Ideas and methods of in vitro model establishment for cell microenvironment in COPD / 中国药理学通报

Chronic obstructive pulmonary disease ( COPD ) major chronic disease threatening public health with complex pathological mechanisms. The change of the cell microenvironment of the lung is an important part of the pathophysiology of COPD. Cell culture technology is an important method to investigate the pathological mechanism of COPD and evaluate the pharmacological effect of medicine. Here we introduce the composition of the cell microenvironment of the lung, the change of the cell microenvironment in the pathological process of COPD, and summarize the application of in vitro model mimics cell microenvironment of COPD in the study of mechanism. In addition, we aim to put forward the ideas of the in vitro model establishment of cell microenvironment of COPD.

Maturation and development of fetal pig intestinal tissue in immunodeficient mice

Purpose: This study aimed to compare the degree of maturation and development of fetal pig segmental intestinal tissue with that of spheroids created by in-vitro reaggregation of dissociated fetal intestinal cells after transplantation into immunodeficient mice. Methods: Fetal pig small intestines were transplanted as segmental grafts into the omentum and subrenal capsules of immunodeficient mice or enzymatically treated to generate single cells. Spheroids made by in-vitro reaggregation of these cells were transplanted into the subrenal capsules of immunodeficient mice. The segmental grafts and spheroids were harvested four and eight weeks after transplantation, and the structural maturity and in-vivo development of these specimens were histologically evaluated. Results: The spheroids were engrafted and supplied blood vessels from the host mice, but an intestinal layered structure was not clearly observed, and there was almost no change in size. On the other hand, the segmental grafts formed deep crypts in the mucus membrane, the inner circular layer, and outer longitudinal muscles. The crypts of the transplanted grafts harvested at eight weeks were much deeper, and the smooth muscle layer and the enteric nervous system were more mature than those of grafts harvested at the fourth week, although the intestinal peristaltic wave was not observed. Conclusions: Spheroids created from fetal small intestinal cells could not form layered structures or mature sufficiently. Conversely, segmental tissues structurally matured and developed after in-vivo transplantation and are therefore potential grafts for transplantation.

Organoides de origen humano como modelo fisiopatológico de evaluación terapéutica de fármacos en COVID-19 / Organoids as a physiopathology model and therapeutic drug evaluation tool in COVID-19

Introducción: La pandemia causada por SARS-CoV-2 ha impactado al mundo gravemente en diversos ámbitos y con ello ha surgido la necesidad de contar con herramientas con mayor relevancia fisiológica para investigar patologías complejas como el COVID-19. Los organoides son un modelo experimental con características únicas como la capacidad de autoformar una estructura tridimensional utilizando células en cultivo. Sobre esta base, surge la siguiente pregunta ¿son los organoides un modelo experimental factible para reflejar la fisiopatología del COVID-19 y evaluar la eficacia de fármacos que limiten su progresión? Metodología: Para abordar esta interrogante, esta revisión plantea el analizar la validez de los organoides como modelo experimental y verificar su utilidad en la evaluación de fármacos para el COVID-19. Para cumplir estos objetivos se realizó una revisión sistemática cualitativa de la literatura, a través de una búsqueda en PubMed con el término 'COVID-19 and stem cells and organoids' y también en un número especial de la revista Cell. Resultados: Se organizaron los resultados relevantes por sistema fisiológico y en la evaluación de fármacos. Los organoides más empleados para estudios de COVID-19 correspondieron a tejido respiratorio, nervioso y digestivo. Algunos resultados encontrados en la revisión fueron similares a aquellos obtenidos a partir de tejidos de pacientes COVID-19 o autopsias, encontrándose hallazgos relevantes como la posible disrupción de la barrera epitelial del sistema nervioso por infección del plexo coroideo. También se logró observar efectividad de fármacos que posteriormente pasaron a ser aprobados y utilizados exitosamente en pacientes. Conclusión: Los organoides se pueden componer a partir de diferentes tipos celulares y bajo diferentes protocolos experimentales, siendo relevante la lectura crítica de los artículos científicos para decidir si sus resultados son extrapolables a la fisiopatología de la enfermedad.

