Endothelial Cells Promote Pseudo-islet Function Through BTC-EGFR-JAK/STAT Signaling Pathways.

Interactions between cells are of fundamental importance in affecting cell function. In vivo, endothelial cells and islet cells are close to each other, which makes endothelial cells essential for islet cell development and maintenance of islet cell function. We used endothelial cells to construct 3D pseudo-islets, which demonstrated better glucose regulation and greater insulin secretion compared to conventional pseudo-islets in both in vivo and in vitro trials. However, the underlying mechanism of how endothelial cells promote beta cell function localized within islets is still unknown. We performed transcriptomic sequencing, differential gene analysis, and enrichment analysis on two types of pseudo-islets to show that endothelial cells can promote the function of internal beta cells in pseudo-islets through the BTC-EGFR-JAK/STAT signaling pathway. Min6 cells secreted additional BTC after co-culture of endothelial cells with MIN6 cells outside the body. After BTC knockout in vitro, we found that beta cells functioned differently: insulin secretion levels decreased significantly, while the expression of key proteins in the EGFR-mediated JAK/STAT signaling pathway simultaneously decreased, further confirming our results. Through our experiments, we elucidate the molecular mechanisms by which endothelial cells maintain islet function in vitro, which provides a theoretical basis for the construction of pseudo-islets and islet cell transplants for the treatment of diabetes mellitus.

Effect of TiC Nanoparticles on a Zn-Al-Cu System for Biodegradable Cardiovascular Stent Applications.

Despite being a weaker metal, zinc has become an increasingly popular candidate for biodegradable implant applications due to its suitable corrosion rate and biocompatibility. Previous studies have experimented with various alloy elements to improve the overall mechanical performance of pure Zn without compromising the corrosion performance and biocompatibility; however, the thermal stability of biodegradable Zn alloys has not been widely studied. In this study, TiC nanoparticles were introduced for the first time to a Zn-Al-Cu system. After hot rolling, TiC nanoparticles were uniformly distributed in the Zn matrix and effectively enabled phase control during solidification. The Zn-Cu phase, which was elongated and sharp in the reference alloy, became globular in the nanocomposite. The strength of the alloy, after introducing TiC nanoparticles, increased by 31% from 259.7 to 340.3 MPa, while its ductility remained high at 49.2% elongation to failure. Fatigue performance also improved greatly by adding TiC nanoparticles, increasing the fatigue limit by 47.6% from 44.7 to 66 MPa. Furthermore, TiC nanoparticles displayed excellent phase control capability during body-temperature aging. Without TiC restriction, Zn-Cu phases evolved into dendritic morphologies, and the Al-rich eutectic grew thicker at grain boundaries. However, both Zn-Cu and Al-rich eutectic phases remained relatively unchanged in shape and size in the nanocomposite. A combination of exceptional tensile properties, improved fatigue performance, better long-term stability with a suitable corrosion rate, and excellent biocompatibility makes this new Zn-Al-Cu-TiC material a promising candidate for biodegradable stents and other biodegradable applications.

Fecal transplantation of young mouse donors effectively improves enterotoxicity in elderly recipients exposed to triphenyltin.

Triphenyltin (TPT) is a widely used biocide known for its high toxicity to various organisms, including humans, and its potential contribution to environmental pollution. The aging process leads to progressive deterioration of physiological functions in the elderly, making them more susceptible to the toxic effects of environmental pollutants. This study aimed to investigate the mitigating effect of fecal transplantation in young mice on the toxicological impairment caused by TPT exposure. For the study, 18-month-old mice were divided into four groups with six replicates each. The control group was fed a basal diet, the TPT group was exposed to 3.75 mg/Kg TPT, the feces group received fecal transplantation from 8-week-old young mice, and the combined group was exposed to 3.75 mg/Kg TPT after receiving fecal transplantation. Compared with the elderly control group, TPT induced significant upregulation of mRNA expression of pro-inflammatory factors (IL-1ß, IL-6, TNF-α), while the anti-inflammatory factor gene IL-10 was significantly suppressed. The mRNA expression of intestinal barrier proteins (Claudin, Occludin, Muc2) was also significantly downregulated. However, fecal transplantation in young mice alleviated TPT-induced changes in inflammatory factors, ameliorated oxidative stress, and increased the activities of antioxidant enzymes (including SOD, CAT, GSH-Px). Further analysis using 16 s RNA showed that exposure to TPT led to changes in the composition of the intestinal flora. Untargeted metabolomics observations of feces from older mice revealed that exposure to TPT resulted in altered fecal metabolites. Fecal transplantation in young mice altered the microbiota of TPT-exposed older mice, especially by enhancing the levels of core probiotics. Similar beneficial effects were observed through untargeted metabolomics. Overall, this study highlights the potential benefits of young fecal transplantation in protecting the elderly from the toxicity of TPT, offering a promising approach to improve healthy aging.

