For the first time in nearly a decade, biomedical scientists and companies are confronting a fundamental question: Will the government pay for research that involves human embryonic stem cells?

Since the mid-2000s, research has dramatically expanded on stem cells, including those not derived from human embryos. There are currently more than 1,300 clinical trials on stem cell-based therapies under way, according to the database, maintained by the National Institutes of Health.

The trend started in California in 2004, when voters approved Proposition 71, appropriating $3 billion for studies using embryonic or other kinds of stem cells. A few years later, President Barack Obama eased restrictions on federal funding for human embryonic stem cell research. (His predecessor, George W. Bush, was the first president to authorize any government money for this research, but restricted the funding to existing stem cell lines.)

Now, President-elect Donald Trump may curtail funding for embryonic stem cell research.Trump himself has said he opposes abortion, a related issue. Tom Price, his nominee to head the Department of Health and Human Services, has opposed embryonic stem cell research on moral grounds because embryos are killed during production of the cell lines.

The embryonic stem cells are collected from extra embryos produced from in vitro fertilization that would otherwise be discarded.

Stem cells, from embryos and non-embryonic sources, are being tested for their ability to regenerate replacement tissues for those lost to disease or injury.

Researchers are also using them to replicate aspects of an illness in the lab, a so-called “disease in a dish.”

Neither Trump nor Price has publicly stated whether federal funding for embryonic stem cell research will be curtailed. That research is funded by the NIH, which falls under the HHS department.

Price has said work with other kinds of stem cells has proven more promising, a view for which there is some evidence.

Although embryonic stem cell-based therapies are in clinical trials, including one from San Diego’s ViaCyte, no such treatments have actually been approved.

The campaign for Prop. 71 gave the impression that many treatments from embryonic stem cells would result in the not-too-distant future. Even some backers of the measure have since said expectations were raised beyond what the science supported.

Momentum has shifted to experimentation with other kinds of stem cells not derived from embryos. Artificially created stem cells called induced pluripotent stem cells, or IPS cells, act like embryonic cells, but are created from adult cells, such as skin cells. Human embryonic stem cells were discovered in 1998, human IPS cells were created in 2007.

And there are “adult” stem cells, which aren’t derived from embryos.

Researchers who back using embryonic stem cells say that description doesn’t tell the whole story.

Because they are natural, human embryonic stem cells remain the “gold standard” for understanding how cells develop from a universal ancestor to adult cells, such as in the skin, the heart, liver and brain, said Deepak Srivastava, a stem cell scientist at the Gladstone Institute in San Francisco.

“IPS cells do replace the need for embryonic stem cells to some extent, but does not make it go away,” said Srivastava, director of the Roddenberry Stem Cell Center at Gladstone. “We are still in the process of trying to optimize the production of IPS cells. And to do that, we have to compare those to what nature itself has made.”

However, for those who consider human life to begin at conception, the process of getting embryonic stem cells involves what they see as a moral evil. And that is the heart of the objection by those who oppose funding the research.

“One is taking advantage of one human being for the benefit of an older and more powerful human being,” said Rev. Tadeusz Pacholczyk, Director of Education for The National Catholic Bioethics Center in Philadelphia. “That is an inherently unjust proposal.”

Even if useful treatments result, the end doesn’t justify the means, Pacholczyk said.

Much of the information obtained from studying human embryonic stem cells can be obtained from other sources, such as animal embryonic stem cells, Pacholczyk said.

It’s morally permissible to use IPS cells because no embryo is ever produced in the process, Pacholczyk said.

Another type, called parthenogenetic stem cells, represents a more ambiguous picture, he said. These cells are derived from unfertilized egg cells, which develop into a structure much like an embryo.

“When one is dealing with a situation when you are not entirely sure whether you have generated a real human embryo or not, the benefit of the doubt should go to that entity you have created,” he said.

Such is the unsettled picture that awaits stem cell researchers beginning Jan. 20, when Trump begins his presidential term.

Full story at The San Diego Union-Tribune.