Recent nanotechnological advances suggest that metal oxide nanoparticles (NPs) have been expected to be used in various fields, ranging from catalysis and opto-electronic materials to sensors, environmental remediation, and biomedicine. However, the growing use of NPs has led to their release into environment and the toxicity of metal oxide NPs on organisms has become a concern to both the public and scientists. Unfortunately, there are still widespread controversies and ambiguities with respect to the toxic effects and mechanisms of metal oxide NPs. Comprehensive understanding of their toxic effect is necessary to safely expand their use. In this review, we use CuO and ZnO NPs as examples to discuss how key factors such as size, surface characteristics, dissolution, and exposure routes mediate toxic effects, and we describe corresponding mechanisms, including oxidative stress, coordination effects and non-homeostasis effects.

Chronic overconsumption of TiO₂NPs-containing foods, such as gum, candy and puddings, is likely to deteriorate the gastrointestinal tract and change the structures of microbiota.

Nanoparticles (NPs) administered orally will meet the gut microbiota, but their impacts on microbiota homeostasis and the consequent physiological relevance remain largely unknown. Here, we describe the modulatory effects and the consequent pharmacological outputs of two orally administered fullerenols NPs (Fol1 C60(OH)7(O)8 and Fol113 C60(OH)11(O)6) on gut microbiota. Administration of Fol1 and Fol113 NPs for 4 weeks largely shifted the overall structure of gut microbiota in mice. The bacteria belonging to putative short-chain fatty acids (SCFAs)-producing genera were markedly increased by both NPs, especially Fol1. Dynamic analysis showed that major SCFAs-producers and key butyrate-producing gene were significantly enriched after treatment for 7–28 days. The fecal contents of SCFAs were consequently increased, which was accompanied by significant decreases of triglycerides and total cholesterol levels in the blood and liver, with Fol1 superior to Fol113. Under cultivation in vitro, fullerenols NPs can be degraded by gut flora and exhibited a similar capacity of inulin to promote SCFA-producing genera. The differential effects of Fol1 and Fol113 NPs on the microbiome may be attributable to their subtly varied surface structures. The two fullerenol NPs remarkably modulate the gut microbiota and selectively enrich SCFA-producing bacteria, which may be an important reason for their anti-hyperlipidemic effect in mice.

A thrombus, known as a blood clot, may form within the vascular system of the body and impede blood flow. Thrombosis is the most common underlying pathology of cardiovascular diseases, contributing to high morbidity and mortality. However, the main thrombolytic drugs (urokinase, streptokinase, etc.) have shortcomings, including a short half-life, serious side effects and a lack of targeting, that limit their clinical application. The use of nano-drug delivery systems is expected to address these problems and a variety of approaches, including biological and physical responsive systems, have been explored. In this report, recent advances in the development of targeted nano-drug delivery systems are thoroughly reviewed.

Nanotechnology developed rapidly in cellular diagnosis and treatment, the endocytic system was an important pathway for targeting cell. In the research of developing macrophages as drug carriers or important therapeutic targets, an interesting phenomenon, internalized nanoparticles induced to form binucleated macrophages, was found although the particles dose did not cause obvious cytotoxicity. Under 25 μg/ml, internalized 30 nm polystyrene beads(30 nm Ps nanoparticles) induced the formation of binucleated macrophages when they entered into endosomes via the endocytic pathway. These internalized 30 nm Ps nanoparticles (25 μg/ml) and 30 nm Au-NPs (1.575 ng/ml) also induced markedly rise of binucleated cell rates in A549, HePG-2 and HCT116. This endosome, aggregated anionic polystyrene particles were dispersed and bound on inner membrane, was induced to form a large vesicle-like structure (LVLS). This phenomenon blocked transport of the particles from the endosome to lysosome and therefore restricted endosomal membrane trafficking through the transport vesicles. Early endosome antigen-1 and Ras-related protein-11 expressions were upregulated; however, the localized distributions of these pivotal proteins were altered. We hypothesized that these LVLS were held by the internalized and dispersed particles decreasing the amount of cell membrane available to support the completion of cytokinesis. In addition, altered distributions of pivotal proteins prevented transfer vesicles from fusion and hampered the separation of daughter cells. 30 nm Ps nanoparticles induced formation of LVLS, blocked the vesicle transport in endocytic system and the distributions of regular proteins required in cytokinesis which led to binucleated cells of macrophages. Markedly raised binucleated rate was also observed in human lung adenocarcinoma epithelial cell line(A549), human hepatoma cell line(HePG-2) and human colorectal cancer cell line(HCT116) treated by 30 nm Ps nanoparticles and Au-NPs.