Three-Dimensional Bioprinting of Organoids: Past, Present, and Prospective.

Organoids are three-dimensional (3D) in vitro tissue models that are derived from stem cells and can closely mimic the structure and function of human organs. The ability to create organoids that recapitulate the complex cellular architecture of organs has emerged as an innovative technique in biomedical research and drug development. However, traditional methods of organoid culture are time consuming and often yield low quantities of cells, which has led to the development of 3D bioprinting of organoids from bioinks containing suspended cells and desired scaffolds. A comparison across different organoid-building techniques, focusing on 3D bioprinting and its benefits, may be helpful and was yet to be distinguished. The goal of this review is to provide an overview of the current state of 3D bioprinting of organoids and its potential applications in tissue engineering, drug screening, and regenerative medicine.

Exposure to triphenyltin impairs gut integrity, disturbs gut microbiota, and alters fecal metabolites.

Triphenyltin is an environmental contaminant widely used in antifouling paints and can cause toxicity in various organs in living organisms. However, its effects on intestinal function and the microbiome of the gut remain unknown. The objective of this study was to explore the intestinal toxicity of triphenyltin in mice by orally administering 0, 1.875, 3.75, and 7.5 mg/Kg to adult male mice for 8 weeks. Results showed that triphenyltin caused ileum tissue damage, induced oxidative stress, upregulated inflammation-related gene expression and increased serum tumor-necrosis factor α (TNF-α) levels in mice. Triphenyltin impaired ileum barrier function by downregulating Muc2, ZO-1, Occludin and their protein levels at 3.75 and 7.5 mg/Kg. TPT exposure led to partial inflammation and decreased mucin mRNA expression in the colon. Triphenyltin altered intestinal micro-ecological balance and fecal metabolome in mice. In conclusion, triphenyltin alters the mouse gut microbiota and fecal metabolome.

Impairment of cerebral vascular reactivity and resting blood flow in early-staged transgenic AD mice: in vivo optical imaging studies.

Background: Alzheimer's disease (AD) is a neurodegenerative disorder with progressive cognitive decline in aging individuals that poses a significant challenge to patients due to an incomplete understanding of its etiology and lack of effective interventions. While "the Amyloid Cascade Hypothesis," the abnormal accumulation of amyloid-ß in the brain, has been the most prevalent theory for AD, mounting evidence from clinical and epidemiological studies suggest that defects in cerebral vessels and hypoperfusion appear prior to other pathological manifestations and might contribute to AD, leading to "the Vascular Hypothesis." However, assessment of structural and functional integrity of the cerebral vasculature in vivo in the brain from AD rodent models has been challenging owing to the limited spatiotemporal resolution of conventional imaging technologies. Methods: We employed two in vivo imaging technologies, i.e., Dual-Wavelength Imaging (DWI) and Optical Coherence Tomography (OCT), to evaluate cerebrovascular reactivity (CVR; responsiveness of blood vessels to vasoconstriction as triggered by cocaine) in a relatively large field of view of the cortex in vivo, and 3D quantitative cerebrovascular blood flow (CBF) imaging in living transgenic AD mice at single vessel resolution. Results: Our results showed significantly impaired CVR and reduced CBF in basal state in transgenic AD mice compared to non-transgenic littermates in an early stage of AD progression. Changes in total hemoglobin (Δ[HbT]) in response to vasoconstriction were significantly attenuated in AD mice, especially in arteries and tissue, and the recovery time of Δ[HbT] after vasoconstriction was shorter for AD than WT in all types of vessels and cortical tissue, thereby indicating hypoperfusion and reduced vascular flexibility. Additionally, our 3D OCT images revealed that CBF velocities in arteries were slower and that the microvascular network was severely disrupted in the brain of AD mice. Conclusions: These results suggest significant vascular impairment in basal CBF and dynamic CVR in the neurovascular network in a rodent model of AD at an early stage of the disease. These cutting-edge in vivo optical imaging tools offer an innovative venue for detecting early neurovascular dysfunction in relation to AD pathology and pave the way for clinical translation of early diagnosis and elucidation of AD pathogenesis in the future.

