Tag Archives: wound dressings

New wound dressings with nanofibres for tissue regeneration

The Rotary Jet-Spinning manufacturing system was developed specifically as a therapeutic for the wounds of war. The dressings could be a good option for large wounds, such as burns, as well as smaller wounds on the face and hands, where preventing scarring is important. Illustration courtesy of Michael Rosnach/Harvard University

This image really gets the idea of regeneration across to the viewer while also informing you that this is medicine that comes from the military. A March 19,2018 news item on phys.org announces the work,

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering have developed new wound dressings that dramatically accelerate healing and improve tissue regeneration. The two different types of nanofiber dressings, described in separate papers, use naturally-occurring proteins in plants and animals to promote healing and regrow tissue.

Our fiber manufacturing system was developed specifically for the purpose of developing therapeutics for the wounds of war,” said Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics at SEAS and senior author of the research. “As a soldier in Afghanistan, I witnessed horrible wounds and, at times, the healing process for those wounds was a horror unto itself. This research is a years-long effort by many people on my team to help with these problems.”

Parker is also a Core Faculty Member of the Wyss Institute.

The most recent paper, published in Biomaterials, describes a wound dressing inspired by fetal tissue.

A March 19, 2018 Harvard University John A. Paulson School of Engineering and Applied Science news release by Leah Burrows (also on EurekAlert), which originated the news item, provides some background information before launching into more detail about this latest work,

In the late 1970s, when scientists first started studying the wound-healing process early in development, they discovered something unexpected: Wounds incurred before the third trimester left no scars. This opened a range of possibilities for regenerative medicine. But for decades, researchers have struggled to replicate those unique properties of fetal skin.

Unlike adult skin, fetal skin has high levels of a protein called fibronectin, which assembles into the extracellular matrix and promotes cell binding and adhesion. Fibronectin has two structures: globular, which is found in blood, and fibrous, which is found in tissue. Even though fibrous fibronectin holds the most promise for wound healing, previous research focused on the globular structure, in part because manufacturing fibrous fibronectin was a major engineering challenge.

But Parker and his team are pioneers in the field of nanofiber engineering.

The researchers made fibrous fibronectin using a fiber-manufacturing platform called Rotary Jet-Spinning (RJS), developed by Parker’s Disease Biophysics Group. RJS works likes a cotton-candy machine — a liquid polymer solution, in this case globular fibronectin dissolved in a solvent, is loaded into a reservoir and pushed out through a tiny opening by centrifugal force as the device spins. As the solution leaves the reservoir, the solvent evaporates and the polymers solidify. The centrifugal force unfolds the globular protein into small, thin fibers. These fibers — less than one micrometer in diameter — can be collected to form a large-scale wound dressing or bandage.

“The dressing integrates into the wound and acts like an instructive scaffold, recruiting different stem cells that are relevant for regeneration and assisting in the healing process before being absorbed into the body,” said Christophe Chantre, a graduate student in the Disease Biophysics Group and first author of the paper.

In in vivo testing, the researchers found that wounds treated with the fibronectin dressing showed 84 percent tissue restoration within 20 days, compared with 55.6 percent restoration in wounds treated with a standard dressing.

The researchers also demonstrated that wounds treated with the fibronectin dressing had almost normal epidermal thickness and dermal architecture, and even regrew hair follicles — often considered one of the biggest challenges in the field of wound healing.

“This is an important step forward,” said Chantre. “Most work done on skin regeneration to date involves complex treatments combining scaffolds, cells, and even growth factors. Here we were able to demonstrate tissue repair and hair follicle regeneration using an entirely material approach. This has clear advantages for clinical translation.”

In another paper published in Advanced Healthcare Materials, the Disease Biophysics Group demonstrated a soy-based nanofiber that also enhances and promotes wound healing.

Soy protein contains both estrogen-like molecules — which have been shown to accelerate wound healing — and bioactive molecules similar to those that build and support human cells.

“Both the soy- and fibronectin-fiber technologies owe their success to keen observations in reproductive medicine,” said Parker. “During a woman’s cycle, when her estrogen levels go high, a cut will heal faster. If you do a surgery on a baby still in the womb, they have scar-less wound healing. Both of these new technologies are rooted in the most fascinating of all the topics in human biology — how we reproduce.”

In a similar way to fibronectin fibers, the research team used RJS to spin ultrathin soy fibers into wound dressings. In experiments, the soy- and cellulose-based dressing demonstrated a 72 percent increase in healing over wounds with no dressing and a 21 percent increase in healing over wounds dressed without soy protein.

“These findings show the great promise of soy-based nanofibers for wound healing,” said Seungkuk Ahn, a graduate student in the Disease Biophysics Group and first author of the paper. “These one-step, cost-effective scaffolds could be the next generation of regenerative dressings and push the envelope of nanofiber technology and the wound-care market.”

Both kinds of dressing, according to researchers, have advantages in the wound-healing space. The soy-based nanofibers — consisting of cellulose acetate and soy protein hydrolysate — are inexpensive, making them a good option for large-scale use, such as on burns. The fibronectin dressings, on the other hand, could be used for smaller wounds on the face and hands, where preventing scarring is important.

