Search Results (74)

Background/Objectives: Organ transplantation is a life-saving intervention for patients with terminal organ failure, but long-term success is hindered by graft rejection and dependence on lifelong immunosuppressants. These drugs pose risks such as opportunistic infections and malignancies. Chimeric antigen receptor (CAR) technology, originally developed for cancer immunotherapy, has been adapted to regulatory T cells (Tregs) to enhance their antigen-specific immunosuppressive function. This systematic review evaluates the preclinical development of CAR-Tregs in promoting graft tolerance and suppressing graft-versus-host disease (GvHD). Methods: A systematic review following PROSPERO guidelines (CRD420251073207) was conducted across PubMed, Scopus, and Web of Science for studies published from 2015 to 2024. After screening 105 articles, 17 studies involving CAR-Tregs in preclinical or in vivo transplant or GvHD models were included. Results: CAR-Tregs exhibited superior graft-protective properties compared to unmodified or polyclonal Tregs. HLA-A2-specific CAR-Tregs consistently improved graft survival, reduced inflammatory cytokines, and suppressed immune cell infiltration across skin, heart, and pancreatic islet transplant models. The inclusion of CD28 as a co-stimulatory domain enhanced Treg function and FOXP3 expression. However, challenges such as Treg exhaustion, tonic signaling, and reduced in vivo persistence were noted. Some studies reported synergistic effects when CAR-Tregs were combined with immunosuppressants like rapamycin or tacrolimus. Conclusions: CAR-Tregs offer a promising strategy for inducing targeted immunosuppression in allogeneic transplantation. While preclinical findings are encouraging, further work is needed to optimize CAR design, ensure in vivo stability, and establish clinical-scale manufacturing before translation to human trials. Full article

Type 1 diabetes (T1D) is caused by autoimmune-mediated destruction of pancreatic β-cells, resulting in insulin deficiency. While islet transplantation presents a potential therapeutic approach, its clinical application is impeded by limited donor availability and the risk of immune rejection. This study proposes an innovative islet encapsulation strategy that utilizes decellularized porcine pancreatic extracellular matrix (pECM) as the sole biomaterial to engineer bioactive, immunoprotective microcapsules. Rat islets were encapsulated within pECM-based microcapsules using the electrospray technology and were compared to conventional alginate-based microcapsules in terms of viability, function, and response to hypoxic stress. The pECM microcapsules maintained a spherical morphology, demonstrating mechanical robustness, and preserving essential ECM components (collagen I/IV, laminin, fibronectin). Encapsulated islets exhibited sustained viability and superior insulin secretion over a two-week period compared to alginate controls. The expression of key β-cell transcription factors (PDX1, MAFA) and structural integrity were preserved. Under hypoxic conditions, pECM microcapsules significantly reduced islet apoptosis, improved structural retention, and promoted functional recovery, likely due to antioxidant and ECM-derived cues inherent to the pECM. In vivo transplantation in immunocompetent mice confirmed the biocompatibility of pECM microcapsules, with minimal immune responses, stable insulin/glucagon expression, and no adverse systemic effects. These findings position pECM-based microencapsulation as a promising strategy for creating immunoprotective, bioactive niches for xenogeneic islet transplantation, with the potential to overcome current limitations in cell-based diabetes therapy. Full article

Type 1 diabetes mellitus (T1DM) involves the destruction of pancreatic β-cells, requiring ongoing insulin therapy. A promising alternative for management is pancreatic islet transplantation, or the bioartificial pancreas. Here, we examine the primary implantation sites for the bioartificial pancreas, highlighting their anatomical, physical, and immunological characteristics in the context of T1DM treatment. Traditionally used for islet transplantation, the liver promotes metabolic efficiency due to portal drainage; however, it presents issues such as hypoxia and inflammatory responses. The omentum offers excellent vascularization but has limited capacity for subsequent transplants. The renal subcapsular space is advantageous when combined with kidney transplants; however, its use is limited due to low vascularization. The subcutaneous space is notable for its accessibility and lower invasiveness, although its poor vascularization poses significant challenges. These challenges can be mitigated with bioengineering strategies. The gastrointestinal submucosa provides easy access and good vascularization, which makes it a promising option for endoscopic approaches. Additionally, the intrapleural space, which remains underexplored, offers benefits such as increased oxygenation and reduced inflammatory response. Selecting the ideal site for bioartificial pancreas implantation should balance graft support, complication reduction, and surgical accessibility. Bioengineered devices and scaffolds can address the limitations of traditional sites and enhance T1DM management. Full article