Introduction: The pandemic caused by SARS-CoV-2 has impacted the world severely in several aspects and has created the need for research tools to study the COVID-19 disease. Organoids are experimental models with unique characteristics, like the ability to self-assemble in a tridimensional structure. Based on this, the following question arises: are organoids an experimental model suitable to reflect the physiopathology of COVID-19 and to allow the evaluation of the efficacy of drugs that limit its progression? Methods: To approach this question, this review aimed to analyze the validity of organoids as an experimental model and verify their utility in COVID-19 drug evaluation. To resolve these objectives, a qualitative systematic review was done through a PubMed search with the terms 'COVID-19 and stem cells and organoids' and on a special issue of the Cell Journal. Results: The results were organized by physiologic system and therapeutic drug evaluation. The most utilized tissues for the COVID-19 study were respiratory, nervous, and digestive. Some results found in the review were like those obtained from COVID-19 patient tissue or autopsies, finding some relevant discoveries like the possibility of the choroid plexus disruption in the nervous system caused by the infection. Efficacy was also observed in approved drugs and used later in patients successfully. Conclusion: Organoids might be composed starting with different cell types and under a variety of experimental protocols, being relevant the critical reading of the scientific literature to decide whether their results can be extrapolated to the pathophysiology of the disease

Research progress on vascularization of organoids / 生物医学工程学杂志

Organoids are three-dimensional structures formed by self-organizing growth of cells in vitro, which own many structures and functions similar with those of corresponding in vivo organs. Although the organoid culture technologies are rapidly developed and the original cells are abundant, the organoid cultured by current technologies are rather different with the real organs, which limits their application. The major challenges of organoid cultures are the immature tissue structure and restricted growth, both of which are caused by poor functional vasculature. Therefore, how to develop the vascularization of organoids has become an urgent problem. We presently reviewed the progresses on the original cells of organoids and the current methods to develop organoids vascularization, which provide clues to solve the above-mentioned problems.

Establishment and preliminary application of organoids in ovarian cancer / 中华妇产科杂志

Objective:To explore the establishment and application of ovarian cancer organoids.Methods:Fresh ovarian tumor tissues, obtaining from patients underwent surgery in the First Affiliated Hospital of Nanjing Medical University between October 2021 and March 2022, were collected, enzymatic degraded, digested, and embedded into matrigel to establish organoids. A total of 32 ovarian cancer samples were collected. Hematoxylin eosin (HE) staining and immunofluorescence (IF) procedure were used to verify the morphological structure of organoids and their expression of molecular markers. 3D cyto-live or dead assay was used to detecte the live or dead cells in organoids. Carboplatin with a concentration ranging from 5 to 80 μmol/L (5, 10, 20, 40, 80 μmol/L) was added to organoids to calculate the 50% inhibitory concentration (IC 50) in different organoids. Results:(1) Organoids from a total of 32 patients were established, of which 18 cases could be passaged stably in the long term in vitro, while 14 could be passaged in the short time. The average amplification time of long-term passage in vitro was over 3 months, and the longest reached 9 months. (2) In HE staining, significant nuclei atypia and local micropapillary structures were observed in organoids. IF staining revealed that ovarian cancer organoids expressed molecular markers similar to primary tumor tissues, such as Pan cytokeratin (Pan-CK), p53, paired box gene 8 (PAX8), and Wilms tumor gene 1 (WT1). (3) In 3D cyto-live or dead assay, a large number of apoptotic cells were observed inside and around the organoids after added carboplatin. The sensitivity to carboplatin varied in 18 organoids could amplify in the long term, with an average IC 50 of (29.5±15.8) μmol/L. Moreover, IC 50 values of 4 organoids derived from patients received neoadjuvant chemotherapy were much higher than the 14 organoids which did not received neoadjuvant chemotherapy [(48.7±11.3) μmol/L vs (24.0±12.1) μmol/L; t=3.429, P=0.022]. Conclusions:Organoids recapitulate ovarian cancers in vitro and could be stably passaged. Organoids derived from patients received neoadjuvant chemotherapy have higher resistance to carboplatin.