Customized Additive Manufacturing in Bone Scaffolds-The Gateway to Precise Bone Defect Treatment.

In the advancing landscape of technology and novel material development, additive manufacturing (AM) is steadily making strides within the biomedical sector. Moving away from traditional, one-size-fits-all implant solutions, the advent of AM technology allows for patient-specific scaffolds that could improve integration and enhance wound healing. These scaffolds, meticulously designed with a myriad of geometries, mechanical properties, and biological responses, are made possible through the vast selection of materials and fabrication methods at our disposal. Recognizing the importance of precision in the treatment of bone defects, which display variability from macroscopic to microscopic scales in each case, a tailored treatment strategy is required. A patient-specific AM bone scaffold perfectly addresses this necessity. This review elucidates the pivotal role that customized AM bone scaffolds play in bone defect treatment, while offering comprehensive guidelines for their customization. This includes aspects such as bone defect imaging, material selection, topography design, and fabrication methodology. Additionally, we propose a cooperative model involving the patient, clinician, and engineer, thereby underscoring the interdisciplinary approach necessary for the effective design and clinical application of these customized AM bone scaffolds. This collaboration promises to usher in a new era of bioactive medical materials, responsive to individualized needs and capable of pushing boundaries in personalized medicine beyond those set by traditional medical materials.

Guided Bone Regeneration Using Barrier Membrane in Dental Applications.

Guided bone regeneration (GBR) is a widely used technique in preclinical and clinical studies due to its predictability. Its main purpose is to prevent the migration of soft tissue into the osseous wound space, while allowing osseous cells to migrate to the site. GBR is classified into two main categories: resorbable and non-resorbable membranes. Resorbable membranes do not require a second surgery but tend to have a short resorption period. Conversely, non-resorbable membranes maintain their mechanical strength and prevent collapse. However, they require removal and are susceptible to membrane exposure. GBR is often used with bone substitute graft materials to fill the defect space and protect the bone graft. The membrane can also undergo various modifications, such as surface modification and biological factor loading, to improve barrier functions and bone regeneration. In addition, bone regeneration is largely related to osteoimmunology, a new field that focuses on the interactions between bone and the immune system. Understanding these interactions can help in developing new treatments for bone diseases and injuries. Overall, GBR has the potential to be a powerful tool in promoting bone regeneration. Further research in this area could lead to advancements in the field of bone healing. This review will highlight resorbable and non-resorbable membranes with cellular responses during bone regeneration, provide insights into immunological response during bone remodeling, and discuss antibacterial features.

Evolution from Bioinert to Bioresorbable: In Vivo Comparative Study of Additively Manufactured Metal Bone Scaffolds.

Additively manufactured scaffolds offer significant potential for treating bone defects, owing to their porous, customizable architecture and functionalization capabilities. Although various biomaterials have been investigated, metals - the most successful orthopedic material - have yet to yield satisfactory results. Conventional bio-inert metals, such as titanium (Ti) and its alloys, are widely used for fixation devices and reconstructive implants, but their non-bioresorbable nature and the mechanical property mismatch with human bones limit their application as porous scaffolds for bone regeneration. Advancements in additive manufacturing have facilitated the use of bioresorbable metals, including magnesium (Mg), zinc (Zn), and their alloys, as porous scaffolds via Laser Powder Bed Fusion (L-PBF) technology. This in vivo study presents a comprehensive, side-by-side comparative analysis of the interactions between bone regeneration and additively manufactured bio-inert/bioresorbable metal scaffolds, as well as their therapeutic outcomes. The research offers an in-depth understanding of the metal scaffold-assisted bone healing process, illustrating that Mg and Zn scaffolds contribute to the bone healing process in distinct ways, but ultimately deliver superior therapeutic outcomes compared to Ti scaffolds. These findings suggest that bioresorbable metal scaffolds hold considerable promise for the clinical treatment of bone defects in the near future.

Efficient keystone species identification strategy based on tabu search.

As species extinction accelerates globally and biodiversity declines dramatically, identifying keystone species becomes an effective way to conserve biodiversity. In traditional approaches, it is considered that the extinction of species with high centrality poses the greatest threat to secondary extinction. However, the indirect effect, which is equally important as the local and direct effects, is not included. Here, we propose an optimized disintegration strategy model for quantitative food webs and introduced tabu search, a metaheuristic optimization algorithm, to identify keystone species. Topological simulations are used to record secondary extinctions during species removal and secondary extinction areas, as well as to evaluate food web robustness. The effectiveness of the proposed strategy is also validated by comparing it with traditional methods. Results of our experiments demonstrate that our strategy can optimize the effect of food web disintegration and identify the species whose extinction is most destructive to the food web through global search. The algorithm provides an innovative and efficient way for further development of keystone species identification in the ecosystem.

