US President Barack Obama on Monday overturned a funding ban on stem cell research in a bid to make America a trail-blazer in finding cures for a number of illnesses, such as Alzheimer's disease. He declared the return of federal funding would open the door for the US to lead the world in lab work.

The president said restrictions imposed by previous president George W Bush on the use of human embryos on moral grounds eight years ago may have held up new cures. He added that the White House would make scientific decisions based on facts, not ideology, from now on.

Addressing an audience on Monday of US lawmakers, scientists - including three Nobel laureates - and religious leaders, President Obama said his move to unleash research on stem cells would "restore scientific integrity to government decision making''.

Obama also paid a tribute to late actor Christopher Reeve, who was paralysed in a fall while riding on a horse. Obama said the Superman star dreamed of being able to walk again. "Christopher did not get that chance. But if we pursue this research maybe one day, maybe not in our lifetime, others like him might," he said.

Obama said the nation owes a debt of gratitude to people like Reeve, who with his wife Dana created a foundation dedicated to finding a cure for spinal cord injuries. He recounted Christopher Reeve's fighting spirit, efforts to regain the ability to walk and upbeat outlook, adding that he wished Reeve and his wife could have been at the White House Monday to witness the event.

Christopher Reeve, who was injured in 1995, died in 2004 of heart failure. Dana Reeve died of lung cancer in 2006. However, the Christopher & Dana Reeve Foundation, which they founded, hailed the decision from Miami.

"With a stroke of his pen, President Obama acknowledged the will of the majority of Americans and harnessed the power of the federal government to move research forward," the group said in a statement.

"By removing politics from science, President Obama has freed researchers to explore these remarkable stem cells, learn from them and possibly develop effective therapies using them."

The foundation's laudatory remarks were echoed around the US medical, scientific and research communities. Dalton Dietrich, scientific director of the Miami Project to Cure Paralysis in Florida, said the lifting of restrictions means that "now we're actually going to be able to ... get funded by the NIH (National Institutes of Health) to solve all these problems."

Another researcher, Joshua Hare of the University of Miami's Interdisciplinary Stem Cell Institute, said the announcement could pave the way for significant medical advances to cure diseases that until now have been incurable.

Stem-cell cos' shares spurt
Meanwhile shares of stem-cell therapy developers continued to gain ground yesterday in anticipation of Obama's decision, which is in keeping with promises made during his campaign.

The main effect of the ban was to choke off funding to government agencies and academic research centres, as most stem cell companies relied on venture capital and other forms of funding to conduct research.

Still, lifting the ban is symbolically positive for many companies, including California-based Geron Corp, which has been working on embryonic stem-cell therapies for about a decade.

Embryonic stem cells are early-stage cells capable of becoming any of the more than 220 cell types in the human body. Their use in research and eventual treatments has been controversial because they are collected by cloning embryos in a laboratory, but the embryo is destroyed in the process.

Other types of stem cells, such as adult stem cells, can be gathered from a person's skin, for example, and are less controversial, though many scientists have said that embryonic stem cells have a greater potential for medical therapies.