Sterile α motif and histidine-aspartate domain–containing protein 1 (SAMHD1) is a multifunctional protein that limits cellular dNTP availability, interacts with specific retroviral proteins to induce degradation. Regulation of dNTP availability is crucial for cell cycle regulation and DNA stability. Demethylating agents such as azacytidine are in clinical use for cancer therapy, and reduce methylation of the SAMHD1 promoter and SAMHD1 gene expression. Here, we evaluated the effect of azacytidine on global DNA methylation in feline lymphocytes, and specifically on the abundance and cellular distribution of phosphorylated and non-phosphorylated SAMHD1. Azacytidine increased cellular and nuclear SAMHD1 but did not increase phosphorylated SAMHD1. Phosphorylation is essential for SAMHD1 stability and function but is unaffected by demethylation. The findings suggest that treatment with azacytidine could increase viral restriction, and they lend support to development of in vivo models utilizing azacytidine to modulate SAMHD1 activity.

Triglycerides of waste cooking oil reacted with methanol in refluxing toluene to yield mixtures of diglycerides, monoglycerides and fatty acid methyl esters (FAMEs) in the presence of 20% (w/w) catalyst/oil using the hydrophilic sulfonated silica (SiO₂-SO₃H) catalyst alone or with the addition of 10% (w/w) co-catalyst/oil [(Bun4N)](BF₄) or Aliquat 336]. The addition of the ammonium salts to the catalyst lead to a decrease in the amounts of diglycerides in the products, but the concentrations of monoglycerides increased. Mixtures of [(Bun4N)](BF4)/catalyst were superior to catalyst alone or Aliquat 336/catalyst for promoting the production of mixtures with high concentrations of FAMEs. The same experiments were repeated using DMSO as the solvent. The use of the more polar solvent resulted in excellent conversion of the triglycerides to FAME esters with all three-catalyst media. A simplified mechanism is presented to account for the experimental results.

Nanofiber (NF) products exhibit outstanding performances in the materials science, textile, and medical fields, which cannot be realized using conventional technologies. However, the safety of such products is debated because of the potential risk of nanomaterials and lack of standardized guidelines for safely evaluating NF products. The global safety evaluations of nanomaterials focused on evaluating the cytotoxicity of zero-dimensional materials including nanoparticles and nanotubes based on OECD criteria. The NFs are one-dimensional materials with nanometer diameters and considerable lengths. Many fibers are applied in a densely woven web-like form, and therefore, assessing cellular penetration and fiber toxicity using the same methods is inappropriate. This study verifies the safety of polyurethane (PU) and polyvinylidene fluoride (PVDF) polymers, which are currently applied in filters and masks. To this end, polymer NFs were collected from each product, and the NFs were compared with reference samples considering their physical properties using FT-IR and Raman spectroscopy. For the safety evaluation, DMSO stocks of varying concentrations of PVDF and PU NFs (at 0.5, 1, 5, and 10 μg/mL) were prepared, and the cytotoxicity and inhibitory effects on nitric oxide production and protein expression obtained via Western blot were identified.

We recently developed a novel hyperspectral excitation-resolved near-infrared fluorescence imaging system (HER-NIRF) based on a continuous-wave wavelength-swept laser. In this study, this technique is applied for measuring the distribution of the therapeutic agent dimethyl sulfoxide (DMSO) by utilizing solvatochromic shift in the spectral profile of albumin-bound Indocyanine green (ICG). Using wide-field imaging in turbid media, complex dynamics of albumin-bound ICG is measured in mixtures of dimethyl sulfoxide (DMSO) and water. Phantom experiments are conducted to evaluate the performance of the HER-NIRF system. The results show that the distribution of DMSO can be visualized in the wide-field reflection geometry. One of the main purposes of the DMSO is to act as a carrier for other drugs, enhancing their effects by facilitating skin penetration. Understanding solubility and permeability of drugs in vivo is very important in drug discovery and development. Hence, this HER-NIRF technique has a great potential to advance the utilization of the therapeutic agent DMSO by mapping its distribution via solvatochromic shift of ICG. By customizing the operational wavelength range, this system can be applied to any other fluorophores in the near infrared region and utilized for a wide variety of drug delivery studies.