Rationale, Procedures, and Response Rates for a Pilot Study to Sample Cancer Survivors for NCI's Health Information National Trends Survey: HINTS-SEER 2021.

The National Cancer Institute's (NCI) Health Information National Trends Survey (HINTS) is a nationally representative survey of U.S. adults in which 12-17% of respondents report a cancer history. To increase representation from adult cancer survivors, in 2021, NCI sampled survivors from three Surveillance, Epidemiology, and End Results (SEER) program cancer registries: Iowa, New Mexico, and the Greater Bay Area. Sampling frames were stratified by time since diagnosis and race/ethnicity, with nonmalignant tumors and non-melanoma skin cancers excluded. Participants completed a self-administered postal questionnaire. The overall response rate for HINTS-SEER (N = 1,234) was 12.6%; a non-response bias analysis indicated few demographic differences between respondents and the pool of sampled patients in each registry. Most of the sample was 10+ years since diagnosis (n = 722; 60.2%); 392 respondents were 5 to < 10 years since diagnosis (29.6%); and 120 were < 5 years since diagnosis (10.2%). Common cancers included male reproductive (n = 304; 24.6%), female breast (n = 284; 23.0%), melanoma (n = 119; 9.6%), and gastrointestinal (n = 106; 8.6%). Tumors were mostly localized (67.8%; n = 833), with 22.4% (n = 282) regional, 6.2% (n = 72) distant, and 3.7% (n = 47) unknown. HINTS-SEER data are available by request and may be used for secondary analyses to examine a range of social, behavioral, and healthcare outcomes among cancer survivors.

Patient-Centered Communication (PCC) scale: Psychometric analysis and validation of a health survey measure.

INTRODUCTION: Patient-centered communication (PCC) is one important component of patient-centered care and seen as a goal for most clinical encounters. Previous research has shown that higher PCC is related to an increase in healthy behaviors and less morbidity, among other outcomes. Given its importance, the National Cancer Institute (NCI) commissioned a monograph in 2007 to synthesize the existing literature on PCC and determine measurement objectives and strategies for measuring this construct, with a particular focus on cancer survivors. Based on this effort, a seven-item PCC scale was included on the Health Information National Trends Survey (HINTS), a probability-based survey of the US adult population. This study used HINTS data collected in 2018 to evaluate the psychometric properties of the PCC scale for the general US adult population including measures of reliability and validity. RESULTS: Through an exploratory factor analysis, the seven-item PCC scale was shown to be unidimensional with good internal consistency (Cronbach's alpha = .92). A confirmatory factor analysis verified the factor structure. Other construct validity metrics included known groups and discriminant validity. Known group comparisons were conducted for several sociodemographic factors and health self-efficacy confirming a priori assumptions. Discriminant validity tests with measures of social support and anxiety/depression showed relatively weak associations. CONCLUSIONS: The psychometric properties of this scale demonstrate its scientific utility for both surveillance research and other smaller-scale studies. Given its association with many health outcomes, it can also be used to better understand the dynamics in a clinical encounter.

Neuroticism, cancer mortality salience, and physician avoidance in cancer survivors: Proximity of treatment matters.

OBJECTIVE: To examine if the relationship between neuroticism and physician avoidance/physician visit concerns are mediated by perceptions that cancer is associated with death ("cancer mortality salience"; CMS) for cancer survivors to inform public health interventions and tailored health communications. METHODS: Cancer survivors comprised 42.3% of the total sample (n = 525). Participants completed a 4-item neuroticism scale, 4-item cancer perceptions scale, and 4-item physician avoidance and concerns scale. Multiple linear regression models were used to assess relationships among variables for cancer survivors and separately for those without a history of cancer. RESULTS: Neuroticism was positively associated with CMS for cancer survivors, b = 0.26, (p < 0.001), and those without cancer, b = 0.22, (p < 0.001). There was an association between neuroticism and physician avoidance among cancer survivors with temporally distant treatment courses after controlling for CMS, b = 0.56 (p = 0.006), but not for those currently or recently having had undergone treatment (p = 0.949). There was also an indirect relationship between neuroticism and physician visit concerns that was mediated by CMS for cancer survivors, b = 0.07, CI = [0.03, 0.13], but this relationship was again driven by cancer survivors with more distal treatment courses. CONCLUSIONS: High neuroticism in cancer survivors is associated with physician avoidance and physician visit concerns when treatment is temporally distant. Interventions aimed at decoupling the association between cancer and death can help increase the willingness of cancer survivors to attain cancer care follow-ups and healthcare more generally.

