Tag Archives: Mingjun Zhang

English ivy’s stickiness may be useful

Researchers have discovered the secret to English ivy’s stickiness and they hope that secret will lead to improved wound healing and more according to a May 24, 2016 news item on Nanowerk,

English ivy’s natural glue might hold the key to new approaches to wound healing, stronger armor for the military and maybe even cosmetics with better staying power.

New research from The Ohio State University illuminates the tiny particles responsible for ivy’s ability to latch on so tight to trees and buildings that it can withstand hurricanes and tornadoes. (Not to mention infuriate those trying to rid their homes of the vigorous green climber.)

The researchers pinpointed the spherical particles within English ivy’s adhesive and identified the primary protein within them.

A May 23, 2016 Ohio State University news release (also on EurekAlert) by Misti Crane, which originated the news item, expands on the theme,

“By understanding the proteins that give rise to ivy’s strength, we can give rise to approaches to engineer new bio-inspired adhesives for medical and industry products,” said Mingjun Zhang, the biomedical engineering professor who led the work.

“It’s a milestone to resolve this mystery. We now know the secret of this adhesive and the underlying molecular mechanism,” said Zhang, who focuses his work on finding answers in nature for vexing problems in medicine.

“Ivy has these very tiny hairy structures that have a wonderful interaction with the surface as the plant climbs. One day I was looking at the ivy in the backyard and I was amazed at the force,” Zhang said.Like many scientists before him, Charles Darwin among them, Zhang found himself captivated by English ivy – the physics of it, the sheer strength of it. The study appears today in the journal Proceedings of the National Academy of Sciences.

“It’s very difficult to tear down, even in a natural disaster. It’s one of the strongest adhesive forces in nature.”

When he and his team took a look at the ivy’s glue with a powerful atomic-force microscope, they were able to identify a previously unknown element in its adhesive.

Zhang said particles rich in those proteins have exceptional adhesive abilities – abilities that could be used to the advantage of many, from biomedical engineers to paint makers.The tiny particles inside the glue on their laboratory slides turned out to be primarily made up of arabinogalactan proteins. And when the scientists investigated further, they discovered that the driving force behind the curing of the glue was a calcium-mediated interaction between the proteins and pectin in the gelatinous liquid that oozes from ivy as it climbs.

Zhang, a member of Ohio State’s Davis Heart and Lung Research Institute, is particularly interested in bioadhesives that could aid in wound healing after injury or surgeries. Others, notably the U.S. military, are interested in surface-coating applications for purposes that include strengthening armor systems, he said.

Many plants are excellent climbers, but scientists have had limited information about the adhesives that enable those plants to affix themselves to walls, fences and just about anything in their way, he said.

“When climbing, ivy secretes these tiny nanoparticles which make initial surface contact. Due to their high uniformity and low viscosity, they can attach to large areas on various surfaces,” Zhang said.

After the water evaporates, a chemical bond forms, Zhang said.

“It’s really a nature-made amazing mechanism for high-strength adhesion,” he said.

The glue doesn’t just sit on the surface of the object that the ivy is clinging to, he said. It finds its way into openings invisible to the naked eye, further solidifying its bond.

To confirm what they found, Zhang and his collaborators used the nanoparticles to reconstruct a simple glue that mimics ivy adhesive. Advanced bioadhesives based on this research will take more time and research.

In addition to its strength, ivy adhesive has other properties that make it appealing to scientists looking for answers to engineering quandaries, Zhang said.

“Under moisture or high or low temperatures, it’s not easily damaged,” he said. “Ivy is very resistant to various environmental conditions, which makes the adhesive a particularly interesting candidate for the development of armor coatings.”

Ivy also is considered a pest because it can be destructive to buildings and bridges. Knowing what’s at the heart of its sticking ability could help scientists unearth approaches to resist the plant, Zhang said.

Zhang and his work have been featured here before in a Jan. 7, 2013 posting about flesh-eating fungus and in a July 22, 2010 posting about English ivy and sunscreens.

Here’s a link to and a citation for Zhang’s latest paper,

Nanospherical arabinogalactan proteins are a key component of the high-strength adhesive secreted by English ivy by Yujian Huang, Yongzhong Wang, Li Tan, Leming Sun, Jennifer Petrosino, Mei-Zhen Cui, Feng Hao, and Mingjun Zhang. PNAS [Proceedings of the National Academy of Sciences] 2016 doi: 10.1073/pnas.1600406113 Published ahead of print May 23, 2016,

This paper is behind a paywall.

