Los Angeles, CA -- Stem cell researchers continue to make progress with induced pluripotent stem cells or iPS cells, which are embryonic-like stem cells that don't require the destruction of human life to obtain. After their discovery last year, pro-life groups hailed the cells as an ethical alternative to embryonic stem cell research.

The UCLA researchers that have advanced the use of the iPS cells before were able progress further and grow functioning heart and blood cells.

They said the success is the first time iPS cells have been differentiated into the three types of cardiovascular cells needed to repair heart and blood vessels.

Dr. Robb MacLellan, the senior author of the study, published in the May 2008 edition of the medical journal Stem Cells, says the discovery could one day lead to clinical trials of new treatments for people who suffer heart attacks, have atherosclerosis or are in heart failure.

He also said the ethical cells don't present the same problems as the use of embryonic stem cells -- that have issues with growing tumors and immune systems rejecting them.

"I believe iPS cells address many of the shortcomings of human embryonic stem cells and are the future of regenerative medicine," he said.

"I'm hoping that these scientific findings are the first step towards one day developing new therapies that I can offer my patients. There are still many limitations with using iPS cells in clinical studies that we must overcome, but there are scientists in labs across the country working to address these issues right now," he explained.

Leading bioethicist Wesley Smith hailed the research results.

"IPSCs will apparently do everything scientists said they wanted from therapeutic cloning--and at far less expense, at no risk to women for their eggs, and without moral contentiousness," he said.

"Too bad California is still borrowing $300 million a year to pay for scientists' research on human cloning," he added.

MacLellan says iPS cells are believed to be very similar to embryonic stem cells but said further study needs to be done to confirm their differentiation potential. He said this new study is an important step in the confirmation process.

If they do, the time may come when a person could use their own skin cells to create individualized iPS cell lines to provide cells for cardiac repair and regeneration, MacLellan said.

That's important, given the problems associated with embryonic stem cells, he explained.

When embryonic stem cells are injected directly into the heart in animal models, they create tumors because the cells differentiate not only into cardiac cells but into other cells found in the human body as well. Likewise, using embryonic stem cells garnered from other sources than the patient could result in rejection of the injected cells.

Last June, UCLA stem cell researchers were among several scientific teams that were the first to reprogram mouse skin cells into iPS cells.