The toxicity of superparamagnetic iron oxide nanoparticles induced on the testicular cells: In vitro study.

Superparamagnetic iron oxide nanoparticles (SPIONs) have gained significant attention in biomedical research due to their potential applications. However, little is known about their impact and toxicity on testicular cells. To address this issue, we conducted an in vitro study using primary mouse testicular cells, testis fragments, and sperm to investigate the cytotoxic effects of sodium citrate-coated SPIONs (Cit_SPIONs). Herein, we synthesized and physiochemically characterized the Cit_SPIONs and observed that the sodium citrate diminished the size and improved the stability of nanoparticles in solution during the experimental time. The sodium citrate (measured by thermogravimetry) was biocompatible with testicular cells at the used concentration (3%). Despite these favorable physicochemical properties, the in vitro experiments demonstrated the cytotoxicity of Cit_SPIONs, particularly towards testicular somatic cells and sperm cells. Transmission electron microscopy analysis confirmed that Leydig cells preferentially internalized Cit_SPIONs in the organotypic culture system, which resulted in alterations in their cytoplasmic size. Additionally, we found that Cit_SPIONs exposure had detrimental effects on various parameters of sperm cells, including motility, viability, DNA integrity, mitochondrial activity, lipid peroxidation (LPO), and ROS production. Our findings suggest that testicular somatic cells and sperm cells are highly sensitive and vulnerable to Cit_SPIONs and induced oxidative stress. This study emphasizes the potential toxicity of SPIONs, indicating significant threats to the male reproductive system. Our findings highlight the need for detailed development of iron oxide nanoparticles to enhance reproductive nanosafety.

Preparation of glass-ionomer cement containing ethanolic Brazilian pepper extract (Schinus terebinthifolius Raddi) fruits: chemical and biological assays.

Plants may contain beneficial or potentially dangerous substances to humans. This study aimed to prepare and evaluate a new drug delivery system based on a glass-ionomer-Brazilian pepper extract composite, to check for its activity against pathogenic microorganisms of the oral cavity, along with its in vitro biocompatibility. The ethanolic Brazilian pepper extract (BPE), the glass-ionomer cement (GIC) and the composite GIC-BPE were characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and thermal analysis. The BPE compounds were identified by UPLC-QTOF-MS/MS. The release profile of flavonoids and the mechanical properties of the GIC-BPE composite were assessed. The flavonoids were released through a linear mechanism governing the diffusion for the first 48 h, as evidenced by the Mt/M∞ relatively to [Formula: see text], at a diffusion coefficient of 1.406 × 10-6 cm2 s-1. The ATR-FTIR analysis indicated that a chemical bond between the GIC and BPE components may have occurred, but the compressive strength of GIC-BPE does not differ significantly from that of this glass-ionomer. The GIC-BPE sample revealed an ample bacterial activity at non-cytotoxic concentrations for the human fibroblast MRC-5 cells. These results suggest that the prepared composite may represent an alternative agent for endodontic treatment.

Theoretical and Experimental Studies of the Controlled Release of Tetracycline Incorporated into Bioactive Glasses.

Several authors have studied the release profile of drugs incorporated in different devices. However, to the best of our knowledge, although many studies have been done on the release of tetracycline, in these release devices, no study has investigated if the released compound is actually the tetracycline, or, instead, a degraded product. This approach is exploited here. In this work, we analyse the influence of two drying methods on the tetracycline delivery behaviour of synthesised glasses using the sol-gel process. We compare the drying methods results using both theoretical models and practical essays, and analyse the chemical characteristic of the released product in order to verify if it remains tetracycline. Samples were freeze-dried or dried in an oven at 37°C and characterised by several methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TG), differential thermogravimetric analysis (DTG), differential thermal analyses (DTA) and gas adsorption analysis (BET). The released concentration of tetracycline hydrochloride was studied as a function of time, and it was measured by ultraviolet spectrophotometry in the tetracycline wavelength. The drug delivery profiles were reasonably consistent with a diffusion model analysis. In addition, we observed higher release rates for the freeze-dried compared to those dried in an oven at 37°C. This higher release can be attributed to larger pore size for the freeze-dried sample systems with tetracycline, which promoted more water penetration, improving the drug diffusion. The analysis of the solution obtained in the release tests using high-performance liquid chromatography- mass spectrometry (HPLC-MS) confirmed that tetracycline was being released.

A tetravalent dengue nanoparticle stimulates antibody production in mice.

BACKGROUND: Dengue is a major public health problem worldwide, especially in the tropical and subtropical regions of the world. Infection with a single Dengue virus (DENV) serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients experiencing secondary infection with a different serotype progresses to the severe form of the disease, dengue hemorrhagic fever/dengue shock syndrome. Currently, there are no licensed vaccines or antiviral drugs to prevent or treat dengue infections. Biodegradable nanoparticles coated with proteins represent a promising method for in vivo delivery of vaccines. FINDINGS: Here, we used a murine model to evaluate the IgG production after administration of inactivated DENV corresponding to all four serotypes adsorbed to bovine serum albumin nanoparticles. This formulation induced a production of anti-DENV IgG antibodies (p < 0.001). However, plaque reduction neutralization assays with the four DENV serotypes revealed that these antibodies have no neutralizing activity in the dilutions tested. CONCLUSIONS: Our results show that while the nanoparticle system induces humoral responses against DENV, further investigation with different DENV antigens will be required to improve immunogenicity, epitope specicity, and functional activity to make this platform a viable option for DENV vaccines.

Magnetic properties of nanoparticles obtained by different chemical routes.

It is well known that nano-sized materials often present chemical, electronic, magnetic, and mechanical properties that are potentially interesting for many technological applications comparatively to their corresponding bulk properties. This paper describes the main differences in magnetic properties among nanomagnetite powders prepared by three methods: (I) reduction-precipitation of ferric chloride by reaction with Na2SO3; (II) reduction of hematite with coal, and (III) reduction of hematite with hydrogen gas. The obtained materials were characterized by powder X-ray diffraction (XRD), saturation magnetization measurements, and Mössbauer spectroscopy. Saturation magnetization values varied from 60 to 86 J T(-1)kg(-1). XRD and Mössbauer spectroscopy results at 298 K showed the clear effect of the preparation routes on the crystallographic structure and crystallite size of the magnetic species. Magnetite was formed in varying proportions in all samples, with crystallite sizes estimated by Scherrer formula of about 10, 26, and 33 nm for samples prepared by methods (I), (II), and (III), respectively. The Mössbauer spectrum of the sample prepared by method (I) consisted of broad lines and hyperfine field for magnetite lower than that typically reported for the bulk material.