TAMPA — Dr. Burton Feinerman has spent more than a decade using stem cell therapies that are banned in the United States, sending desperate families to Peru seeking treatments for their babies' terminal conditions like Tay-Sachs disease.

The therapies are costly and unproven, and no insurer will cover them. But there is no law against a U.S. doctor recommending them, as long as they aren't performed here.

Now the 85-year-old pediatrician is focusing on a stem cell therapy he can perform in Tampa, for seniors with such incurable lung conditions as chronic obstructive pulmonary disease, or COPD.

Feinerman, medical director of the Tampa-based Lung Institute, says lung patients tend to get the most benefit from stem cell therapies. And he can treat them in the United States because he is re-infusing patients with their own stem cells, a legal process under certain circumstances.

But it's not approved as a lung disease therapy in this country. Neither the American Lung Association nor the International Society for Stem Cell Research have endorsed it. Medicare won't cover it.

So Feinerman's patients must pay cash — between $7,500 and $12,000 for a three-day treatment, plus $4,500 for additional "boosters'' of cells extracted from their blood or abdominal fat.

The Lung Institute has produced a slick website and an advertising campaign, and it puts on seminars at which prospects can hear the testimonials of satisfied patients.

But there are no clinical data showing stem cell therapies benefit patients with lung disease, said Dr. Daniel Weiss, a professor at the University of Vermont College of Medicine and a leading lung disease researcher. Further, studies of mice suggest that if the therapies work, it likely would help only acute lung conditions like respiratory distress syndrome, not chronic conditions like COPD.

"I do not recommend any type of cell therapy (for lung disease) at this point," Weiss said.

Feinerman insists the doubters are wrong. "Just go to Google," he told a Times reporter who asked him for clinical research to back his claims. Lung Institute employees later provided citations for three journal articles, but none showed the treatments worked. In fact, Weiss wrote two of the articles.

Feinerman said the American medical establishment is too slow to embrace developments.

"The U.S. is so far behind the rest of the world, it's pathetic," he said. "Doctors are not scientists. They know how to read a cookbook, but God forbid if you want to add a new recipe."

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Stem cells can reproduce themselves to repair tissues and mature into cells that perform a specific function, such as in the skin, muscle or blood.

Though stem cell therapy is thought to hold great promise, so far the therapies have been shown to work in only a few diseases, most notably for leukemia and lymphoma patients who get the cells through bone marrow transplants.

Stem cells come from a variety of sources, including human embryos (the most controversial), umbilical cord blood and, in the case of adult stem cells, from anyone's body.

At the Lung Institute clinic, a suite on the fourth floor of a downtown Tampa office building, the treatments are autologous, meaning adult stem cells are harvested from individual patients and later reintroduced. The promise: to restore deteriorating tissue, such as the scarred lung tissue that often marks COPD.

Here's how the therapy is administered:

First, the staff takes samples from patients in one of two ways. Technicians draw about three tablespoons of blood. Or a doctor or nurse practitioner performs a mini liposuction on the patient's abdomen, extracting about a coffee cup's worth of fat.

Using fat is more involved and $4,500 more expensive than blood. About a third of patients opt for the fat option, which Feinerman says gives a greater concentration of stem cells.

The sample is then taken into a lab at the office, where a centrifuge pulls out the stem cells. The stem cells go back into the patient, usually intravenously, but sometimes they are inhaled via a nebulizer. The infusion takes about two hours a day, for three days.

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The concept that stem cell therapy could heal damaged lungs by regenerating new tissue dates to 2001, after an early promising study in mice. However, researchers subsequently determined that the study and related studies were flawed, said Weiss, the University of Vermont professor. No evidence suggests stem cell therapy results in growth of new lung tissues either in animal or patients, he added.

But animal studies do show that a particular type of stem cell — one that is found in umbilical cord blood, fat, placenta and bone marrow, though not in the circulating blood system — released anti-inflammatory substances, he said.

After injection, these cells initially end up in the lungs where they can act to reduce inflammation. But evidence suggests the stem cells stick around for only a few days, Weiss said. That's bad news for people with chronic conditions like COPD.

"What that means, in terms of having any rational chance on lung disease, is the best targets are acute inflammatory (conditions)," he said, such as acute respiratory distress syndrome, which can develop in patients in intensive care units.

COPD is, as the name suggests, a long-term condition unlikely to be improved by this type of stem cell therapy, he said.

Multiyear clinical trials looking at the potential effectiveness of these particular stem cells for acute lung conditions are under way, he said. But at this point, scientists can't say if the treatment — and remember, the cells being studied are not found in a regular blood draw — will offer relief to patients with any type of lung disease.

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Still, stem cell clinics promoting unproved remedies are big business. Paul Knoepfler, a stem cell researcher at the University of California at Davis, wrote in an email to the Tampa Bay Times that there are an estimated 100 stem cell clinics in the United States operating on questionable claims — and under little oversight.

