Common plastics, such as polyethylene terephthalate (PET), as pollutants in aquatic environments in the form of micro/nanoparticles are of environmental and public health concern.

Plastic pollution is a major environmental concern due to its pervasiveness which continues to increase year on year, as a result of a continuing acceleration in global plastic production and use. Polyethylene terephthalate (PET) is among the most produced plastics, commonly used as food and beverage containers. Once released in the environment, the degradation of plastic materials produces micro-and nano-plastics, with a particular concern about potential toxicological effects if they cross epithelial barriers via inhalation or ingestion. In this work, the effect of PET nanoparticles (PET-NPs) (≤ 250 d.nm) was assayed on mouse macrophages cell line (RAW 264.7) in in vitro experiments. Results showed that PET nanoparticles were easily internalized by the cells, 15 μg/mL of nanoparticles concentration had exhibited effects in cell proliferation and a slightly increased production of Reactive Oxygen Species (ROS), which seems to trigger cell response as foreign particles related to upregulation of PCDH12, IGH-V10, ROBO1 genes, and cell maintenance functions, related to FTSJ2 gene upregulation. Thus, the RAW 264.7 results showed here are useful towards for a preliminary and understanding of the potentially toxic effects related to PET nanoparticles and complementary to other in vitro assays, as the first step into the development of the risk assessment framework.

Tamoxifen is the standard endocrine therapy for breast cancers, which require metabolic activation by cytochrome P450 enzymes (CYP). However, the lower and variable concentrations of CYP activity at the tumor remain major bottlenecks for the efficient treatment, causing severe side-effects. Combination nanotherapy has gained much recent attention for cancer treatment as it reduces the drug-associated toxicity without affecting the therapeutic response. Here we show the modular design of P22 bacteriophage virus-like particles for nanoscale integration of virus-driven enzyme prodrug therapy and photodynamic therapy. These virus capsids carrying CYP activity at the core are decorated with photosensitizer and targeting moiety at the surface for effective combinatory treatment. The estradiol-functionalized nanoparticles are recognized and internalized into ER+ breast tumor cells increasing the intracellular CYP activity and showing the ability to produce reactive oxygen species (ROS) upon UV365 nm irradiation. The generated ROS in synergy with enzymatic activity drastically enhanced the tamoxifen sensitivity in vitro, strongly inhibiting tumor cells. This work clearly demonstrated that the targeted combinatory treatment using multifunctional biocatalytic P22 represents the effective nanotherapeutics for ER+ breast cancer.

ObjectivesThe aim of this study was to determine the antibacterial properties of silver-doped titanium surfaces prepared with a novel electrochemical anodizing process. Material and methodsTitanium samples were anodized with a pulsed process in a solution of silver nitrate and sodium thiosulphate at room temperature with stirring. Samples were processed with different electrolyte concentrations and treatment cycles to improve silver deposition. Physicochemical properties were determined by X-ray photoelectron spectroscopy, contact angle measurements, white-light interferometry, and scanning electron microscopy. Cellular cytotoxicity in human fibroblasts was studied with lactate dehydrogenase assays. The in vitro effect of treated surfaces on two oral bacteria strains (Streptococcus sanguinis and Lactobacillus salivarius) was studied with viable bacterial adhesion measurements and growth curve assays. Nonparametric statistical Kruskal-Wallis and Mann-Whitney U-tests were used for multiple and paired comparisons, respectively. Post hoc Spearman's correlation tests were calculated to check the dependence between bacteria adhesion and surface properties. ResultsX-ray photoelectron spectroscopy results confirmed the presence of silver on treated samples and showed that treatments with higher silver nitrate concentration and more cycles increased the silver deposition on titanium surface. No negative effects in fibroblast cell viability were detected and a significant reduction on bacterial adhesion in vitro was achieved in silver-treated samples compared with control titanium. ConclusionsSilver deposition on titanium with a novel electrochemical anodizing process produced surfaces with significant antibacterial properties in vitro without negative effects on cell viability.

Nanomaterials have become part of our daily lives, particularly nanoparticles contained in food, water, cosmetics, additives and textiles. Nanoparticles interact with organisms at the cellular level. The cell membrane is the first protective barrier against the potential toxic effect of nanoparticles. This first contact, including the interaction between the cell membranes -and associated proteins- and the nanoparticles is critically reviewed here. Nanoparticles, depending on their toxicity, can cause cellular physiology alterations, such as a disruption in cell signaling or changes in gene expression and they can trigger immune responses and even apoptosis. Additionally, the fundamental thermodynamics behind the nanoparticle-membrane and nanoparticle-proteins-membrane interactions are discussed. The analysis is intended to increase our insight into the mechanisms involved in these interactions. Finally, consequences are reviewed and discussed.