Researchers at Johns Hopkins have created an injectable hydrogel stem cell carrier designed to help treat a difficult complication of Crohn’s disease, perianal fistulas. Perianal fistulas are very difficult to treat, but stem cells have shown promise in aiding this process. However, it is difficult for the cells to stay in place. This hydrogel delivery vehicle acts as a stable cell depot when injected near the fistula, keeping the cells alive and in place so they can positively influence the healing process. The technology showed promise in a rat model of perianal fistulas associated with Crohn’s.
Approximately 30-40% of patients with Crohn’s disease will develop perianal fistulas. They consist of an inflamed tunnel between the surface of the body and the inside of the anus, which can sometimes form as a result of a perianal abscess. The structures are painful and uncomfortable, may swell, and may ooze blood or pus. This is one part of the body where no one needs an extra hole.
Surgery is often required, but more than half of patients see little benefit from current treatment approaches. “A large number of patients are diagnosed with Crohn’s disease in their late teens to early 20s, and they consider a lifetime of suffering from perianal fistulas,” said Florin Sellaru, a researcher involved in the study. “This condition in Crohn’s patients is extremely difficult to treat. We hope that these results offer a potential new treatment paradigm that can be translated and improve the quality of life of these patients.
Stem cell injections have been shown to provide some therapeutic efficacy in clinical trials when injected into or around the fistula tract. However, as with many cell therapies, keeping the cells alive and available in the target tissue is a challenge. Simply injecting a cell suspension directly into tissue is a very poor way to deal with this, and so researchers are developing a bewildering array of biomaterial carriers that can protect and retain cells.
The researchers used their gel to deliver adipose-derived stem cells into a rat model of perianal fistulas associated with Crohn’s. The gel itself contains nanofiber fragments that are designed to create sufficient mechanical strength so that the cells are held in place regardless of the mechanical deformation of the gel bolus in the tissue.
Gel treatment reduced the size of the fistula tract six times compared to surgical treatment, suggesting that the technology has significant potential as a treatment for perianal fistulas. “Think of it as local delivery of tissue regeneration on a nanogel-nanofibrous composite that also preserves stem cells at the site of injury and allows healing to occur,” Sellaru said.
Study in Scientific progress: A nanofiber-hydrogel composite improves tissue repair in a rat model of perianal fistulas of Crohn’s disease
Through: Johns Hopkins Medicine
