Pig brain cells wrapped in a seaweed derivative could be implanted into human brains by next year to treat Huntington's disease, if approved.
There have been safety concerns about using animal tissue
Researchers at New Zealand's Living Cell Technologies in Auckland have already had good results in monkeys.
They told New Scientist they were seeking approval to do the same in humans in the US.
The Food and Drugs Administration has already approved trials with animal tissue for Parkinson's disease.
However, there is concern that using animal cells in humans could spread infections from animals to humans.
Huntington's Disease is an inherited condition caused by a single faulty gene and affects one in 100,000 people.
Although present from birth, symptoms normally appear when the person is between 30 and 50.
Cells start to die in an area of the brain which helps control the movement of the body's muscles.
Patients experience gradually worsening twitches, loss of muscle control, and memory loss and eventually die from the condition.
In an attempt to minimise this damage in primates, the New Zealand team used pig brain cells taken from the lining of a brain structure known as the choroid plexus.
These cells have a nurturing role, mopping up toxins and secreting a range of chemicals that are reduced in Huntington's and are essential for brain cell function.
To overcome rejection of the implant, which has been a problem in the past with work such as this, the team wrapped the cells to be implanted in alginate - a derivative of seaweed.
This protects the cells from the immune system.
Human trial hope
They put the implants into four of seven monkeys that were given a toxin to simulate the brain damage caused by Huntington's.
A month later, brain cell damage was five times less in the animals treated with live pig cell transplants than in the other primates - approximately 50% cell death versus 10%.
This work is yet to be published. Similar work in using pig brain cell implants in rats was published in NeuroReport last November.
Al Vasconcellos, head of the Biopharma subsidiary of Living Cell Technologies in Rhode Island, the US, which plans to carry out the human research, told New Scientist: "The findings are so remarkable that I am confident that the FDA will fast-track approval of clinical trials for early next year, and we will see product approval in two years."
A spokeswoman from the Huntington's Disease Association said: "We are always excited to hear about any research that shows promise for Huntington's disease.
"However, it would take many years to see if approaches like these would be safe and work in humans."
Dr Roger Barker from the Cambridge Centre for Brain Repair said he would like to see more work in animal models before moving to human research.
Professor Anne Rosser, professor of clinical neurology at Cardiff University, said: "It's potentially exciting.
"However, we need more work and we need to check whether it is a real effect that will translate into long term benefits for humans."