Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
Scientists study adverse effects of carbon, silicon nanotubes and carbon nanofibers

Scientists study adverse effects of carbon, silicon nanotubes and carbon nanofibers

Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. This algae species is widely spread in the Russian Far East marine area. The acute toxic effect exhibited at concentrations of 100 mg/l of carbon nanotubes (CNTs) and silicon nanotubes (SiNTs) in the sea- or fresh water.

The international team of toxicologists led by scientists of Far Eastern Federal University (FEFU) has researched the environmental adverse effects of carbon nanotubes (CNTs), silicon nanotubes (SiNTs) and carbon nanofibers (CNFs) contained in the plastic materials and composites. Research outcome is published in the Environmental Research magazine.

The reason why researchers paid attention to the problem of the toxic effects of nanoparticles is the rapid growth of their applying in the different fields of the world manufacturing. It’s estimated that to 2020 the world market of CNTs will reach 5,64 billion USD, i.e. it will more than doubled compared to 2000 when it was 2, 26 billion USD.

During the plastic and composites fabrication CNTs and SiNTs added in their structure to improve physical properties of the final materials. In the modern medicine nanotubes of different nature are proposed as the drugs adsorbents and drug delivery systems.

At the present time, all kinds of synthesized carbon-based nanoparticles are well described concerning their physical parameters. Nevertheless, scientists declare lack of toxicity data necessary for risk appraisal and modeling.

“From 60 to 80 percent of the world plastic materials and composites and about 10 percent of their annual production end up into the World Ocean where degradation of such materials takes several hundred years. As a rule, all these materials contain nanoparticles added for their physical properties improvement,” comments on one of the article’s authors Kirill Golokhavast, M.D., Ph.D., FEFU provost for science. “Marine microalgae toxicology research is of a big importance because they are widespread and constitute the basis of the food chain in the ocean.”

For the nanotoxicology research purposes, scientists chose the unicellular marine microalgae Heterosigma akashiwo isolated from Peter the Great Gulf of Japan Sea. This choice was made due to the fact that this type of algae is typical for the Russian Far East and its research could be relevant for all microalgae of the local marine basin. The other important reason is that H. akashiwo has a thin cell wall that could render it rather susceptible for the chemical pollution.

The experiment performed in accordance to the guidance OECD No.201 (OECD, 2006) with minor modifications. For the criteria of nanotubes toxic effect scientist took the statistically significant reduction of the number of algal cells in experimental sample compared to control one. The toxicity tests were performed in 24-well cell culture plates.

Carbon nanotubes and nanofibers used in this research were synthesized in the Boreskov Institute of Catalysis (Novosibirsk, Russia) and their toxic effects were previously studied on rats.

Silicon nanotubes SiNTs and SiNTs INC-2 were kindly provided by the Department of Chemistry, Inha University Republic of Korea.

The research methodology is based on Raman spectroscopy to characterize samples of CNTs and confocal microscopy by optical microscope Axio Imager A2 (Carl Zeiss, Germany) with a magnification of 200 × and 600 × to image microalgae.

Algal cell analysis and counting of the propidium iodide stained cells were conducted by CytoFLEX flow cytometer (Beckman Coulter, USA) with the excitation light of 405 nm, 488 nm, and 638 nm.

Conducting the research, scientists concluded that CNTs and SiNTs toxic effect emerged when nanotubes concentration is 100 mg/l of water. The acute toxic effect revealed on the third day of the experiment and chronic intoxication took place on the seventh day. Herewith, SiNTs is much more toxic than CNTs due to the less size and hydrophilic properties of SiNTs nanotubes.

Scientists assumed that the main reason that caused the algal cells’ death during the experiment is mechanical damage to cells integrity by nanoparticles. Compared to nanotubes carbon nanofibers didn’t inhibit algal cells growth and didn’t reveal toxicity at concentration 100 mg/l of water but influenced on the cells’ shape distortion. The reason of these deformations, according to scientists, was Nickel (Ni) impurities contained in CNFs.

“The volume of nanomaterials presence in our life has increased enormously from early laboratory samples delivered in microgram quantities. Up to date, it’s multi-ton production of plastic and composites contained nanoparticulate matter such as carbon and silicon nanotubes. The further the more important to know what environment burden may be caused by this particles. We already know that nanotube diameter is crucial to their toxicity. The thinner the significantly more toxic they are. Silicon nanotubes is more toxic than carbon, but carbon-based compounds could cause a series of neurodegenerative disorders, mainly due to oxidative stress accumulation and a parallel reduction in antioxidant protection mechanisms”, comments on Aristidis Tsatsakis, article co-main author, D.Sc, PhD, the Director of the Department of Toxicology and Forensic Sciences of the Medical School at the University of Crete and the University Hospital of Heraklion.

Tagged with:

About author

Related Articles