Background: Pancreatic organoids are a rapidly advancing field of research with new discoveries being made every day. A literature review was performed to answer the question of how relevant 3D pancreatic organoids are for surgery. Materials and Methods: We started our investigation by identifying articles in PubMed within the last 5 years using the keywords ((“pancreatic organoid”, OR “organ-on-a-chip”, OR “pancreatic chip” OR “3D culture methods”) AND pancreatic surgery). Only English articles were included in this literature review. This literature review was performed in a non-systematic way; articles were chosen without a predetermined protocol of inclusion and were based on the aim of the review. Results and Conclusions: There are many promising innovations in the field of 3D cultures. Drug sensitivity testing in particular holds great potential for surgical application. For locally advanced PDAC, EUS-FNB obtained cancer tissue can be cultured as organoids, and after 4 weeks, neoadjuvant treatment could be adjusted for each patient individually. Utilizing this approach could increase the number of R0 resections and possibly cure the disease. Furthermore, microfluidic devices, as a platform for pancreatic islet pre-transplant evaluation or cultivation of beta cells derived from HiPSC in vitro, promise broad application of islet transplantation to T1DM patients in the near future. Full article

Background/Objectives: Type 1 diabetes (T1D) is a chronic autoimmune condition characterized by the destruction of pancreatic β-cells, leading to insulin deficiency. Current therapies, such as islet transplantation, face significant challenges, including limited donor availability and the need for lifelong immunosuppression. Encapsulation technologies offer a promising alternative, providing immune protection and maintaining β-cell viability. In this study, we propose an encapsulation device featuring a spiral tubular semipermeable polyethersulfone (PES) membrane reinforced with a rigid biocompatible resin scaffold. Methods: The PES membrane was engineered with a tailored porosity of 0.5 µm, enabling efficient nutrient and oxygen exchange while preventing immune cell infiltration. Using INS-1E insulin-secreting cells aggregated into size-controlled islet-like spheroids (ILSs), we evaluated the device’s performance. Results: The device achieved high ILS viability and insulin secretion over 48 h at therapeutic densities, maintaining functionality comparable to free-floating ILSs (control). The PES membrane, with its mechanical stability and biocompatibility, ensured durability without compromising diffusion dynamics, overcoming a critical limitation of other encapsulation approaches. Importantly, the device geometry allowed for the encapsulation of up to 356,000 islet equivalents (IEQs) in a single capillary fiber, reaching therapeutic thresholds for T1D patients. Conclusions: this device, with its innovative design, enables high-density encapsulation while preserving ILS functionality and scalability, making it a potential platform for clinical application. This work highlights the potential of PES-based encapsulation devices to overcome key barriers in T1D treatment, paving the way for personalized, long-term solutions to restore insulin independence. Full article

Pancreatic islet transplantation (PIT) is a promising treatment for type 1 diabetes (T1D) but faces challenges pre- and post-transplantation. Co-transplantation with mesenchymal stromal cells (MSCs), known for their regenerative properties, has shown potential in improving PIT outcomes. This study examined the secretome of islets cultured alone compared to the secretomes of islets co-cultured with adipose-derived stromal cells (ASCs), a subtype of MSCs, under transplantation-relevant stressors: normoxia, cytokines, high glucose, hypoxia, and combined hypoxia and high glucose. Islet co-culture with ASCs significantly altered the proteome, affecting pathways related to energy metabolism, angiogenesis, extracellular matrix organization, and immune modulation. Key signaling molecules (e.g., VEGF, PDGF, bFGF, Collagen I alpha 1, IL-1α, and IL-10) were differentially regulated depending on culture conditions and ASC presence. Functional assays demonstrated that the co-culture secretome could enhance angiogenesis, collagen deposition, and immune modulation, depending on the stress conditions. These findings highlight possible mechanisms through which ASCs may support islet survival and function, offering insights into overcoming PIT challenges. Moreover, this work contributes to identifying biomarkers of the post-transplantation microenvironment, advancing therapeutic strategies for T1D and regenerative medicine. Full article

