In vivo percutaneous permeation of gold nanomaterials in consumer cosmetics: implication in dermal safety assessment of consumer nanoproducts.

The increasing emergence of nano-cosmetics in the marketplace provokes safety concerns with respect to percutaneous permeation and toxicity of nanomaterials inside the human body. In this study, in vivo percutaneous permeation and dermal safety of cosmetic cream containing Au nanosheets and extracted Au nanosheets from cosmetic creams are investigated with guinea pigs. Quantitative percutaneous permeation data suggests that Au nanosheets in cosmetic creams permeate into the skin epidermis, dermis, and subcutaneous layer after 10 d cutaneous exposure, but cannot enter the systemic circulation. However, more Au nanosheets are accumulated in the skin and the permeation of Au nanosheets increased after embedded into the cream matrix. Synchrotron radiation X-ray fluorescence (SRXRF) imaging reveals that Au nanosheets in cosmetics penetrate mainly through hair follicles in a time-dependent manner. Cosmetic creams rather than extracted Au nanosheets decrease the cell viability of keratinocytes and slightly induce apoptosis/necrosis of keratinocytes and skin dermal fibroblasts. Intriguingly, the growth of hair is inhibited by the cosmetic cream and the extracted Au nanosheets revealed by HE staining and immunohistochemistry (IHC) assay. Altogether this study provides insights into the comprehensive understanding of percutaneous permeation and dermal safety of cosmetic creams containing Au nanosheets. This work provides reliable methods to study the skin permeation, biodistribution, and dermal safety of nano-cosmetics and reminds the community of the crucial need to combine the assays at molecular, cellular, and organ levels in nanotoxicology research.

Safety Assessment of Nanomaterials for Antimicrobial Applications.

The interplay between nanotechnology and pathogens offers a new quest to fight against human infections. Inspiring from their unique thermal, magnetic, optical, or redox potentials, numerous nanomaterials have been employed for bacterial theranostics. The past decade has seen dramatic progress in the development of various nanoantimicrobials, which demands more focus on their safety assessment. The present review critically discusses the toxicity of nanoantimicrobials and the role of key features, including composition, size, surface charge, loading capability, hydrophobicity/philicity, precise release, and functionalization, that can contribute to modulating the effects on microbes. Moreover, how differences in microbe's structure, biofilm formation, persistence cells, and intracellular pathogens bestow resistance or sensitivity toward nanoantimicrobials is broadly investigated. In extension, the most important types of nanoantimicrobial with clinical prospective and their safety assessment are summarized, and finally, based on available evidence, an insight of the principles in designing safer nanoantimicrobials for overcoming pathogens and future challenges in the field is provided.

Assessment of Air Pollutant PM2.5 Pulmonary Exposure Using a 3D Lung-on-Chip Model.

Airborne particulate matters have posed significant risk to human health worldwide. Fine particulate matters (PM2.5, aerodynamic diameter <2.5 µm) are associated with increased morbidity and mortality attributed to pulmonary diseases. An advanced in vitro model would benefit the assessment of PM2.5 induced pulmonary injuries and drug development. In this work, we present a PM2.5 exposure model to evaluate the pulmonary risk of fine particulate matter exposure in an organotypic manner with the help of 3D human lung-on-a-chip. By compartmentalized co-culturing of human endothelial cells, epithelial cells, and extra cellular matrix, our lung-on-a-chip recapitulated the structural features of the alveolar-blood barrier, which is pivotal for exogenous hazard toxicity evaluation. PM2.5 was applied to the channel lined with lung epithelial cells to model the pulmonary exposure of fine particulate matter. The results indicated acute high dose PM2.5 exposure would lead to various malfunctions of the alveolar-capillary barrier, including adheren junction disruption, increased ROS generation, apoptosis, inflammatory biofactor expression in epithelial cells and endothelial cells, elevated permeability, and monocyte attachments. Collectively, our lung-on-a-chip model provides a simple platform to investigate the complex responses after PM2.5 exposure in a physiologically relevant level, which could be of great potential in environmental risk assessment and therapeutic treatment development.

Intelligent testing strategy and analytical techniques for the safety assessment of nanomaterials.

Nanomaterials (NMs) are widely used in various areas because of their unique and useful physicochemical properties. However, they may pose toxicity risks to human health after exposure. Applicable and reliable approaches are needed for risk assessment of NMs. Herein, an intelligent analytical strategy for safety assessment of NMs is proposed that focuses on toxicity assessment using an in vitro cell model. The toxicity assessment by testing on the adverse outcome pathway in a cell culture system was defined by application of a tiered testing approach. To provide an overview of the applicable approach for risk assessment of NMs, we discuss the most commonly used techniques and analytical methods, including computational toxicology methods in dosimetry assessment, high-throughput screening for toxicity testing with high efficiency, and omics-based toxicology assessment methods. The final section focuses on the route map for an integrated approach to a testing and assessment strategy on how to extrapolate the in vitro NM toxicity testing data to in vivo risk assessment of NMs. The intelligent analytical strategy, having evolved step-by-step, could contribute to better applications for safety evaluation and risk assessment of NMs in reality.

Gold Nanomaterials in Consumer Cosmetics Nanoproducts: Analyses, Characterization, and Dermal Safety Assessment.