Affective determinants of physical activity in cancer survivors.

Objective: Research with non-cancer survivor populations finds affective variables to be important determinants of physical activity. This study assessed the ability of explicit and implicit affective variables to predict the physical activity of cancer survivors, above that accounted for by cognitive variables. The study also tested whether the affective variables were connected to physical activity directly or indirectly through their association with behavioural intentions. Design: In a cross-sectional design, cancer survivors (n = 122) completed questionnaires and an implicit affect task. Main outcome measures: Self-report measures assessed three affective variables (e.g. positive affective associations), five cognitive variables (e.g. cognitive beliefs), physical activity estimates, behavioural intentions and participants also completed an implicit affect task regarding physical activity. Results: Two of the three explicit affect variables and the implicit affect variable accounted for significant variability in physical activity estimates beyond that accounted for by the cognitive variables. Positive affective associations were the strongest predictor in multivariate analyses. Behavioural intentions did not mediate the link between the affect variables and physical activity estimates. Conclusions: Explicit and implicit affective variables are direct and unique predictors of physical activity in cancer survivors. Physical activity interventions for cancer survivors should target both explicit affect and implicit affect.

Assessing the Relationship Between Implicit and Explicit Evaluations of Fruit and Vegetable Consumption by Cancer Survivors.

BACKGROUND: Currently, little is known about the implicit evaluations that cancer survivors have for health behaviors, such as eating fruits and vegetables. Understanding both the implicit and explicit evaluations of fruit and vegetable consumption among cancer survivors may aid future interventions for changing motivations and intentions in this higher risk population. METHODS: A cross-sectional study at a university cancer center assessed explicit and implicit evaluations of fruit and vegetable consumption among 122 cancer survivors. The explicit evaluations regarding fruit and vegetable consumption were self-report data. To obtain implicit evaluations, participants completed an implicit evaluation task, the Affect Misattribution Paradigm. Moderating variables of time since first cancer treatment and if participants had a prior cancer occurrence were also self-reported. RESULTS: Simple correlations found no significant association between the implicit and explicit evaluations of fruit and vegetable consumption. Moderation regression analyses showed that the implicit and explicit evaluations became negatively associated as time since first treatment increased and when participants had a prior cancer occurrence. CONCLUSION: The results support the view that implicit and explicit measures of fruit and vegetable consumption diverge for cancer survivors, consistent to implicit and explicit evaluations in other domains and samples. Further, the association between these evaluations differed depending on time since first treatment and if they have been treated for a prior cancer occurrence. By knowing more about implicit and explicit positive evaluations, and their moderators, it may be possible for interventionists to alter cancer survivors' motivation and intention to eat fruits and vegetables.

Optimizing Community-Based HIV Testing and Linkage to Care for Young Persons in Metropolitan Atlanta.