Establishment of mouse pancreatic ductal organoids and exploration of its physiological functions / 中华胰腺病杂志

Objective:To establish culture system for mouse pancreatic ductal organoids and investigate the morphology and physiological functions of the organoids.Methods:Pancreatic tissues were taken from C57BL/6 mice (6-8 weeks) and digested by collagenase Ⅳ. The pancreatic ducts were separated and collected and then the pancreatic organoids were cultured in the complete medium after Matrix gel embedding. Morphological evaluation of the organoids was performed after hematoxylin-eosin staining. The expression and localization of markers for organoids were identified by Western Blot and immunofluorescence staining; and the expression and localization of ion channels and antimicrobial peptides of the organoids were detected by agarose gel electrophoresis and immunofluorescence staining.Results:Mouse pancreatic organoids were successfully established, which could be stably passaged for 10 generations. The organoids grew spherically and formed a duct-like structure. The internal cavity corresponded to the lumen of pancreatic duct tissue. The pancreatic organoids stably expressed stem progenitor cell marker gene SOX9 and ductal epithelial cell-specific gene KRT19, which were both localized in the epithelium. The organoids did not express amylase. The organoids maintained stable expression of epithelial ion channels Clcn1, Kcnma1, CFTR, Slc12a5, Slc26a3, Slc26a6 and Scnn1a, low expression of Ano1 and no expression of Clcn3, Kcna1, Kcna2, Kcnd3, Kcnh1, Atp12a, Slc4a4, Slc9a1, Slc12a2 and Slc26a11; and CFTR highly expressed in epithelial cells. The organoids maintained high expression of antimicrobial peptides Reg3a, CRAMP and glycoprotein 2, low expression of Defb1, Defb2, and Defb3 and no expression of Defa1 and Defa4; and both CRAMP and Reg3a were expressed in the epithelial cells and secreted into the lumen of the organoids.Conclusions:Mouse pancreatic organoids are successfully established, which can be stably passaged. The organoids maintain the characteristics of ductal epithelial cells and can be used as an in vitro model to study the physiology of pancreatic ducts.

Research Progress and Ethical Issues of Brain Organoids / 中国医学伦理学

Organoids are three-dimensional (3D) biological structures constructed in vitro by stem cells, which partially mimic the function of real organs. Brain organoids are an extremely important branch of organoid research. This technology can differentiate pluripotent stem cells into the required cell types in a 3D culture environment, and self-assemble into structural bodies, but it is currently unable to fully replicate the structural and physiological features of the real human brain. The maturity of brain organoids may form consciousness, which poses ethical issues such as determining moral status and informed consent in brain organoids research. This paper elaborated on the research progress and future development direction of brain organoids, and proposed multidimensional governance strategies for ethical issues faced in brain organoids research from the perspectives of ethical principles, ensuring public informed consent, and legal supervision. By exploring the above issues, reference will be provided for formulating ethical principles to guide the research and application of brain organoids in the future.

Regulatory role of mechanical forces in the formation of liver organoids / 临床肝胆病杂志

In recent years， the continuous advances in material sciences and techniques have helped with the establishment and development of liver organoids that can simulate the structure and function of organs in vivo. In addition to the research on traditional biological factors， the construction of microenvironments with different mechanical cues to investigate the influence of mechanical stimulation on the growth of liver organoids has also become a research focus. This article first discusses the development of liver organoids and then reviews the influence of mechanical forces of different properties on the formation of liver organoids， so as to lay a foundation for the construction of more complex and ordered liver organoids in vitro and provide ideal research models for understanding the interaction between biological and mechanical factors in the formation of liver organoids.

Application of Microfluidic Liver and Kidney Chips in Toxicology Research of Chinese Medicine / 中国实验方剂学杂志

Microfluidic liver and kidney chips have become preferred model carriers in recent years for new drug development， pharmacological and toxicological research， mechanism exploration， and disease model construction. In the context of the USA. Food and Drug Administration allowing the use of in vitro model data as a substitute for animal model data in new drug applications when animal disease models are difficult to construct， microfluidic chips have received widespread attention due to their high throughput， ability to highly mimic biological characteristics of living organisms， convenient evaluation of drug toxicity in normal or pathological states with repeated dosing， real-time induction and monitoring of culture processes， and real-time data acquisition and analysis. In toxicology research， liver and kidney chips can construct in vitro models suitable for the pharmacological and toxicological detection of different substances by combining 2D monocultures and co-cultures from different species sources， 3D cultures， spheroids/organoid cells， precision-cut liver and kidney slices， immortalized cell lines， or sandwich-cultured cell lines. This model maximally simulates or retains the organ function and in vivo microenvironment of the liver and kidney， including specific physiological tissue structures， multicellular interactions/crosstalk， and multi-organ coordination/feedback， to obtain results similar to or the same as in vivo experimental data， reducing interspecies differences. At the same time， it greatly reduces the use of experimental animals and lowers costs. Microfluidic technology provides necessary shear force microenvironments for the cultivation of contents and solves problems encountered in the cultivation process of liver and kidney chips， such as insufficient tissue oxygen supply， nutrient deficiencies， and accumulation of metabolites， leading to cell apoptosis and even tissue necrosis fibrosis， which make it difficult to maintain long-term structure and function. This article reviewed the application of microfluidic technology combined with liver and kidney chips in Chinese medicine toxicology research. By summarizing the development of microfluidic technology， liver chips， kidney chips， and providing application examples of microfluidic liver and kidney chips in Chinese medicine toxicology research， combined with the characteristics of Chinese medicine administration， the article explored the advantages and future development directions of their application in the field of Chinese medicine toxicology research.