Background/Objectives: Human pancreatic islet transplantation shows promise for long-term glycemic control in diabetes patients. A shortage of healthy donors and the need for continuous immunosuppressive therapy complicates this. Enhancing our understanding of the immune tolerance mechanisms related to graft rejection is crucial to generate safer transplantation strategies. This review will examine advancements in immune protection strategies for stem cell-derived islet therapy and discuss key clinical trials involving stem cell-derived β-cells and their protective strategies against the host immune system. Methods: A comprehensive literature search was performed on peer-reviewed publications on Google Scholar, Pubmed, and Scopus up to September 2024 to extract relevant studies on the various strategies of immune evasion of stem cell-derived β-cells in humans. The literature search was extended to assimilate all relevant clinical studies wherein stem cell-derived β-cells are transplanted to treat diabetes. Results: Our analysis highlighted the importance of human pluripotent stem cells (hPSCs) as a potentially unlimited source of insulin-producing β-cells. These cells can be transplanted as an effective source of insulin in diabetes patients if they can be protected against the host immune system. Various strategies of immune protection, such as encapsulation and genetic manipulation, are currently being studied and clinically tested. Conclusions: Investigating immune tolerance in hPSC-derived islets may help achieve a cure for diabetes without relying on exogenous insulin. Although reports of clinical trials show promise in reducing insulin dependency in patients, their safety and efficacy needs to be further studied to promote their use as a long-term solution to cure diabetes. Full article

Type 1 diabetes mellitus is an autoimmune condition characterized by the destruction of pancreatic β-cells, necessitating insulin therapy to prevent life-threatening complications such as diabetic ketoacidosis. Despite advancements in glucose monitoring and pharmacological treatments, managing this disease remains challenging, often leading to long-term complications and psychological burdens, including diabetes distress. Advanced treatment options, such as whole-pancreas transplantation and islet transplantation, aim to restore insulin production and improve glucose control in selected patients with diabetes. The risk of transplant rejection necessitates immunosuppressive therapy, which increases susceptibility to infections and other adverse effects. Additionally, surgical complications, including infection and bleeding, are significant concerns, particularly for whole-pancreas transplantation. Recently, stem cell-derived therapies for type 1 diabetes have emerged as a promising alternative, offering potential solutions to overcome the limitations of formerly established transplantation methods. The purpose of this scoping review was to: (1) summarize the current evidence on achieved insulin independence following various transplantation methods of insulin-producing cells in patients with type 1 diabetes; (2) compare insulin independence rates among whole-pancreas transplantation, islet cell transplantation, and stem cell transplantation; and (3) identify limitations, challenges and potential future directions associated with these techniques. We systematically searched three databases (PubMed, Scopus, and Web of Science) from inception to November 2024, focusing on English-language, peer-reviewed clinical studies. The search terms used were ‘transplantation’ AND ‘type 1 diabetes’ AND ‘insulin independence’. Studies were included if they reported on achieved insulin independence, involved more than 10 patients with type 1 diabetes, and had a mean follow-up period of at least one year. Reviewers screened citations and extracted data on transplant type, study population size, follow-up duration, and insulin independence rates. We identified 1380 papers, and after removing duplicates, 705 papers remained for title and abstract screening. A total of 139 English-language papers were retrieved for full-text review, of which 48 studies were included in this review. The findings of this scoping review indicate a growing body of literature on transplantation therapy for type 1 diabetes. However, significant limitations and challenges, like insufficient rates of achieved insulin independence, risks related to immunosuppression, malignant diseases, and ethical issues remain with each of the established techniques, highlighting the need for innovative approaches such as stem cell-derived islet transplantation to promote β-cell regeneration and protection. Full article

Background/Objectives: This study focuses on the development and evaluation of novel alginate–poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PMETAC) microcapsules for encapsulating pancreatic islets to address insulin deficiency in diabetes. Methods: In previous research, we fabricated and characterized PMETAC microcapsules, evaluating their stability and permeability in vitro. This study further probes the capsules in vivo, focusing on the functional activity of the encapsulated islets post-transplantation, their viability extension, and the assessment of the immunoprotective, antifibrotic properties, and biostability of the capsules. Results: Rabbit-derived islets were encapsulated and transplanted into diabetic rats. The encapsulated islets maintained insulin secretion for up to 90 days, significantly longer than non-encapsulated ones, which ceased functioning after 7 days. Histological analysis demonstrated high biocompatibility of the PMETAC coating, resulting in minimal fibrotic overgrowth around the capsules. Conclusions: The study highlights the critical role of immunoprotection and the tendency to reduce fibrosis in prolonging islet function. These findings suggest that PMETAC-coated capsules offer a promising solution for cell-based therapies in diabetes by improving graft longevity and reducing fibrotic overgrowth. Full article

