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We encounter titanium dioxide nanoparticles (TiO2NPs) throughout our daily lives in the form of food coloring, cosmetics, and industrial materials. They are used on a massive industrial scale, with over 1 million metric tons in the global market. For the workers who process these materials, inhalation is a major concern. The goal of our current research is to provide a direct comparison of the three major types of TiO2NPs (P25, E171, R101) in terms of surface characterization, cellular response, and in vivoresponse following introduction into the lungs of mice. In both cellular and in vivoexperiments, we observe a pro-inflammatory response to the P25 TiO2NPs that is not observed in the E171 or R101 TiO2NPs at mass-matched concentrations. Cellular experiments measured a cytokine, TNF-α, as a marker of a pro-inflammatory response. In vivoexperiments in mice measured the number of immune cells and four pro-inflammatory cytokines (IL-6, MIP-2, IP-10, and MCP-1) present in bronchoalveolar lavage fluid. A detailed physical and chemical characterization of the TiO2NPs shows that the P25 TiO2NPs are distinguished by smaller primary particles suggesting that samples matched by mass contain a larger number of P25 TiO2NPs. Cellular dose–response measurements with the P25, E171, and R101 TiO2NPs support this hypothesis showing increased TNF-α release by macrophages as a function of TiO2NP dose. Overall, this direct comparison of the three major types of TiO2NPs shows that the number of particles in a dose, which is dependent on the particle diameter, is a key parameter in TiO2NP-induced inflammation.

Health care providers play an important role in adolescent sex education, including in discussions on contraceptive use. (1,2) Adolescents may start engaging in sexual activity while undergoing the numerous physical [...]

Health care providers play an important role in adolescent sex education, including in discussions on contraceptive use. (1,2) Adolescents may start engaging in sexual activity while undergoing the numerous physical and emotional changes that occur during their transformative period. (3) By the age of 20 years, approximately 80% of young women have had sexual intercourse; however, adolescents (aged 15 to 19 years) have limited understanding of the various contraceptive methods available to them, and the lowest rates of contraceptive use. (1,2) Counseling individuals about the various methods of contraception and increasing access to care can help address unplanned pregnancies and sexually transmitted diseases. (3) As most females prefer oral contraceptives over other forms, such as injections, transdermal patch, and vaginal rings, familiarizing themselves with the safest and most effective use of all these products is good practice (1,2) (Table 1). This article delves into the contraceptives available for adolescents and discusses their efficacy and safety., Contraception Various methods of contraception are available for adolescents (3) (Table 22, (3,7)). Medical providers should counsel them on the efficacy, safety, and adverse effects of contraception. (1). Contraceptive options [...]

Inhalation is a major exposure route to nanoparticles. Following inhalation, nanoparticles first interact with the lung lining fluid, a complex mixture of proteins, lipids, and mucins. We measure the concentration and composition of lung fluid proteins adsorbed on the surface of titanium dioxide (TiO2) nanoparticles. Using proteomics, we find that lung fluid results in a unique protein corona on the surface of the TiO2nanoparticles. We then measure the expression of three cytokines (interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and macrophage inflammatory protein 2 (MIP-2)) associated with lung inflammation. We find that the corona formed from lung fluid leads to elevated expression of these cytokines in comparison to bare TiO2nanoparticles or coronas formed from serum or albumin. These experiments show that understanding the concentration and composition of the protein corona is essential for understanding the pulmonary response associated with human exposure to nanoparticles.

The increasing use of multiwalled carbon nanotubes (MWCNTs) could increase the risk of allergic lung disease in occupational or consumer settings. We previously reported that MWCNTs exacerbated allergic lung disease in mice induced by extract from house dust mites (HDM), a common cause of asthma in humans. Because MWCNTs avidly bind biomolecules to form protein coronas that can modify immunotoxicity, we hypothesized that exacerbation of allergic lung disease in mice caused by coexposure to MWCNTs and HDM extract was due to the formation of an allergen corona. In a first set of experiments, male and female C57BL/6J mice were coexposed to MWCNTs and HDM extract over 3 weeks compared to MWCNTs or HDM extract alone. In a second set of experiments, mice were exposed to pristine MWCNTs or MWCNTs with an HDM allergen corona (HDM-MWCNTs). HDM-MWCNTs were formed by incubating MWCNTs with HDM extract, where ∼7% of proteins adsorbed to MWCNTs, including Der p 1 and Der p 2. At necropsy, bronchoalveolar lavage fluid was collected from lungs to assess lactate dehydrogenase, total protein and inflammatory cells, while lung tissue was used for histopathology, qPCR, and Western blotting. Compared to MWCNTs or HDM extract alone, coexposure to MWCNTs and HDM extract or exposure to HDM-MWCNTs increased pathological outcomes associated with allergic lung disease (eosinophilia, fibrosis, mucous cell metaplasia), increased mRNAs associated with fibrosis (Col1A1, Arg1) and enhanced STAT6 phosphorylation in lung tissue. These findings indicated that exacerbation of HDM-induced allergic lung disease by MWCNTs is due to an allergen corona.

Titanium dioxide (TiO2) nanoparticles, used as pigments and photocatalysts, are widely present in modern society. Inhalation or ingestion of these nanoparticles can lead to cellular-level interactions. We examined the very first step in this cellular interaction, the effect of TiO2nanoparticles on the lipids of the plasma membrane. Within 12 h of TiO2nanoparticle exposure, the lipids of the plasma membrane were oxidized, determined with a malondialdehyde assay. Lipid peroxidation was inhibited by surface passivation of the TiO2nanoparticles, incubation with an antioxidant (Trolox), and the presence of serum proteins in solution. Subsequent experiments determined that serum proteins adsorbed on the surface of the TiO2nanoparticles, forming a protein corona, inhibit lipid peroxidation. Super-resolution fluorescence microscopy showed that these serum proteins were clustered on the nanoparticle surface. These protein clusters slow lipid peroxidation, but by 24 h, the level of lipid peroxidation is similar, independent of the protein corona or free serum proteins. Additionally, over 24 h, this corona of proteins was displaced from the nanoparticle surface by free proteins in solution. Overall, these experiments provide the first mechanistic investigation of plasma membrane oxidation by TiO2nanoparticles, in the absence of UV light and as a function of the protein corona, approximating a physiological environment.

The article discusses the contraceptives available for adolescents and their efficacy and safety. Topics discussed include Various methods of contraception including intrauterine devices/progestin implants, progestin injections, and combined oral contraception; different methods of Combined Hormonal Contraception that contain both an estrogen and progestin; and vaginal ring (NuvaRing), a round, flexible device that is inserted into the vagina weekly.