Nanoparticles From Air Pollution Travel Into Blood To Cause Heart Disease

Inhaled nanoparticles – like those released from vehicle exhausts – can work their way through the lungs and into the bloodstream, potentially raising the risk of heart attack and stroke, according to new research part-funded by the British Heart Foundation. The findings, published today in the journal ACS Nano, build on previous studies that have found tiny particles in air pollution are associated with an increased risk of cardiovascular disease, although the cause remains unproven. However, this research shows for the first time that inhaled nanoparticles can gain access to the blood in healthy individuals and people at risk of stroke. Most worryingly, these nanoparticles tend to build-up in diseased blood vessels where they could worsen coronary heart disease – the cause of a heart attack.

It is not currently possible to measure environmental nanoparticles in the blood. So, researchers from the University of Edinburgh, and the National Institute for Public Health and the Environment in the Netherlands, used a variety of specialist techniques to track the fate of harmless gold nanoparticles breathed in by volunteers. They were able to show that these nanoparticles can migrate from the lungs and into the bloodstream within 24 hours after exposure and were still detectable in the blood three months later. By looking at surgically removed plaques from people at high risk of stroke they were also able to find that the nanoparticles accumulated in the fatty plaques that grow inside blood vessels and cause heart attacks and strokesCardiovascular disease (CVD) – the main forms of which are coronary heart disease and stroke – accounts for 80% of all premature deaths from air pollution.


It is striking that particles in the air we breathe can get into our blood where they can be carried to different organs of the body. Only a very small proportion of inhaled particles will do this, however, if reactive particles like those in air pollution then reach susceptible areas of the body then even this small number of particles might have serious consequences,”  said Dr Mark Miller, Senior Research Fellow at the University of Edinburgh who led the study.


‘Protective’ DNA strands are shorter in adults who had more infections as infants

New research indicates that people who had more infections as babies harbor a key marker of cellular aging as young adults: the protective stretches of DNA which “cap” the ends of their chromosomes are shorter than in adults who were healthier as infants.

TELOMERESThe 46 chromosomes of the human genome, with telomeres highlighted in white

These are important and surprising findings because — generally speaking — shorter chromosome ‘caps’ are associated with a higher burden of disease later in life,” said lead author Dan Eisenberg, an assistant professor of anthropology at the University of Washington.

The ‘caps’ Eisenberg and his co-authors measured are called telomeres. These are long stretches of DNA at the ends of our chromosomes, which protect our genes from damage or improper regulation. One Nobel Prize-winning scientist who studies telomeres has compared them to aglets — the plastic or metal sheath covering ends of shoelaces. When aglets wear down, the shoelace is exposed to fraying and degradation from environmental forces.

Like aglets, telomeres don’t last forever. In most of our cells, telomeres get shorter each time that cell divides. And when they get too short, the cell either quits dividing or dies.

That makes telomere length particularly important for the cells of our immune system, especially the white blood cells circulating in our bloodstream. When activated against a pathogen, white blood cells undergo rapid rounds of cell division to raise a defensive force against the infectious invader. But if telomeres in white blood cells are already too short, the body may struggle to mount an effective immune response.

Many studies — in laboratory animals and humans — have associated shorter telomeres with poor health outcomes, especially in adults,” said Eisenberg. But few studies have addressed whether or not events early in a person’s life might affect telomere length. To get at this question, Eisenberg turned to the Cebu Longitudinal Health and Nutrition Survey, which has tracked the health of over 3,000 infants born in 1983-1984 in Cebu City in the Philippines. Researchers collected detailed data every two months from mothers on the health and feeding habits of their babies up through age two. Mothers reported how often their babies had diarrhea — a sign of infection — as well as how often they breastfed their babies. As these babies grew up, scientists collected additional health data during follow-up surveys over the next 20 years. In 2005, 1,776 of these offspring donated a blood sample. By then, they were 21- or 22-year-old young adults.

Eisenberg measured telomere length in cells from those blood samples. He then combined the data on adult telomere length with information about their health and feeding habits as babies. He found that babies with higher reported cases of diarrhea at 6 to 12 months also had the shortest telomeres as adults.

The findings have been published in the American Journal of Human Biology.


Neuron Triggers Insulin

Research led by a Johns Hopkins University biologist demonstrates the workings of a biochemical pathway that helps control glucose in the bloodstream, a development that could potentially lead to treatments for diabetes. In a paper published in the current issue of Developmental Cell, Jessica Houtz, a graduate student working with Rejji Kuruvilla in the Department of Biology at Johns Hopkins, shows that a protein that regulates the development of nerve cells also plays a role in prompting cells in the pancreas to release insulin, a hormone that helps to maintain a normal level of blood sugar.

Kuruvilla worked on the project with Johns Hopkins colleagues, Houtz who is the lead author, and Philip Borden and Alexis Ceasrine, all doctoral students in the biology department. Also taking part was Liliana Minichiello of the Department of Pharmacology at the University of Oxford.