HIV continuum of care analyses in Georgia during 2013 revealed that 82% of adolescents and adults living with HIV knew their diagnosis and that 75% were linked to care. However, of all persons in Georgia living with HIV in 2014, only 60% had at least one HIV care visit, and just 48% were retained in care. Understanding barriers for HIV testing, linkage, and retention in youth may strengthen HIV-related encounters and improve patient outcomes. We conducted 17 qualitative focus groups with HIV-positive and -negative youth, ages 18-24 years, from the Atlanta Metropolitan Statistical Area. Using computer-assisted thematic analyses, we examined focus group responses on ways to approach youth for community-based HIV testing and how service providers should discuss a new positive HIV diagnosis with youth. Of 68 participants, 85% were male, 90% were African American, 68% were HIV positive, and 50% had high school education or less. Mean age was 21.5 years (standard deviation: 1.8 years). Thematic analyses identified the following three key themes for approaching someone for HIV testing: (1) discretion, (2) being candid about testing, and (3) incentivizing testing. When service providers discuss an HIV positive test, participants recommended enhanced emotional support and reassurance of a potential healthy life span despite an HIV diagnosis. Community-based testing may be a viable option for increasing HIV screening of at-risk youth. Structuring an empathetic new diagnosis disclosure that addresses potential misconceptions and describes successful HIV treatment is essential to improving linkage to care among youth.

"We Deserve Better!": Perceptions of HIV Testing Campaigns Among Black and Latino MSM in New York City.

In 2014, Black/African-American and Hispanic/Latino men who have sex with men (BLMSM) comprised 64.1% of HIV diagnoses among MSM in the U.S. Routine HIV testing allows earlier diagnosis, linkage to care, and improved health outcomes. HIV testing campaigns may increase HIV awareness and testing behaviors, but perceptions of these campaigns by BLMSM have been understudied. We explored perceptions of HIV testing campaigns with BLMSM in New York City (NYC) to inform campaign strategies that target BLMSM for HIV testing. Using respondent-driven sampling methods, we conducted semi-structured interviews from 2011 to 2012 with BLMSM in NYC who participated in a larger HIV research study. Interview responses from 108 participants were examined for main themes using computer-assisted thematic analyses. The four main themes identified were that HIV testing campaigns should: (1) use non-stereotypical messages and images on the basis of race and sexuality, (2) use non-gay identified images, (3) be maximally inclusive and visible, and (4) raise risk perception of HIV. These findings can inform future campaigns for strengthening HIV testing among BLMSM in support of earlier diagnosis, linkage to care, and reduced disparities.

Mediation of the single-walled carbon nanotubes induced pulmonary fibrogenic response by osteopontin and TGF-ß1.

PURPOSE OF THE STUDY: A number of in vivo studies have shown that pulmonary exposure to carbon nanotubes (CNTs) may lead to an acute local inflammatory response, pulmonary fibrosis, and granulomatous lesions. Among the factors that play direct roles in initiation and progression of fibrotic processes are epithelial-mesenchymal transition and myofibroblasts recruitment/differentiation, both mediated by transforming growth factor-ß1 (TGF-ß1). Yet, other contributors to TGF-ß1 associated signaling, such as osteopontin (OPN) has not been fully investigated. MATERIALS AND METHODS: OPN-knockout female mice (OPN-KO) along with their wild-type (WT) counterparts were exposed to single-walled carbon nanotubes (SWCNT) (40 µg/mouse) via pharyngeal aspiration and fibrotic response was assessed 1, 7, and 28 days post-exposure. Simultaneously, RAW 264.7 and MLE-15 cells were treated with SWCNT (24 hours, 6 µg/cm2 to 48 µg/cm2) or bleomycin (0.1 µg/ml) in the presence of OPN-blocking antibody or isotype control, and TGF-ß1 was measured in supernatants. RESULTS AND CONCLUSIONS: Diminished lactate dehydrogenase activity at all time points, along with less pronounced neutrophil influx 24 h post-exposure, were measured in broncho-alveolar lavage (BAL) of OPN-KO mice compared to WT. Pro-inflammatory cytokine release (IL-6, TNF-α, MCP-1) was reduced. A significant two-fold increase of TGF-ß1 was found in BAL of WT mice at 7 days, while TGF-ß1 levels in OPN-KO animals remained unaltered. Histological examination revealed marked decrease in granuloma formation and less collagen deposition in the lungs of OPN-KO mice compared to WT. RAW 264.7 but not MLE-15 cells exposed to SWCNT and bleomycin had significantly less TGF-ß1 released in the presence of OPN-blocking antibody. We believe that OPN is important in initiating the cellular mechanisms that produce an overall pathological response to SWCNT and it may act upstream of TGF-ß1. Further investigation to understand the mechanistic details of such interactions is critical to predict outcomes of pulmonary exposure to CNT.

