Clinical challenges of short bowel syndrome and the path forward for organoid-based regenerative medicine

Short bowel syndrome (SBS) is a rare condition, the main symptom of which is malabsorption following extensive resection of the small intestine. Treatment for SBS is mainly supportive, consisting of supplementation, prevention and treatment of complications, and promotion of intestinal adaptation. While development of parenteral nutrition and drugs promoting intestinal adaptation has improved clinical outcomes, the prognosis of patients with SBS remains poor. Intestinal transplantation is the only curative therapy but its outcome is unsatisfactory. In the absence of definitive therapy, novel treatment is urgently needed. With the advent of intestinal organoids, research on the intestine has developed remarkably in recent years. Concepts such as the "tissue-engineered small intestine" and "small intestinalized colon," which create a functional small intestine by combining organoids with other technologies, are potentially novel regenerative therapeutic approaches for SBS. Although they are still under development and there are substantial issues to be resolved, the problems that have prevented establishment of the complex function and structure of the small intestine are gradually being overcome. This review discusses the current treatments for SBS, the fundamentals of the intestine and organoids, the current status of these new technologies, and future perspectives.

Silk sericin-enhanced microstructured bacterial cellulose as tissue engineering scaffold towards prospective gut repair

As a first step towards the production of functional cell sheets applicable for the regeneration of gut muscle layer, microstructured bacterial cellulose (mBC) was assessed for its ability to support the growth of enteric nervous system (ENS) and gut smooth muscle cells (SMCs). To improve the cellular response, mBC was modified with silk sericin (SS) which has renowned abilities in supporting tissue regeneration. While SS did not impair the line structures imparted to BC by PDMS templates, similarly to the patterns, it affected its physical properties, ultimately leading to variations in the behavior of cells cultured onto these substrates. Enabled by the stripes on mBC, both SMCs and ENS cells were aligned in vitro, presenting the in vivo-like morphology essential for peristalsis and gut function. Interestingly, cell growth and differentiation remarkably enhanced upon SS addition to the samples, indicating the promise of the mBC-SS constructs as biomaterial not only for gut engineering, but also for tissues where cellular alignment is required for function, namely the heart, blood vessels, and similars.