"Duck Tape" a huge breakthrough in surgical field: alternative to sutures

Duct tape is a go-to item on any engineer's workbench for repairing fractures and tears in a variety of structural materials. MIT engineers have created a type of surgical duct tape: a strong, flexible, and biocompatible sticky patch that can be put to biological tissues and organs quickly and easily to help seal tears and wounds.

The new patch is sticky on one side and smooth on the other, similar to duct tape. The adhesive is currently formulated to seal flaws in the gastrointestinal tract, which the engineers refer to as the body's own organic ductwork.

The patch has been demonstrated to stick to major tears and punctures in the colon, stomach, and intestines of many animal models in several trials. Within seconds, the glue forms a strong bond with tissues and lasts for up to a month. It's also adaptable, allowing it to expand and contract with a healthy organ as it heals. The patch progressively fades after an injury has healed completely, without producing inflammation or adhering to surrounding tissues.

The surgical adhesive patch, according to the researchers, could one day be kept in operating rooms and used to mend leaks and tears in the gut and other biological tissues as a rapid and safe alternative or reinforcement to hand-sewn sutures.

"We think this surgical tape is a good basis technology to be converted into a genuine, off-the-shelf product," says Hyunwoo Yuk, an MIT mechanical engineering research scientist. "Surgeons may use it in the same way that nonsurgical people use duct tape. It does not necessitate any prior preparation or steps. Simply pull it out, open it, and start using it."

Yuk and his colleagues published their findings in the journal Science Translational Medicine as co-lead and co-corresponding authors. Jingjing Wu, an MIT postdoctoral researcher and lead author; Xuanhe Zhao, an MIT professor of mechanical engineering and civil and environmental engineering; and partners from the Mayo Clinic and Southern University of Science and Technology are among the other co-authors.

The new surgical duct tape is based on the team's double-sided tape design from 2019. The first version consisted of a single layer that was sticky on both sides and was intended to connect two wet surfaces.

Polyacrylic acid, an absorbent substance commonly found in diapers, starts out dry and absorbs moisture when it comes into touch with a wet surface or tissue, momentarily attaching to the tissue in the process. NHS esters, chemical molecules that can connect with proteins in the tissue to generate stronger links, were added into the substance by the researchers. Finally, they used natural materials like gelatin or chitosan to enhance the glue and keep the tape's shape.

The double-sided tape was discovered to have a strong bond with different tissues, according to the researchers. However, after speaking with surgeons, they determined that a single-sided version would be more feasible.

"It's not usual in practise to have to put two tissues together — organs need to be distinct from one another," Wu explains. "One idea was to utilise this sticky substance to patch up leaks and flaws in the intestine."

Surgical sutures are commonly used to repair leaks and tears in the gastrointestinal tract. However, sewing the stitches needs skill and training, and sutures can cause scarring around the area after surgery. The tissue between the stitches may rupture, resulting in subsequent leaks and the risk of infection.

"We thought our adhesive ingredient could be turned into a product to repair intestinal leaks, similar to how duct tape seals pipes," Wu explains. "As a result, we decided to go with something more akin to single-sided tape."

The researchers initially tweaked their adhesive recipe, replacing gelatin and chitosan with a longer-lasting hydrogel (polyvinyl alcohol in this case). This change maintained the glue physically stable for almost a month, enough time to repair a typical gut damage. To protect the patch from clinging to the surrounding tissue, they placed a second, nonsticky top layer. This layer is constructed of a biodegradable polyurethane with a flexibility and rigidity similar to that of normal gut tissue.

"We don't want the patch to be weaker than the tissue because it can explode," Yuk explains. "We also don't want it to be stiffer because it would limit the crucial peristaltic movement in the guts."

The patch adhered to tissues in early experiments, but it also expanded, much like a fully wet, hydrogel-based diaper would. The tape and the underlying tear it was supposed to cover swelled as a result of the swelling.

"Because hydrogel naturally swells," Yuk explains, "it was practically an insurmountable challenge." "However, we used a simple trick: we prestretched the adhesive layer a little before introducing the nonadhesive layer, which balances out the swelling when applied to a tissue."

After that, the team ran tests on the patch's attributes and performance. The cells continued to thrive after the patch was placed in a culture with human epithelial cells, indicating that the patch is biocompatible. The patch biodegraded after about 12 weeks when implanted under the skin of rats, with no harmful effects.

The patch was also put to flaws in the animals' colons and stomachs, and the researchers discovered that it maintained a strong link while the injuries healed. In comparison to traditional suture repairs, it also caused less scarring and irritation.

Finally, the researchers applied the patch on pigs with colon abnormalities and found that the animals continued to eat normally with no fever, lethargy, or other negative health effects. The defects were completely repaired after four weeks, with no signs of subsequent leakage.

The findings show that the surgical patch might be used to successfully heal gastrointestinal injuries, and that it could be applied as readily as commercial duct tape. Yuk and Zhao are working on a new firm to further develop the adhesive, with the goal of getting FDA approval to test the patch in medical settings.

"We're looking at adhesion, a fundamental mechanical problem, in a very difficult environment: within the body. Every year, millions of procedures are performed throughout the world to correct gastrointestinal abnormalities, with a leakage rate of up to 20% in high-risk patients "Zhao explains. "This tape has the ability to address that problem and save millions of lives."

Reference:

Jingjing Wu, Hyunwoo Yuk, Tiffany L. Sarrafian, Chuan Fei Guo, Leigh G. Griffiths, Christoph S. Nabzdyk, Xuanhe Zhao. An off-the-shelf bioadhesive patch for sutureless repair of gastrointestinal defects. Science Translational Medicine, 2022; 14 (630) DOI: 10.1126/scitranslmed.abh2857