Graphene oxide attenuates Th2-type immune responses, but augments airway remodeling and hyperresponsiveness in a murine model of asthma.

Several lines of evidence indicate that exposure to nanoparticles (NPs) is able to modify airway immune responses, thus facilitating the development of respiratory diseases. Graphene oxide (GO) is a promising carbonaceous nanomaterial with unique physicochemical properties, envisioned for a multitude of medical and industrial applications. In this paper, we determined how exposure to GO modulates the allergic pulmonary response. Using a murine model of ovalbumin (OVA)-induced asthma, we revealed that GO, given at the sensitization stage, augmented airway hyperresponsiveness and airway remodeling in the form of goblet cell hyperplasia and smooth muscle hypertrophy. At the same time, the levels of the cytokines IL-4, IL-5, and IL-13 were reduced in broncho-alveolar lavage (BAL) fluid in GO-exposed mice. Exposure to GO during sensitization with OVA decreased eosinophil accumulation and increased recruitment of macrophages in BAL fluid. In line with the cytokine profiles, sensitization with OVA in the presence of GO stimulated the production of OVA-specific IgG2a and down-regulated the levels of IgE and IgG1. Moreover, exposure to GO increased the macrophage production of the mammalian chitinases, CHI3L1 and AMCase, whose expression is associated with asthma. Finally, molecular modeling has suggested that GO may directly interact with chitinase, affecting AMCase activity, which has been directly proven in our studies. Thus, these data show that GO exposure attenuates Th2 immune response in a model of OVA-induced asthma, but leads to potentiation of airway remodeling and hyperresponsiveness, with the induction of mammalian chitinases.

Long-term effects of carbon containing engineered nanomaterials and asbestos in the lung: one year postexposure comparisons.

The hallmark geometric feature of single-walled carbon nanotubes (SWCNT) and carbon nanofibers (CNF), high length to width ratio, makes them similar to a hazardous agent, asbestos. Very limited data are available concerning long-term effects of pulmonary exposure to SWCNT or CNF. Here, we compared inflammatory, fibrogenic, and genotoxic effects of CNF, SWCNT, or asbestos in mice 1 yr after pharyngeal aspiration. In addition, we compared pulmonary responses to SWCNT by bolus dosing through pharyngeal aspiration and inhalation 5 h/day for 4 days, to evaluate the effect of dose rate. The aspiration studies showed that these particles can be visualized in the lung at 1 yr postexposure, whereas some translocate to lymphatics. All these particles induced chronic bronchopneumonia and lymphadenitis, accompanied by pulmonary fibrosis. CNF and asbestos were found to promote the greatest degree of inflammation, followed by SWCNT, whereas SWCNT were the most fibrogenic of these three particles. Furthermore, SWCNT induced cytogenetic alterations seen as micronuclei formation and nuclear protrusions in vivo. Importantly, inhalation exposure to SWCNT showed significantly greater inflammatory, fibrotic, and genotoxic effects than bolus pharyngeal aspiration. Finally, SWCNT and CNF, but not asbestos exposures, increased the incidence of K-ras oncogene mutations in the lung. No increased lung tumor incidence occurred after 1 yr postexposure to SWCNT, CNF, and asbestos. Overall, our data suggest that long-term pulmonary toxicity of SWCNT, CNF, and asbestos is defined, not only by their chemical composition, but also by the specific surface area and type of exposure.

Oxidative stress, inflammatory biomarkers, and toxicity in mouse lung and liver after inhalation exposure to 100% biodiesel or petroleum diesel emissions.

