Regeneration Sans Stem Cells

When a worm is chopped in two, the missing part often re-grows. Researchers at several biotech companies are challenging the assumption that humans can't perform a similar feat by developing drugs that encourage self-regeneration.

Hydra Biosciences is working a regeneration drug that stimulates heart muscle-cell regrowth, and could lead to better recoveries for heart attack sufferers. The protein-based drug induces mature cells to become a little bit like stem cells.

Hydra hopes its cardiac-muscle drugs will prove to be just the tip of the regenerative medicine iceberg -- the company is already considering investigating ways to re-grow retinas in macular degeneration sufferers and pancreatic cells in diabetics.

Other companies are starting to explore regenerative techniques as well. Genzyme, for instance, has developed a little-known drug called Carticel, which is FDA-approved to regenerate damaged cartilage and has proven useful in treating slow-healing knee injuries. Meanwhile, Epicell, in the United Kingdom, is developing ways to generate sheets of extra skin from the body's own epithelial cells, techniques that are becoming instrumental in many types of reconstructive and plastic surgery.