Tag Archives: BC Centre for Disease Control

Killing bacteria on contact with dragonfly-inspired nanocoating

Scientists in Singapore were inspired by dragonflies and cicadas according to a March 28, 2018 news item on Nanowerk (Note: A link has been removed),

Studies have shown that the wings of dragonflies and cicadas prevent bacterial growth due to their natural structure. The surfaces of their wings are covered in nanopillars making them look like a bed of nails. When bacteria come into contact with these surfaces, their cell membranes get ripped apart immediately and they are killed. This inspired researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR to invent an anti-bacterial nano coating for disinfecting frequently touched surfaces such as door handles, tables and lift buttons.

This technology will prove particularly useful in creating bacteria-free surfaces in places like hospitals and clinics, where sterilization is important to help control the spread of infections. Their new research was recently published in the journal Small (“ZnO Nanopillar Coated Surfaces with Substrate-Dependent Superbactericidal Property”)

Image 1: Zinc oxide nanopillars that looked like a bed of nails can kill a broad range of germs when used as a coating on frequently-touched surfaces. Courtesy: A*STAR

A March 28, 2018 Agency for Science Technology and Research (A*STAR) press release, which originated the news item, describes the work further,

80% of common infections are spread by hands, according to the B.C. [province of Canada] Centre for Disease Control1. Disinfecting commonly touched surfaces helps to reduce the spread of harmful germs by our hands, but would require manual and repeated disinfection because germs grow rapidly. Current disinfectants may also contain chemicals like triclosan which are not recognized as safe and effective 2, and may lead to bacterial resistance and environmental contamination if used extensively.

“There is an urgent need for a better way to disinfect surfaces without causing bacterial resistance or harm to the environment. This will help us to prevent the transmission of infectious diseases from contact with surfaces,” said IBN Executive Director Professor Jackie Y. Ying.

To tackle this problem, a team of researchers led by IBN Group Leader Dr Yugen Zhang created a novel nano coating that can spontaneously kill bacteria upon contact. Inspired by studies on dragonflies and cicadas, the IBN scientists grew nanopilllars of zinc oxide, a compound known for its anti-bacterial and non-toxic properties. The zinc oxide nanopillars can kill a broad range of germs like E. coli and S. aureus that are commonly transmitted from surface contact.

Tests on ceramic, glass, titanium and zinc surfaces showed that the coating effectively killed up to 99.9% of germs found on the surfaces. As the bacteria are killed mechanically rather than chemically, the use of the nano coating would not contribute to environmental pollution. Also, the bacteria will not be able to develop resistance as they are completely destroyed when their cell walls are pierced by the nanopillars upon contact.

Further studies revealed that the nano coating demonstrated the best bacteria killing power when it is applied on zinc surfaces, compared with other surfaces. This is because the zinc oxide nanopillars catalyzed the release of superoxides (or reactive oxygen species), which could even kill nearby free floating bacteria that were not in direct contact with the surface. This super bacteria killing power from the combination of nanopillars and zinc broadens the scope of applications of the coating beyond hard surfaces.

Subsequently, the researchers studied the effect of placing a piece of zinc that had been coated with zinc oxide nanopillars into water containing E. coli. All the bacteria were killed, suggesting that this material could potentially be used for water purification.

Dr Zhang said, “Our nano coating is designed to disinfect surfaces in a novel yet practical way. This study demonstrated that our coating can effectively kill germs on different types of surfaces, and also in water. We were also able to achieve super bacteria killing power when the coating was used on zinc surfaces because of its dual mechanism of action. We hope to use this technology to create bacteria-free surfaces in a safe, inexpensive and effective manner, especially in places where germs tend to accumulate.”

IBN has recently received a grant from the National Research Foundation, Prime Minister’s Office, Singapore, under its Competitive Research Programme to further develop this coating technology in collaboration with Tan Tock Seng Hospital for commercial application over the next 5 years.

1 B.C. Centre for Disease Control

2 U.S. Food & Drug Administration

(I wasn’t expecting to see a reference to my home province [BC Centre for Disease Control].) Back to the usual, here’s a link to and a citation for the paper,

ZnO Nanopillar Coated Surfaces with Substrate‐Dependent Superbactericidal Property by Guangshun Yi, Yuan Yuan, Xiukai Li, Yugen Zhang. Small https://doi.org/10.1002/smll.201703159 First published: 22 February 2018

This paper is behind a paywall.

