Search Results (168)

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

The treatment of type 1 diabetes through pancreatic islet transplantation faces significant limitations, including donor organ shortages and poor islet survival due to post-transplantation loss of extracellular matrix support and inadequate vascularization. Developing biocompatible scaffolds that mimic the native islet microenvironment could substantially improve transplantation outcomes. This study aimed to create and evaluate decellularized (DCL) matrices from porcine organs as potential platforms for islet transplantation. Porcine lung and pancreatic tissues were decellularized using four different protocols combining detergents (Triton X-100, SDS and SDC) with optimized incubation times. The resulting matrices were characterized through DNA quantification and histological staining (H&E and Van Gieson). Islet viability was assessed in vitro using Live/Dead staining after 3 and 7 days of culture on the matrices. In vivo biocompatibility was evaluated by implanting matrices into rat omentum or peritoneum, with histological analysis at 1-, 4-, and 8 weeks post-transplantation. Protocols 3 (for lung tissue) and 4 (for pancreas tissue) demonstrated optimal decellularization efficiency with residual DNA levels below 8%, while preserving the collagen and elastin networks. In vitro, islets cultured on decellularized lung matrix had maintained 95% viability by day 7, significantly higher than the controls (60%) and pancreatic matrix (83%). The omentum showed superior performance as an implantation site, exhibiting minimal inflammation and fibrosis compared to the peritoneum sites throughout the 8-week study period. These findings establish DCL as a promising scaffold for islet transplantation due to its superior preservation of ECM components and excellent support of islet viability. This work provides a significant step toward developing effective tissue-engineered therapies for diabetes treatment. 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: Pig islets have the potential to address the limited supply of human islets available for transplantation. However, the knowledge of the biology of pig islets is currently limited. Thus, this study evaluated the molecules involved in cell-to-cell adhesion and insulin secretion pathways during the in vitro development of neonatal pig islets to understand the tissue we hope to use as a possible solution to the shortage of human islets for transplantation. Methods: Through RT-qPCR, immunoassays, and assessments of islet function, we explored the expression of E-cadherin and its correlation with the molecules involved in the insulin secretion pathway including GTPase, RAC1, and the membrane fusion protein SNAP25 during neonatal pig islet development. Results: Despite no significant difference observed in gross morphology and viability, as well as variable expression of RAC1, insulin, and SNAP25 in islets from 1-, 3-, and 7-day-old neonatal pigs, there was an apparent trend towards improved function in islets obtained from 3- and 7-day-old pigs compared with 1-day-old pigs. In the presence of 30 mM KCl, the amount of insulin secreted by islets from 3- and 7-day-old pigs but not from 1-day-old pigs was increased. Disruption of E-cadherin interactions with monoclonal antibodies resulted in decreased insulin secretion capacity of islets from 3-day old pigs. Conclusions: Our results show that blocking E-cadherin interactions with monoclonal antibodies resulted in disrupted peri-islet capsule and impaired islet insulin secretion under high glucose conditions. Thus, E-cadherin is important in the in vitro postnatal development and function of pig islets. Full article

The engraftment of transplanted islets depends on the rapid establishment of a novel vascular network. The present study evaluated the effects of cord blood-derived blood outgrowth endothelial cells (BOECs) on the viability of neonatal porcine islets (NPIs) and the post-transplant outcome of grafted NPIs. Dispersed NPIs and human BOECs were reaggregated on microwell cell culture plates and tested for their anti-apoptotic and pro-angiogenic capacity by qRT-PCR and immunohistochemistry. The in vivo functionality was analyzed after transplantation into diabetic NOD-SCID IL2rγ^−/− (NSG) mice. The spheroids, which contained reaggregated neonatal porcine islet cells (REPIs) and BOECs, exhibited enhanced viability and a significantly elevated gene expression of VEGFA, angiopoetin-1, heme oxygenase-1, and TNFAIP3 (A20) in vitro. The development of normoglycemia was significantly faster in animals transplanted with spheroids in comparison to the only REPI group (median 51.5 days versus 60 days) (p < 0.05). Furthermore, intragraft vascular density was substantially increased (p < 0.01). The co-transplantation of prevascularized REPI-BOEC spheroids resulted in superior angiogenesis and accelerated in vivo function. These findings may provide a novel tool to enhance the efficacy of porcine islet xenotransplantation. 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

