An innovative orthopedic medical device fabricated from a novel biomaterial pioneered in the laboratory of Northwestern University professor Guillermo A. Ameer has received clearance from the U.S. Food and Drug Administration (FDA) for use in surgeries to attach soft tissue grafts to bone.
The biomaterial is the first thermoset biodegradable synthetic polymer ever approved for use in an implantable medical device. It’s unique chemical and mechanical properties enable cutting-edge implant designs that protect the soft tissue graft during insertion and optimize graft fixation to bone… Continue reading.
Three Northwestern University faculty members have been elected 2018 fellows of the American Association for the Advancement of Science (AAAS), the world’s largest general scientific society.
Guillermo Ameer, Jian Cao and Frederic Rasio have been recognized for their distinguished efforts to advance science or its applications. They will be honored on Saturday, Feb. 16, at the 2019 AAAS Annual Meeting in Washington, D.C.
Ameer is the Daniel Hale Williams Professor of Biomedical Engineering in the McCormick School of Engineering, professor of surgery in the Feinberg School of Medicine and director of the Center for Advanced Regenerative Engineering. He is recognized for his contributions to the fields of biomaterials science, tissue engineering and regenerative engineering, particularly for pioneering the development and applications of citrate-based biomaterials… Continue reading.
Northwestern Engineering’s Guillermo Ameer, a pioneer in the field of regenerative engineering, was presented the Key to Panama City, Panama, by Vice Mayor Raisa Banfield last week. The event was covered by Telemetro, a national Spanish-language television network based in Panama City.
Ameer, the Daniel Hale Williams Professor of Biomedical Engineering with the McCormick School of Engineering, was in his hometown to attend at APANAC 2018, the XVIII Congreso Nacional de Ciencia y Tecnologia, the nation’s premier science conference. He also serves as a professor of surgery at Northwestern University’s Feinberg School of Medicine, and he is the director of the Center for Advanced Regenerative Engineering (CARE)… Continue reading.
To advance the engineering of biology at the molecular and cellular levels, the National Science Foundation (NSF) has awarded $16 million for research to characterize the regulation of gene activity and expression, and to create strategies to modify those processes without altering the DNA sequence.
Chromatin — a combination of DNA, RNA and proteins within a cell’s nucleus — can be modified by attaching additional molecules. This can cause altered gene expression without actually changing the cell’s DNA. These so-called epigenetic changes can alter an organism’s traits, or phenotype, and may even be passed to offspring.
The NSF EFRI Chromatin and Epigenetic Engineering (CEE) investment will support potentially transformative research by eight interdisciplinary teams:
A simple scrape or sore might not cause alarm for most people. But for diabetic patients, an untreated scratch can turn into an open wound that could potentially lead to a limb amputation or even death.
A Northwestern University team has developed a new device, called a regenerative bandage, that quickly heals these painful, hard-to-treat sores without using drugs. During head-to-head tests, Northwestern’s bandage healed diabetic wounds 33 percent faster than one of the most popular bandages currently on the market.
“The novelty is that we identified a segment of a protein in skin that is important to wound healing, made the segment and incorporated it into an antioxidant molecule that self-aggregates at body temperature to create a scaffold that facilitates the body’s ability to regenerate tissue at the wound site,” said Northwestern’s Guillermo Ameer, who led the study. “With this newer approach, we’re not releasing drugs or outside factors to accelerate healing. And it works very well… Continue reading.
Neointimal hyperplasia is the main factor that determines the long- term durability of vascular interventions, such as angioplasty and by- pass grafting. As these interventions result in localized injury, several clinical therapeutics have been developed to deliver antiproliferative agents locally. Currently, several drug-eluting stents delivering anti- proliferative drugs (e.g., sirolimus and paclitaxel) are clinically avail- able for use after balloon angioplasty procedures . However, to date, no durable alternatives are available to improve the patency of synthetic prosthetics grafts like expanded polytetrafluoroethylene (ePTFE) . While similar pathophysiologic responses are involved following both interventions, injury that results following angioplasty is limited to the time of the procedure, while bypass grafting causes a continued stimulus for intimal hyperplasia due to changes in mechanical forces at the anastomosis and is influenced by the biocompatibility of the conduit utilized. These effects are greatest when prosthetic materials are uti- lized, and are responsible for the poor patency rates observed with these materials as compared with the performance of autologous saphenous vein. Cumulatively, the prior investigations suggest that successful in- hibition of intimal hyperplasia requires sustained delivery of a selective therapeutic agent from new bypass grafts… Continue reading this editor’s pick.
Life depends on keeping things flowing. Blood in our veins, nutrients in our digestive tracts, or air in our lungs, all need to be kept moving. When disease or damage obstruct the flow, medical stents and scaffolds can save lives. They hold crucial arteries open, while these blood vessels repair themselves, or maintain the necessary structure of a damaged esophagus or intestine.
Soon, making stents may be easier than ever, thanks to 3D printing technology. Guillermo Ameer, Cheng Sun and colleagues at Northwestern University in Chicago, US, report their progress with making 3D-printed vascular stents in the journal Materials Today Chemistry.
Despite their benefits and widespread use, existing stents can promote damaging inflammation, may become the site of further blockage due to sluggish flow, or can break in situ. Each clinical condition and each patient also ideally requires a customized stent or scaffolding graft with a specific size, shape, and strength… Continue reading.
Northwestern Engineering’s Guillermo Ameer has been elected as a fellow of the American Institute of Chemical Engineers (AIChE), the world’s leading organization for chemical engineering professionals.
An expert in biomaterials and regenerative engineering, Ameer was recognized for his valuable contributions to the field. He officially received the award on October 31 at the AIChE Fellows Breakfast in Minneapolis.
“It’s an honor to be recognized and receive this distinction from AIChE,” said Ameer, the Daniel Hale Williams Professor of Biomedical Engineering and Surgery. “It puts me in the company of such highly accomplished chemical engineers… Continue reading.
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.
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.
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.”
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.
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.
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?