A Multicellular Approach Forms a Significant Amount of Tissue-Engineered Small Intestine in the Mouse

Abstract

Tissue-engineered small intestine (TESI) has successfully been used to rescue Lewis rats after massive small bowel resection. In this study, we transitioned the technique to a mouse model, allowing investigation of the processes involved during TESI formation through the transgenic tools available in this species. This is a necessary step toward applying the technique to human therapy. Multicellular organoid units were derived from small intestines of transgenic mice and transplanted within the abdomen on biodegradable polymers. Immunofluorescence staining was used to characterize the cellular processes during TESI formation. We demonstrate the preservation of Lgr5-and DcamKl1-positive cells, two putative intestinal stem cell populations, in proximity to their niche mesenchymal cells, the intestinal subepithelial myofibroblasts (ISEMFs), at the time of implantation. Maintenance of the relationship between ISEMF and crypt epithelium is observed during the growth of TESI. The engineered small intestine has an epithelium containing a differentiated epithelium next to an innervated muscularis. Lineage tracing demonstrates that all the essential components, including epithelium, muscularis, nerves, and some of the blood vessels, are of donor origin. This multicellular approach provides the necessary cell population to regenerate large amounts of intestinal tissue that could be used to treat short bowel syndrome.

Tissue Engineering of the Intestine in a Murine Model

“…To address these issues, experiments to characterize the function of our tissue-engineered intestinal constructs in an in vitro fashion are ongoing. Additional limitations to this technique include an 89% success rate in the generation of TESI 4 . That is, 89% of OU loaded scaffolds will successfully generate TESI.…”

“…Form 2-mm long, 5-mm outer diameter cylindrical scaffolds from nonwoven polyglycolic acid (2-mm sheet thickness, 60 mg cm-3 bulk density; porosity > 95%, Concordia Fibers, Coventry RI) as described in Ref. 4. 2.…”

“…Organoid units are multicellular aggregates derived from the intestine that contain both mucosal and mesenchymal elements, 3 the relationship between which preserves the intestinal stem cell niche. 4 In ongoing and future research, the transition of our technique into the mouse will allow for investigation of the processes involved during TESI formation by utilizing the transgenic tools available in this species. …”

Tissue Engineering Functional Gastrointestinal Regions: The Importance of Stem and Progenitor Cells

“…Later, the TESI model was transitioned to a mouse host providing the advantage of investigating the mechanism via various transgenic strains (Chen et al 2006;Sala et al 2011). Murine TESI formed structurally similar to native small intestine and contained the same differentiated Paneth, goblet, enteroendocrine, and enterocyte cells.…”

Bioengineering of Colo-Rectal Tissue

“…Given the inert nature of their surfaces, it remains doubtful whether they were suitable for acting as "real" tissue engineering scaffolds that would facilitate engraftment and promote growth of host tissue cells. PGA scaffolds are successfully being used for small intestinal tissue engineering (Mooney et al, 1994;Sala et al, 2009;Sala et al, 2011). These principles were applied to bioengineering of the colon.…”