Biological cements to repair burst fractures of the spine are being developed and tested in a project between the University of Leeds and Queen’s University Belfast. The team is working to develop and examine the effects of novel cement materials for the treatment of burst fractures.
Bone cements are used to strengthen damaged vertebrae of patients with diseases such as osteoporosis, in a procedure known as vertebroplasty. Burst fractures to the spine, injuries that are often sustained in major impact accidents and falls, are more difficult to treat. The current standard of treatment is to join bone fragments together and stabilize the spine using of metal screws and rods. However, the treatment is invasive and patients with such injuries often experience other traumas, which increases risk.
The project team is developing and testing synthetic biomaterials for the repair of bone defects. The team hopes these materials can be delivered to the fracture site by injection and mimic the chemical composition of bone.
The team will also perform computational modeling of the spine to assist in the development of novel biomaterials and to simulate how these will perform in patients.
The team leaders attribute the difficulty in treating burst fractures to the fact that people that need the procedure are typically younger than those that have osteoporosis. In addition, currently used cements are stiffer than bone, which causes imbalance and increases the load of neighboring vertebrae.
The team says using bone cements for burst fractures would be simpler, quicker, and much less invasive for the patient, reducing both recovery times and costs.
Reports from Messe Düsseldorf’s K2007 international plastics industry fair highlighted some of the company presentations from manufacturers.
Among them, Solvay Advanced Polymers introduced its Solviva family of biomaterials, offered for use in implantable medical devices. These material blends include Zeniva PEEK , Proniva SRP (a self-reinforced polyphenylene), Veriva PPSU (polyphenylsulphone), and Eviva PSU (polysulphone).
According to a press release, the launch of Solviva Biomaterials is the culmination of more than 18 months of planning and extensive investments by the company in its production facilities, biocompatibility testing, and the installation of a highly stringent production process.
The line of Solviva biomaterials is currently undergoing clinical trials with several medical device manufacturers including Zimmer Medical.
A new biomaterial developed at the New Jersey Center for Biomaterials (NJCBM) at Rutgers University is being used in a coronary stent undergoing its first-in-human clinical trial in Germany and in Brazil.
The stent, designed by REVA Medical Inc. (San Diego), is intended to act as a temporary scaffold to support the blood vessel during the healing process and maintain blood flow. It subsequently dissolves, leaving the patient free of any permanent implant.
In collaboration with REVA, Joachim Kohn and his colleagues at Rutgers developed a polymer that is suitable for stent applications. In addition, the material was designed to be radiopaque so it is visible by x-ray, which is critical for proper placement of the stent in the artery. It is also biodegradable and biocompatible.
Fully degradable coronary stents have been explored for more than 20 years. But, according to Kohn, no clinically useful products could be developed, in part, because of the lack of polymers that could meet the extremely demanding performance requirements. Kohn and his team addressed this problem by developing a library of degradable polymers comprising 10,000 theoretically possible compositions and applying combinatorial methods to identify the best possible biomaterial. The resulting material was selected for use in combination with the stent design.
The library developed by Kohn could be used for many different biomaterials design challenges. The RESORB trial is evaluating the stent’s safety in approximately 30 patients at multiple sites in Germany and Brazil.
Finally! During the MD&M Minneapolis conference session Gail Naughton from San Diego University gave one of the most practical talks I’ve seen regarding biotech and biomaterials. Her presentation reviewed various tissue engineered products, all of which were interesting. But even more exciting was her frank disscussion about getting to the market and learning from the mistakes (such as not following up with clinical trials, or misdesigning those trials).
One of the aspects of tissue engineering is cost. Naughton said there is a significant cost associated with building a product and many companies have gone under because the estimated market (over $100 billion) was nowhere near the real market (closer to $5 billion) in its initial years. Companies that had spent exorbitant amounts on overhead found that the financial hurdles were more than they could cover. Naughton said that taking one product and applying it to over clinical uses is key to using resourses. “Using the same product for various clinical applications is a must for tissue engineeering,” she said. Naughton also mentioned using less-ophisticated robotics and employing outsourcers as a way to cut costs for new companies during ramp up. Â
Learning from other mistakes is critical to creating biomaterials and bioengineered materials that are functional, safe, and most of all marketable.
As reported in NewScientist: Congestive heart failure happens when the heart cannot pump enough blood to meet the body’s metabolic needs. The condition is poorly understood, but generally thought to be caused by problems with the heart’s valves or damage to its walls.
In the short term, the heart tries to compensate by expanding so that it can pump more blood. But this starts a vicious cycle of decline that damages the overstretched heart even more.
A protective band around the heart to reinforce its walls and prevent it from becoming enlarged could be the answer, say Bilal Shafi and colleagues at the Stanford University School of Medicine in Palo Alto, CA.
They suggest building up the walls with two layers of polymer. The first is made of polyethylene glycol to provide strength, and the second is a layer of collagen that provides elasticity and biocompatibility. The key to the technique is the ability to deliver the polymer mix to the heart in the form of a powder or gel. It can then be cured in place by UV light or heat to form a thin, strong film.
Read the full heart-wall reinforcement patent application.
The New Jersey Center for Biomaterials (NJCBM) is seeking candidates for its postdoctoral training program in tissue engineering and biomaterials science. The program offers interdisciplinary training, ranging from design and synthesis of new biomaterials, materials characterization and processing, and cell biology, to the engineering of prototype implants and their testing in clinically relevant animal models. Previous exposure to one or more of these techniques is highly desirable.
All applicants must be US citizens or permanent residents. Applications from underrepresented minority individuals are strongly encouraged.
Go to http://www.njbiomaterials.org/postdoc for application instructions and to download an application form. Submit your completed application with accompanying documentation to: New Jersey Center for Biomaterials, 145 Bevier Road, Piscataway, NJ 08854, E-mail: aranzamendez@biology.rutgers.edu.
