nanoparticles with d50=72 nm are coated with polymers. Radioactive 125-Iodine ((125)I), a low energy gamma emitter, was used to develop a novel in situ method for the radiolabeling of particles and investigation of their biodistribution. (125)I-labeled particles exhibited high stability in saline and serum over the second day, which justified their use in the following in vivo studies. The biodistribution of (125)I-labeled particles after intravenous injection in rats differed significantly: HAp particles mostly targeted the liver, HAp/Ch the spleen and the liver, while HAp/Ch-PLGA targeted the lungs. Twenty-four hours post injection, HAp particles were excreted completely, while both (125)I-HAp/Ch and (125)I-HAp/Ch-PLGA were retained in the body for a prolonged period of time with more than 20% of radioactivity still found in different organs.

Radiolabeled albumin microspheres with encapsulated citric acid-coated magnetite nanoparticles were developed as a targeting approach to localize both radioactivity and magnetic energy at the tumor site. We present in vitro and in vivo studies of yttrium-90 (⁹⁰Y)-labeled human serum albumin magnetic microspheres (HSAMMS) as a multifunctional agent for possible applications in a bimodal radionuclide-hyperthermia cancer therapy. The HSAMMS were produced using a modified emulsification-heat stabilization technique and contained 11 nm magnetite nanoparticles coated with citric acid, distributed as inhomogeneous clusters within the albumin microspheres. The size, size distribution and the morphology of magnetite nanoparticles and HSAMMS were determined by FESEM, HRTEM and SEM/FIB dual beam. The average particle size of the complete HSAMMS was 20 μm, and they exhibited superparamagnetic behavior at room temperature. The in vitro experiments (in saline and human serum) revealed the high stability of the labeled HSAMMS in saline and human serum after 72 h. Following the intravenous administration of the ⁹⁰Y-HSAMMS in rats, 88.81% of the activity localizes in the lungs after 1 h, with 82.67% remaining after 72 h. These data on ⁹⁰Y-HSAMMS provide good evidence for their potential use in bimodal radionuclide-hyperthermia cancer therapy.