About 46 million people suffer from arthritis in the United States alone. The worst cases require painful surgeries to drill holes in and reinforce joints. Now, researchers working at the National Institute of Standards and Technology (NIST) are studying an unusually pliant, yet strong, synthetic cartilage replacement in hopes of providing arthritis victims with some relief.
Double-network hydrogels are gels that have the pliancy of gelatin but won't break apart, even when deformed over 1,000 percent. NIST scientists added a second polymer to the gel, making it so tough that it rivaled cartilage-tissue, which can withstand the abuse of hundreds of pounds of pressure. The combination of a brittle hydrogel and a soft polymer solution led to a surprisingly tough material.
Using NIST's neutron scattering techniques, it was discovered that the two polymers were attracted to each other - despite the fact that one polymer is negatively charged and the other neutral - and can withstand a certain force before they can be pulled apart. The researchers hope a good synthetic cartilage could endure year after year under the rigors of the body before needing to be replaced.