Over the past decade, soy biodiesel (BD) has become a first alternative energy source that is economically viable and meets requirements of the Clean Air Act. Due to lower mass emissions and reduced hazardous compounds compared to diesel combustion emissions (CE), BD exposure is proposed to produce fewer adverse health effects. However, considering the broad use of BD and its blends in different industries, this assertion needs to be supported and validated by mechanistic and toxicological data. Here, adverse effects were compared in lungs and liver of BALB/cJ mice after inhalation exposure (0, 50, 150, or 500 µg/m3; 4 h/d, 5 d/wk, for 4 wk) to CE from 100% biodiesel (B100) and diesel (D100). Compared to D100, B100 CE produced a significant accumulation of oxidatively modified proteins (carbonyls), an increase in 4-hydroxynonenal (4-HNE), a reduction of protein thiols, a depletion of antioxidant gluthatione (GSH), a dose-related rise in the levels of biomarkers of tissue damage (lactate dehydrogenase, LDH) in lungs, and inflammation (myeloperoxidase, MPO) in both lungs and liver. Significant differences in the levels of inflammatory cytokines interleukin (IL)-6, IL-10, IL-12p70, monocyte chemoattractant protein (MCP)-1, interferon (IFN) γ, and tumor necrosis factor (TNF)-α were detected in lungs and liver upon B100 and D100 CE exposures. Overall, the tissue damage, oxidative stress, inflammation, and cytokine response were more pronounced in mice exposed to BD CE. Further studies are required to understand what combustion products in BD CE accelerate oxidative and inflammatory responses.

Oxidative stress and dermal toxicity of iron oxide nanoparticles in vitro.

A number of commercially available metal/metal oxide nanoparticles (NPs) such as superparamagnetic iron oxide (SPION) are utilized by the medical field for a wide variety of applications. These NPs may able to induce dermal toxicity via their physical nature and reactive surface properties. We hypothesize that SPION may be toxic to skin via the ability of particles to be internalized and thereby initiate oxidative stress, inducing redox-sensitive transcription factors affecting/leading to inflammation. Due to the skin's susceptibility to UV radiation, it is also of importance to address the combined effect of UVB and NPs co-exposure. To test this hypothesis, the effects of dextran-coated SPION of different sizes (15-50 nm) and manufacturers (MicroMod, Rostock-Warnemunde, Germany and KTH-Royal Institute of Technology, Stockholm, Sweden) were evaluated in two cell lines: normal human epidermal keratinocytes (HEK) and murine epidermal cells (JB6 P(+)). HEK cells exposed to 20 nm (KTH and MicroMod) had a decrease in viability, while the 15 and 50 nm particles were not cytotoxic. HEK cells were also capable of internalizing the KTH particles (15 and 20 nm) but not the MicroMod SPION (20 and 50 nm). IL-8 and IL-6 were also elevated in HEK cells following exposure to SPION. Exposure of JB6 P(+) cells to all SPIONs evaluated resulted in activation of AP-1. Exposure to SPION alone was not sufficient to induce NF-κB activation; however, co-exposure with UVB resulted in significant NF-κB induction in cells exposed to 15 and 20 nm KTH SPION and 50 nm MicroMod particles. Pre-exposure of JB6 P(+) cells to UVB followed by NPs induced a significant depletion of glutathione, release of cytokines, and cell damage as assessed by release of lactate dehydrogenase. Altogether, these data indicate that co-exposure to UVB and SPIONs was associated with induction of oxidative stress and release of inflammatory mediators. These results verify the need to thoroughly evaluate the adverse effects of UVB when evaluating dermal toxicity of engineered NPs on skin.

Factoring-in agglomeration of carbon nanotubes and nanofibers for better prediction of their toxicity versus asbestos.

