Tag Archives: synthetic windpipe

New type of scaffolding for tissue engineering

Since the international July 2011 coverage of Andemariam Teklesenbet Beyene’s synthetic trachea transplant (mentioned in my Aug. 2, 2011 posting), I’ve been quite interested in tissue engineering. Scientists at Northwestern University (US) have developed a new type of scaffolding for tissue engineering.

There’s a description in the Feb. 12, 2012 news release on EurekAlert of  tissue engineering and scaffolding and some of the disadvantages with the current technology,

Through tissue engineering, researchers seek to regenerate human tissue, such as bone and cartilage, that has been damaged by injury or disease. Scaffolds — artificial, lattice-like structures capable of supporting tissue formation — are necessary in this process to provide a template to support the growing cells. Over time, the scaffold resorbs into the body, leaving behind the natural tissue.

Scaffolds are typically engineered with pores that allow the cells to migrate throughout the material. The pores are often created with the use of salt, sugar, or carbon dioxide gas, but these additives have various drawbacks; They create an imperfect pore structures and, in the case of salt, require a lengthy process to remove the salt after the pores are created, said Guillermo Ameer, professor of biomedical engineering at the McCormick School of Engineering and professor of surgery at the Feinberg School of Medicine.

The new scaffolds are more flexible and can be tailored to ‘resorb’ at different times,

The new scaffolds, created from a combination of ceramic nanoparticles and elastic polymers, were formed in a vacuum through a process termed “low-pressure foaming” that requires high heat, Ameer said. The result was a series of pores that were highly interconnected and not dependent on the use of salt.

The new process creates scaffolds that are highly flexible and can be tailored to degrade at varying speeds depending on the recovery time expected for the patient. The scaffolds can also incorporate nano-sized fibers, providing a new range of mechanical and biological properties, Ameer said. [emphasis mine]

I wonder what “new range of mechanical and biological properties” will be enabled; I was not able to find any speculation.

In the meantime, here’s an image of the scaffolding from the McCormick School (at Northwestern University) http://www.mccormick.northwestern.edu/news/articles/article_1043.html,

For anyone who’s interested in an update on Andemariam Teklesenbet Beyene, according to this Dec. 9, 2011 posting on StemSave, he’s doing well.

ETA Feb. 14, 2012: Michael Berger at Nanowerk has written an article titled, Tissue engineering of 3D tubular structures, which provides some insight into another aspect of creating scaffolding, the tubular nature of many of our organs.

More on synthetic windpipe; Swedes and Italians talk about nanoscience and medicine

There was a Swedish-Italian workshop on nanoscience and medical technology held in Stockholm, Sweden, Sept. 29 and 30, 2011. It rates a mention here largely because there’s some additional information about the synthetic windpipe transplant that took place in June 2011 in Sweden. From the Oct. 14, 2011 news item on Nanowerk,

A very important session was devoted to “tissue engineering”, i.e. the creation of artificial tissues and organs to replace diseased or damaged ones, thus reducing the need for human organs from donors for transplantation, whose availability is always difficult to predict. A “keynote lecturer”, in this field was held by Prof. Paolo Macchiarini, who recently joined the Karolinska Institute in Stockholm (the Institute that awards the Nobel Prize in Medicine each year).

Prof. Macchiarini presented the results of his recent surgery works, performed at the Karolinska, where for the first time a synthetic trachea (windpipe) made of porous nanocomposites was transplanted into a human patient. This was the base for the trachea reconstruction using stem cells from the patient himself, thus eliminating any possible problem of rejection. The artificial structure was designed to dissolve in a few months, leaving a totally natural organ. [emphasis mine] It is clear that this could be a first step in a revolution in regenerative medicine, reducing the need for conventional transplants, but it is also clear that the Prof. Macchiarini was able to perform this action thanks to the collaboration of experts in nanotechnology for the design of the scaffold, bioreactors for the growth of stem cells and biological tissues and dedicated infrastructure in Stockholm.

I must have missed it when the event (trachea transplant) was first made public (mentioned in my Aug. 2, 2011 posting) but I never realized the biocomposite was meant to dissolve.