Background: T1D is a severe metabolic disorder due to selective autoimmune pancreatic islet β-cell killing, which results in complete abrogation of endogenous insulin secretion. The affected patients, once the disease is clinically overt, must immediately undertake insulin supplementation according to intensive therapy regimens to prevent the onset of acute and chronic complications, some of them potentially lethal. Replacement of the destroyed β-cells with fresh and vital pancreatic endocrine tissue, either of the whole organ or isolated islets transplantation, started a few decades ago with progressively encouraging results, although exogenous insulin withdrawal was obtained in a minor cohort of the treated patients. The restricted availability of donor organs coupled with general immunosuppression treatment of recipients to avoid graft immune rejection may, at least partially, explain the limited success achieved by these procedures. Results: The introduction of pluripotent stem cells (either of human embryonic origin or adult cells genetically induced to pluripotency) that can be differentiated toward insulin secretory β-like cells could provide an indefinite resource for insulin-producing cells (IPCs). Conclusions: Because the use of human embryos may encounter ethical problems, employment of adult multipotent mesenchymal stem cells (MSCs) extracted from several tissues may represent an alternative option. MSCs are associated with strong immunoregulatory properties that can alter early stages of β-cell-directed autoimmunity in T1D, other than holding the potential to differentiate themselves into β-like cells. Lights and shadows of these new strategies for the potential cure of T1D and their advancement state are reviewed. Full article

Islet transplantation represents a promising therapeutic approach for diabetes management, yet the isolation and evaluation of pancreatic islets remain challenging. This study focuses on the isolation of islets from rabbit pancreases, followed by a comprehensive assessment of their viability and functionality. We developed a novel method for isolating islet cells from the pancreas of adult rabbits. We successfully isolated viable islets, which were subsequently evaluated through a combination of viability assays, an insulin enzyme-linked immunosorbent assay (ELISA), and fluorescence lifetime imaging microscopy (FLIM). The viability assays indicated a high percentage of intact islets post-isolation, while the insulin ELISA demonstrated robust insulin secretion in response to glucose stimulation. FLIM provided insights into the metabolic state of the islets, revealing distinct fluorescence lifetime signatures correlating with functional viability. Our findings underscore the potential of rabbit islets as a model for studying islet biology and diabetes therapy, highlighting the efficacy of combining traditional assays with advanced imaging techniques for comprehensive functional assessments. This research contributes to the optimization of islet isolation protocols and enhances our understanding of islet functional activity dynamics in preclinical settings. Full article

Type 1 diabetes mellitus (T1DM) is a chronic condition primarily managed with insulin replacement, leading to significant treatment costs. Complications include vasculopathy, cardiovascular diseases, nephropathy, neuropathy, and reticulopathy. Pancreatic islet transplantation is an option but its success does not depend solely on adequate vascularization. The main limitations to clinical islet transplantation are the scarcity of human pancreas, the need for immunosuppression, and the inadequacy of the islet isolation process. Despite extensive research, T1DM remains a major global health issue. In 2015, diabetes affected approximately 415 million people, with projected expenditures of USD 1.7 trillion by 2030. Pancreas transplantation faces challenges due to limited organ availability and complex vascularization. T1DM is caused by the autoimmune destruction of insulin-producing pancreatic cells. Advances in biomaterials, particularly the extracellular matrix (ECM), show promise in tissue reconstruction and transplantation, offering structural and regulatory functions critical for cell migration, differentiation, and adhesion. Tissue engineering aims to create bioartificial pancreases integrating insulin-producing cells and suitable frameworks. This involves decellularization and recellularization techniques to develop biological scaffolds. The challenges include replicating the pancreas’s intricate architecture and maintaining cell viability and functionality. Emerging technologies, such as 3D printing and advanced biomaterials, have shown potential in constructing bioartificial organs. ECM components, including collagens and glycoproteins, play essential roles in cell adhesion, migration, and differentiation. Clinical applications focus on developing functional scaffolds for transplantation, with ongoing research addressing immunological responses and long-term efficacy. Pancreatic bioengineering represents a promising avenue for T1DM treatment, requiring further research to ensure successful implementation. Full article

