A New In Vivo Model System to Assess the Toxicity of Semiconductor Nanocrystals

In the emerging area of nanotechnology, a key issue is related to the potential impacts of the novel nanomaterials on the environment and human health, so that this technology can be used with minimal risk. Specifically designed to combine on a single structure multipurpose tags and properties, smart nanomaterials need a comprehensive characterization of both chemicophysical properties and adequate toxicological evaluation, which is a challenging endeavour; the in vitro toxicity assays that are often employed for nanotoxicity assessments do not accurately predict in vivo response. To overcome these limitations and to evaluate toxicity characteristics of cadmium telluride quantum dots in relation to surface coatings, we have employed the freshwater polyp Hydra vulgaris as a model system. We assessed in vivo acute and sublethal toxicity by scoring for alteration of morphological traits, population growth rates, and influence on the regenerative capabilities providing new investigation clues for nanotoxicology purposes

Mechanisms underlying toxicity induced by CdTe quantum dots determined in an invertebrate model organism

A systematic and thorough quantitative analysis of the in vivo effects of inorganic nanoparticles is extremely important for the design of functional nanomaterials for diagnostic and therapeutic applications, better understanding of their non-specificity toward tissues and cell types, and for assessments of their toxicity. This study was undertaken to examine the impact of CdTe quantum dots (QDs) on an invertebrate freshwater model organism, Hydra vulgaris, for assessment of long term toxicity effects. The continuous exposure of living polyps to sub-lethal doses of QDs caused time and dose dependent morphological damages more severe than Cd2+ ions at the same concentrations, impaired both reproductive and regenerative capability, activated biochemical and molecular responses. Of remarkable interest, low QD doses, apparently not effective, caused early changes in the expression of general stress responsive and apoptotic genes. The occurrence of subtle genetic variations, in the absence of morphological damages, indicates the importance of genotoxicity studies for nanoparticle risk assessment. The versatility in morphological, cellular, biochemical and molecular responses renders Hydra a perfect model system for high-throughput screening of toxicological and ecotoxicological impact of nanomaterials on human and environmental health

Targeted Nanoparticles for the Treatment of Alzheimer's Disease

Background: Alzheimer's disease (AD) has a dramatic impact on society. The therapeutic targets are located in the central nervous system (CNS), which limits the efficacy of drugs systemically administered: the blood-brain barrier (BBB) selectively allows the permeation of just a few kinds of molecules from the systemic circulation to the CNS. On the other hand, local administration routes to CNS are highly invasive. Methods: In this article, we have reviewed therapeutic approaches against AD, which are based on nanoparticles targeted to the brain and to the pathological hallmarks of the disease. The existing literature has been classified according to the AD feature that is addressed. Results: Nanoparticles have been used for the targeted delivery of drugs aiming to reduce the AD symptoms or to reverse the course of the disease. For this task the multivalency of nanoparticles has allowed their functionalization with several kinds of targeting groups, to cross the BBB and to target the place of treatment. With this approach an increased drug bioavailability has been achieved in the CNS using intravenous administration in place of more invasive administration routes. Additionally, nanoparticles have also been used in the development of vaccines and therapeutic formulations for intranasal administration. Conclusion: Targeted nanoparticles have been proved useful to enhance the performance of therapies against AD in animal models. A better understanding of AD mechanisms will help the successful application of targeted nanoparticles for combined therapies

An Integrated Multilevel Analysis Profiling Biosafety and Toxicity Induced by Indium- and Cadmium-Based Quantum Dots in Vivo

Indium phosphide quantum dots (QDs) have emerged as a new class of fluorescent nanocrystals for manifold applications, from biophotonics to nanomedicine. Recent efforts in improving the photoluminescence quantum yield, the chemical stability and the biocompatibility turned them into a valid alternative to well established Cd-based nanocrystals. In vitro studies provided first evidence for the lower toxicity of In-based QDs. Nonetheless, an urgent need exists for further assessment of the potential toxic effects in vivo. Here we use the freshwater polyp Hydra vulgaris, a well-established model previously adopted to assess the toxicity of CdSe/CdS nanorods and CdTe QDs. A systematic multilevel analysis was carried out in vivo, ex vivo, and in vitro comparing toxicity end points of CdSe- and InP-based QDs, passivated by ZnSe/ZnS shells and surface functionalized with penicillamine. Final results demonstrate that both the chemical composition of the QD core (InP vs CdSe) and the shell play a crucial role for final outcomes. Remarkably, in absence of in vivo alterations, cell and molecular alterations revealed hidden toxicity aspects, highlighting the biosafety of InP-based nanocrystals and outlining the importance of integrated multilevel analyses for proper QDs risk assessment

Serum Oxidized Protein and Prostate Cancer Risk within the Prostate Cancer Prevention Trial

Overall view of the three tower complex and white connecting base, looking south from the US 1 (Brickell Ave.) bridge; Located on the south side of the Miami River in Downtown's northern Brickell Financial District. The complex consists of three skyscrapers and the Icon Brickell Plaza, connecting the towers at their base. The first two towers, the Icon Brickell North Tower and South Tower, are twin buildings.The third phase of the complex is the Viceroy Tower (Viceroy Hotel, a "condo-hotel"), which is 500 feet (150 m) tall with 50 floors. In total there are 1,800 units (1,648 residential, 162 hotel). Arriving guests are greeted by a spectacular two story entrance, lined with 100 columns throughout the driveway, some with lit “eyes” that glow to guide your way and “watch over each arriving guest.” The gigantic columns, estimated at 5 million dollars, are modeled to resemble Moai Statues of Easter Island heads that embrace your journey into Starck’s world of playful spirit. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 9/4/2015