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Healing the body with a golden touch

ASU engineer comes up with a golden technique for sealing tissue.
December 2, 2015

Laser technology, nanomaterials combine to offer promising body-tissue repair technique

In the age of nanotechnology, medical advances are increasingly a matter of finding the right combinations of materials to help perform specific therapeutic or restorative functions.

Used at the nanoscale — the typical thickness of a single human hair is about 100,000 nanometers wide — common materials take on characteristics and abilities that they don’t exhibit in bulk quantities.

Gold, for instance, is an effective photothermal converter at the nanoscale, meaning it’s good for converting light into heat.

Kaushal Rege, an associate professor of chemical engineering in the Ira A. Fulton Schools of Engineering at Arizona State University, has been using gold nanorods as a key ingredient in a new kind of body-tissue sealant.

Using near-infrared laser light to heat a nanocomposite of gold nanorods embedded in a matrix of polypeptides (chains of amino acids that can fuse with ruptured tissues), Rege’s laboratory team can process the mixture of materials into a “nanosolder” for sealing tissues separated by rupture or surgical incisions.

The technique could, in many cases, improve on or at least supplement conventional stitches and sutures used in tissue repair.

Collaborations with medical experts

Rege’s progress has brought support from the National Institutes of Health (NIH), most recently an R01 grant to provide $1.6 million over three and a half years to expand his research and development in this area.

RO1 grants support health-related research and development that helps to fulfill the central mission of the NIH to seek and apply new knowledge that can enhance health, lengthen life and reduce illness and disability.

The work was initially seeded by funds from the Mayo Center for Regenerative Medicine in collaboration with Dr. Tonia Young-Fadok, a colorectal surgeon at the Mayo Clinic in Phoenix.

Rege will lead a team of collaborators from ASU; the College of Veterinary Medicine at Midwestern University in Glendale, Arizona; and the Mayo Clinic College of Medicine in Phoenix in efforts to improve on such nanobiomaterial sealants.

“You could envision this being done to aid ocular and microvascular surgeries or even nerve repair." 
— Kaushal Rege, associate professor of chemical engineering

They will concentrate on ways to make the welded seals leak-proof. Leaks in sutures and common sealants, particularly in delicate tissues like those of intestines, can cause bacterial infections that are sometimes life-threatening.

Rege’s team will strive to create nanocomposites with mechanical properties — such as tensile strength and burst pressures — that will enable sealants to maintain elasticity while at the same time withstanding the levels of pressure from body fluids that can causes other sealants to leak or burst.

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Arizona State University chemical engineer Kaushal Rege (left) is giving graduate students the opportunity to help develop a technique that uses lasers to seal body tissue that has been separated by surgical incisions or torn by injury. Photos by Nora Skrodenis/ASU

Researchers will focus on one of the more delicate kinds of tissues, those of the colorectal system.

“These are tissues with some of the highest susceptibility to leakage due the wear and tear around the sites of surgical incisions and suturing,” Rege said. “I think we can make some engineering contributions to preventing this by coming up with stronger nanocomposite solders that hold up even on the more fragile tissues.”

Expanded uses of welding technique envisioned

Researchers are exploring the use of laser welding to fuse tissues that make up the liver, urinary tract, nerves, skin, cartilage, corneas and blood vessels. Providing a more effective liquid-tight but elastic weld for those tissues could enhance treatment of diseases and maladies that afflict tens of millions of people throughout the world.

Beyond use for welding of tissues to close surgical incisions and repair injury, Rege said it could be possible to use laser-welding techniques to attach small implantable medical devices containing protective or curative mixtures of nanobiomaterials to certain types of tissues inside the body.

“You could envision this being done to aid ocular and microvascular surgeries or even nerve repair. But this is still very new technology, so ideas about these applications are speculative,” he said.

Rege, who is also on the faculties of the graduate studies programs in biomedical engineering, materials science and engineering, and biological design, is directing a multidisciplinary team for the project titled Photothermal Nanocomposites for Tissue Repair. The team includes:

• Dr. Michael Jaffe, an assistant professor of veterinary medicine and surgeon on the faculty of Midwestern University

• Dr. Valerie Wong, an assistant professor of veterinary medicine and pathologist on the faculty of Midwestern University

• Garrick Wallstrom, an assistant professor in the Department of Biomedical Informatics in ASU’s College of Health Solutions, and faculty member in the Center for Personalized Diagnostics in the Biodesign Institute at ASU

• Sarah Stabenfeldt, an assistant professor of biomedical engineering in the School of Biological and Health Systems Engineering at ASU.