BACKGROUND: Carbon nanotubes (CNT) and carbon nanofibers (CNF) are allotropes of carbon featuring fibrous morphology. The dimensions and high aspect ratio of CNT and CNF have prompted the comparison with naturally occurring asbestos fibers which are known to be extremely pathogenic. While the toxicity and hazardous outcomes elicited by airborne exposure to single-walled CNT or asbestos have been widely reported, very limited data are currently available describing adverse effects of respirable CNF. RESULTS: Here, we assessed pulmonary inflammation, fibrosis, oxidative stress markers and systemic immune responses to respirable CNF in comparison to single-walled CNT (SWCNT) and asbestos. Pulmonary inflammatory and fibrogenic responses to CNF, SWCNT and asbestos varied depending upon the agglomeration state of the particles/fibers. Foci of granulomatous lesions and collagen deposition were associated with dense particle-like SWCNT agglomerates, while no granuloma formation was found following exposure to fiber-like CNF or asbestos. The average thickness of the alveolar connective tissue--a marker of interstitial fibrosis--was increased 28 days post SWCNT, CNF or asbestos exposure. Exposure to SWCNT, CNF or asbestos resulted in oxidative stress evidenced by accumulations of 4-HNE and carbonylated proteins in the lung tissues. Additionally, local inflammatory and fibrogenic responses were accompanied by modified systemic immunity, as documented by decreased proliferation of splenic T cells ex vivo on day 28 post exposure. The accuracies of assessments of effective surface area for asbestos, SWCNT and CNF (based on geometrical analysis of their agglomeration) versus estimates of mass dose and number of particles were compared as predictors of toxicological outcomes. CONCLUSIONS: We provide evidence that effective surface area along with mass dose rather than specific surface area or particle number are significantly correlated with toxicological responses to carbonaceous fibrous nanoparticles. Therefore, they could be useful dose metrics for risk assessment and management.

Impaired clearance and enhanced pulmonary inflammatory/fibrotic response to carbon nanotubes in myeloperoxidase-deficient mice.

Advancement of biomedical applications of carbonaceous nanomaterials is hampered by their biopersistence and pro-inflammatory action in vivo. Here, we used myeloperoxidase knockout B6.129X1-MPO (MPO k/o) mice and showed that oxidation and clearance of single walled carbon nanotubes (SWCNT) from the lungs of these animals after pharyngeal aspiration was markedly less effective whereas the inflammatory response was more robust than in wild-type C57Bl/6 mice. Our results provide direct evidence for the participation of MPO - one of the key-orchestrators of inflammatory response - in the in vivo pulmonary oxidative biodegradation of SWCNT and suggest new ways to control the biopersistence of nanomaterials through genetic or pharmacological manipulations.

Comparative proteomics and pulmonary toxicity of instilled single-walled carbon nanotubes, crocidolite asbestos, and ultrafine carbon black in mice.

Reflecting their exceptional potential to advance a range of biomedical, aeronautic, and other industrial products, carbon nanotube (CNT) production and the potential for human exposure to aerosolized CNTs are increasing. CNTs have toxicologically significant structural and chemical similarities to asbestos (AB) and have repeatedly been shown to cause pulmonary inflammation, granuloma formation, and fibrosis after inhalation/instillation/aspiration exposure in rodents, a pattern of effects similar to those observed following exposure to AB. To determine the degree to which responses to single-walled CNTs (SWCNT) and AB are similar or different, the pulmonary response of C57BL/6 mice to repeated exposures to SWCNTs, crocidolite AB, and ultrafine carbon black (UFCB) were compared using high-throughput global high performance liquid chromatography fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR-MS) proteomics, histopathology, and bronchoalveolar lavage cytokine analyses. Mice were exposed to material suspensions (40 micrograms per mouse) twice a week for 3 weeks by pharyngeal aspiration. Histologically, the incidence and severity of inflammatory and fibrotic responses were greatest in mice treated with SWCNTs. SWCNT treatment affected the greatest changes in abundance of identified lung tissue proteins. The trend in number of proteins affected (SWCNT [376] > AB [231] > UFCB [184]) followed the potency of these materials in three biochemical assays of inflammation (cytokines). SWCNT treatment uniquely affected the abundance of 109 proteins, but these proteins largely represent cellular processes affected by AB treatment as well, further evidence of broad similarity in the tissue-level response to AB and SWCNTs. Two high-sensitivity markers of inflammation, one (S100a9) observed in humans exposed to AB, were found and may be promising biomarkers of human response to SWCNT exposure.

