Ty Haywood went around the world to get access to stem cell treatments for his illness. But future generations of Californians may not have to travel so far.

Extensive research efforts are under way to find ways to use the promising cells — which can mature into a wide range of tissues and so may be useful in multiple treatments — in the Golden State and elsewhere.

Although policy for stem cell research varies wildly from state to state, federal law remains firm. In 2001, President Bush freed up approximately $90 million of federal funds for stem cell research — but only for stem cell lines created before the statute’s passage. While current law forbids the use of federal money for the creation of new stem cell lines, it does not disallow private or state monies for such research.

Two attempts to change federal stem cell research law failed in recent years. Although two versions of the Stem Cell Research Enhancement Act passed in the House and Senate in 2005 and 2007, President Bush vetoed both bills, which would have elicited more federal funding and loosened restrictions for stem cell research.

On the state level, California is one of the nation’s leaders of stem cell research. On the heels of New Jersey — the first state to designate monies explicitly for stem cell study — Californians passed Proposition 71 in 2004. Also known as the California Stem Cell Research and Cures Initiative, the proposition freed up to $3 billion in state bond proceeds over 10 years for stem cell research. The California Institute for Regenerative Medicine — which makes policy determining what organizations receive state monies for stem cell research purposes — was also born of the legislation.

In spite of the passage of Proposition 71, several years passed before California universities and other researchers received funding. Until recently, a lawsuit — initiated by stem cell research opponents who claimed that the proposition was unconstitutional — stalled the distribution of funds.

Gov. Arnold Schwarzenegger addressed state funding needs in 2006, when he released $150 million in state loans for research.

The flow of state funding sped up in May, when the California Supreme Court ruled against the plaintiff in the case — an organization called the California Family Bioethics Council — freeing up funds allocated by Proposition 71. The California Institute for Regenerative Medicine is expected to dole out more than $622 million for stem cell research in California through 2009.

Dr. Rich Murphy, interim president of the institute, said since May’s ruling, about $200 million has been released for stem cell research in California. By next summer, he said, total research funding should climb to approximately $500 million.

Murphy said although stem cell treatment is now available for some illnesses in the U.S., potential future treatment options depend on additional research.

“California is really the world’s leader in terms of how much money we put into it, the level of our activity and the ethical standards that regulate our activity. But many other countries like the United Kingdom, Singapore and China are making major efforts in stem cell research. It’s a world effort; there’s no question about it,” said Murphy.

Dr. David Pleasure, associate director of the UC Davis Stem Cell Program, said the availability of stem cell treatments in the U.S. is limited to treating blood disorders, such as leukemia. Pending testing in the next few years, he said, the treatments could be used to treat people with Type 1 diabetes, retinal degeneration and eventually even Alzheimer’s disease and other illnesses.

In the meantime, advances in stem cell medicine continue. Pleasure said scientists have recently injected genes into adult skin cells — via a retrovirus — to create units which work like embryonic stem cells. In theory, the transformed cells would eliminate the problem of tissue rejection, he said, adding that while future treatment possibilities are heartening, more research is needed to evaluate the risks of tumor growth and other potential threats.