Here’s a little more about the workshop, from the news item,

During the workshop, 18 Swedish and 18 Italian experts offered a comprehensive overview of the most prominent activities in the two Countries in several fields: bio-sensors, bio-electronics, contrast media for imaging and bio-analysis, nanoparticles for drug delivery eventually combined with diagnosis possibilities (known in the field as “theranostics”).

Several companies from both countries, including Bracco, Finceramica and Colorbbia from Italy as well as AstraZeneca and Spago Imaging from Sweden, presented their recent results in the field and gave a clear overview of the potential impact of nanotechnology in improving existing products as well as generating new solutions for the grand challenges that medicine is facing.

There are more details in the news item and at the Italian Embassy in Sweden’s Office of the Scientific Attaché in Sweden, Norway and Iceland workshop page.

Globe and Mail discovers nanomedicine

Business writer, Nick Rockel, has an October 4, 2011 article titled, Nano-technology [sic] coming to the doctor’s office, in The Globe and Mail newspaper. Dr. Jillian Buriak and her colleague, Dr.Lori West (my latest posting about their work was April 28, 2011) were heavily featured in it. From the Oct. 4, 2011 article in The Globe and Mail,

One of Dr. Buriak’s key collaborators on the transplantation project is Lori West, a U of A [University of Alberta] professor of pediatrics, surgery and immunology. Dr. West, a renowned cardiac transplant expert, is known for her discovery that children younger than two will not reject a heart from a donor with a different blood type.

That’s because the immune system is still developing during infancy. Even more remarkably, if a baby with Type A blood gets a Type B heart, it will develop a lifelong tolerance for B and AB blood.

The U of A team “functionalized” so-called stealth nano-particles with the antigens, or markers, that blood cells use to recognize each other. In animal tests, it introduced these particles into the bloodstream in an attempt to teach the body to tolerate every blood type.

Dr. Buriak, who hopes to move to more advanced models by 2015, says the nano-particles could eventually join the standard set of shots that children receive. “Later, if you ever had to have an organ transplant or a transfusion, you wouldn’t have to wait for the right one – you could just take any of them.”

Buriak’s and West’s strategy for avoiding organ rejection contrasts with the strategy used by a joint (Swedish/UK/US) team, which I featured in an August 2, 2011 posting about their work transplanting a synthetic windpipe coated with stem cells harvested from the patient receiving the new organ.

Rockel’s article goes on to provide descriptions of other nanomedicine initiatives (a mix of Canadian- and US-based projects). He employs the usual ‘war against disease’ rhetorical style common to articles about any kind of medicine even when he’s including a ‘kinder, gentler’ quote such as,

People keep asking when her field will deliver a killer app like the cure for cancer, Dr. Buriak says. “But what nanotechnology has done more than anything else is bring people together who normally would never talk to each other,” she explains. [emphases mine]

As one would expect from a business writer, the article concludes with a list of three commercially available nanomedicne products. I wish Rockel had stated whether or not he’s done additional research into these products since this list is culled from the Project on Emerging Nanotechnologies (PEN) database. As I’ve noted before (my July 26, 2011 posting) there is no oversight provided by PEN nor does the organization require any description of how the product is nanotechnology-enable, as they openly admit.

I’m glad to see more coverage of nanotechnology and that writers from many specialties are learning about it. As for why I described Nick Rockel as a business writer, here’s his description of his work,

Market forces are one thing, but you can’t force somebody to read about the markets. Nick Rockel helps you connect with your audience. A veteran writer and editor, Nick knows how to grab people’s attention by giving them access to the financial and investment world. Whether it’s hedge funds or herding behaviour, he presents complex subjects in clear and simple terms, without any jargon or bafflegab. Most important, Nick finds the story behind the numbers and makes it resonate with readers.

He advertizes himself as providing Financial Wrting, Editing & Research.

Body parts nano style

In early July 2011, there were reports of a new kind of transplant involving a body part made of a biocomposite. Andemariam Teklesenbet Beyene underwent a trachea transplant that required an artificial windpipe crafted by UK experts then flown to Sweden where Beyene’s stem cells were used to coat the windpipe before being transplanted into his body.

It is an extraordinary story not least because Beyene, a patient in a Swedish hospital planning to return to Eritrea after his PhD studies in Iceland, illustrates the international cooperation that made the transplant possible.

