The California Supreme Court has declined to hear an appeal challenging the state’s $3-billion program to foster stem-cell research, paving the way for it to begin in earnest this year.

Voters approved the program, to be run through an agency called the California Institute for Regenerative Medicine, in 2004. But its start was delayed by lawsuits filed by opponents of the research, who consider human embryos, from which the stem cells are obtained, to be human lives.

The court’s decision, which was announced on Wednesday and upholds rulings by a trial court and an appellate court, frees the state to issue bonds to raise money for the research. The expected amounts, $300-million a year for 10 years, will dwarf what the federal government is now providing for research nationally on human embryonic stem cells, and will easily make California the world leader in research activity and financing in the field.

The agency has already issued its first research grants, worth a total of $158-million, using money from loans advanced by the state and by private investors. With the Supreme Court’s decision, the agency will now pay back those loans. —Jeffrey Brainard