An implantable, programmable robot induced cell growth and lengthened part of the esophagus in an animal model by more than 75%, according to researchers from Boston Children’s Hospital.
The team reported in Science Robotics today that the robot triggered tissue growth without interfering with organ function. The system could help regrow parts of the esophagus that are missing in people with long-gap esophageal atresia, the researchers noted.
“This project demonstrates proof-of-concept that miniature robots can induce organ growth inside a living being for repair or replacement, while avoiding the sedation and paralysis currently required for the most difficult cases of esophageal atresia,” co-investigator Dr. Russell Jennings, surgical director of the Esophageal and Airway Treatment Center at Boston Children’s Hospital, said in prepared remarks.
“The potential uses of such robots are yet to be fully explored, but they will certainly be applied to many organs in the near future.”
The motorized robot attaches only to the esophagus, the team reported, and is covered by a smooth, biocompatible skin. A programmable control unit outside of the body applies traction forces to two attachment rings placed around the esophagus, pulling the tissue in a opposing directions.
The implant was tested on five pigs for nine days. Each day, researchers increased the distance between the two rings by 2.5 mm. According to the researchers, the animals ate normally and showed no signs of discomfort during the testing period.
After ten days, the part of the esophagus where the device was placed increased, on average, by 77%. The organ kept its normal diameter and when researchers studied the tissue, they noticed that esophageal cells had grown.
“This shows we didn’t simply stretch the esophagus – it lengthened through cell growth,” senior investigator Pierre Dupont, chief of pediatric cardiac bioengineering at Boston Children’s, said.
The team is looking to study the robotic system in an animal model of short bowel syndrome, which is more common than long-gap esophageal atresia.
“Short bowel syndrome is a devastating illness requiring patients to be fed intravenously,” co-author Dr. Peter Ngo said. “This, in turn, can lead to liver failure, sometimes requiring a liver or multivisceral (liver-intestine) transplant, outcomes that are both devastating and costly.”
The Boston Children’s researchers said they plan to continue testing the device in large animal models, as well as in clinical trials.
“No one knows the best amount of force to apply to an organ to induce growth,” Dupont explained. “Today, in fact, we don’t even know what forces we are applying clinically. It’s all based on surgeon experience. A robotic device can figure out the best forces to apply and then apply those forces precisely.”