Artificial Organs: Corneas from Calf Skin

Though few people outside medicine and biology know the word, collagen is one of the most important constituents of the human body, making up 30% of its protein. In bone and tooth enamel, its long chains of molecules serve the same purpose as that of steel reinforcing rods in concrete. In mobile tissues' such as tendons, arteries and heart valves, they are like flexible steel wires. And despite the unfamiliarity of its name, collagen (from the Greek kolla, or glue, and pronounced col-uh-jen) has been popular in the humblest homes for centuries. When the hides and bones of...

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