Flesh-eating fungus, ivy and other inspirations from nature

Michael Berger has featured Dr. Mingjun Zhang’s team’s fascinating work on flesh-eating fungus in a Dec. 18, 2012 Spotlight article on Nanowerk,

“Most studies on naturally occurring organic nanoparticles have focused on higher organisms,” Mingjun Zhang, an associate professor of biomedical engineering at the University of Tennessee, Knoxville, tells Nanowerk. “Given the earth’s rich biological diversity, it is reasonable to hypothesize that naturally occurring nanoparticles, of various forms and functions, may be produced by a wide range of organisms from microbes to metazoans.”

In his research, Zhang has focused on looking at nature for inspirations for solutions to challenges in engineering and medicine, especially in small-scale, such as bioinspired nanomaterials, bioinspired energy-efficient propulsive systems, and bioinspired nanobio systems for interfacing with cellular systems.

In new work, Zhang and his research associate Dr. Yongzhong Wang have turned their focus to Arthrobotrys oligospora, a representative flesh eater with a predatory life stage in the fungal kingdom.

The researchers have published their work in Advanced Functional Materials ((early online publication behind a paywall),

Naturally Occurring Nanoparticles from Arthrobotrys oligospora as a Potential Immunostimulatory and Antitumor Agent by Yongzhong Wang, Leming Sun, Sijia Yi, Yujian Huang, Scott C. Lenaghan, and Mingjun Zhang in Advanced Functional Materials

Article first published online: 4 DEC 2012 DOI: 10.1002/adfm.201202619

Here’s the abstract,

Arthrobotrys oligospora, a representative flesh eater in the fungal kingdom, is a potential source for natural-based biomaterials due to the presence of specialized 3D adhesive traps that can capture, penetrate, and digest free-living nematodes in diverse environments. The purpose of this study is to discover novel nanoparticles that occur naturally in A. oligospora and to exploit its potential biomedical applications. A new culture method, fungal sitting drop culture method, is established in order to monitor the growth of A. oligospora in situ, and observe the nanoparticle production without interfering or contamination from the solid media. Abundant spherical nanoparticles secreted from the fungus are first revealed by scanning electron microscopy and atomic force microscopy. They have an average size of 360–370 nm, with a zeta potential of –33 mV at pH 6.0. Further analyses reveal that there is ≈28 μg of glycosaminoglycan and ≈550 μg of protein per mg of nanoparticles. Interestingly, the nanoparticles significantly induce TNF-α secretion in RAW264.7mouse macrophages, indicating a potential immunostimulatory effect. The nanoparticles themselves are also found slightly cytotoxic to mouse melanoma B16BL6 and human lung cancer A549 cells, and show a synergistic cytotoxic effect upon conjugation with doxorubicin against both cells. This study proposes a new approach for producing novel organic nanoparticles secreted from microorganisms under controlled conditions. The findings here also highlight the potential roles of the naturally occurring nanoparticles from A. oligospora as an immunostimulatory and antitumor agent for cancer immunochemotherapy.

In more generalized language (from Berger’s Spotlight article),

“It is really exciting to use a natural microbe system to produce nanoparticles for potential cancer therapy,” says Zhang. “Originally, we were trying to understand how the fungus secretes an adhesive trap that can capture, penetrate, and digest free-living nematodes in diverse environments. By doing that we almost accidentally discovered the nanoparticles produced.”

Zhang’s team investigated the fungal nanoparticles’ potential as a stimulant for the immune system, and found through an in vitro study that the nanoparticles activate secretion of an immune-system stimulant within a white blood cell line. They also investigated the nanoparticles’ potential as an antitumor agent by testing in vitro the toxicity to cells using two tumor cell lines, and discovered nanoparticles do kill cancer cells.

Berger’s article in addition to giving more details about Zhang’s current work and his work with ivy and possible applications for ivy-based nanoparticles in sunscreens also provides some discussion of naturally occurring nanoparticles as opposed to engineered (or man-made)  nanoparticles.

The University of Tennessee’s Dec. 4, 2012 press release is also a good source of information on Zhang’s latest work on flesh-eating fungus. For the indefatiguable who are interested in Zhang’s work on ivy and potential nanosunscreens, there’s also my July 22, 2010 posting.