The scaffolding material for the artificial windpipe was developed by Professor Alex Seifalian at the University College London in a landmark piece of nanotechnology-enabled tissue engineering. Tim Harper in his July 25, 2011 posting provides more details about the scaffolding,

A team led by Professor Alexander Seifalian (UCL Division of Surgery & Interventional Science; professor of nanotechnology and regenerative medicine at University College London, UK), whose laboratories are headquartered at the Royal Free Hospital, created a glass mold of the patient’s trachea from X-ray computed tomography (CT) scans of the patient. In CT, digital geometry processing is employed to generate a 3D image of the inside of an object from a large series of 2D X-ray images taken around one single axis of rotation.

Then, they manufactured a full size y-shaped trachea scaffold at Professor Seifalian’s laboratories. The scaffold of the trachea was built using a novel nanocomposite polymer developed and patented by Professor Seifalian. Professor Seifalian worked together with Professor Paolo Macchiarini at Karolinska Institutet, Stockholm, Sweden (who also holds an Honorary appointment at UCL).

Professor Seifalian and his team used a porous novel nanocomposite polymer to build the y-shaped trachea scaffold. The pores were millions of little holes, providing this way a place for the patient’s stem cells to grow roots. The team cut strips of the novel nanocomposite polymer and wrapped them around the glass mold creating this way the cartilage rings that conferred structural strength to the trachea.

After the scaffold construct was finished, it was taken to Karolinska Institutet where the patient’s stem cells were seeded by Professor Macchiarini’s team.

Harper goes on to provide more details and insight into what makes this event such an important one.

Meanwhile, Dexter Johnson’s (Nanoclast blog in the IEEE website) July 21, 2011 posting poses a question,

While the nanocomposite scaffold is a critical element to the artificial organ, perhaps no less important was the bioreactor used to grow the stem cells onto it, which was developed at Harvard Bioscience.

If you needed any evidence of how nanotechnology is not only interdisciplinary, but also international, you could just cite this case: UK-developed nanocomposite for the scaffolding material, US-based bioreactor in which the stem cells were grown onto the scaffolding and a Swedish-based medical institute to perform the transplant.

So I ask, which country or region is going to get rich from the breakthrough?

It’s an interesting question and I don’t think I would have framed it in quite that fashion largely because I don’t tend to think of countries or regions getting wealthy from biomedical products since pharmaceutical companies tend to be internationally based. Is Switzerland richer for Novartis?

I suppose I’m a product of the Canadian landscape from which I spring so I think of trees and mines as making a country or region richer as they are inextricably linked to their environment but pharmaceuticals or biomedical appliances can be manufactured anywhere. Consequently, a synthetic organ could be manufactured anywhere once the technology becomes easily available. Who gets rich from this development? I suspect that will be a person or persons if anyone but, not a region or a country.

Getting back to Beyene, here are more details from the July 7, 2011 BBC News article by Michelle Roberts,

Dr Alex Seifalian and his team used this fragile structure [the scaffold] to create a replacement for the patient, whose own windpipe was ravaged by an inoperable tumour.

Despite aggressive chemotherapy and radiotherapy, the cancer had grown to the size of a golf ball and was blocking his breathing. Without a transplant he would have died.

During a 12-hour operation Professor Macchiarini removed all of the tumour and the diseased windpipe and replaced it with the tailor-made replica [now covered with tissue grown from the patient’s bone marrow tricked into growing like cells found in a trachea].

And, importantly, Mr Beyene’s body will accept it as its own, meaning he will not need to take the strong anti-rejection drugs that other transplant patients have to.

Professor Macchiarini said this was the real breakthrough.

“Thanks to nanotechnology, this new branch of regenerative medicine, we are now able to produce a custom-made windpipe within two days or one week.

“This is a synthetic windpipe. The beauty of this is you can have it immediately. There is no delay. This technique does not rely on a human donation.”

He said many other organs could be repaired or replaced in the same way.

A month on from his operation, Mr Beyene is still looking weak, but well.

Sitting up in his hospital bed, he said: “I was very scared, very scared about the operation. But it was live or die.”

My best wishes to Beyene and his family who are also pioneers.