Redox-Active Cerium Fluoride Nanoparticles Selectively Modulate Cellular Response against X-ray Irradiation In Vitro

Ionizing radiation-induced damage in cancer and normal cells leads to apoptosis and cell death, through the intracellular oxidative stress, DNA damage and disorders of their metabolism. Irradiation doses that do not lead to the death of tumor cells can result in the emergence of radioresistant clones of these cells due to the rearrangement of metabolism and the emergence of new mutations, including those in the genes responsible for DNA repair. The search for the substances capable of modulating the functioning of the tumor cell repair system is an urgent task. Here we analyzed the effect of cerium(III) fluoride nanoparticles (CeF3 NPs) on normal (human mesenchymal stem cells-hMSC) and cancer (MCF-7 line) human cells after X-ray radiation. CeF3 NPs effectively prevent the formation of hydrogen peroxide and hydroxyl radicals in an irradiated aqueous solution, showing pronounced antioxidant properties. CeF3 NPs are able to protect hMSC from radiation-induced proliferation arrest, increasing their viability and mitochondrial membrane potential, and, conversely, inducing the cell death of MCF-7 cancer cells, causing radiation-induced mitochondrial hyperpolarization. CeF3 NPs provided a significant decrease in the number of double-strand breaks (DSBs) in hMSC, while in MCF-7 cells the number of γ-H2AX foci dramatically increased in the presence of CeF3 4 h after irradiation. In the presence of CeF3 NPs, there was a tendency to modulate the expression of most analyzed genes associated with the development of intracellular oxidative stress, cell redox status and the DNA-repair system after X-ray irradiation. Cerium-containing nanoparticles are capable of providing selective protection of hMSC from radiation-induced injuries and are considered as a platform for the development of promising clinical radioprotectors.

Dimedone nanoparticle as a promising approach against toxoplasmosis: In vitro and in vivo evaluation

Toxoplasma gondii, an intracellular parasite, has shown drug resistance and therapeutic failure in recent years. Dimedone (DIM) has been introduced as a new chemical compound with anti-bacterial and anti-cancer properties. The aim of this study was to investigate the potential protective role of DIM nanoparticles in an animal model of toxoplasmosis. Cytotoxicity of DIM on Vero cell line assessed using MTT, and the effect of DIM on Toxoplasma gondii was evaluated by counting the number of parasites compared to the control group in vitro. The rate of pathogenesis and virulence of the parasite was checked on the liver cells of the animal model using hematoxylin-eosin staining. Furthermore, various parameters indicating oxidative stress were compared in mouse liver tissue in different groups. The release of the nanoparticle form was significantly longer than the free drugs. The IC50 of Nano-DIM was 60 µM and the reduction of intracellular parasite proliferation in the group Nano-DIM and Nano-PYR (Nano-primethamine) was significantly lower than the free drugs in vitro. Histopathology examination in the groups treated with dimedone nanomedicine showed that the degree of disintegration of the epithelium of the central vein of the liver and infiltration and vacuolization of liver cells were lower compared to the toxoplasmosis group. Additionally, the level of some oxidative stress indicators was observed to be lower in the nano-treated groups compared to other groups. The results of this study showed DIM can be used as a promising compound for anti-T. gondii activity and can prevent the proliferation of it in cells.

Exploring the Journey of Zinc Oxide Nanoparticles (ZnO-NPs) toward Biomedical Applications

The field of nanotechnology is concerned with the creation and application of materials having a nanoscale spatial dimensioning. Having a considerable surface area to volume ratio, nanoparticles have particularly unique properties. Several chemical and physical strategies have been used to prepare zinc oxide nanoparticles (ZnO-NPs). Still, biological methods using green or natural routes in various underlying substances (e.g., plant extracts, enzymes, and microorganisms) can be more environmentally friendly and cost-effective than chemical and/or physical methods in the long run. ZnO-NPs are now being studied as antibacterial agents in nanoscale and microscale formulations. The purpose of this study is to analyze the prevalent traditional method of generating ZnO-NPs, as well as its harmful side effects, and how it might be addressed utilizing an eco-friendly green approach. The study’s primary focus is on the potential biomedical applications of green synthesized ZnO-NPs. Biocompatibility and biomedical qualities have been improved in green-synthesized ZnO-NPs over their traditionally produced counterparts, making them excellent antibacterial and cancer-fighting drugs. Additionally, these ZnO-NPs are beneficial when combined with the healing processes of wounds and biosensing components to trace small portions of biomarkers linked with various disorders. It has also been discovered that ZnO-NPs can distribute and sense drugs. Green-synthesized ZnO-NPs are compared to traditionally synthesized ones in this review, which shows that they have outstanding potential as a potent biological agent, as well as related hazardous properties.

On a local (de-)trapping model for highly doped Pr3+ radioluminescent and persistent luminescent nanoparticles

Trivalent praseodymium exhibits a wide range of luminescent phenomena when doped into a variety of different materials. Herein, radioluminescent NaLuF4:20%Pr3+ nanoparticles are studied. Four different samples of this composition were prepared ranging from 400-70 nm in size. Kinetic studies of radioluminescence as a function of X-ray irradiation time revealed a decrease in the emissions originating from the 1S0 level, due to the formation or optical activation of defects during excitation, and a simultaneous increase in the visible emissions resulting from the lower optical levels. Thermoluminescence measurements elucidated that a local de-trapping mechanism was responsible for the increase in steady state emission and persistent luminescence originating from the lower optical levels. The results and mechanism described through this study serve to provide a novel nanoparticle composition with versatile luminescent properties and provides experimental evidence in favor of a local trapping model.

Enhancement of antioxidant activity of levan through the formation of nanoparticle systems with metal ions

Levan, a natural polymer, is widely used in biomedical applications, such as antioxidants, anti-inflammatory, and anti-tumor. The present study aimed to enhance the antioxidant activity of levan by combining it with various metal ions in the nanoparticle (NP) system. Levansucrase encoding gene from Bacillus licheniformis BK1 has been inserted into an expression vector and the obtained recombinant was labeled as Lsbl-bk1 (accession number MF774877.1). That enzyme was used for in vitro levan synthesis in 12% (w/v) sucrose as a substrate and about 4.28 mg/mL of levan was obtained. Levan-based metal ion NPs were synthesized using the coprecipitation method. In the production of NPs, levan acts as a reducing and stabilizing agent. Four types of levan-based metal ion NPs were synthesized, namely, levan–Fe²⁺ NPs, levan–Cu⁺ NPs, levan–Co²⁺ NPs, and levan–Zn²⁺ NPs. The transmission electron microscopy (TEM) technique was applied to visualize the size and shape of the synthesized levan–metal NPs. All levan-based metal ion NPs have a particle size of less than 100 nm, and even levan–Cu⁺ and levan–Zn²⁺ have particle sizes less than 50 nm. Levan–Fe²⁺ NPs and levan–Cu⁺ NPs exhibited prominent antioxidant activity with an inhibition level of up to 88% and 95%, respectively. And the inhibition level of two metal ion NPs had about 33%–40% higher antioxidant activity compared with the inhibition level of levan only. The two levan–metal ion NPs, therefore, have future prospects to be developed as the new formulation for the antioxidant drugs.