Researchers at Pohang University of Science & Technology in Korea have developed a bioglue, containing a mussel adhesive protein and hyaluronic acid, that can seal fistulas within the body. It works even on fistulas present in particularly challenging areas, such as the wall of the bladder. The researchers delivered the glue using a thin syringe, and showed that it could plug fistulas in the bladder walls of pigs.
Fistulas are abnormal openings between spaces in the body, such as between the bladder and surrounding organs and structures, including the intestine and vagina. Fistulas in the bladder can have a variety of complications, including urine leakage and fecal incontinence. The condition can be difficult to treat, and current solutions include suturing the opening, which can be hampered by the inaccessibility of the fistula. Moreover, the repeated expansion and contraction of the bladder wall can damage the sutured fistula and prevent healing. These issues have inspired these Korean researchers to develop a minimally invasive alternative in the form of a bioglue that can be delivered using a thin needle.
“Vesico-vaginal fistula is a disorder difficult to treat and it significantly impacts the patient’s quality of life,” said Professor Seokho Kang, a researcher involved in the study, in a press release. “We expect the newly developed treatment method to be applicable to minimally-invasive surgical methods such as robotic surgery and endoscopic surgery as well as open surgeries in the future based on its excellent water-immiscibility and underwater adhesion.”
The glue contains the mussel adhesive protein used by mussels to anchor themselves in place and catechol-conjugated hyaluronic acid. The glue demonstrates thixotropic properties, meaning that it is viscous at rest, but its viscosity decreases when shear force is applied, meaning that it can be syringed. It is also immiscible in water, and so can be applied even in very wet environments, such as the bladder.
So far, the researchers have tested the technology in pigs with fistulas, and found that the material successfully plugged the holes over a sustained period, and adapted well to the expansion and contraction of the bladder wall. The glue biodegrades over time, allowing the fistula to heal itself.
“We have confirmed the mussel adhesive protein – a technology that originated in Korea – as an effective vesico-vaginal fistula treatment method by applying it to an actual vesico-vaginal fistula of a large animal model,” added Professor Hyung Joon Cha, another researcher involved in the study. “It is anticipated to be successfully applicable to fistulas and perforations in other similar environments.”
Study in Acta Biomaterialia: Preclinical evaluation of a regenerative immiscible bioglue for vesico-vaginal fistula