One final comment, this research reminds me of research into simulating shark skin because that too has bacteria-killing nanostructures. My latest about the sharkskin research is a Sept, 18, 2014 posting.

9 am on (Friday) Oct. 21, 2016 University of British Columbia professors take on a zombie apocalypse

Thanks to an Oct. 19, 2016 University of British Columbia (UBC) news release (received via email) for this information about a talk on the zombie apocalypse. This is in the form of a Q&A (question and answer) interview,

Hordes of flesh-eating zombies haven’t yet made the leap from the horror-movie screen to downtown city streets, but that hasn’t stopped two professors from the UBC school of population and public health from sharing tips on how to handle an invasion of the living dead.

Assistant professor Jennifer Gardy and professor David Patrick are taking part in a free public talk on October 21 to discuss how public health workers would diagnose, model and respond to a zombie virus. The talk is part of the school of population and public health’s Grand Round series and will feature faculty, students and guest speakers from UBC and the BC Centre for Disease Control.

Do zombies really exist and how likely is a zombie apocalypse?

JG: Absolutely! They’re just not the humanoid ones we recognize from movies. There are loads of zombie parasites out there in other species. While preparing for the rise of the undead is a little over the top, new diseases are emerging all the time, and thinking about how we’d prep for a zombie apocalypse is a great way of getting us thinking about more realistic disease scenarios, like a viral pandemic.

DP: In comparison, zombie behaviour is pretty unique, so we suspect that most emergency doctors would begin to ask questions. The difference with a zombie epidemic is the uncontrolled and aggressive behaviour of the zombie – that certainly increases the chances of transmission. This behaviour is reminiscent of animal and even human behaviour associated with rabies.  The number of people that could be infected with a zombie virus would be highly dependent on the efficiency of transmission. Rabies is transmitted by a bite, but it’s not so efficient that it results in a giant epidemic in people.

How can the average citizen prepare for, and escape, a zombie attack?  

DP:  The first part of preparation is common to earthquakes and other disasters: make sure you have a survival kit. The more portable it is, like a loaded knapsack, the better.

In every other epidemic we’ve seen, infected people are not all running around exhibiting behaviour that would threaten others. So a zombie epidemic would raise a whole bunch of new ethical issues around our duty to the sick, the healthy, and the role of civil society in protecting itself. Movies aside, the medical imperative is clearly to get to the root of the problem, interrupt transmission, heal the sick, if possible, and protect the healthy. But we’d sure need to pay attention to building security!

How would we respond to an outbreak of the zombie virus?

JG: We use mathematical modelling techniques to understand how quickly a pathogen might spread – these same models are used in zombie movies when they’re showing the projected spread of the outbreak.

Remember that in any outbreak, rumours and misinformation will abound. Listen to public-health officials and heed their advice – you can trust that we’ll share everything we know with you.

Should you try and help an infected relative or friend?  

DP: As long as this can be done while minimizing risk to yourself, it’s worth a try. The Ebola outbreak in West Africa, for example, could have been even worse. But people were able to put aside fear, employ rational measures for infection control, and care for the sick.

The ethical argument for sedating a zombie is pretty straightforward.  As a physician I would sure want to know if I could protect others by isolating and, if necessary, sedating the zombie before I entertained vigilante solutions. “Any idiot can pump a shotgun” but a real healthcare worker is going to do what he or she can to preserve life.

What should you do if you get bitten by a zombie?

DP: Contribute to a natural history study or volunteer for a clinical trial.

(Logistics are just after this bit.) I’m glad to see UBC has hopped on board the ‘zombie’ craze. Interestingly, Canada’s House of Commons got there first in 2013, not to mention the US Public Health Service which had a zombie preparedness plan prior to any declarations in the House,

For anyone who wants to attend the UBC event, here are the logistics (from the event page),

When: Friday, October 21, 2016 9:00 AM – 10:00 am

Where: MICHAEL SMITH LABORATORIES at UBC Point Grey Campus

Description:    Just in time for Hallowe’en, join School of Population and Public Health [SPPH] faculty and BC Centre for Disease Control researchers for October Grand Rounds, where they’ll walk you through how to diagnose, model, and control a plague of the undead, as well as show you the non-fiction zombies that exist today.

Join us for the real public health science behind the zombie epidemic, live or online via www.youtube.com/user/UBCSPPH1

Friday 21st October, 9am to 10am at Michael Smith Laboratories Room 102

Please direct any queries to spph.communications@spph.ubc.ca

Enjoy!