Characteristics of endoplasmic reticulum stress in colorectal cancer for predicting prognosis and developing treatment options.

BACKGROUND: An increasing body of evidence supports an essential role for endoplasmic reticulum stress (ERS) in colorectal cancer (CRC). In this study, we developed an ERS-related genes (ERSRGs) model to aid in the prognostic evaluation and treatment of CRC patients. METHODS: The training set and validation set data were extracted from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), respectively. ERSRGs were obtained from the GeneCards database. A prognostic risk scoring model was constructed using the least absolute shrinkage and selection operator (LASSO) along with univariate Cox regression analysis. To further predict the probability of survival for patients at 1, 2, and 3 years, a nomogram was devised. The advantages of the prognostic risk score model in screening patients' sensitive to chemotherapy and immunotherapy were analyzed by drug sensitivity analysis and immune correlation analysis. Finally, hub genes associated with poor prognosis in the risk model were screened by Protein-protein interaction (PPI) network and their expression was validated using clinical specimens. RESULTS: A risk model for overall survival (OS) was developed using 16 ERSRGs associated with prognosis. Through analyses, we demonstrated a high degree of reliability for the prognostic risk scoring model. The constructed nomograms performed well in predicting patient survival over 1, 3, and 5 years. The calibration curve and decision curve analysis (DCA) supported a high degree of accuracy for the model. Patients in the low-risk group had a lower IC50 for the common chemotherapy drug, 5-FU, and responded better to immunotherapy. hub poor prognostic genes were validated in CRC clinical specimens. CONCLUSION: We have identified and validated a new ERS prognostic marker that can accurately predict the survival status of CRC patients for clinicians and better provide personalized treatment plans.

Current progress of cerebral organoids for modeling Alzheimer's disease origins and mechanisms.

Alzheimer's disease (AD) is a progressive, neurodegenerative disease that has emerged as a leading risk factor for dementia associated with increasing age. Two-dimensional (2D) cell culture and animal models, which have been used to analyze AD pathology and search for effective treatments for decades, have significantly contributed to our understanding of the mechanism of AD. Despite their successes, 2D and animal models can only capture a fraction of AD mechanisms due to their inability to recapitulate human brain-specific tissue structure, function, and cellular diversity. Recently, the emergence of three-dimensional (3D) cerebral organoids using tissue engineering and induced pluripotent stem cell technology has paved the way to develop models that resemble features of human brain tissue more accurately in comparison to prior models. In this review, we focus on summarizing key research strategies for engineering in vitro 3D human brain-specific models, major discoveries from using AD cerebral organoids, and its future perspectives.

Blending with transition metals improves bioresorbable zinc as better medical implants.

Zinc (Zn) is a new class of bioresorbable metal that has potential for cardiovascular stent material, orthopedic implants, wound closure devices, etc. However, pure Zn is not ideal for these applications due to its low mechanical strength and localized degradation behavior. Alloying is the most common/effective way to overcome this limitation. Still, the choice of alloying element is crucial to ensure the resulting alloy possesses sufficient mechanical strength, suitable degradation rate, and acceptable biocompatibility. Hereby, we proposed to blend selective transition metals (i.e., vanadium-V, chromium-Cr, and zirconium-Zr) to improve Zn's properties. These selected transition metals have similar properties to Zn and thus are beneficial for the metallurgy process and mechanical property. Furthermore, the biosafety of these elements is of less concern as they all have been used as regulatory approved medical implants or a component of an implant such as Ti6Al4V, CoCr, or Zr-based dental implants. Our study showed the first evidence that blending with transition metals V, Cr, or Zr can improve Zn's properties as bioresorbable medical implants. In addition, three in vivo implantation models were explored in rats: subcutaneous, aorta, and femoral implantations, to target the potential clinical applications of bioresorbable Zn implants.

Fabrication and characterization of biodegradable Zn-Cu-Mn alloy micro-tubes and vascular stents: Microstructure, texture, mechanical properties and corrosion behavior.

