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Guillermo Ameer, Sc..D.

AIMBE College of Fellows Class of 2009
For outstanding contributions to medical and biological engineering through his noted work with vascular and orthopaedic tissues.

New Material Regrows Bone

Via Northwestern | March 8, 2017

A team of researchers repaired a hole in a mouse’s skull by regrowing “quality bone,” a breakthrough that could drastically improve the care of people who suffer severe trauma to the skull or face.The work by a joint team of Northwestern Engineering and University of Chicago researchers was a resounding success, showing that a potent combination of technologies was able to regenerate the skull bone with supporting blood vessels in just the discrete area needed without developing scar tissue — and more rapidly than with previous methods.“The results are very exciting,” said Guillermo Ameer, professor of biomedical engineering at Northwestern’s McCormick School of Engineering, and professor of surgery at Feinberg School of Medicine. Supported by the China Scholarship Council, National Institute of Dental and Craniofacial Research, Chicago Community Trust, and National Center for Advancing Translational Sciences, the research was published last week in the journal PLOS One. Russell Reid, associate professor of surgery at the University of Chicago Medical Center, is the article’s corresponding author. Reid, his long-time collaborator Dr. Tong-Chuan He, and colleagues in Hyde Park brought the surgical and biological knowledge and skills. Zari P. Dumanian, affiliated with the medical center’s surgery department, was the paper’s first author. Guillermo Ameer: “This project was a true collaborative team effort in which our Regenerative Engineering Laboratory provided the biomaterials expertise,” Ameer said.Injuries or defects in the skull or facial bones are very challenging to treat, often requiring the surgeon to graft bone from the patient’s pelvis, ribs, or elsewhere, a painful procedure in itself. Difficulties increase if the injury area is large or if the graft needs to be contoured to the angle of the jaw or the cranial curve.

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Regenerative Bandage Heals Diabetic Wounds Faster

Via Northwestern | August 16, 2016

At some point in their lives, 15 percent of people with diabetes will develop a painful and hard-to-treat foot ulcer. Twenty-four percent of those affected will require a lower-leg amputation because of it. And, in some instances, what seems like a harmless sore might even lead to death.

A Northwestern Engineering team has developed a new treatment for this severe and potentially deadly complication of diabetes. Called a “regenerative bandage,” the novel material heals diabetic wounds four times faster than a standard bandage and has the added benefit of promoting healing without side effects.

“Foot ulcers cause many serious problems for diabetic patients,” said Guillermo Ameer, professor of biomedical engineering in the McCormick School of Engineering and surgery in the Feinberg School of Medicine. “Some sores don’t heal fast enough and are prone to infection. We thought that we could use some of our work in biomaterials for medical applications and controlled drug release to help heal those wounds.”

An expert in biomaterials and tissue engineering, Ameer’s research was published online last week in the Journal of Controlled Release. Yunxiao Zhu, a PhD student in Ameer’s laboratory, is the paper’s first author. Northwestern Engineering’s Hao F. Zhang, associate professor of biomedical engineering, and Feinberg’s Robert Galliano, associate professor of surgery, also contributed to the work.

Diabetes can cause nerve damage that leads to numbness in the feet. A diabetic person might experience something as simple as a blister or small scrape that goes unnoticed and untreated because they cannot feel it to know that its there. As high glucose also thickens capillary walls, blood circulation slows, making it more difficult for these wounds to heal. It’s a perfect storm for a small nick to become a life-threatening sore.

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Antioxidant Biomaterial Promotes Healing

Via Northwestern McCormick Engineering | July 24, 2014

When a foreign material like a medical device or surgical implant is put inside the human body, the body always responds. According to Northwestern’s Guillermo Ameer, most of the time, that response can be negative and affect the device’s function.

“You will always get an inflammatory response to some degree,” said Ameer, professor of biomedical engineering in McCormick School of Engineering and Applied Science and professor of surgery in the Feinberg School of Medicine. “A problem with commonly used plastic materials, in particular, is that in addition to that inflammatory response, oxidation occurs.”

We all need oxygen to survive, but a high concentration of oxygen in the body can cause oxidative reactions to fall out of balance, which modifies natural proteins, cells, and lipids and causes them to function abnormally. This oxidative stress is toxic and can contribute to chronic disease, chronic inflammation, and other complications that may cause the failure of implants.

For the first time ever, Ameer and his team have created a biodegradable biomaterial that is inherently antioxidant. The material can be used to create elastomers, liquids that turn into gels, or solids for building devices that are more compatible with cells and tissues. The research is described in the June 26 issue of Biomaterials.

“Plastics can self-oxidize, creating radicals as part of their degradation process,” Ameer said. “By implanting devices made from plastics, the oxidation process can injure nearby cells and create a cascade that leads to chronic inflammation. Our materials could significantly reduce the inflammatory response that we typically see.”

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Bone Marrow Cells, Synthetic Scaffold Used in Bladder Regeneration

Via Northwestern Engineering | March 1, 2013

For patients suffering from spina bifida, the most common disabling birth defect in the United States, bladder dysfunction is common. Surgery is often considered the best treatment, but it comes with a host of complications, and today’s bladder tissue engineering strategies are unable to sufficiently reform bladder tissue without causing other problems.

In a new study, Northwestern University researchers explore an alternative to contemporary tissue-engineering strategies. The result is a new approach to bladder regeneration that can reform bladder smooth muscle, vasculature, and promote peripheral nerve tissue growth, all while using populations of cells from the patient himself.

The approach utilizes a synthetic scaffold developed by Guillermo Ameer, professor of biomedical engineering at Northwestern’s McCormick School of Engineering and professor of surgery at Feinberg School of Medicine, and two distinct cell populations harvested from a patient’s healthy bone marrow. The work was conducted in collaboration with researchers at Feinberg, the Ann & Robert H. Lurie Children’s Hospital of Chicago, and other institutions.

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Researchers Develop New Method for Creating Tissue Engineering Scaffolds

Via Northwestern Engineering | February 10, 2012

Researchers at Northwestern University have developed a new method for creating scaffolds for tissue engineering applications, providing an alternative that is more flexible and less time-intensive than current technology.

A paper describing the results, “Low-Pressure Foaming: A Novel Method for the Fabrication of Porous Scaffolds for Tissue Engineering,” was featured in the February issue of the journal Tissue Engineering.

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.

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Getting Rid of the Stent

Via Northwestern Engineering | March 1, 2010

Late one night several years ago in a shared office on the top floor of the Robert H. Lurie Medical Research Center on the Chicago campus, Guillermo Ameer and Melina Kibbe came up with a new idea for their research. Kibbe, associate professor of vascular surgery at the Feinberg School of Medicine, had spread out the different kinds of stents she uses in surgery; Ameer, associate professor of biomedical engineering at McCormick and of surgery at Feinberg, wanted to know why certain aspects of one or another are good or bad, and what causes devices to fail, and how biomaterials could be more successful. after a long discussion the two came up with a radical idea: What is you got rid of the stent altogether?

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