We previously demonstrated that boundary cap neural crest stem cells (BCs) induce the proliferation of beta-cells in vitro, increase survival of pancreatic islets (PIs) in vivo after transplantation, and themselves strongly increase their proliferation capacity after exposure to space conditions. Therefore, we asked if space conditions can induce the proliferation of beta-cells when PIs are alone or together with BCs in free-floating or 3D-printed form. During the MASER 15 sounding rocket experiment, half of the cells were exposed to 6 min of microgravity (µg), whereas another group of cells were kept in 1 g conditions in a centrifuge onboard. The proliferation marker EdU was added to the cells just before the rocket reached µg conditions. The morphological assessment revealed that PIs successfully survived and strongly proliferated, particularly in the free-floating condition, though the fusion of PIs hampered statistical analysis. Proliferation of beta-cells was displayed in 3D-printed islets two weeks after µg exposure, suggesting that the effects of µg may be delayed. Thus, PIs in 3D-printed scaffolds did not fuse, and this preparation is more suitable than free-floating specimens for morphological analysis in µg studies. PIs maintained their increased proliferation capacity for weeks after µg exposure, an effect that may not appear directly, but can emerge after a delay. Full article

Cell-based therapy using insulin-producing cells (IPCs) is anticipated as an alternative treatment option to insulin injection or pancreatic islet transplantation for the treatment of diabetes mellitus in both human and veterinary medicine. Several protocols were reported for the differentiation of mesenchymal stem cells (MSCs) into IPCs; to date, glucose-responsive IPCs have only been obtained from canine adipose tissue-derived MSCs (cAD-MSCs), but not from canine bone marrow-derived MSCs (cBM-MSCs). Therefore, this study aims to generate in vitro glucose-responsive IPCs from cBM-MSCs using two differentiation protocols: a two-step protocol using trichostatin (TSA) and a three-step protocol using mercaptoethanol to induce pancreatic and duodenal homeobox gene 1 (PDX-1) expression. A single experiment was carried out for each protocol. BM-MSCs from one dog were successfully cultured and expanded. Cells exposed to the two-step protocol appeared rarely grouped to form small clusters; gene expression analysis showed a slight increase in PDX-1 and insulin expression, but no insulin protein production nor secretion in the culture medium was detected either under basal conditions or following glucose stimulation. Conversely, cells exposed to the three-step protocol under a 3D culture system formed colony-like structures; insulin gene expression was upregulated compared to undifferentiated control and IPCs colonies secreted insulin in the culture medium, although insulin secretion was not enhanced by high-glucose culture conditions. The single experiment results suggest that the three-step differentiation protocol could generate IPCs from cBM-MSCs; however, further experiments are needed to confirm these data. The ability of IPCs from cBM- MSCs to produce insulin, described here for the first time, is a preliminary interesting result. Nevertheless, the IPCs’ unresponsiveness to glucose, if confirmed, would affect its clinical application. Further studies are necessary to establish a differentiation protocol in this perspective. Full article

Despite the effectiveness of insulin injections in managing hyperglycemia in type 1 diabetes mellitus (T1DM), they fall short in addressing autoimmunity and regenerating damaged islets. This review aims to explore the potential and prospects of emerging treatment modalities for T1DM, including mesenchymal stem cells (MSCs), MSC-derived exosomes, gene therapy, islet allotransplantation, pancreatic islet cell transplantation, and teplizumab. We review emerging treatment modalities for T1DM, highlighting several promising strategies with varied mechanisms and outcomes. Mesenchymal stem cells demonstrate potential in modulating the immune response and preserving or restoring beta-cell function, although variability in sources and administration routes necessitates further standardization. Similarly, MSC-derived exosomes show promise in promoting beta-cell regeneration and immune regulation, supported by early-stage studies showing improved glucose homeostasis in animal models, albeit with limited clinical data. Gene therapy, utilizing techniques like CRISPR-Cas9, offers targeted correction of genetic defects and immune modulation; however, challenges in precise delivery and ensuring long-term safety persist. Islet allotransplantation and pancreatic islet cell transplantation have achieved some success in restoring insulin independence, yet challenges such as donor scarcity and immunosuppression-related complications remain significant. Teplizumab, an anti-CD3 monoclonal antibody, has demonstrated potential in delaying T1DM onset by modulating immune responses and preserving beta-cell function, with clinical trials indicating prolonged insulin production capability. Despite significant progress, standardization, long-term efficacy, and safety continue to pose challenges across these modalities. Conclusion: While these therapies demonstrate significant potential, challenges persist. Future research should prioritize optimizing these treatments and validating them through extensive clinical trials to enhance T1DM management and improve patient outcomes. Full article