Accommodating growth Arabchat adult
The proprietary design of the braided sleeve developed by del Nido and Karp's team doesn't just share resemblance to a Chinese finger trap but also to an organic structure engineered by nature itself.
"We solved this problem of growth accommodation with a concept that already exists in nature: the octopus has a special ability to stretch its arms into confined cracks and spaces between rocks, in search of its prey," says Yuhan Lee, Ph D, co-first author on the study and a materials researcher at BWH.
“It can do this because of unique, braid-like crossfibers of connective tissue that enable the simultaneous elongation and shrinking diameter of its arms, allowing it to extend its reach two to three times beyond the original arm length.” Based on the team’s promising experiments in animal models, the biomedical device company Cryo Life Inc., is currently doing pre-clinical research to develop the concept into a growth-accommodating annuloplasty ring implant for pediatric heart valve repair in humans.
“Medical implants and devices are rarely designed with children in mind, and as a result, they almost never accommodate growth,” says Pedro del Nido, MD, co-senior author on the study, who is chief of cardiac surgery at Boston Children’s and the William E."The implant design consists of two components: a degrading, biopolymer core and a braided, tubular sleeve that elongates over time in response to the tensile forces exerted by the surrounding growing tissue," says Eric Feins, MD, co-first author on the paper, who was formerly a research fellow in del Nido's lab and is currently a fellow in cardiothoracic surgery at Massachusetts General Hospital."As the inner biopolymer degrades, the tubular sleeve becomes thinner and elongates in response to native tissue growth." To create the degrading core, Karp's team recommended the use of an extra-stiff, biocompatible polymer that begins to erode on its surface following implantation."Medical implants and devices are rarely designed with children in mind, and as a result, they almost never accommodate growth," says Pedro del Nido, MD, co-senior author on the study, who is chief of cardiac surgery at Boston Children's and the William E.Ladd Professor of Child Surgery at Harvard Medical School (HMS).