The research is potentially relevant to type-2 diabetes, the most common form of the disease, affecting nearly one in ten Americans. With this form of the condition, which can appear at any time of life, the body makes insulin, but is either not releasing enough of it or not using the regulatory chemical efficiently to control blood sugar. In type-1 diabetes, which appears in childhood, an immune response gone awry destroys the body’s ability to produce insulin altogether.

The research on insulin represents a detour for Kuruvilla, whose work has focused on development of the peripheral nervous system. She has studied a group of proteins called neurotrophins, and in particular nerve growth factor [NGF]. These proteins nurture the growth of neurons, the cells of the nervous system.


It has been known for some time that neurons and the pancreatic beta cells, or β-cells, that reside in clusters called islets of Langerhans and produce insulin, have many similarities in molecular makeup and signaling receptors. Receptors are proteins on cell surfaces that respond to particular chemicals and have critical roles in biochemical pathways. Both neurons and pancreatic β-cells have the receptors for neurotrophins.

This project was sparked by seeing NGF receptors present in beta-cells,” said Kuruvilla. The question was, she said: “what are these receptors doing outside the nervous system?”

Turns out that NGF performs a function in the mature pancreas that has nothing to do with supporting neurons. Specifically, the research team traced a chain of biochemical signals showing that elevated blood glucose causes NGF to be released from blood vessels in the pancreas, and that the NGF signal then prompts pancreatic β-cells to relax their rigid cytoskeletal structure, releasing insulin granules into the blood stream. Although β-cells also make NGF, Kuruvilla and her team found that it was the NGF released from the blood vessels that is needed for insulin secretion.

Using genetic manipulation in mice and drugs to block NGF signaling in β-cells, they were able to disrupt distinct elements of this signaling sequence, to show that this classical neuronal pathway is necessary to enhance insulin secretion and glucose tolerance in mice. Importantly, Kuruvilla and colleagues found that NGF’s ability to enhance insulin secretion in response to high glucose also occurs in human β-cells.

It is not yet clear how this system is affected in people with diabetes. “We are very interested in knowing whether aspects of this pathway are disrupted in pre-diabetic individuals,” said Kuruvilla. It would be of interest to determine if NGF or small molecules that bind and activate NGF receptors in the pancreas could be of potential use in the treatment of type-2 diabetes.


“Liquid Biopsy” Chip Detects Metastatic Cancer Cells in a Drop of Blood

A chip developed by mechanical engineers at Worcester Polytechnic Institute (WPI) can trap and identify metastatic cancer cells in a small amount of blood drawn from a cancer patient. The breakthrough technology uses a simple mechanical method that has been shown to be more effective in trapping cancer cells than the microfluidic approach employed in many existing devices.


The chip is tested in the lab. The electrodes detect electrical changes that occur when cancer cells are captured (click on the image to enjoy the video)

The WPI device uses antibodies attached to an array of carbon nanotubes at the bottom of a tiny well. Cancer cells settle to the bottom of the well, where they selectively bind to the antibodies based on their surface markers (unlike other devices, the chip can also trap tiny structures called exosomes produced by cancers cells). This “liquid biopsy,”  could become the basis of a simple lab test that could quickly detect early signs of metastasis and help physicians select treatments targeted at the specific cancer cells identified.

Metastasis is the process by which a cancer can spread from one organ to other parts of the body, typically by entering the bloodstream. Different types of tumors show a preference for specific organs and tissues; circulating breast cancer cells, for example, are likely to take root in bones, lungs, and the brain. The prognosis for metastatic cancer (also called stage IV cancer) is generally poor, so a technique that could detect these circulating tumor cells before they have a chance to form new colonies of tumors at distant sites could greatly increase a patient’s survival odds.

The focus on capturing circulating tumor cells is quite new,” said Balaji Panchapakesan, associate professor of mechanical engineering at WPI and director of the Small Systems Laboratory. “It is a very difficult challenge, not unlike looking for a needle in a haystack. There are billions of red blood cells, tens of thousands of white blood cells, and, perhaps, only a small number of tumor cells floating among them. We’ve shown how those cells can be captured with high precision.

The findings have been described in  the journal Nanotechnology,


Legions Of Nanorobots Attack Cancerous Cells

Researchers from Polytechnique Montréal, Université de Montréal and McGill University have just achieved a spectacular breakthrough in cancer research. They have developed new nanorobotic agents capable of navigating through the bloodstream to administer a drug with precision by specifically targeting the active cancerous cells of tumours. This way of injecting medication ensures the optimal targeting of a tumour and avoids jeopardizing the integrity of organs and surrounding healthy tissues. As a result, the drug dosage that is highly toxic for the human organism could be significantly reduced.

legions of nanorobots attack cancerous cells

These legions of nanorobotic agents were actually composed of more than 100 million flagellated bacteria – and therefore self-propelled – and loaded with drugs that moved by taking the most direct path between the drug’s injection point and the area of the body to cure,” explains Professor Sylvain Martel,  Director of the Polytechnique Montréal Nanorobotics Laboratory, who heads the research team’s work. “The drug’s propelling force was enough to travel efficiently and enter deep inside the tumours.”

