Although a reliable, easy-to-use laser system is essential, many researchers believe simply using a laser to melt the proteins found at the site of the wound can’t make a seal strong enough for clinical use. So, like plumbers and electricians, surgeons have turned to “solders”-in this case, proteins derived from animal or human tissues that melt into the wound and bolster tissue bonding.
While still a medical student in the mid-1980s, Poppas spent several frustrating months in the lab operating on rat urethras, using a laser alone to seal them. “I kept seeing a potential there,” he recalls, “but something wasn’t right.” The laser wasn’t reliably producing a bond strong enough to compete with sutures. So Poppas started playing with protein-rich strips of muscle or vein, or drops of blood that he laid over the cut vessel before hitting it with the laser light. The results were better but still not good enough. He then tried pure protein-a compound called albumin that is abundant in blood serum and egg whites. “I mixed it up and put it on the wound and bonded this thing and it was unbelievable, the results were just phenomenal,” he says. “In fact, I was supposed to go to a [Grateful] Dead concert that day and I missed it because I kept doing these experiments.”