A new engineering review has outlined nanomaterial based drug delivery platforms designed to exploit differences in enzyme activity between the healthy gut microbiome and inflamed colonic tissue in inflammatory bowel disease (IBD). Published in the International Journal of Nanomedicine, the work describes how these engineered carriers could allow treatments to be released more precisely at sites of inflammation in Crohn’s disease and ulcerative colitis, potentially reducing exposure of the rest of the body to active drug.
Background
Current oral therapies for IBD, including some forms of mesalazine and corticosteroids, already rely on coatings that take advantage of conditions in the lower gastrointestinal tract, such as changes in pH or transit time, to control where a drug is released. The colonic microbiome adds a further layer of biological specificity. Symbiotic bacteria that normally populate the colon produce enzymes such as azoreductase and various polysaccharide-degrading enzymes as part of their everyday metabolism. These enzymes are largely absent or altered in other parts of the digestive tract and in the inflamed tissue itself, creating a potential biochemical signature that engineers can design materials to respond to.
Key findings
According to the review, nanomaterials can be engineered with chemical bonds or coatings that remain stable until they encounter specific bacterial enzymes in the colon. Azoreductase-responsive designs incorporate azo bonds that are broken down by bacterial azoreductase, triggering release of the drug payload once the particle reaches the colon. Separately, coatings made from naturally occurring polysaccharides, such as pectin, chitosan or guar gum, are broken down by polysaccharide-degrading enzymes produced by commensal bacteria, again releasing their contents at the intended site. The authors note that inflamed colonic tissue in IBD differs enzymatically and chemically from the surrounding healthy mucosa, and that some platforms are being engineered to respond to this altered inflammatory environment, including changes associated with oxidative stress, in addition to microbial enzyme activity. Combining more than one of these triggers, the review suggests, may allow more selective targeting than single-mechanism systems. The findings described are based on material science and engineering research rather than clinical trial data, and the review does not report outcomes in human patients.
Clinical relevance
For people living with IBD, the appeal of this approach lies in the possibility of delivering treatment more selectively to inflamed areas of the bowel, which could in principle reduce the systemic side effects associated with some existing medications. For clinicians and researchers, the review highlights an active area of pharmaceutical engineering that draws directly on knowledge of the gut microbiome’s enzymatic activity, an area of growing interest within IBD research more broadly. However, this remains an early-stage, preclinical engineering concept. Considerable further testing would be needed before any such nanomaterial platform could be evaluated in patients, and the review does not suggest any change to current treatment approaches.
Reference
Dove Medical Press. Engineering Nanomaterial Platform for Inflammatory Bowel Disease. International Journal of Nanomedicine. Full author details, volume, page range and digital object identifier were not available in the source material provided and have therefore been omitted rather than invented.
This article is a journalistic summary for informational purposes only. It does not constitute clinical advice or a recommendation to alter treatment decisions.