Biotechnology has introduced many wonders to the world. New drugs to treat deadly diseases. Microbes that digest oil spills. Fluorescent fish. Remarkable inventions all.

But what has biotech ever done for bald people?

Some may feel sheepish raising the question, given the weightier problems needing a scientific fix. Hair loss is not a life-threatening condition, concedes Kaiser Permanente dermatologist Paradi Mirmirani. But half the population, both male and female, see their locks thinning by age 50 - and many can't take the loss lightly, Mirmirani said.

"I have tearful patients in my office many times a day," she said. "When they lose their hair, they feel like they've lost their identity."

That passionate attachment is helping to speed research on new treatments because investors see a potential gold mine in the field. Most health plans don't reimburse for anti-balding drugs or transplants, but many people will pay out of their own pockets even if the cost is a bit hair-raising.

Industry sources estimate that Americans spend more than $1 billion a year on approved drugs for hair loss and hair transplants.

That explains why a small but determined bunch of companies and academics are mining the hair shaft for clues to the molecular mechanisms of balding. They're throwing an arsenal of high-tech tools at the condition: genome studies, stem cell stimulation, gene therapy, a type of tissue engineering often called "hair cloning" and even robotics.

The chance of much better treatments in time for your high school reunion? A big maybe.

Much is still unknown about the phenomenon of balding, a trait that only humans and some monkeys share, said Stanford University Professor Anthony Oro. It's not even clear why humans, over the course of evolution, shed most of their thicker body hair but kept a crop on the head.

For a minority of balding people, episodes of hair loss stem from diseases such as skin infections and immune system disorders, or stresses such as surgery and childbirth. Treatments for such hair loss are often geared to fix the underlying cause.

But by far the most common type of hair loss is the slow, inexorable thinning of the locks on a timetable set by genes inherited from the father or mother.

Certain genes make the top of the scalp more vulnerable to a male hormone, dihydrotestosterone or DHT, that shuts down follicles so they don't produce new hairs. The result is male-pattern baldness, which starts with a receding hairline and bald spot. The same interplay of male hormones and heredity can cause a general thinning of hair in women.

Only two drugs are approved by the Food and Drug Administration to treat common baldness - Merck's Propecia and Johnson & Johnson's Rogaine (and its generic equivalent, minoxidil).

Propecia, a pill usually prescribed only for men, blocks production of DHT. The mechanism is not fully understood for Rogaine, an over-the-counter solution that is applied to the scalp.

Both drugs can promote regrowth or slow the rate of hair loss for some people, to some extent. But there's plenty of room for improvement.

Multibillion-dollar market

"There is clearly a great need for more treatments for hair growth," said Dr. Vera Price, a UCSF dermatology professor who heads the medical center's hair research center. "Pharmas, the biotech industry, venture capitalists are aware of this huge consumer need and the fact that it represents a multibillion-dollar market."

Pfizer Inc. of New York is working on an experimental drug that works the same way as Rogaine, as well as another compound that mimics the effect of thyroid hormones.

Among the small biotech companies attacking the problem is AndroScience Corp. of San Diego, which is developing a drug that degrades the cell receptors for DHT. Drugs for balding, however, usually work only on follicles that are still active.

The alternative is transplants. A Mountain View startup, Restoration Robotics, is developing automated equipment to help surgeons perform hair transplants faster, and possibly cheaper.

Hair-transplant surgeons take follicles from the back and sides of the head, which seem immune to the balding effects of male hormones, and move them to the crown. The success of transplants has always been limited, however, by the finite amount of hair a patient still has left to move around.

Reviving follicles

For those hoping for a new technology that will carpet a bald scalp like Astroturf, the best shot may come from a small group of companies that are trying to cultivate new follicles like seedlings. Experiments are challenging the long-held notion that new follicles are never formed in humans and that follicles can never be revived once they become inactive.

A pilot study in humans is planned within a few months using a strategy outlined in May by Dr. George Cotsarelis, a University of Pennsylvania dermatology professor who discovered that mice healing from wounds could produce hair follicles. Cotsarelis theorized that the healing process created a window of time when new skin structures could form.

The Boston company he co-founded, Follica Inc., is trying to duplicate the regenerative environment of wound healing in humans by using a modified form of microdermabrasion, a form of skin treatment that grinds off dead surface skin cells and encourages repair by deeper cells.

Along with that mild injury to the scalp, Follica applies drugs to promote the growth of new follicles.

If new follicles form on top of a bald scalp, will they have the decadeslong lifespan of a baby's follicles, or will they quickly succumb to the male hormones that caused the baldness in the first place? That's a question raised by Chris Ehrlich, a partner in the Menlo Park VC firm InterWest Partners, which has helped fund Follica.

"We view it as a very early, very high-risk project," Ehrlich said. "But if it works, it would be great."

In another approach, company scientists at Atlanta's Aderans Research Institute are taking certain key cells from the scalp and trying to multiply their numbers by growing them in culture. Two cell types were chosen because they exchange chemical signals that foster follicle formation. If the method works, the propagated cells could be injected into the scalp as "hair seeds" to create new follicles.

Wigmaker does research

The tactic is often called "hair cloning," but no hairs or follicles are produced in the culturing step, said Aderans executive Dr. Ken Washenik. The research is a project of Aderans Co. Ltd, the world's largest wigmaker, and its affiliate Bosley, a major hair transplant company.

Other companies are trying variations of this method. Washenik said he once predicted a treatment would be ready in five years. "But at this point I think it's better not to make an estimate because I'm really not sure," he said.

Oro, who studies hair stem cells at Stanford, said work on the regeneration of the follicle mini-organs could some day yield health benefits that go beyond defeating hair loss.

The scalp provides an accessible means of studying the role of stem cells in the regeneration of an organ. And many organs use the same similar chemical growth signals as follicles, he said.

"If we understood how to regrow hair, it would help us understand how to regenerate the liver, the pancreas and other organs," Oro said.

New approaches to baldness

Drugs: Companies including Pfizer of New York and AndroScience of San Diego are working on experimental drugs that would promote regrowth of hair and slow down hair thinning.

Tissue engineering: Aderans Corp. in Japan and other companies are trying to multiply key cells that could seed the regrowth of follicles on a bald scalp.

Hair through healing: Follica Inc. of Boston is hoping the process by which the body heals skin wounds can also give rise to new follicles.

Source: Chronicle research

E-mail Bernadette Tansey at btansey@sfchronicle.com.