The researchers invented a biodegradable composite material made of silk fibers that can be used to repair fractured load bearing bones without producing complications like other materials.
A three-dimensional rendering of a new type of bone-repairing composite developed by the University of Connecticut. The composite is made from silk fibers and polylactic acid fibers. While maintaining flexibility, it is coated with fine bioceramic particles. Degraded composites can help heal bones without causing complications such as metal parts.
Repairing major load-bearing bones such as leg bones may be a long and difficult process.
For ease of repair, doctors sometimes install a metal plate to support the bone while the bone is healing. But this can be problematic. Some metals will inject ions into the surrounding tissue, which will cause inflammation and irritation. In addition, the metal is also very hard. If a metal The board is subjected to excessive load in the legs. The new bones may become more fragile and more likely to fracture.
In order to find a solution to this problem, material scientist, biomedical engineer Professor Mei Wei seeks help from spiders and moths in search of inspiration. Wei is particularly concerned about silk fibroin, which is found in the silk fibers of spiders and moths. The protein is known for its good toughness and tensile strength.
The medical community has long realized the existence of silk fibroin. Because of its high strength and good biodegradability, it is a common part of medical sutures and tissue engineering. However, no one has tried to make it dense. The polymer material, and Wei knows that silk fibroin is the key if she wants to make a better device to repair broken loadbone.
In collaboration with Prof. Dianyun Zhang, a mechanical engineer at the University of Connecticut, Prof. Wei’s laboratory began testing silk fibroin in various composite materials by finding the right combination and ratio of different materials to achieve the best strength and flexibility. Sex. The new composition of course needs its high strength. Hardness. But it doesn't need too much strength. Excessive hardness will inhibit the growth of dense bones. At the same time, the composite material needs to be flexible so that the patient can heal the bone. At the same time, it can maintain its natural range of movement and movement.
After dozens of tests, Wei and Zhang discovered what they were looking for. This new composite material consists of filaments and polylactic acid fiber (a biodegradable thermoplastic made from corn starch and sugar cane). In solution, each solution is coated with fine microbial ceramic particles made of hydroxyapatite (calcium phosphate minerals found in teeth and bones). The coated fibers are then layered on small steel frames. Above, and pressed into a compact composite rod in a hot compression mold.
In a recent study published in the “Mechanical Behavior of Biomedical Materials,” Wei reports that high-performance biodegradable composites show high strength and good flexibility, which is the same type of biomaterials in the literature. The highest value recorded in the above. In addition, their performance will become more excellent.
Wei is also an Associate Dean of the School of Engineering. He has been dedicated to research and postgraduate education. He said: 'Our research results show that: This new type of composite material has very high strength and flexibility. But we think that if we can make every component To achieve our goal, we will get better results. '
The new composites also have toughness. The femurs of adults and the elderly can take months to heal. The composite materials developed by Wei's laboratory complete its work and then begin to degrade after a year. No surgery is required. Remove.
Joining Wei and Zhang's research team were Bryant Heimbach, a doctoral student and materials scientist at Wei Labs, and Beril Tonyali from UConn who studied for materials science and engineering.
The team has begun testing new derivatives of composites, including those that use single crystals of hydroxyapatite for more strength compounds, and a change to a coating mixture to make it more weightable Maximize mechanical properties.