A fateful encounter with a premature baby spurred David Hackam’s drive to create an artificial intestine.
Hackam, who in September became pediatric surgeon-in-chief for the Johns Hopkins Children’s Center, was then an attending surgeon at the Children’s Hospital of Pittsburgh who was covering the surgical care at a community hospital. This infant he cared for suddenly took a turn for the worse, becoming critically ill with an intestinal disorder called necrotizing enterocolitis (NEC). Marked by the rapid and irreversible death of intestinal tissue, NEC occurs in 12 percent of premature babies. It is among the hardest-to-treat conditions; the only therapy is surgical excision of the dying portions of intestine.
Hackam became close with the baby’s parents. The infant did reasonably well for a while but eventually died waiting for a liver transplant. The experience was sobering.
Surgery for NEC, while lifesaving, leads to short bowel syndrome in children who survive the disease. Children are then unable to absorb food and require feeding support for life, placing them at risk for liver toxicity and recurrent infections. Many require transplantation, he says, but donor tissue is hard to come by, and post-transplant immune suppression therapy poses long-term challenges and risks.
With 5,000 children suffering from short bowel syndrome nationwide, “the artificial intestine is the next major stop in modern medicine that needs to be achieved,” he says.
Hackam and John March, a biomedical engineer at Cornell, have made inroads in creating an artificial gut grown by taking gut stem cells and growing them on three-dimensional scaffolds made from biodegradable synthetic materials. The work has “generated a structure that bears remarkable similarity to the normal intestine,” Hackam says, including delicate, fingerlike projections of the human intestine called microvilli that absorb nutrients. They have implanted the model successfully in baby mice and dogs, and are now evaluating how well it will absorb nutrients.
Hackam brought a team of six scientists from his previous post at the University of Pittsburgh. Collaborating with Johns Hopkins experts in microbiology, biomedical engineering, tissue engineering and stem cell biology, he says, he hopes to accelerate the pace of research to have a prototype available for human testing within five years.