Anion-Mediated Effects on the Size and Mechanical Properties of Enzymatically Crosslinked Suckerin Hydrogels.

The suckerin family of proteins, identified from the squid sucker ring teeth assembly, offers unique mechanical properties and potential advantages over other natural biomaterials. In this study, a small suckerin isoform, suckerin-12, is used to create enzymatically crosslinked, macro-scale hydrogels. Upon exposure to specific salt conditions, suckerin-12 hydrogels contracted into a condensed state where mechanical properties are found to be modulated by the salt anion present.

Toxicological Implications of Platinum Nanoparticle Exposure: Stimulation of Intracellular Stress, Inflammatory Response, and Akt Signaling In Vitro.

Due to their distinctive physicochemical properties, platinum nanoparticles (PtNPs) have emerged as a material of interest for a number of biomedical therapeutics. However, in some instances NP exposure has been correlated to health and safety concerns, including cytotoxicity, activation of cellular stress, and modification to normal cell functionality. As PtNPs have induced differential cellular responses , the goal of this study was to further characterize the behavior and toxicological potential of PtNPs within a HepG2 liver model.

Implementation of physiological fluids to provide insight into the characterization, fate, and biological interactions of silver nanoparticles.

Silver nanoparticles (AgNPs) are being increasingly utilized in consumer and medical applications. However, there remains conflicting reports on their safety, which are evaluated through a combination of in vitro and in vivo exposure models. These discrepancies may arise, in part, due to the inherent differences between cell-based and animal systems.

Immunogenicity and antimicrobial effectiveness of Pseudomonas aeruginosa specific bacteriophage in a human lung in vitro model.

The rise of antibiotic resistant bacteria is posing a serious threat to human health. For example, resistant strains of Pseudomonas aeruginosa have resulted in untreatable and potentially lethal infections in both cystic fibrosis and immunocompromised patients. Due to the growing need for alternative treatment options, bacteriophage, or phage, therapy is gaining considerable attention.

Exposure to metal oxide nanoparticles in physiological fluid induced synergistic biological effects in a keratinocyte model.

Nanoparticles (NPs) possess distinctive physicochemical properties that in addition to differentiating them from their bulk counterparts can induce negative cellular consequences. Standard in vitro systems have served as the primary model for NP safety evaluations, but suffer from a lack physiological relevance. One way to overcome this limitation and evaluate NP characteristics under more accurate conditions is through the use of artificial physiological fluids, which mimic the composition of in vivo environments.

Modification of the protein corona-nanoparticle complex by physiological factors.

Nanoparticle (NP) effects in a biological system are driven through the formation and structure of the protein corona-NP complex, which is dynamic by nature and dependent upon factors from both the local environment and NP physicochemical parameters. To date, considerable data has been gathered regarding the structure and behavior of the protein corona in blood, plasma, and traditional cell culture medium. However, there exists a knowledge gap pertaining to the protein corona in additional biological fluids and following incubation in a dynamic environment.

The role of biological fluid and dynamic flow in the behavior and cellular interactions of gold nanoparticles.

Background: Due to their distinctive physicochemical properties, nanoparticles (NPs) have proven to be extremely advantageous for product and application development, but are also capable of inducing detrimental outcomes in biological systems. Standard in vitro methodologies are currently the primary means for evaluating NP safety, as vast quantities of particles exist that require appraisal. However, cell-based models are plagued by the fact that they are not representative of complex physiological systems.

At the Crossroads of Nanotoxicology in vitro: Past Achievements and Current Challenges.

The exponential growth in the employment of nanomaterials (NMs) has given rise to the field of nanotoxicology; which evaluates the safety of engineered NMs. Initial nanotoxicological studies were limited by a lack of both available materials and accurate biodispersion characterization tools. However, the years that followed were marked by the development of enhanced synthesis techniques and characterization technologies; which are now standard practice for nanotoxicological evaluation.

Dynamic characteristics of silver nanoparticles in physiological fluids: toxicological implications.

The field of nanotoxicology has made tremendous progress identifying novel and potentially adverse biological effects following nanomaterial (NM) exposure. However, one facet yet to be satisfactorily explored is how a physiological environment modifies NM physicochemical properties, thus introducing novel complexities associated with solid phase material exposures. In this study, artificial alveolar, lysosomal, and interstitial fluids were used to identify environmental-specific modulations to the properties and behavior of hydrocarbon-coated (Ag-HC) and polysaccharide-coated (Ag-PS) silver NMs.

Slow release of ions from internalized silver nanoparticles modifies the epidermal growth factor signaling response.