• Dr. Tonia M. Young-Fadok, 
a professor of surgery at Mayo Clinic College of Medicine 
and chair of the Division of Colon and Rectal Surgery 
at Mayo Clinic in Phoenix

ASU chemical engineering graduate students Russell Urie and Huang-Chaio Huang and undergraduate students Sana Quraishi, Alisha Nanda, Jerry Crum and Tanner Flake have contributed to early research in this area.

Joe Kullman

Science writer , Ira A. Fulton Schools of Engineering


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Language: the key to understanding

Foreign educators give ASU students global perspective through Fulbright program
Four foreign educators are enjoying the beauty of Arizona while teaching at ASU.
December 2, 2015

Foreign educators bring global perspectives to ASU language students

It took patience and practice, but Azamat Mamadaliev was able to master the skateboard as a mode of transportation in about a week. Now he uses one every day to get to Arizona State University’s Tempe campus, where he teaches his native Uzbek as a Fulbright foreign language teaching assistant.

Administered by the Institute of International Education, the Fulbright Foreign Language Teaching Assistant (FLTA) Program allows for young educators from around the world to spend a year in America teaching their native language at colleges and universities across the country to help internationalize post-secondary education in the U.S. — a key goal of many institutions as they prepare students for the 21st-century workforce and globalized world.

Four FLTAs from four different countries were chosen to teach their respective languages at ASU for the 2015-2016 academic year. Besides Mamadaliev, they are: Valeria Caldas (pictured above, second from right) from Brazil, teaching Portuguese; Berrin Karasaç from Turkey, teaching Turkish; and Wilman Septiana from Indonesia, teaching Indonesian.

With the exception of Caldas, this is the first time any of them have been stateside. After the initial culture shock wore off — both Karasaç and Mamadaliev admit it took a while to adjust to American food and beverages — they began to settle in quite nicely.

“There are so many nice landscapes to see around Arizona,” Karasaç said. “You have the desert and the heat, but if you go to Flagstaff it’s cold. I’ve been to the Grand Canyon, Sedona, Sunset Crater, Tucson, Antelope Canyon. ... It’s all really beautiful.”

Each FLTA at ASU is paired with a faculty mentor from the Critical Languages Institute or the School of International Letters and Cultures (SILC) to ensure their success.

Overseeing Mamadaliev and Karasaç is Kathleen Evans-Romaine, director of the Critical Languages InstituteThe Critical Languages Institute is a project of the Melikian Center, an instructional and research unit of the College of Liberal Arts and Sciences.. SILC professors Peter Suwarno and David William Foster are overseeing Septiana and Caldas, respectively.

“[Kathleen] is always willing to help me. She answers all of my questions and supports me when I need it,” Mamadaliev said.

As for the FLTAs themselves, their students have nothing but good things to report.

“She’s really sweet, and she has an awesome way of giving us lessons about Brazilian cultures and also learning grammar,” business sophomore Adnan Aljifry said of Caldas.

Zachary Bundy, an architectural studies undergrad, signed up for Uzbek on a whim. He was wooed by the prospect of traveling to the region for graduate research and witnessing its striking Islamic architecture firsthand.

“I have to be able to speak the language to get permission to look at those sites and talk about their preservation,” he said.

Indonesian student Donald Santoso is majoring in law but wanted to study the language because he grew up in the country and plans to move back one day. He appreciates the conversation-based nature of Septiana’s class, saying it allows for more organic discussions and encourages student inquiry.

Even if students aren’t planning on moving to foreign countries in the future, though, Septiana points out that being multilingual is practically a must in today’s society.

“We now live in a globalized world, so we need language to cope with that. It’s the key to understanding,” he said.

On more than one level.

“[Language learning] is very important for job opportunities,” Caldas said, “but also, if not for that, for personal growth. Because when we learn language, we are also learning culture. And I think that’s extremely important.”

Emma Greguska

Editor , ASU News

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