When they enter a tumour, the nanorobotic agents can detect in a wholly autonomous fashion the oxygen-depleted tumour areas, known as hypoxic zones, and deliver the drug to them. This hypoxic zone is created by the substantial consumption of oxygen by rapidly proliferative tumour cells. Hypoxic zones are known to be resistant to most therapies, including radiotherapy.

But gaining access to tumours by taking paths as minute as a red blood cell and crossing complex physiological micro-environments does not come without challenges. So Professor Martel and his team used nanotechnology to do it.


This scientific breakthrough has just been published in the prestigious journal Nature Nanotechnology in an article titled “Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions.” The article notes the results of the research done on mice, which were successfully administered nanorobotic agents into colorectal tumours.


Sunscreen Nanoparticles Eliminate Skin-Cancer

A research team including scientists funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) has developed a nanotechnology-based sunscreen that provides excellent protection from ultraviolet (UV) damage while eliminating a number of harmful effects of currently used sunscreens. The team encapsulated the UV-blocking compounds in bio-adhesive nanoparticles (BNPs), which adhere to the skin well, but do not penetrate beyond the skin’s surface. These properties resulted in highly effective UV protection in a mouse model, without the adverse effects observed with commercial sunscreens, including penetration into the bloodstream and generation of reactive oxygen species, which can damage DNA and lead to cancer. Commercial sunscreens use compounds that effectively filter out damaging UV light. However, there is concern that these agents have a variety of harmful effects due to penetration past the surface skin. For example, these products have been found in human breast tissue and urine and are known to disrupt the normal function of some hormones. Also, the exposure of the UV filters to light can produce toxic reactive oxygen species that are destructive to cells and tissues and can cause tumors through DNA damage.



BNPs remain on skin for a full day but are gone due to normal exfoliation in five days

This work applies a novel bioengineering idea to a little known but significant health problem, adds Jessica Tucker, Ph.D., Director of the NIBIB Program in Delivery Systems and Devices for Drugs and Biologics. “While we are all familiar with the benefits of sunscreen, the potential toxicities from sunscreen due to penetration into the body and creation of DNA-damaging agents are not well known.Bioengineering sunscreen to inhibit penetration and keep any DNA-damaging compounds isolated in the nanoparticle and away from the skin is a great example of how a sophisticated technology can be used to solve a problem affecting the health of millions of people.

Bioengineers and dermatologists at Yale University in New Haven, Connecticut combined their expertise in nanoparticle-based drug delivery and the molecular and cellular characteristics of the skin to address these potential health hazards of current commercial sunscreens. The results of their collaboration were reported in the September issue of Nature Materials.


Lung Cancer Detected Years Before

Lung cancer is one of the most lethal cancers. According to the American Cancer Society (ACS), one-year survival among these patients is 44%, and 5-year survival only 16%. Only 15% of these cancers are presently diagnosed at a stage where the disease is localised. Early detection could both improve patient survival and help to improve health economics. COPD is the 3rd leading cause of deaths in the USA, and is mainly caused by smoking.
Now a team of researchers from Inserm – France – led by Paul Hofman (Inserm Unit 1081/University of Nice) has just made a significant advance in the area of early diagnosis of invasive cancers. In a study which has just been published in the journal Plos One, the team shows that it is possible to detect, in patients at risk of developing lung cancer, early signs, in the form of circulating cancer cells, several months, and in some cases several years, before the cancer becomes detectable by CT scanning. This warning could play a key role in early surgical intervention, thereby making it possible to attempt the early eradication of the primary cancer site.
lung cancerThe team of researchers led by Paul Hofman used a blood test developed during French research, which isolates all types of tumour cells from the bloodstream, without any loss, leaving them intact. The team studied a group of 245 people without cancer, including 168 patients at risk of later developing lung cancer because they had Chronic Obstructive Pulmonary Disease (COPD). Participants systematically underwent the blood test and standard diagnostic imaging tests. Using the blood test, circulating cancer cells were identified in 5 patients (3%), whereas imaging did not show any nodules in the lungs. In these 5 patients, a nodule became detectable 1-4 years after detection of circulating cancer cells by the blood test. They immediately underwent surgery, and analysis of the nodule confirmed the diagnosis of lung cancer. Monitoring of the patients for a minimum of one year after surgery showed no sign of recurrence in the 5 patients, leading one to hope that the cancer had been eradicated. At the same time, no nodules were detected during monitoring of subjects who did not have circulating cancer cells, and no cancer cells were detected in the bloodstream of “control” subjects without COPD.