UV-activated biodegradable patch for minimally invasive repair of perforations in visceral organ
Certain Congenital Heart Defects (CHD) called Atrial Septal Defect (ASD) and Ventricular Septal Defect (VSD) occur when openings in the septum that divides the upper and lower heart chambers causes oxygen-rich blood from the upper chamber to mix with oxygen–poor blood from lower chamber. According to the Centers for Disease Control and Prevention, ASD alone occurs in 1 out of 770 babies born each year in the United States.
For a long time, such defective hearts have been repaired in patients by invasive open-heart surgery. More recently, a less invasive method involving catheterization and occlusion via a metallic mesh device has been frequently performed as an alternative to surgery. However, because many of these mesh-devices are permanently implanted in the body, they can cause blood clots and block in nerves. Therefore, a more universal approach to patch perforations in defective hearts and other visceral organs is urgently needed.
Scientists at Harvard’s Wyss Institute for Biologically Inspired Engineering, the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and MIT in collaboration with clinicians at Harvard-affiliated hospitals have engineered a special catheter that can patch holes in the septum of the heart with the help of a UV-activated adhesive. The catheter device is inserted via a vein and delivered to an opening in the septum without the need for surgical or laparoscopic intervention. It contains two balloons, a UV-light-responsive adhesive patch and a UV fiber optic light source housed in a shaft. A more distal balloon is crossed through the whole to the other side of the septum, and a more proximal balloon remains on the other side. Inflating both balloons firmly presses the unfolding patch to the edges of the whole. UV-light then travels through the optic fiber and is reflected by the balloon’s inner surface onto the patch to activate its adhesive surface, and simultaneously shielded from the rest of the body. This way a tight seal is immediately formed around an opening in the septum, while over time, the patch itself dissolves to be replaced by normal tissue growing over it.
The team has validated the catheter’s performance in a series of in vivo and ex vivo experiments. Tests in rodent and pig hearts demonstrated that adhesive patches could be successfully applied with the catheter to beating hearts where they maintained great stability without triggering major inflammatory or scarring responses.
This new catheter platform can be extended to perforations in other organs because of its ease of delivery and adjustable adhesive strength. Because the procedure is minimally invasive and does not require sutures or staples, it allows for faster healing and recovery.
The Harvard Office for Technology Development (OTD) has currently issued a medical license of the UV-light enabled soft patch for heart defects to the startup HoliStick Medical. The Intellectual Property rights (IP) for this technology are shared among the Wyss Institute, SEAS, MIT, Brigham and Women’s Hospital, and Boston Children’s Hospital.