Effect of Flavanomarein from Coreopsis tinctoria Ethanol Extract in Small Intestinal Organoids in Insulin-resistant Mice Based on Transcriptome Sequencing / 中国实验方剂学杂志

ObjectiveTo investigate the effects of flavanomarein on the transcriptome of small intestinal organoids in insulin-resistant mice. MethodFirstly， small intestinal organoids of C57BL/6J and db/db mice were established. Ki-67 and E-cadherin expression was determined by immunofluorescence. Small intestinal organoids were divided into the following three groups： C57BL/6J mouse small intestinal organoids as the normal control group， db/db mouse small intestinal organoids as the model group （IR group）， and db/db mouse small intestinal organoids treated with flavanomarein as the administration group （FM group）. Western blot was used to detect the expression of glucagon-like peptide-1（GLP-1） protein on the small intestinal organoids of the three groups. Finally， transcriptome sequencing was performed on samples from the three groups. ResultOn the 6th day of small intestine organoids culture， a cyclic structure was formed around the lumen， and a small intestine organoids culture model was preliminarily established. Immunofluorescence detection showed that ki-67 and E-cadherin were expressed in small intestinal organoids. Western blot results showed that the expression of GLP-1 protein was increased by flavanomarein. In the results of differential expressed gene （DEG） screening， there were 1 862 DEGs in the IR group as compared with the normal control group， and 2 282 DEGs in the FM group as compared with the IR group. Through protein-protein interaction（PPI） network analysis of the DEGs of the two groups， 10 Hub genes， including Nr1i3， Cyp2c44， Ugt2b1， Gsta1， Gstm2， Ptgs1， Gstm4， Cyp2c38， Cyp4a32， and Gpx3， were obtained. These genes were highly expressed in the normal control group， and their expression was reduced in the IR group. After the intervention of flavanomarein， the expression of the above genes was reversed. ConclusionFlavanomarein may play its role in improving insulin resistance by reversing the expression levels of 10 Hub genes， including Nr1i3， Cyp2c44， Ugt2b1， Gsta1， Gstm2， Ptgs1， Gstm4， Cyp2c38， Cyp4a32， and Gpx3.

Liver cell therapies: cellular sources and grafting strategies / 医学前沿

The liver has a complex cellular composition and a remarkable regenerative capacity. The primary cell types in the liver are two parenchymal cell populations, hepatocytes and cholangiocytes, that perform most of the functions of the liver and that are helped through interactions with non-parenchymal cell types comprising stellate cells, endothelia and various hemopoietic cell populations. The regulation of the cells in the liver is mediated by an insoluble complex of proteins and carbohydrates, the extracellular matrix, working synergistically with soluble paracrine and systemic signals. In recent years, with the rapid development of genetic sequencing technologies, research on the liver's cellular composition and its regulatory mechanisms during various conditions has been extensively explored. Meanwhile breakthroughs in strategies for cell transplantation are enabling a future in which there can be a rescue of patients with end-stage liver diseases, offering potential solutions to the chronic shortage of livers and alternatives to liver transplantation. This review will focus on the cellular mechanisms of liver homeostasis and how to select ideal sources of cells to be transplanted to achieve liver regeneration and repair. Recent advances are summarized for promoting the treatment of end-stage liver diseases by forms of cell transplantation that now include grafting strategies.