Due to their distinctive physiochemical properties, including a robust antibacterial activity and plasmonic capability, hundreds of consumer and medical products contain colloidal silver nanoparticles (AgNPs). However, even at sub-toxic dosages, AgNPs are able to disrupt cell functionality, through a yet unknown mechanism. Moreover, internalized AgNPs have the potential to prolong this disruption, even after the removal of excess particles.

Less is more: long-term in vitro exposure to low levels of silver nanoparticles provides new insights for nanomaterial evaluation.

In view of the vast number of new nanomaterials (NMs) that require testing and the constraints associated with animal models, the majority of studies to elucidate nanotoxicological effects have occurred in vitro, with limited correlation and applicability to in vivo systems and realistic, occupational exposure scenarios. In this study, we developed and implemented a chronic in vitro model coupled with lower, regulatory dosages in order to provide a more realistic assessment of NM-dependent consequences and illuminate the implications of long-term NM exposure. When keratinocytes were exposed to 50 nm silver nanoparticles (Ag-NPs), we determined that chronically dosed cells operated under augmented stress and modified functionality in comparison to their acute counterparts.

Tannic acid coated gold nanorods demonstrate a distinctive form of endosomal uptake and unique distribution within cells.

One of the primary challenges associated with nanoparticle-dependent biological applications is that endosomal entrapment in a physiological environment severely limits the desired targeting and functionality of the nanoconstructs. This study sought to overcome that challenge through a systematic approach of gold nanorod (GNR) functionalization: evaluating the influence of both aspect ratio and surface chemistry on targeted cellular internalization rates and preservation of particle integrity. Owing to their unique spectral properties and enhanced surface area, GNRs possess great potential for the advancement of nanobased delivery and imaging applications.

High aspect ratio gold nanorods displayed augmented cellular internalization and surface chemistry mediated cytotoxicity.

Due to their unique properties, gold nanorods (GNRs) have shown tremendous potential for advancing bio-imaging and sensing applications. As these nanoparticles display size-dependent optical properties, high aspect ratio GNRs are of particular interest for these applications because of their increased scattering contrast. While studies are emerging that demonstrate successful synthesis of high aspect ratio GNRs, their behavior and fate in a physiological environment has yet to be investigated.

The biological impact of concurrent exposure to metallic nanoparticles and a static magnetic field.

The rapid advancement of technology has led to an exponential increase of both nanomaterial and magnetic field utilization in applications spanning a variety of sectors. While extensive work has focused on the impact of these two variables on biological systems independently, the existence of any synergistic effects following concurrent exposure has yet to be investigated. This study sought to ascertain the induced alterations to the stress and proliferation responses of the human adult low calcium, high temperature keratinocyte (HaCaT) cell line by the application of a static magnetic field (approximately 0.

Novel platform development using an assembly of carbon nanotube, nanogold and immobilized RNA capture element towards rapid, selective sensing of bacteria.

This study examines the creation of a nano-featured biosensor platform designed for the rapid and selective detection of the bacterium Escherichia coli. The foundation of this sensor is carbon nanotubes decorated with gold nanoparticles that are modified with a specific, surface adherent ribonucleiuc acid (RNA) sequence element. The multi-step sensor assembly was accomplished by growing carbon nanotubes on a graphite substrate, the direct synthesis of gold nanoparticles on the nanotube surface, and the attachment of thiolated RNA to the bound nanoparticles.

Interference of silver, gold, and iron oxide nanoparticles on epidermal growth factor signal transduction in epithelial cells.

Metallic nanomaterials, including silver, gold, and iron oxide, are being utilized in an increasing number of fields and specialties. The use of nanosilver as an antimicrobial agent is becoming ever-more common, whereas gold and iron oxide nanomaterials are frequently utilized in the medical field due to their recognized "biocompatibility". Numerous reports have examined the general toxicity of these nanomaterials; however, little data exists on how the introduction of these nanomaterials, at nontoxic levels, affects normal cellular processes.

Combinatorial Signal Transduction Responses Mediated by Interleukin-2 and -4 Receptors in a Helper T Cell Line.

The cytokines interleukin (IL)-2 and IL-4 are important regulators of the adaptive immune response, due in part to their effects on clonal expansion and differentiation of T cells. When IL-2 and IL-4 are administered together, both antagonistic and synergistic effects have been reported, but little is known in general concerning the mechanisms underlying such combinatorial effects. We found evidence for both effects in the proliferation responses of the IL-2 and IL-4 responsive T cell line, HT-2; IL-4 delays the onset of cell growth yet ultimately allows a higher cell density to be achieved in static culture.