Sprayable Gel to Make Minimally Invasive Surgeries Simpler and Safer

Routine screenings for colon cancer frequently identify small precancerous polyps that can be excised before turning cancerous, typically via endoscopy. During polyp removal, if bleeding ensues, cauterization is a common method to stem the bleeding, though it leaves scars and may slow healing, leading to further complications. Complicating matters, some patients experience delayed bleeding days after the procedure, leading to hospital readmission for treatment. Additionally, the development of minor tears may cause intestinal content leakage into the abdomen, risking severe infection and necessitating emergency intervention. For tissue reinforcement, doctors sometimes employ metal clips, which are unsuitable for larger polyps and may fail. Previous attempts to create a sealing gel have been unsuccessful, mainly due to the inability of materials to adhere to the surgical site beyond a period of 24 hours.

Now, researchers at MIT (Cambridge, MA, USA) have developed a new gel named GastroShield that can be sprayed onto surgical sites using an endoscope. This gel forms a durable, yet flexible layer, acting as a protective barrier over the affected area, preventing delayed bleeding and reinforcing the mechanical integrity of the tissue. The team experimented with several material combinations in search of a formulation that could be easily delivered through an endoscope's catheter nozzle and rapidly transform into a sturdy gel upon contacting tissue. The selected formulation comprised a polymer known as pluronic, a block copolymer forming micelles with amine groups on their surface, and oxidized dextran, a polysaccharide forming strong, reversible bonds with pluronic's amine groups. This interaction instantaneously creates a solid gel upon application, capable of self-repair against forces generated by digestive movements and food passage.

The novel gel can withstand the digestive tract's acidity and enzymatic activity to protect the healing tissues from these aggressive conditions, thus holding the potential for other gastrointestinal wounds prone to bleeding like stomach ulcers. Animal testing demonstrated all subjects treated with GastroShield exhibited quick sealing without subsequent perforations, leakages, or bleeding over the following week. GastroShield integrates seamlessly with existing endoscopic techniques and provides up to a week of wound protection to facilitate post-surgery healing. The team conducted several biocompatibility assessments that confirmed the gel's safety without any adverse outcomes. Ongoing research aims to adapt the material for human application, with potential for use beyond colonoscopies to include stomach ulcer treatments, Crohn’s disease management, and potentially for delivering chemotherapy for cancer.

“A key feature of this new technology is our aim to make it translational. GastroShield was designed to be stored in liquid form in a ready-to-use kit. Additionally, it doesn’t require any activation, light, or trigger solution to form the gel, aiming to make endoscopic use easy and fast,” said Gonzalo Muñoz Taboada, CEO of BioDevek, who is currently leading the translational effort for GastroShield.

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