Advances in three-dimensional tumor models for colorectal cancer / 中华肿瘤杂志

Conventional tumor culture models include two-dimensional tumor cell cultures and xenograft models. The former has disadvantages including lack of tumor heterogeneity and poor clinical relevance, while the latter are limited by the slow growth, low engraftment successful rate, and high cost. In recent years, in vitro three-dimensional (3D) tumor models have emerged as the tool to better recapitulate the spatial structure and the in vivo environment of tumors. In addition, they preserve the pathological and genetic features of tumor cells and reflect the complex intracellular and extracellular interactions of tumors, which have become a powerful tool for investigating the tumor mechanism, drug screening, and personalized cancer treatment. 3D tumor model technologies such as spheroids, organoids, and microfluidic devices are maturing. Application of new technologies such as co-culture, 3D bioprinting, and air-liquid interface has further improved the clinical relevance of the models. Some models recapitulate the tumor microenvironment, and some can even reconstitute endogenous immune components and microvasculature. In recent years, some scholars have combined xenograft models with organoid technology to develop matched in vivo/in vitro model biobanks, giving full play to the advantages of the two technologies, and providing an ideal research platform for individualized precision therapy for specific molecular targets in certain subtypes of tumors. So far, the above technologies have been widely applied in the field of colorectal cancer research. Our research team is currently studying upon the application of patient-derived tumor cell-like clusters, a self-assembly 3D tumor model, in guiding the selection of postoperative chemotherapy regimens for colorectal cancer. A high modeling success rate and satisfactory results in the drug screening experiments have been achieved. There is no doubt that with the advancement of related technologies, 3D tumor models will play an increasingly important role in the research and clinical practice of colorectal cancer.

Organoides de cérebro como modelos de doenças de Alzheimer e Parkinson: uma revisão narrativa sobre as perspectivas para medicina regenerativa e personalizada / Brain organoids as models of Alzheimer's and Parkinson's diseases: a narrative review on perspectives for regenerative and personalized medicine

Há muitos anos a cultura celular bidimensional (2D) é utilizada como modelo de estudo de doenças, possuindo grande importância na medicina regenerativa, apesar de ainda conter limitações significativas. A fim de contornar essas limitações, a cultura celular tridimensional (3D) propõe uma organização mais complexa e sustentável que pode ser produzida a partir de células-tronco adultas (ASCs), células-tronco embrionárias (ESCs) ou células-tronco pluripotentes induzidas (iPSCs). A cultura 3D possibilitou o cultivo de células em um ambiente mais próximo do fisiológico, levando à formação de distintos tecidos órgãos-específicos. Em outras palavras, a cultura de células 3D possibilita a criação de estruturas orgânicas muito semelhantes aos órgãos de um ser humano, tanto estruturalmente, quanto funcionalmente. Desse modo, tem-se o que é chamado de organoides. O uso dos organoides tem crescido exponencialmente em ambientes in vitro, permitindo a análise e observação dos diversos fenômenos fisiológicos existentes. Como exemplo, pode-se citar os organoides cerebrais ("mini-brains") reproduzidos in vitro buscando delinear as peculiaridades e complexidades do cérebro humano, com o objetivo de compreender algumas disfunções neurológicas que acometem esse sistema, como as duas principais doenças neurodegenerativas: Doenças de Alzheimer e Parkinson. Portanto, os organoides cerebrais podem permitir notável avanço da medicina regenerativa aplicada a doenças neurodegenerativas, já que esses "mini-brains" podem ser produzidos a partir de células do próprio paciente. Isso permitirá intervenções personalizadas, como testagens farmacológicas, a fim de definir qual seria o melhor tratamento medicamentoso. Consequentemente, essa tecnologia pode permitir terapias mais eficientes e individualizadas - o que é fundamental para a Medicina Personalizada (AU).