Here’s are links and citations for both papers mentioned in the news release,

Soy Protein/Cellulose Nanofiber Scaffolds Mimicking Skin Extracellular Matrix for Enhanced Wound Healing by Seungkuk Ahn, Christophe O. Chantre, Alanna R. Gannon, Johan U. Lind, Patrick H. Campbell, Thomas Grevesse, Blakely B. O’Connor, Kevin Kit Parker. Advanced Healthcare Materials https://doi.org/10.1002/adhm.201701175 First published: 23 January 2018

Production-scale fibronectin nanofibers promote wound closure and tissue repair in a dermal mouse model by Christophe O. Chantre, Patrick H. Campbell, Holly M. Golecki, Adrian T. Buganza, Andrew K. Capulli, Leila F. Deravi, Stephanie Dauth, Sean P. Sheehy, Jeffrey A.Paten. KarlGledhill, Yanne S. Doucet, Hasan E.Abaci, Seungkuk Ahn, Benjamin D.Pope, Jeffrey W.Ruberti, Simon P.Hoerstrup, Angela M.Christiano, Kevin Kit Parker. Biomaterials Volume 166, June 2018, Pages 96-108 https://doi.org/10.1016/j.biomaterials.2018.03.006 Available online 5 March 2018

Both papers are behind paywalls although you may want to check with ResearchGate where many researchers make their papers available for free.

One last comment, I noticed this at the end of Burrows’ news release,

The Harvard Office of Technology Development has protected the intellectual property relating to these projects and is exploring commercialization opportunities.

It reminded me of the patent battle between the Broad Institute (a Harvard University and Massachusetts Institute of Technology joint venture) and the University of California at Berkeley over CRISPR (clustered regularly interspaced short palindromic repeats) technology. (My March 15, 2017 posting describes the battle’s outcome.)

Lest we forget, there could be major financial rewards from this work.

First Canadian Governor-General’s innovation award goes to professor Robert Burrell (nanoscientist) at the University of Alberta

The first innovation award ever given by the Canadian Governor General* has gone to a nanomedicine pioneer at the University of Alberta. From a May 12, 2016 news article by Marc Montgomery for Radio Canada International*, Note: A link has been removed,

Professor Robert Burrell of the University of Alberta has won a prestigious Governor-General’s Innovation Award for the world’s first therapeutic use of nanotechnology.

Professor Burrell used nano-technology on a wound bandage that has already begun transforming treatment of wounds in situations around the world.

Robert Burrell,  Professor in the Faculty of Chemical and Mechanical Engineering at the University of Alberta, is also Canada Research Chair in Nanostructured Biomaterials, and Chair, Biomedical Engineering at the university.

Burrell’s development called Acticoat came from research into nano-forms of silver.  When silver is reduced to nano scale it’s properties and chemical activity change.

In his research prior to joining the University in 2002, Burrell created a coating of nano-crystals of silver which not only kills bacteria but also has anti-inflammatory properties.

A May 9, 2016 University of Alberta news release has a bit more information,

… The chair of the U of A Department of Biomedical Engineering has been awarded a new national innovation prize in recognition of an invention that transformed wound care around the world.

Rob Burrell PhD, FCAHS, who holds the Canada Research Chair in Nanostructure Biomaterials and leads the Department of Biomedical Engineering, is one of six Canadians to win the inaugural round of the Governor General’s Innovation Awards. The awards recognize “exceptional and transformative work” that has helped “shape our future and positively impact our quality of life.”

“It was a nice surprise,” Burrell says of receiving the award. “I got an email in April—and was wondering why the Secretary to the Governor General of Canada [David Johnston is the current Governor General] wanted to talk to me. When we had our phone call he congratulated me on winning the award.”

Burrell invented Acticoat, a new wound dressing that uses nanocrystalline silver to fight bacteria and inflammation in wounds, while working for Westaim Biomedical, later Nucryst Pharmaceuticals. He joined the Faculty of Engineering in 2002.

The dressing was the world’s first therapeutic use of nanotechnology and has saved thousands of lives and limbs, transforming the treatment of burns and wounds.

“We have three projects on the go now. We’ve developed a new dressing and applied for a patent on it for scar control and we’re looking at commercializing that,” he said. “I have two of my grad students—and this summer we will have three summer students—working on a diagnostic tool that will allow a surgeon in an operating room to assess a tumour in 10 to 15 minutes. The analysis of the tumour can determine the type of surgery and post-surgical care the patient receives.”

You can find out more about the Governor General awards, which include, in addition to the new innovation category, the arts,  the sciences and humanities, and more here.

* I have a couple of explanatory notes for those unfamiliar with the concept of a Governor General and/or those who may be curious about Radio Canada International.

The Governor General is the Queen’s or the British monarch’s representative in Canada. Here’s another more general definition from a Wikipedia entry,

Governor-general or governor general, in modern usage, is the title of an office-holder appointed to represent the monarch of a sovereign state in the governing of an independent realm. Governors-general have also previously been appointed in respect of major colonial states or other territories held by either a monarchy or republic, such as French Indochina.

Radio Canada International is a little complicated. Radio Canada is the French language arm of the Canadian Broadcasting Corporation (CBC) and the name ‘Radio Canada’ refers to its radio, television, and internet services.

Interestingly Radio Canada International is the global outreach for both Radio Canada and CBC, presumably, uniting the English and French language services under one banner.