Establishment of analytical methods of engineered nanomaterials in consumer products for their human and environmental risk assessment becomes urgent for both academic and industrial needs. Owing to the difficulties and challenges around nanomaterials in complex media, proper chemical separation and biological assays of nanomaterials from nanoproducts needs to be firstly developed. Herein, a facile and rapid method to separate and analyze gold nanomaterials in cosmetics is reported. Gold nanomaterials are successfully separated from different facial or eye creams and their physiochemical properties are analyzed by quantitative and qualitative state-of-the art techniques with high sensitivity or high spatial resolution. In turn, a protocol including quantification of gold by inductively coupled plasma mass spectrometry and thorough characterization of morphology, size distribution, and surface property by electron microscopes, atomic force microscope, and X-ray photoelectron spectroscope is developed. Subsequently, the preliminary toxicity assessment indicates that gold nanomaterials in cosmetic creams have no observable toxicity to human keratinocytes even after 24 h exposure up to a concentration of 200 µg mL-1 . The environmental scanning electron microscope reveals that gold nanomaterials are mostly attached on the cell membrane. Thus, the present study provides a full analysis protocol for toxicity assessment of gold nanomaterials in consumer products (cosmetic creams).

Role of nanotechnology in HIV/AIDS vaccine development.

HIV/AIDS is one of the worst crises affecting global health and influencing economic development and social stability. Preventing and treating HIV infection is a crucial task. However, there is still no effective HIV vaccine for clinical application. Nanotechnology has the potential to solve the problems associated with traditional HIV vaccines. At present, various nano-architectures and nanomaterials can function as potential HIV vaccine carriers or adjuvants, including inorganic nanomaterials, liposomes, micelles and polymer nanomaterials. In this review, we summarize the current progress in the use of nanotechnology for the development of an HIV/AIDS vaccine and discuss its potential to greatly improve the solubility, permeability, stability and pharmacokinetics of HIV vaccines. Although nanotechnology holds great promise for applications in HIV/AIDS vaccines, there are still many inadequacies that result in a variety of risks and challenges. The potential hazards to the human body and environment associated with some nano-carriers, and their underlying mechanisms require in-depth study. Non-toxic or low-toxic nanomaterials with adjuvant activity have been identified. However, studying the confluence of factors that affect the adjuvant activity of nanomaterials may be more important for the optimization of the dosage and immunization strategy and investigations into the exact mechanism of action. Moreover, there are no uniform standards for investigations of nanomaterials as potential vaccine adjuvants. These limitations make it harder to analyze and deduce rules from the existing data. Developing vaccine nano-carriers or adjuvants with high benefit-cost ratios is important to ensure their broad usage. Despite some shortcomings, nanomaterials have great potential and application prospects in the fields of AIDS treatment and prevention.

Safety assessment of ovarian cryopreservation and transplantation in nude mice bearing human epithelial ovarian cancer.

OBJECTIVE: Nude mice with orthotopic transplantation of human ovarian epithelial cancer were used to investigate screening criteria for paraneoplastic normal ovarian tissue and the security of the freezing and thawing for ovarian tissue transplantation. METHODS: Expression of CK-7, CA125, P53, survivin, MMP-2/TIMP- 2 in paraneoplastic normal ovarian tissues were detected by RT-PCR as well as immunohistochemistry. The tissues of the groups with all negative indicators of RT-PCR, all negative indicators of immunohistochemistry, negative expression of CK-7, CA125 and survivin, positive expression of CK-7, CA125 and survivin, cancer tissues and normal ovarian tissues of nude mice were used for freezing and thawing transplantation, to analyze overt and occult carcinogenesis rates after transplantation. RESULTS: When all indicators or the main indicators, CK-7, CA125 and survivin, were negative, tumorigenesis did not occur after transplantation. In addition the occult carcinogenesis rate was lower than in the group with positive expression of CK-7, CA125 and survivin (P<0.01). After subcutaneous and orthotopic transplantation of ovarian tissues, rates did not change (P>0.05). There was no statistical significance among rates after transplantation of ovarian tissues which were obtained under different severity conditions (P>0.05). CONCLUSION: Negative expression of CK-7, CA125 and survivin can be treated as screening criteria for security of ovarian tissues for transplantation. Immunohistochemical methods can be used as the primary detection approach. Both subcutaneous and orthotopic transplantation are safe. The initial severity does not affect the carcinogenesis rate after tissue transplantation. Freezing and thawing ovarian tissue transplantation in nude mice with human epithelial ovarian carcinoma is feasible and safe.

Gold nanomaterials: preparation, chemical modification, biomedical applications and potential risk assessment.

Gold nanomaterials (Au NMs) have attracted increasing attention in biomedicine due to their facile preparation, multifunctional modifications, unique optical and electrical properties, and good biocompatibility. The physicochemical properties of Au NMs at nanoscale, like size, shape, surface chemistry, and near field effects, are rendering Au NMs potent candidates in biomedicine. Thus, risk assessment of negative effects of Au NMs on biological systems is becoming urgent and necessary for future applications. In this review, we summarize up-to-date progresses on the preparation and modification of Au NMs and their biomedical applications, including biosensor, bioimaging and phototherapy, gene/drug delivery. Finally, we discuss the potential risk of Au NMs to biological systems, which is instructive for rationally designing and preparing nanomaterials for safe applications in nanomedicine.

Full assessment of fate and physiological behavior of quantum dots utilizing Caenorhabditis elegans as a model organism.

We evaluated the in vivo fate and physiological behavior of quantum dots (QDs) in Caenorhabditis elegans by GFP transfection, fluorescent imaging, synchrotron radiation based elemental imaging, and speciation techniques. The in situ metabolism and degradation of QDs in the alimentary system and long-term toxicity on reproduction are fully assessed. This work highlights the utility of the C. elegans model as a multiflexible platform to allow noninvasively imaging and monitoring in vivo consequences of engineered nanomaterials.