Differences between intermittent and light daily smokers in a population of U.S. military recruits.

INTRODUCTION: Few studies have assessed differences between intermittent and light smokers, particularly among young adults. Exploring these differences promotes a systematic approach to research and treatment in low-level smokers. This study explored demographic, tobacco-related, and psychosocial predictors of intermittent nondaily smoking relative to light smoking among basic military training (BMT) recruits. The impact of smoking status on abstinence rates at follow-up was also assessed. METHODS: Participants were 5,603 U.S. Air Force BMT intermittent nondaily (n = 3,134) or light daily (n = 2,469) smoking recruits participating in a population-based group randomized trial targeting tobacco use prevention and cessation (Klesges et al., 2006, Efficacy of a tailored tobacco control program on long-term use in a population of U.S. military troops. Journal of Consulting and Clinical Psychology, 74, 295-306.). Participants completed baseline measures assessing demographics; tobacco use and history; and common social, attitudinal, and behavioral risk factors for tobacco use. Flights of recruits were randomly assigned to a tobacco use intervention or health education control intervention. At the 1-year follow-up, participants reported 7-day point prevalence and continuous abstinence. RESULTS: Intermittent nondaily smoking relative to light daily smoking was associated with lesser perceived addiction, intermittent and daily use of smokeless tobacco, nonsmoking male and female heads of household, lesser likelihood of smoking while stressed or while bored, and higher likelihood of intentions to quit smoking. Intermittent smokers were significantly more likely than light daily smokers to report abstinence at follow-up. DISCUSSION: Intermittent and daily light smokers differ on several tobacco-related and psychosocial variables. Attending to these factors in prevention and cessation programs may enhance abstinence in both groups.

Phosphatidylserine targets single-walled carbon nanotubes to professional phagocytes in vitro and in vivo.

Broad applications of single-walled carbon nanotubes (SWCNT) dictate the necessity to better understand their health effects. Poor recognition of non-functionalized SWCNT by phagocytes is prohibitive towards controlling their biological action. We report that SWCNT coating with a phospholipid "eat-me" signal, phosphatidylserine (PS), makes them recognizable in vitro by different phagocytic cells - murine RAW264.7 macrophages, primary monocyte-derived human macrophages, dendritic cells, and rat brain microglia. Macrophage uptake of PS-coated nanotubes was suppressed by the PS-binding protein, Annexin V, and endocytosis inhibitors, and changed the pattern of pro- and anti-inflammatory cytokine secretion. Loading of PS-coated SWCNT with pro-apoptotic cargo (cytochrome c) allowed for the targeted killing of RAW264.7 macrophages. In vivo aspiration of PS-coated SWCNT stimulated their uptake by lung alveolar macrophages in mice. Thus, PS-coating can be utilized for targeted delivery of SWCNT with specified cargoes into professional phagocytes, hence for therapeutic regulation of specific populations of immune-competent cells.

Single-walled carbon nanotubes: geno- and cytotoxic effects in lung fibroblast V79 cells.

With the development of nanotechnology, there is a tremendous growth of the application of nanomaterials, which increases the risk of human exposure to these nanomaterials through inhalation, ingestion, and dermal penetration. Among different types of nanoparticles, single-walled carbon nanotubes (SWCNT) with extremely small size (1 nm in diameter) exhibit extraordinary properties and offer possibilities to create materials with astounding features. Since the release of nanoparticles in an enclosed environment is of great concern, a study of possible genotoxic effects is important. Our previous data showed that pharyngeal aspiration of SWCNT elicited pulmonary effects in C57BL/6 mice that was promoted by a robust, acute inflammatory reaction with early onset resulting in progressive interstitial fibrogenic response and the formation of granulomas. In the present study, the genotoxic potential of SWCNT was evaluated in vitro. The genotoxic effects of nanoparticles were examined using three different test systems: the comet assay and micronucleus (MN) test in a lung fibroblast (V79) cell line, and the Salmonella gene mutation assay in strains YG1024/YG1029. Cytotoxicity tests showed loss of viability in a concentration- and time-dependent manner after exposure of cells to SWCNT. Results from the comet assay demonstrated the induction of DNA damage after only 3 h of incubation with 96 microg/cm2 of SWCNT. The MN test indicated some but not significant micronucleus induction by SWCNT in the V79 cell line at the highest concentrations tested. With two different strains of Salmonella typhimurium, no mutations were found following SWCNT exposure.

