Hong Kong Polytechnic University has developed a novel biomimetic hydrogel material with extremely strong acid resistance, providing an innovative solution for the treatment of gastrointestinal diseases. This material, named "Ultra-Stable Mucus-like Hydrogel" (UMIH), can effectively resist the highly acidic environment of the stomach, adhere firmly to damaged sites, significantly promote tissue repair, and demonstrates the potential for targeted drug delivery, which is expected to drive innovation in gastrointestinal medical technology.

This achievement, a collaborative research and clinical effort between Hong Kong Polytechnic University and Sichuan University, has been published in the internationally renowned academic journal *Cell Reports Physical Science*. The study shows that under extreme acidic conditions simulating gastric juice (pH 2), UMIH exhibits a wet adhesion strength of 64.7 kPa, 15 times that of aluminum phosphate gel (APG), a commonly used clinical gastric mucosal protectant. While APG completely degrades within three days, UMIH retains approximately 50% of its structural integrity after seven days, demonstrating exceptional stability.

Professor Wang Zuankai, the research team leader and Vice President of Hong Kong Polytechnic University, pointed out: "This hydrogel has broad application prospects in the treatment of gastroesophageal reflux, gastric ulcers, and postoperative wound protection. It can not only be combined with endoscopic drug delivery technology to achieve minimally invasive treatment, but its strong acid resistance also makes it a revolutionary platform for gastrointestinal repair and targeted drug delivery, and opens up new paths for the development of next-generation implantable smart medical devices."

Unlike traditional hydrogels that readily decompose in acid, UMIH's design is inspired by the natural properties of human gastric mucus. The research team integrated three key molecular components to construct a multi-crosslinked polymer network structure: a special protein binds hydrogen ions in an acidic environment, reducing local acidity; tannic acid significantly enhances the material's adhesive properties; and another molecule is responsible for maintaining overall structural stability under acidic conditions. This synergistic effect allows UMIH to maintain its soft, injectable, and clinically friendly properties while possessing exceptional acid tolerance.

Experiments showed that UMIH was non-toxic to cultured gastrointestinal cells and could inhibit the growth of Escherichia coli and Staphylococcus aureus, demonstrating antibacterial potential. In esophageal injury models in pigs and mice, compared with the blank control group and the APG treatment group, UMIH could more firmly cover the wound, effectively reduce tissue damage and inflammatory response, and promote the healing process, which is crucial for angiogenesis.

Researcher Zhou Yangyang, a member of the team, said: "UMIH is the result of the synergistic effect of three molecular components. Its unique structure ensures its integrity in strong acids, while retaining the flexibility and injectability suitable for clinical applications."

Although the safety and efficacy of this material in humans still require further verification through clinical studies, its industrialization prospects are very bright. UMIH raw materials are inexpensive, its components are safe and reliable, and its production process is easy to scale up, making it suitable for direct application in operating rooms and production lines. In the future, the research team plans to combine UMIH with drug delivery systems and implantable flexible electronic devices to develop intelligent gastrointestinal devices capable of real-time treatment and monitoring.