Toxicity of Quantum Dots

Quantum dots (QD) have been deeply studied due to their physicochemical and optical properties with important advantages of a wide range biomedical applications. Nevertheless, concern prevails about its toxic effects, mainly in those QD whose core contains cadmium. Therefore, there are reports about the toxicity caused by the release of ions of cadmium and the effects related to its tiny nanometric size. The aim of this chapter is to show the evaluations about the toxicity of QD, which include studies on viability, proliferation, uptake, and distribution in vitro and in vivo models. What are the worrying toxic effects of QD? There are reports about some mechanisms of toxicity caused by QD, such as immunological toxicity, cell death (apoptosis and necrosis), genotoxicity, among others. In addition, we discuss how coating QD with passivating agents that improve their biocompatibility. Likewise, this coating modifies their size and surface charge, which are fundamental aspects of the interaction with other biomolecules. We consider highlighting information about more precise techniques and methodologies that help us to understand how QD induce damage in several biological systems

Interaction of Nanoparticles with Blood Components and Associated Pathophysiological Effects

Nanotechnology currently plays a pivotal role in several fields and has enabled substantial advances in a relatively short time. In biomedicine, nanomaterials can be potentially employed as a tool for early diagnosis and an innovative mode of drug delivery. Novel nanomaterials are currently widely manipulated without a full assessment of their potential health risks. It is commonly thought that nanomaterials’ first contact with the organism is through the different components of the immune system. However, if the entry route is intravenous, the first contact will be with the blood’s components (erythrocytes, platelets, white cells, plasma and complement proteins). The presence of nanomaterials within a dynamic environment such as the bloodstream can produce potential harmful effects following interaction with several blood components. The design of innovative strategies leading to the development of more hemocompatible nanomaterials is also necessary

Potential Harm of Maltodextrin‐Coated Cadmium Sulfide Quantum Dots in Embryos and Fetuses

Over the past years, there has been significant interest in the study of nanoparticles for clinical applications, particularly quantum dots (QDs). However, previous studies have also shown that QDs can reach the embryo through the placenta, a natural barrier for a large variety of organic substances with diverse molecular structures, and may cause developmental deformities. Due to its essential role in a toxicological profile and its relevance to human safety, knowledge regarding embryotoxicity is of great importance. Previous studies by this research group have shown that CdS‐maltodextrin QDs are biocompatible and nontoxic to cells and animals; however, QDs are able to induce embryotoxic effects. Therefore, as an effort to further address the issue, we studied the effects of CdS‐maltodextrin QDs on embryo and fetus development using an embryotoxicity and teratogenicity assay on chicken embryos. Chicken embryos exposed to CdS‐maltodextrin QDs (0.001, 0.01, 0.1 and 1 µg/kg) in ovo for 72 h showed growth and developmental alterations during the early stage and at the end of their development in a dose‐dependent manner. Decreased development was observed during early stages (Stages 9/10 on the Hamburger‐Hamilton scale) when compared with untreated eggs (Stage 13). Chicken embryos exposed to lower CdS‐maltodextrin QDs doses (0.01, 0.1 and 1 ng/kg) and incubated in ovo for 21 h also showed growth and development alterations during the early stages and at the end of their development in a dose‐dependent manner. However, reduced development was observed at the end of the development period (21 days), and this was associated with death of the chick. Current studies have also shown that CdS‐dextrin induces embryotoxicity and teratogenicity, affecting mainly the CNS, the neural tube and somites in chicken embryos. The nature of the observed abnormalities suggests that these effects could be directly associated with nanoparticle concentrations affecting somitogenesis. Therefore, according to the results, there is a high probability that the prolonged accumulation of QDs in the maternal organism may be potentially harmful on embryo and fetus development. This study is limited to the analysis of embryotoxic and teratogenic effects induced by CdS‐maltodextrin QDs

Models of Hepatotoxicity for the Study of Chronic Liver Disease

Chronic liver disease affects globally and has a high morbidity and mortality rate. It is histopathologically characterized by the presence of inflammation, and the progressive destruction and regeneration of the hepatic parenchyma, which can lead to the development of fibrosis, cirrhosis, and hepatocellular carcinoma. Most liver diseases tend to become chronic and can be therefore studied in animal models, as it is possible to quickly develop pathological processes in animals with a high degree of reproducibility and obtain predictive data regarding the different hepatopathies. The development of animal models in the field of hepatology has been geared toward the search for new knowledge meant to favor human well-being and proved useful in translational medicine focused on liver disease. Like any other methodological tool, animal models provide valuable. Obviously, a single model cannot reproduce the complexity and spectrum of all liver diseases, which is why a wide variety are currently employed: they include chemically, immune, diet, surgically, and genetically modified damage in animals and involve biological agents or the use of humanized livers in rodents. This chapter surveys some of the main animal models used in the study of chronic liver disease and the disease characteristics they mimic

自称表現に見られる日中両言語の人称代名詞と親族語彙

千葉大学社会文化科学研究科研究プロジェクト報告書第84集『日中両言語における代名詞及び親族語彙の対照研究-琉球方言との比較研究も含めて』所

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries