US health officials have approved a treatment for diabetic foot ulcers, hard-to-heal wounds that lead to tens of thousands of limb amputations each year.

The product, called Apligraf, is made by combining human skin cells with collagen from cattle to make a product that looks and feels similar to human skin. Apligraf is shipped with a supply of nutrients to keep it alive.

Foot ulcers afflict between 6,00,000 and 8,00,000 US diabetics each year and lead to more than 50,000 amputations annually.

The product, which is made by Canton, Mass.-based Organogenesis Inc. and marketed by Novartis AG , has been sold in the US market since 1998 for treating leg ulcers caused by circulatory problems. With the FDA's approval, the companies can promote Apligraf specifically for diabetic foot ulcers.

Normally doctors treat the foot ulcers by cleaning them, applying temporary wound dressings and advising patients to keep weight off their foot. But the Food and Drug Administration said those treatments were limited.

In a clinical trial, Apligraf combined with standard care healed 56 percent of diabetic foot ulcers within 12 weeks, compared to 39 percent that healed with standard care alone.

In both groups, more than 80 percent of the ulcers remained closed after four weeks. Side effects, including wound infections, occurred at similar rates for both groups.

Apligraf should be used in combination with the standard care, the FDA said.

``We are delighted our technology now provides physicians with a major new treatment option for these potentially serious wounds,'' said Michael Sabolinski, senior vice president for medical and regulatory affairs for Organogenesis.

The Canton, Mass.-based company is working to develop other products in the emerging field of engineered tissue and organs.