The FDA in 2008 determined that the procedure in which a person's own stem cells are re-injected constitutes a "drug," meaning the clinics would be subject to the same rigorous testing requirements that govern the pharmaceutical companies.

However, the agency later released a narrow list of exceptions to the regulations. This list includes minimal processing of the stem cells, as well as the requirement that the entire process take place at one establishment. The Lung Institute says it operates under those exceptions.

The Florida Department of Health has no specific regulations for stem cell therapies, though the doctors who run them are required to meet the same standards of care required of all physicians. No report of harm has been filed against the Lung Institute, and Feinerman has no complaints recorded against him with the health department.

But there is risk with all medical procedures. Late last year, a state appeals court upheld the Florida Board of Medicine's 2013 decision to revoke the license of Bonita Springs cardiologist Zannos Grekos. In 2010, Grekos performed an autologous stem cell therapy on a Naples woman, who suffered a stroke and died as a result, documents show.

"The overall bottom line with most stem cell clinics in the U.S. is that collectively they could be viewed as conducting a huge, unapproved and for-profit stem cell experiment of a sort, on thousands of vulnerable patients who are often desperately looking for hope," Knoepfler wrote in a January blog post.

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The nearly 2-year-old Lung Institute, started in Tampa, now has a clinic in Nashville and is poised to open one in Scottsdale, Ariz. It markets directly to patients across the nation through Internet and newspaper ads. Half-page ads in the Tampa Bay Times featured newspaper-style stories comparing the importance of stem cell therapies to penicillin or the Beatles.

The Lung Institute is part of a company called Regenerative Solutions, which offers stem cell therapies for a broad range of diseases. Feinerman is also medical director of Regenerative Solutions, which maintains an office in Peru for treatments banned in the United States.

Regenerative Solutions' direct-to-consumer marketing model is much like that of Tampa-based Laser Spine Institute. In fact, Regenerative Solutions merged with a consulting venture started by former Laser Spine executive Jimmy St. Louis.

In 2014, its first full year of operation, the Lung Institute says it treated more than 400 patients in its Tampa clinic and another 50 in Nashville. Feinerman is licensed to practice in Florida, Arizona, Hawaii, New Mexico and Minnesota, but has no local hospital privileges, according to the Florida Department of Health. As he advertises on his website, Feinerman is board certified — in pediatrics, state records show.

Publishing research in peer-reviewed journals is considered an essential part of the scientific process, as it opens the work to informed scrutiny.

The Lung Institute has not published results of its treatments. Feinerman said in an interview with the Times that about 70 percent of patients report some benefit after the treatment.

Rigorous scientific studies also require objective measures, such as lung capacity, and use comparison groups to see if the therapy is better than other options. But the Lung Institute reports only on its patients' subjective experiences, such as whether walking to the mailbox seems easier after having the treatment.

The clinic's website and ads feature testimonials from satisfied patients such as Vickie Blackstock, a 66-year-old Texan diagnosed with COPD in 2010.

Blackstock, who spoke with the Times, required oxygen at night and during the day even for minor exertion like making the bed. Her doctor told her she eventually would need a double lung transplant. She found the Lung Institute online.

She arrived in Tampa last May and received the three-day venous treatment. Within a month, she said, she no longer required supplemental oxygen. She bought a treadmill and started walking again.

"All I had to lose was what it cost me to do," said Blackstock, who returned to Tampa for a booster treatment. "If it did work, then I had everything to gain. I wasn't leading a quality life."

But patient testimonials on their own aren't convincing evidence for the therapy, Knoepfler said. Aside from the lack of scientific data, there's the possibility of a placebo effect in people who have paid a lot of money for something they badly need.

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"Stem cells are not the future of medicine," Feinerman said one recent afternoon. "They're the future of medicine, today."

The physician was speaking to nearly 20 seniors gathered at the downtown Tampa Fifth Third Bank building where the Lung Institute is a tenant.

The audience — some toting portable oxygen tanks — was there for a free seminar on stem cell treatment for COPD.

Feinerman said the goal was to get them off the oxygen within six months and, eventually, off the expensive medications COPD patients are prescribed to open damaged airways and control inflammation so they can breathe. After viewing a video featuring patient testimonials, the clinic staff offered a $2,000 discount for patients who acted by February.

Then they took questions from the audience.

Why doesn't insurance pay?

"Money, money, money," Feinerman said.

Is there any published research?

"By the thousands," said Feinerman, who, again, could not cite a particular study.

George Mideaker, a 77-year-old New Port Richey resident, lugged his oxygen unit to the session. Diagnosed with COPD about 20 years ago, he said the condition left him struggling to get through the days. His doctors said they could not offer any more help.

Mideaker said his sister agreed to help pay for his Lung Institute treatments if he liked what he heard. He did. "It'll give me a little life," he said.

He waved down a staffer to sign up.

Times researcher John Martin contributed to this report. Contact Jodie Tillman at jtillman@tampabay.com or (813) 226-3374. Follow @jtillmantimes.