For many years, two-dimensional (2D) cell culture has been used as a model to study diseases, having great importance in regenerative medicine, despite still having significant limitations. In order to circumvent these limitations, three-dimensional (3D) cell culture proposes a more complex and sustainable organization that can be produced from adult stem cells (ASCs), embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs). The 3D culture enabled the cultivation of cells in an environment closer to the physiological one, leading to the formation of different organ-specific tissues. In other words, 3D cell culture makes it possible to create organic structures very similar to the organs of a human being, both structurally and functionally. In this way, we have what are called organoids. The use of organoids has grown exponentially in in vitro environments, allowing the analysis and observation of the various existing physiological phenomena. As an example, we can mention the brain organoids ("mini-brains") reproduced in vitro, seeking to delineate the peculiarities and complexities of the human brain, in order to understand some neurological dysfunctions that affect this system, such as the two main neurodegenerative diseases: Alzheimer's and Parkinson's Diseases. Therefore, brain organoids may allow a remarkable advance in regenerative medicine applied to neurodegenerative diseases, as these "mini-brains" can be produced from the patient's own cells. This will allow for personalized interventions, such as drug testing, in order to define what would be the best drug treatment. Consequently, this technology can enable more efficient and individualized therapies - which is fundamental for Personalized Medicine (AU).

Advances in research of heart organoid and its application in drug discovery / 药学学报

Cardiovascular diseases are fatal threats to human health and also important fields in drug discovery. Organoid is a miniature with the structure and function similar to the organ, which is formed by the self-updating and specific differentiation of stem cells during the in vitro culture. Considering its characteristics of human origin, physical features, self-assembling and genetic stability, heart organoid has attracted much attention in the study of cardiogenesis, cardiovascular diseases modeling and related drug research. Hence, this article will review the development of heart organoids and its construction strategies, highlighting its application and prospects in drug discovery.

Establishment and characterization of high-throughput culture platform for kidney organoids / 中华肾脏病杂志

Objective:To establish and identify a high-throughput culture platform for induced pluripotent stem cells to differentiated kidney organoids.Methods:Human urine-derived induced pluripotent stem cells were selected and plated at a suitable cell density, and differentiated using small molecule compounds such as CHIR99021/fibroblast growth factor 9/heparin during day 1-6. On day 7, cells with appropriate density were digested and resuspended, than added to a 96-well 3D culture plate for 24 hours. After the cells formed spheroids, fibroblast growth factor 9 and heparin were added to induce differentiation till day 24. The immunofluorescence and transmission electron microscopy were used to compare the differences of kidney organoids obtained by the reported differentiation protocol (transwell protocol) method and high-throughput culture platform.Results:Kidney organoids were successfully differentiated by two protocols. Immunofluorescence results showed that LTL, GATA-3, and synaptopodin, which were major kidney cell markers, were all expressed, and mature renal organoids were formed. The results of transmission electron microscopy showed that the kidney organoids successfully developed foot processes, the unique cellular feature of the glomerular podocytes, which were evenly distributed and neatly interspersed with each other. At the same intermediate mesodermal cell count of 1.0×10 7, approximately 7 renal organoids were obtained by the transwell protocol, while approximately 1 000 renal organoids were obtained by the high-throughput culture platform. Conclusion:A high-throughput culture platform for kidney organoids is successfully established, and a large amount of mature kidney organoids with complete structure and function can be obtained. The differentiation efficiency of kidney organoids is greatly improved.

Establishment of a culture system for human nasal mucosa organoids with controllable differentiation / 南方医科大学学报

OBJECTIVE@#To establish a culture system for human nasal mucosal organoids with controllable differentiation to reproduce the structure and function of the source tissue through staged expansion-differentiation culture.@*METHODS@#Fresh samples of surgically resected middle turbinate and nasal polyp tissues were collected, from which the nasal mucosa epithelial cells were isolated by enzymatic digestion and filtration for continuous culture at the air-liquid interface for expansion (EO group) or staged culture for expansion and differentiation (DO group). Immunohistochemical staining was used to characterize the structure, cellular composition and ciliary function of nasal mucosal organoids in the two groups. The secretion function of the differentiated nasal mucosal organoids in DO group was evaluated using PAS staining.@*RESULTS@#Both of the two organoid culture systems yielded vacuolar or solid spherical 3D organoids, and their diameters increased progressively with time. On day 16 of culture, more vacuolar organoids occurred in DO group, while more solid spherical organoids were seen in EO group, and the proportion of vacuoles was significantly greater in DO group than in EO group [(54.67±13.26)% vs (21.67±8.57)%, P < 0.05]. Short tandem repeat (STR) test of the nasal mucosal organoids and the source tissue showed a 100% match between them. On day 21 of culture, scanning and transmission electron microscopy of the nasal mucosal organoids identified ultrastructure of cilia in DO group and short villi structure in most of the organoids in EO group. Immunohistochemical staining showed positivity for P63 (basal cells), β-tubulin (ciliated columnar cells), and MUC5AC (goblet cells) in the organoids. Compared with those in EO group, the organoids in DO group showed significantly greater percentages of ciliated cells [(7.95±1.81)% vs (27.04±5.91)%, P < 0.05] and goblet cells [(14.46±0.93)% vs (39.85±5.43)%, P < 0.05) with a similar percentage of basal cells [(56.91±14.12)% vs (53.42±15.77)%, P > 0.05]. The differentiated nasal mucosal organoids in DO group were positively stained for glycogen.@*CONCLUSION@#The staged expansion-differentiation culture method allows more stable and prolonged growth of the cultured cells in vitro to produce organoids with controllable differentiation closely resembling the morphological structure and functions (ciliary function and secretory function) of the source tissue.

