Titanium Nanoparticles Enhance Production and Suppress Stabilin-1-Mediated Clearance of GDF-15 in Human Primary Macrophages

Macrophages are key innate immune cells that mediate implant acceptance or rejection. Titanium implants degrade over time inside the body, which results in the release of implant wear-off particles. Titanium nanoparticles (TiNPs) favor pro-inflammatory macrophage polarization (M1) and lower tolerogenic activation (M2). GDF-15 regulates immune tolerance and fibrosis and is endocytosed by stabilin-1. How TiNPs affect the healing activities of macrophages and their release of circulating cytokines is an open question in regenerative medicine. In this study for the first time, we identified the transcriptional program induced and suppressed by TiNPs in human pro-inflammatory and healing macrophages. Microarray analysis revealed that TiNPs altered the expression of 5098 genes in M1 (IFN-γ-stimulated) and 4380 genes in M2 (IL-4–stimulated) macrophages. 1980 genes were differentially regulated in both M1 and M2. Affymetrix analysis, confirmed by RT-PCR, demonstrated that TiNPs upregulate expression of GDF-15 and suppress stabilin-1, scavenger receptor of GDF-15. TiNPs also significantly stimulated GDF-15 protein secretion in inflammatory and healing macrophages. Flow cytometry demonstrated, that scavenging activity of stabilin-1 was significantly suppressed by TiNPs. Confocal microscopy analysis showed that TiNPs impair internalization of stabilin-1 ligand acLDL and its transport to the endocytic pathway. Our data demonstrate that TiNPs have a dual effect on the GDF-15/stabilin-1 interaction in macrophage system, by increasing the production of GDF-15 and suppressing stabilin-1-mediated clearance function. In summary, this process can result in a significant increase of GDF-15 in the extracellular space and in circulation leading to unbalanced pro-fibrotic reactions and implant complications.

Fabrication of Lightweight and Low Cost Shields for Gamma Ray Attenuation

Films of biopolymer (PVA) doped with titanium nanoparticles (Ti NPs) have been prepared with several ratios of PVA and Ti NPs to apply for gamma ray shielding with low unit cost, flexible, lightweight, and high corrosion resistance. The prepared nanocomposites tested for gamma ray shielding. The experimental results showed the PVA/ Ti nanocomposites films have high coefficients of attenuation for gamma ray.

Novel Alhagi maurorum leaves mediated synthesis of titanium nanoparticles for human breast carcinoma applications: a preclinical trial

IntroductionIn this study, titanium nanoparticles (TiNPs) were synthesized in an aqueous medium using Alhagi maurorum extract as stabilizing and reducing agents.Material and methodsUltraviolet–visible spectrophotometry (UV-Vis), fourier-transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Energy Dispersive X-ray Spectrometry (EDS) were the techniques to characterize the biosynthetic of TiNPs. According to the XRD analysis. To survey the anti-human breast cancer effects of TiNPs, MTT assay was used on the common breast cancer cell lines i.e., breast cancer (Breast adenocarcinoma (MCF7), infiltrating ductal cell carcinoma (Hs 319.T), inflammatory carcinoma of the breast (UACC-732), and metastatic carcinoma (MDA-MB-453) cell lines.Results16.08 nm was measured for TiNPs crystal size. SEM images exhibited a uniform spherical morphology in range size of 12.16 to 43.46 nm for the biosynthesized nanoparticles respectively. The cell viability of breast carcinoma cells decreased dose-dependently in the titanium nanoparticles presence. The IC50 of A. maurorum and titanium particles on MCF7 cell line were 680 and 359 µg/mL, on Hs 319.T cell line were 507 and 191 µg/mL, on UACC-732 cell line were 477 and 217 µg/mL, and on MDA-MB-453cell line were 507 and 191 µg/mL, respectively. TiNPs had high anti-breast cancer activities dose-dependently against MCF7, Hs 319.T, UACC-732, and MDA-MB-453 cell lines.ConclusionsThe best result of anti-breast cancer effects was seen in the case of the Hs 319.T cell line.

Possible mechanisms of the destruction of spores of the vaccine strain Bacillus anthracis STI-1 under the influence of alcohol sols of metal nanoparticles

The results are presented of a comparative study of the sporicidal activity of alcohol sols of nanoparticles of titanium, copper, zinc and tantalum metals in the course of their interaction with a rehydrated lyophilized culture of spores of the vaccine strain Bacillus anthracis STI-1 with the loss of the ability of spores to germinate in nutrient media under optimal conditions using bacteriology and electronic microscopy. The most pronounced sporicidal effect is observed when titanium alcohol sol is exposed to spores. At the same time, spores of B. anthracis STI-1 in titanium alcohol sol are affected by ethyl alcohol, which causes dehydration and denaturation of the protein, the antiseptic cetylpyridinium chloride as a surfactant, which is also a strong electrophilic agent that destroys the exosporium and spore shells, and titanium nanoparticles, which, due to the high surface energy when exposed to spores, cause their pronounced massive adhesion. In addition, titanium nanoparticles, the zeta (? -) value of the potential of which is -44.5 mV, cause a stable energy state of the dispersed system of alcohol sol, which acts as a biocatalyst for intracellular enzymes, causing the hydrolysis of polymer structures of the spore shells and cortex, as well as destroyed nucleoid – an area of spores containing structured genetic material. Spores that do not have a nucleoid in electron microscopy acquire the form of "shadows". As a result of the action of titanium alcohol sol, the activation of germination and the formation of the so-called "metabolic" spores, from which the vegetative cells of B. anthracis STI-1 should have been formed, are prevented. The reason for the high sporicidal efficiency of the alcohol sol of titanium nanoparticles is associated both with the structure and properties and with the technology of synthesis of titanium nanoparticles in the low-temperature plasma zone with the formation, due to the excess of the surfactant cetylpyridinium chloride, of a two-layer shell around the metal nanoparticles, which leads to their "conservation" until the moment of contact with spores and a sharp slowdown in their oxidation in the aquatic environment. The destruction of the formed two-layer shell of metal nanoparticles begins with contact with spores with the simultaneous onset of the formation of titanium ions from the phase of nanoparticles, which actively destroy chemically the shells of the spores. Keywords: microorganisms, Bacillus anthracis STI-1, spores, metal nanoparticles, zeta potential, disinfectant compositions, sporicidal activity.