A new treatment involving the implanting of nerve cells has given a 40-year-old Polish paralyzed man the ability to walk again.

Surgeons in Poland worked with scientists in London to transplant nerve cells from the nasal cavity into the spinal cord of Darek Fidyka, who was paralyzed after being stabbed repeatedly in the back in 2010, according to BBC News.

Fidyka was able to walk with assistance from a frame, and said being able to walk again was "an incredible feeling."

"When you can't feel almost half your body, you are helpless, but when it starts coming back it's like you were born again," he said.

The procedure involved the use of specialist olfactory ensheathing cells (OECs) that form part of the sense of smell, Discovery News reported. These cells work as pathway cells and allow nerve fibers close by to be continually regenerated.

The surgeons removed one of Fidyka's olfactory bulbs in the first of two operations, and then transplanted cultured cells above and below the injured area on the spinal cord in the second operation. The goal is for the cells to allow damaged fibers to reconnect with one another.

Fidyka had been paralyzed for two years after the attack, and despite going through months of physiotherapy, he did not show any sign of recovery, BBC News reported. However, he made his first movement three months after the surgery when his left thigh started to put on muscle. He was able to take his first steps along parallel bars six months after the procedure. Two years after the procedure, he can walk outside the rehabilitation center with help from a frame.

Additional improvements include more feeling in his bladder and better sexual function.

"I think it's realistic that one day I will become independent," Fidyka said. "What I have learned is that you must never give up but keep fighting, because some door will open in life."

The surgery received funding from the U.K. Stem Cell Foundation and the Nicholls Spinal Injury Foundation (NSIF), which was started by David Nicholls after his son Daniel was paralyzed in a swimming accident in 2003, Discovery News reported.

"When Dan had his accident I made him a promise that, one day, he would walk again," Nicholls said. "I set up the charity to raise funds purely for research into repairing the spinal cord. The results with Darek show we are making significant progress towards that goal."

The U.K. Stem Cell Foundation is looking for the best way to find olfactory ensheathing cells and creating prototype nanofiber biomaterials that transplanted OECs could grow on. The organization also plans to raise money to hold clinical trials for 10 patients in Poland and the U.K. for this new procedure.