Vitamin E deficiency enhances pulmonary inflammatory response and oxidative stress induced by single-walled carbon nanotubes in C57BL/6 mice.

Exposure of mice to single-walled carbon nanotubes (SWCNTs) induces an unusually robust pulmonary inflammatory response with an early onset of fibrosis, which is accompanied by oxidative stress and antioxidant depletion. The role of specific components of the antioxidant protective system, specifically vitamin E, the major lipid-soluble antioxidant, in the SWCNT-induced reactions has not been characterized. We used C57BL/6 mice, maintained on vitamin E-sufficient or vitamin E-deficient diets, to explore and compare the pulmonary inflammatory reactions to aspired SWCNTs. The vitamin E-deficient diet caused a 90-fold depletion of alpha-tocopherol in the lung tissue and resulted in a significant decline of other antioxidants (GSH, ascorbate) as well as accumulation of lipid peroxidation products. A greater decrease of pulmonary antioxidants was detected in SWCNT-treated vitamin E-deficient mice as compared to controls. Lowered levels of antioxidants in vitamin E-deficient mice were associated with a higher sensitivity to SWCNT-induced acute inflammation (total number of inflammatory cells, number of polymorphonuclear leukocytes, released LDH, total protein content and levels of pro-inflammatory cytokines, TNF-alpha and IL-6) and enhanced profibrotic responses (elevation of TGF-beta and collagen deposition). Exposure to SWCNTs markedly shifted the ratio of cleaved to full-length extracellular superoxide dismutase (EC-SOD). Given that pulmonary levels of vitamin E can be manipulated through diet, its effects on SWCNT-induced inflammation may be of practical importance in optimizing protective strategies.

Unusual inflammatory and fibrogenic pulmonary responses to single-walled carbon nanotubes in mice.

Single-walled carbon nanotubes (SWCNT) are new materials of emerging technological importance. As SWCNT are introduced into the life cycle of commercial products, their effects on human health and environment should be addressed. We demonstrated that pharyngeal aspiration of SWCNT elicited unusual pulmonary effects in C57BL/6 mice that combined a robust but acute inflammation with early onset yet progressive fibrosis and granulomas. A dose-dependent increase in the protein, LDH, and gamma-glutamyl transferase activities in bronchoalveolar lavage were found along with accumulation of 4-hydroxynonenal (oxidative biomarker) and depletion of glutathione in lungs. An early neutrophils accumulation (day 1), followed by lymphocyte (day 3) and macrophage (day 7) influx, was accompanied by early elevation of proinflammatory cytokines (TNF-alpha, IL-1beta; day 1) followed by fibrogenic transforming growth factor (TGF)-beta1 (peaked on day 7). A rapid progressive fibrosis found in mice exhibited two distinct morphologies: 1) SWCNT-induced granulomas mainly associated with hypertrophied epithelial cells surrounding SWCNT aggregates and 2) diffuse interstitial fibrosis and alveolar wall thickening likely associated with dispersed SWCNT. In vitro exposure of murine RAW 264.7 macrophages to SWCNT triggered TGF-beta1 production similarly to zymosan but generated less TNF-alpha and IL-1beta. SWCNT did not cause superoxide or NO.production, active SWCNT engulfment, or apoptosis in RAW 264.7 macrophages. Functional respiratory deficiencies and decreased bacterial clearance (Listeria monocytogenes) were found in mice treated with SWCNT. Equal doses of ultrafine carbon black particles or fine crystalline silica (SiO2) did not induce granulomas or alveolar wall thickening and caused a significantly weaker pulmonary inflammation and damage.