Medical Implants Should Have Rough Surfaces

Catheters and other medical implants that deliver long-term life-support joint replacement work better when their surfaces are rough, according to new research.

Instead, implants often have surfaces that soft tissues such as skin and connective tissue cannot attach to. So the body forms a tissue capsule around the implant, sealing it off from the rest of the body. This can lead to a variety of serious problems, such as hip and knee implants, which usually last for 10-12 years until they become loose and quite painful.

"Being encased in connective tissue seriously compromises an implant's function,” said lead author Andreas von Recum, professor of biomedical engineering at Ohio State University (Columbus, OH, USA). "And connective tissue can't tolerate constantly moving against a foreign object. This friction, and ensuing inflammation, kills healthy cells and creates a steadily growing capsule of dead tissue.”

Researchers coated disk-shaped polyester wafers with titanium. Some were covered with grooves. Fibroblasts from mice were left to grow on both the smooth and textured discs for three days. Then the researchers used photomicrography to determine the distance between cell membranes and disk surfaces. The distance between the fibroblasts and the surface of the textured disks was immeasureable, suggesting that these cells had adhered to the surface. Conversely, the researchers could measure the distance between cell membranes and the surface of a smooth disk.




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