New ways to diagnose and treat cardio failures
In my previous blog we have looked at nano- and biosensor technologies that are opening new ways to diagnose and treat cancer. This blog deals with another fatal area – cardiovascular disease (CVD), the number one cause of death globally. An estimated 17.5 million people died from CVDs in 2012, representing 31% of all global deaths.
One of them was my friend. A sport fan, he was running, biking, regularly dropping into jims with all the nice gadgets around: Polar, Runtastic, you name it. Until one day he fell down from his treadmill, his heart stopped beating. He was always proud of his health, with no bad habits such as tobacco or alcohol consumption, saying nothing of addiction.
CVD cunningly disguises itself under treacherous symptoms such as pain in your arm(s), back, neck, jaw or stomach sickness (especially with women). Sometimes, we simply do not want to accept the fact that we are unconsciously trying to convince ourselves that unpleasant feelings we experience are attributed to a mere fatigue, nervousness of stress. Can technology, at least partially, assume the role of an unbiased judged? There are at least three important areas where it can:
Continuous monitoring with flexible sensor/patches
Flexible skin patches, almost invisible on your body, are gradually surpassing wearable devices such as smart watches or bands providing high quality ECG measurements. A team of researchers of University of Illinois, Urbana-Champaign, have demonstrated the device that can be stuck to the skin to provide continuous ECG and EEG monitoring. The patch is wirelessly powered, sending and displaying data on an external device, e.g., a smartphone. When compared to commercially available ECG and EEG devices the patch “performed equally to conventional sensors, while being significantly more comfortable for patients.”
Thus Vital Connect debuted with VitalPatch biosensor that was presented at the 2016 Healthcare Information and Management Systems Society (HIMSS) conference and exhibition in Las Vegas.
This wireless, adhesive patch continuously monitors and records single-lead electrocardiogram (ECG), heart rate variability, respiratory rate, skin temperature, posture and fall detection with clinical accuracy. In case of suspicious deviations from the regularly heart performance the signal goes to the Vital Connect platform and is shared with the respective physician.
A professional 12–channel 24 hours (or more) ECG Holter device will soon be part of our standard dress code. Wearable garments such as Niturit, a seemingly ordinary T-shirt developed by the University of Aveiro in Portugal and the Israeli “Moked Enosh” company can record the heart activity transmitting it via a smart phone over a number of hours up to four consecutive days directly from a patient to a cardiologist. The T-shirt is being offered as part of examinations by the Moked Enosh center at the cost of $ 117.
Nanosensors for preventive diagnostics
Many hopes are associated with the development of nanosensors. Being attached to the molecular nanoparticles, such sensors are able to register the slightest alterations of a molecule’s spectrum instigated by the changed biochemical processes in the damaged cell. For example, this method can detect a heart attack by measuring stress symptoms in the heart.
The group of researchers from the Indian Institute of Technology , Mumbai, under Prof. V. Ramgopal Rao are developing a three-dimensional sensor system that measures the stress symptom (that can signify myocardial infarction) in the heart converting it into electrical signals. A severe stress prompts the excess of enzymes (protein or, rarely, RNA molecules that catalyze biochemical reactions) in the heart and the heart area, which may cause excessive pressure and exertion on blood vessels. When involved in a biochemical process with the enzymes, nanoparticle polymer generates the electric current which can be detected. The researchers are determined to produce a low cost system that will use molecular markers to predict and locate cardiac attacks, especially the fatal ones.
Scientists from the Massachusetts Institute of Technology and Harvard University are designing the system that can signal a heart attack by measuring the cumulative concentration of the respective biomarkers. The system consists of sensors housing iron oxide nanoparticles attached to antibodies of the protein in question. When target proteins go through the sensor membrane, nanoparticles are clinging to them, which alters the transverse relaxivity of surrounding water protons. This change in relaxivity can be read via magnetic resonance imaging (MRI) to quantify the concentration of biomarker over extended period of time. Scientists believe that the level of biomarkers’ concentration can help detecting cases of unrecognized MIs, which are accompanied by few or no symptoms and which, according to data from the Framingham Heart Study, constitute 28 percent and 35 percent of heart attacks in men and women, respectively.
One of the strongest proponents of the consumer oriented nanotechnology is Dr. Eric Topol, the chief academic officer in Scripps Health (San Diego). Together with his colleague Axel Scherer, PhD, of Caltech, Mr. Topol is designing tiny blood stream nanosensor chips that might spot predecessors of a heart attack. The sensors are picking up a specific genomic signal coming from endothelial cells that are sloughed off an artery wall in a precursory period before a heart attack. By transmitting the alert via smartphone to the cardiologist the myocardial infarction potentially can be prevented. When such technologies finally reach consumers, millions of unexpected heart arrests can potentially be avoided.
Heart on a Chip
After the first experiment with cloning the sheep Dolly in 1996 many were dreaming: can we clone if not our whole body, but at least some of its vital organs? Would not it be nice getting a set of spare parts for a newly born just as spare parts are available for your new car?
Unfortunately, natural organs are reluctant to grow artificially. Human organs need a congenital medium to be connected to one another. For example, all the fancy collagens in the world can’t anchor a cell to a basement membrane that is not innate or induce the cell to reproduce in the lab environment while separated from other cells. But the dream is waiting for its proponents.
Professor Milica Radisic and the graduate student Boyang Zhang from U of T Engineering are among those researchers who attempted to grow human tissues in the lab. The result is AngioChip, a fully three-dimensional structure complete with internal blood vessels. For human cells to attach and grow around the chip, the researchers have built a scaffold out of POMaC polymer that is both biodegradable and biocompatible. The scaffold consists of several layers carved with a pattern of channels that are about 100 micrometers wide, the diameter of a human hair. The layers are covered with the 3D structure of synthetic blood vessels. The UV light is cross-linking the polymer bonding it to the layer below. The whole structure is then immersed into a liquid containing living cells. The cells quickly attach to the inside and outside of the channels and start growing just as they would in the human body.
The team is currently building models for heart and liver that function as the real ones. For example, liver, according to the researchers, can produced urea and metabolized drugs. The blood vessels of the two artificial organs could be connected, thereby modelling not just the organs themselves, but the interactions between them. So far, such “organ on a chip” is designed for testing new drugs, but the researchers believe that it could eventually be used to repair or replace damaged organs.
If flexible patches and biosensors may finally reach the consumers within the foreseeable future, it is still hard to imagine that we will receive a key from a locker stuffed with our human spear parts. But the studies are definitely going into this direction. As patients we are used to be patient. We will wait.