Linking human intestinal scaffolds and organoids to combat intestinal failure

A Novel Organoid-Based Strategy Using Hybrid Colon Interposition for Short Bowel Syndrome: A Mini Review of In Vivo Models and Possible Human Candidates

This comprehensive review focuses on advances in surgical techniques and in vivo animal models for treating short bowel syndrome (SBS) with intestinal organoids. Notably, this review discusses a novel method involving the replacement of the epithelium of large intestinal tissue with small intestinal organoids, which improves function and prognosis when grafted back into the small intestine. This study not only underscores the importance of integrating organoid technology and surgical techniques to improve the outcomes of patients with SBS but also acknowledges the challenges that lie ahead, including achieving functional organoids with peristaltic movement and vascularization.

In Vivo Intestinal Research Using Organoid Transplantation

Our understanding of the biology of the intestinal epithelium has advanced since the establishment of an organoid culture system. Although organoids have enabled investigation of the mechanism of self-renewal of human intestinal stem cells in vitro, it remains difficult to clarify the behavior of human normal and diseased intestinal epithelium in vivo. Recently, we developed a xenotransplantation system in which human intestinal organoids are engrafted onto epithelium-depleted mouse colons. This xenograft recapitulated the original tissue structures. Upon xenotransplantation, normal colon organoids developed normal colon crypt structures without tumorigenesis, whereas tumor-derived organoids formed colonic tumors resembling the original tumors. The non-tumorigenicity of human intestinal organoids highlights the safety of organoid-based regenerative medicine. As an example of regenerative medicine for short bowel syndrome, we devised a unique organ-repurposing approach to convert colons into small intestines by organoid transplantation. In this approach, the transplanted rat small intestinal organoids not only engrafted onto the rat colons but also remodeled the colon subepithelial structures into a small intestine-like conformation. Luminal flow accelerated the maturation of villi in the small intestine, which promoted the formation of a lymphovascular network mimicking lacteals. In this review, we provide an overview of recent advances in gastrointestinal organoid transplantation and share our understanding of human disease biology and regenerative medicine derived from these studies.

Application Progress of Organoids in Colorectal Cancer

Currently, colorectal cancer is still the third leading cause of cancer-related mortality, and the incidence is rising. It is a long time since the researchers used cancer cell lines and animals as the study subject. However, these models possess various limitations to reflect the cancer progression in the human body. Organoids have more clinical significance than cell lines, and they also bridge the gap between animal models and humans. Patient-derived organoids are three-dimensional cultures that simulate the tumor characteristics in vivo and recapitulate tumor cell heterogeneity. Therefore, the emergence of colorectal cancer organoids provides an unprecedented opportunity for colorectal cancer research. It retains the molecular and cellular composition of the original tumor and has a high degree of homology and complexity with patient tissues. Patient-derived colorectal cancer organoids, as personalized tumor organoids, can more accurately simulate colorectal cancer patients’ occurrence, development, metastasis, and predict drug response in colorectal cancer patients. Colorectal cancer organoids show great potential for application, especially preclinical drug screening and prediction of patient response to selected treatment options. Here, we reviewed the application of colorectal cancer organoids in disease model construction, basic biological research, organoid biobank construction, drug screening and personalized medicine, drug development, drug toxicity and safety, and regenerative medicine. In addition, we also displayed the current limitations and challenges of organoids and discussed the future development direction of organoids in combination with other technologies. Finally, we summarized and analyzed the current clinical trial research of organoids, especially the clinical trials of colorectal cancer organoids. We hoped to lay a solid foundation for organoids used in colorectal cancer research.

An organoid-based organ-repurposing approach to treat short bowel syndrome

The small intestine is the main organ for nutrient absorption, and its extensive resection leads to malabsorption and wasting conditions referred to as short bowel syndrome (SBS). Organoid technology enables an efficient expansion of intestinal epithelium tissue in vitro¹, but reconstruction of the whole small intestine, including the complex lymphovascular system, has remained challenging². Here we generate a functional small intestinalized colon (SIC) by replacing the native colonic epithelium with ileum-derived organoids. We first find that xenotransplanted human ileum organoids maintain their regional identity and form nascent villus structures in the mouse colon. In vitro culture of an organoid monolayer further reveals an essential role for luminal mechanistic flow in the formation of villi. We then develop a rat SIC model by repositioning the SIC at the ileocaecal junction, where the epithelium is exposed to a constant luminal stream of intestinal juice. This anatomical relocation provides the SIC with organ structures of the small intestine, including intact vasculature and innervation, villous structures, and the lacteal (a fat-absorbing lymphatic structure specific to the small intestine). The SIC has absorptive functions and markedly ameliorates intestinal failure in a rat model of SBS, whereas transplantation of colon organoids instead of ileum organoids invariably leads to mortality. These data provide a proof of principle for the use of intestinal organoids for regenerative purposes, and offer a feasible strategy for SBS treatment.