Zinc (Zn) alloys are a promising biodegradable material for vascular stent applications. This study aimed to fabricate biodegradable Zn-2.0Cu-0.5Mn alloy micro-tubes and vascular stents with high dimensional accuracy and suitable mechanical properties, and to investigate their microstructure, texture, mechanical properties and corrosion behavior. The micro-tubes and vascular stents were successfully fabricated by a combined process of extrusion, drawing, laser cutting and electrochemical polishing. The microstructures of as-extruded and as-drawn micro-tubes consisted of Zn matrix with near-equiaxed grains (average grain size: ∼2 µm) and second phases of ε (CuZn4) and MnZn13 with different sizes. The texture evolved from basal planes approximately paralleling to deformation direction for as-extruded micro-tube to approximately perpendicular to deformation direction for as-drawn micro-tube, because predominant deformation mechanisms changed from basal dislocation slip during tube extrusion to prismatic dislocation, pyramidal dislocations, and {101¯2} twins during tube drawing. As-drawn micro-tube exhibited suitable mechanical properties with an ultimate tensile strength of about 298 MPa and elongation of about 26% as a stent material. Moreover, the processed stent with a thickness of about 125 µm possessed sufficient radial strength of about 150 kPa and good balloon expandability. In addition, as-drawn tube exhibited an in vitro corrosion rate of about 158 µm/year with a basically uniform corrosion morphology. These results indicated that biodegradable Zn-2.0Cu-0.5Mn alloy is a promising vascular stent material candidate, and the procedure for processing the micro-tube and stent is practical and effective. STATEMENT OF SIGNIFICANCE: Fabrication of micro-tubes followed by laser cutting and polishing is a common way to prepare metallic vascular stents. However, it is quite challenging to fabricate Zn-based stents using this standard method, and there is a lack of studies reporting processing details in the past. Biodegradable Zn-2.0Cu-0.5Mn alloy micro-tubes and vascular stents with high dimensional accuracy and suitable mechanical properties were successfully fabricated by a combined process in this study. As-drawn micro-tube exhibited an ultimate tensile strength of about 298 MPa and elongation of about 26%. The stent possessed sufficient radial strength of about 150 kPa and good balloon expandability. We demonstrated a practical method to fabricate biodegradable Zn-based micro-tubes and stents with high dimensional accuracy and mechanical properties.

Modeling of Internal Geometric Variability and Statistical Property Prediction of Braided Composites.

Due to the advantages of high specific strength, specific stiffness, and excellent fatigue resistance, carbon fiber reinforced braided composites have been widely applied in engineering. Since the molding process of braided composites is complex and immature, substantial variability of the internal geometry exists in composites, in which the yarn path with uncertainty is a main factor, so it is necessary to establish an uncertainty model to study the influence of randomness of the yarn path on mechanical properties, which is significantly related to the fatigue resistance properties of composite. An uncertain mesoscopic model with uniform distribution of yarn paths is proposed. Assuming the yarn path is spatially varying in interval range, the variability of yarn path is represented geometrically in the unit cell of composite. The three-dimensional coordinates of the yarn trajectory are calculated, the meso-uncertainty models of 2-D and 2.5-D braided composites are established. The equivalent elastic parameters and the thermal expansion coefficients are obtained by applying homogenization method and temperature field boundary conditions to the mesoscopic model. The effect of yarn path uncertainty on the statistical characteristics of elastic and thermal parameters of braided composites was studied by using Monte-Carlo simulation. A simulation method for modeling yarn path uncertainty of braided composites is provided in this paper for predicting the statistical characteristics of the equivalent elastic and thermal parameters.

Cellular mechanisms of biodegradable zinc and magnesium materials on promoting angiogenesis.

Biodegradable metals, zinc and magnesium, have been regarded as next-generation, biomedical implant materials to promote tissue repair and regeneration. These implants might also promote the vascularization of surrounding neotissue. Released metallic ions, Zn2+ and Mg2+, show promise in vitro to implement vessel growth by stimulating the expression of pro-angiogenic cytokines, yet there is little known regarding how cellular responses transcend to influence the tissue environment. This study serves to optimize angiogenic behavior using EA.hy926 endothelial cultures exposed to Zn2+ and Mg2+ gradients and observe the translation of these effects on blood vessel development via the in ovo chorioallantoic membrane (CAM) assay. Findings indicate that Zn2+ 10 µM and Mg2+ 10 mM instigate the most prominent effects using endothelial cultures via scratch wound and tube formation assays, yet higher concentrations at Zn2+ 50 µM and Mg2+ 50 mM encourage significant angiogenesis along the CAM. Immunoblotting results also conclude the presence and upregulation of cytokines involved in vessel growth. Optimizing the angiogenic potential of Zn2+ and Mg2+ separately sheds light to design future engineering constructs for promoting blood vessel development and successful assimilation between host and implant tissue.