Preliminary research on breast cancer organoids as a radiobiological model / 中华放射肿瘤学杂志

Objective:To construct breast cancer organoid culture system and conduct histological characterization and preliminary radiobiological characteristics study.Methods:Different molecular types of breast cancer cell lines and patient-derived tumor cells were cultured in vitro to form breast cancer organoids and characterize their tissue structure. In addition, Ki-67, ER, PR and Her2 markers were evaluated by immunohistochemical staining. Breast cancer organoids were irradiated with 4 Gy and 8 Gy. The numbe and diameter changes of breast cancer organoids at 0, 24, 48 and 96 h after irradiation were observed to evaluate the irradiation-induced damage to the organoids. Results:Breast cancer cell lines and patient-derived tissues formed organoid structures at 6 d. HE staining showed the microstructures, and the expression profile of markers was spatially heterogeneous. The expression patterns of markers were similar between patient-derived organoids and original tumor tissues. Irradiation of MCF-7 breast cancer organoids led to growth arrested, and some of the formed organoids collapsed and the proliferating trend gradually recovered from 48 h to 96 h. MDA-MB-231 breast tumor organoids showed radioresistance, growth arrested, but the structures remained intact, the recovery trend was still not observed at 96 h. The tissue-derived organoids from triple-negative patients also showed radiation tolerance. After irradiation, the organoids continued to grow without significant structural changes, whereas the growth trend was significantly smaller than that in the non-irradiated group.Conclusions:Breast cancer organoids formed by in vitro culture of breast cancer cells from different sources and different molecular types have microstructure and heterogeneity, which can reflect the expression of source tissue markers and show different radioresistance. Organoids derived from triple-negative breast cancer are more resistant to irradiation.

A new strategy for bone defect repair: bone organoids / 中华创伤杂志

Bone tissue repair has long been a hot topic and difficult issue in the field of regenerative medicine research. Although the rapid development of bone tissue engineering technology significantly accelerates the level of bone repair in recent years, bone regeneration research still faces many challenges such as difficulty in regeneration under pathological condition and unclear regenerative regulatory mechanisms. As a result, the evelopment of bone tissue engineering technology encounters a bottleneck, restricting more researches over bone regeneration and repair. As a novel concept, bone organoids are proposed and constructed in vitro with the help of tissue engineering technology based on biological theory, and can simulate the complex biological functions of bone in vivo. Bone organoids show broad application prospects in the research of bone regeneration, including elucidating regulatory regeneration mechanisms, screening biomaterials and promoting regeneration, etc. In this study, the authors preliminarily discuss the features, construction and value of bone organoids so as to provide new insight for the treatment of bone defect.

Development and challenge of human lentoid bodies generation / 中华实验眼科杂志

Organoid is one of the hottest areas of research in the field of stem cells, which is an organ in a dish with three-dimensional structure and physiological functions that are highly similar to organs in vivo.At present, the generation methods of lens organoids, namely the lentoid bodies, have been established and continuously developed.The double-convex transparent lentoid bodies, with refractive function and all microscopic components of natural lenses, act as reliable in vitro models of human lenses and provide convenience for studying the mechanism of lens development.Moreover, the establishment of age-related cataract and congenital cataract models based on the lentoid bodies also provides great convenience and reliability for the study of pathological mechanism of cataract and drug screening, showing broad prospects in basic research and even clinical transformation for cataract.

Decellularized extracellular matrix mediates tissue construction and regeneration / 医学前沿

Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell-matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.