New coating kills germs on hospital surfaces with light

A new coating material has been developed for fighting healthcare-associated infections (HAI) using overhead lighting. It’s a new coating for hospital walls and surfaces that uses quantum dots and crystal violet to kill germs.

It’s well-known that a hospital stay can be as life-threatening as most medical conditions that might send you there. Healthcare-associated infections (HAI) are common, with about one hospitalized person out of every 25 having an HAI on any given day in the U.S. according to the CDC. Worldwide, the number’s one in 10. One bacteria that spreads through physical contact with objects or other people, Clostridium difficile, resulted in 29,000 U.S. fatalities in 2011. The longer one’s stay, the more likely it is that your life is in danger than when you check in. In 2011, 75,000 patients with HAIs died while hospitalized. Hospitals are working to make things better by being ever-more vigilant about hygiene, and recent statistics show improvement, but the emergence of infectious superbugs such as HA-MRSA adds an element of urgency to fighting the spread of bacteria. These organisms are hard, sometimes impossible, to treat. This month, a team of chemists at a Materials Research Society conference described a new light-activated material for walls and other hospital surfaces that contains bacteria-killing molecules that may keep superbugs from gaining traction.


(ksb via Shutterstock)

Other materials have been experimented with and are in use, such as polymer-based antimicrobial coatings that activate when sprayed with water. Copper and steel are also microbe-resistant but are rigid and hard to use on anything other than flat surfaces.

The new material

The new polymer-based coating, developed by a team of chemists led by University College London’s Ethel Koranteng, can be used as a flexible film that can encase a wide variety of shapes, including the door handles, computer keyboards and telephones on which bacteria are known to spread from person to person.

Even more interesting is that the material activates upon exposure to overhead lighting, making it ideal for use in hospitals.

(G10ck via Shutterstock)

The material is a type of polyurethane in which are embedded “quantum dots,” tiny, cadmium-free semiconductor nanoparticles. It also contains crystal violet dye particles, so it’s referred to by Koranteng and her team as “QD-CV” material. The quantum dots absorb light and transfer its energy to the crystal violet, which then releases high-energy oxygen molecules into the air that destroy microbes.

Electron wave functions in rectangular and triangular quantum dots shown in 2010 gif (Saumitra R Mehrotra & Gerhard Klimeck)

Does it work?

The QD-CV material looks to be impressively effective, too, “resulting in complete kill of a laboratory strain of Staphylococcus aureus after 1 hour irradiation at 6000 lux light intensity and 99.99% reduction of a laboratory strain of Escherichia coli” according to the team that developed it. It also killed 99.7% of MRSA. The polymer also performed well against a multidrug-resistant strain of E. Coli, killing 99.85% of it.

These results are heartening. The new material could become an important element in fighting infections in any healthcare setting, such as the one in four nursing homes through which infections often run rampant. Along with the ongoing prioritization of hygienic practices, QD-CV coatings may mean that someday staying in a hospital will no longer be taking on an additional risk on top of whatever it was that made you check in in the first place.

'Upstreamism': Your zip code affects your health as much as genetics

Upstreamism advocate Rishi Manchanda calls us to understand health not as a "personal responsibility" but a "common good."

Sponsored by Northwell Health
  • Upstreamism tasks health care professionals to combat unhealthy social and cultural influences that exist outside — or upstream — of medical facilities.
  • Patients from low-income neighborhoods are most at risk of negative health impacts.
  • Thankfully, health care professionals are not alone. Upstreamism is increasingly part of our cultural consciousness.
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  • A huge segment of America's population — the Baby Boom generation — is aging and will live longer than any American generation in history.
  • The story we read about in the news? Their drain on social services like Social Security and Medicare.
  • But increased longevity is a cause for celebration, says Ashton Applewhite, not doom and gloom.


After death, you’re aware that you’ve died, say scientists

Some evidence attributes a certain neurological phenomenon to a near death experience.

Credit: Petr Kratochvil. PublicDomainPictures.net.
Surprising Science

Time of death is considered when a person has gone into cardiac arrest. This is the cessation of the electrical impulse that drive the heartbeat. As a result, the heart locks up. The moment the heart stops is considered time of death. But does death overtake our mind immediately afterward or does it slowly creep in?

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Yale scientists restore brain function to 32 clinically dead pigs

Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.

Still from John Stephenson's 1999 rendition of Animal Farm.
Surprising Science
  • Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
  • They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
  • The research raises many ethical questions and puts to the test our current understanding of death.

The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?

But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.

What's dead may never die, it seems

The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. Think a dialysis machine for the mind. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.

BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.

The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.

As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.

The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.

"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.

An ethical gray matter

Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.

The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.

Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.

Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?

"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."

One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.

The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.

"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.

It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.

Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?

The dilemma is unprecedented.

Setting new boundaries

Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."

She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.