Cyclic microchip assay for measurement of hundreds of functional proteins in single neurons.

Despite the fact that proteins carry out nearly all cellular functions and mark the differences of cells, the existing single-cell tools can only analyze dozens of proteins, a scale far from full characterization of cells and tissue yet. Herein, we present a single-cell cyclic multiplex in situ tagging (CycMIST) technology that affords the comprehensive functional proteome profiling of single cells. We demonstrate the technology by detecting 182 proteins that include surface markers, neuron function proteins, neurodegeneration markers, signaling pathway proteins, and transcription factors. Further studies on cells derived from the 5XFAD mice, an Alzheimer's Disease (AD) model, validate the utility of our technology and reveal the deep heterogeneity of brain cells. Through comparison with control mouse cells, we have identified differentially expressed proteins in AD pathology. Our technology could offer new insights into cell machinery and thus may advance many fields including drug discovery, molecular diagnostics, and clinical studies.

Improved mechanical, degradation, and biological performances of Zn-Fe alloys as bioresorbable implants.

Zinc (Zn) is a promising bioresorbable implant material with more moderate degradation rate compared to magnesium (Mg) and iron (Fe). However, the low mechanical strength and localized degradation behavior of pure Zn limit its clinical applications. Alloying is one of the most effective ways to overcome these limitations. After screening the alloying element candidates regarding their potentials for improvement on the degradation and biocompatibility, we proposed Fe as the alloying element for Zn, and investigated the in vitro and in vivo performances of these alloys in both subcutaneous and femoral tissues. Results showed that the uniformly distributed secondary phase in Zn-Fe alloys significantly improved the mechanical property and facilitated uniform degradation, which thus enhanced their biocompatibility, especially the Zn-0.4Fe alloy. Moreover, these Zn-Fe alloys showed outstanding antibacterial property. Taken together, Zn-Fe alloys could be promising candidates as bioresorbable medical implants for various cardiovascular, wound closure, and orthopedic applications.

Exosomes from ß-Cells Promote Differentiation of Induced Pluripotent Stem Cells into Insulin-Producing Cells Through microRNA-Dependent Mechanisms.

OBJECTIVE: Exosomes have emerged as potential tools for the differentiation of induced pluripotent stem cells (iPSCs) into insulin-producing cells (IPCs). Exosomal microRNAs are receiving increasing attention in this process. Here, we aimed at investigating the role of exosomes derived from a murine pancreatic ß-cell line and identifying signature exosomal miRNAs on iPSCs differentiation. METHODS: Exosomes were isolated from MIN6 cells and identified with TEM, NTA and Western blot. PKH67 tracer and transwell assay were used to confirm exosome delivery into iPSCs. qRT-PCR was applied to detect key pancreatic transcription gene expression and exosome-derived miRNA expression. Insulin secretion was determined using FCM and immunofluorescence. The specific exosomal miRNAs were determined via RNA-interference of Ago2. The therapeutic effect of 21 day-exosome-induced IPCs was validated in T1D mice induced by STZ. RESULTS: iPSCs cultured in medium containing exosomes showed sustained higher expression of MAFA, Insulin1, Insulin2, Isl1, Neuroud1, Nkx6.1 and NGN3 compared to control iPSCs. In FCM analysis, approximately 52.7% of the differentiated cells displayed insulin expression at the middle stage. Consistent with the gene expression data, immunofluorescence assays showed that Nkx6.1 and insulin expression in iPSCs were significantly upregulated. Intriguingly, the expression of pancreatic markers and insulin was significantly decreased in iPSCs cultured with siAgo2 exosomes. Transplantation of 21 day-induced IPCs intoT1D mice efficiently enhanced glucose tolerance and partially controlled hyperglycemia. The therapeutic effect was significantly attenuated in T1D mice that received iPSCs cultured with siAgo2 exosomes. Of the seven exosomal microRNAs selected for validation, miR-706, miR-709, miR-466c-5p, and miR-423-5p showed dynamic expression during 21 days in culture. CONCLUSION: These data indicate that differentiation of exosome-induced iPSCs into functional cells is crucially dependent on the specific miRNAs encased within exosomes, whose functional analysis is likely to provide insight into novel regulatory mechanisms governing iPSCs differentiation into IPCs.