Both continuous aerobic training (CAT) and high-intensity interval training (HIIT) are recommended to promote health and prevent diseases. Exercise-induced circulating extracellular vesicles (EX-EVs) have been suggested to play essential roles in mediating organ crosstalk, but corresponding molecular mechanisms remain unclear. To assess and compare the systemic effects of CAT and HIIT, five healthy male volunteers were assigned to HIIT and CAT, with a 7-day interval between sessions. Plasma EVs were collected at rest or immediately after each training section, prior to proteomics and miRNA profile analysis. We found that the differentially expressed (DE) miRNAs in EX-EVs were largely involved in the regulation of transcriptional factors, while most of the DE proteins in EX-EVs were identified as non-secreted proteins. Both CAT and HIIT play common roles in neuronal signal transduction, autophagy, and cell fate regulation. Specifically, CAT showed distinct roles in cognitive function and substrate metabolism, while HIIT was more associated with organ growth, cardiac muscle function, and insulin signaling pathways. Interestingly, the miR-379 cluster within EX-EVs was specifically regulated by HIIT, involving several biological functions, including neuroactive ligand–receptor interaction. Furthermore, EX-EVs likely originate from various tissues, including metabolic tissues, the immune system, and the nervous system. Our study provides molecular insights into the effects of CAT and HIIT, shedding light on the roles of EX-EVs in mediating organ crosstalk and health promotion. 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

Introduction: Diabetes mellitus (DM) has a millennia-long history, with early references dating back to ancient Egypt and India. However, it was not until the 20th century that the connection between diabetes and insulin was fully understood. The sequencing of insulin in the 1950s initiated the convergence of biotechnology and diabetes management, leading to the development of recombinant human insulin in 1982. This marked the start of peptide-based therapies in DM. Recombinant peptides for DM treatment: Numerous recombinant peptides have been developed since, starting with modified insulin molecules, with the aim of bettering DM management through fine-tuning the glycemic response to insulin. Peptide-based therapies in DM have expanded substantially beyond insulin to include agonists of Glucagon-like peptide-1 receptor and Glucose-dependent insulinotropic polypeptide receptor, glucagon receptor antagonists, and even peptides exerting multiple receptor agonist effects, for better metabolic control. Insulin pumps, continuous glucose monitoring, and automated insulin delivery systems: The development of modern delivery systems combined with real-time glucose monitoring has significantly advanced diabetes care. Insulin pumps evolved from early large devices to modern sensor-augmented pumps with automated shutoff features and hybrid closed-loop systems, requiring minimal user input. The second-generation systems have demonstrated superior outcomes, proving highly effective in diabetes management. Islet cell transplantation, organoids, and biological pancreas augmentation represent innovative approaches to diabetes management. Islet cell transplantation aims to restore insulin production by transplanting donor beta cells, though challenges persist regarding graft survival and the need for immunosuppression. Organoids are a promising platform for generating insulin-producing cells, although far from clinical use. Biological pancreas augmentation relies on therapies that promote beta-cell (re)generation, reduce stress, and induce immune tolerance. Further biotechnology-driven perspectives in DM will include metabolic control via biotechnology-enabled tools such as custom-designed insulin hybrid molecules, machine-learning algorithms to control peptide release, and engineering cells for optimal peptide production and secretion. Full article

Producing a tissue-engineered pancreas based on a tissue-specific scaffold from a decellularized pancreas, imitating the natural pancreatic tissue microenvironment and the islets of Langerhans, is one of the approaches to treating patients with type 1 diabetes mellitus (T1DM). The aim of this work was to investigate the ability of a fine-dispersed tissue-specific scaffold (DP scaffold) from decellularized human pancreas fragments to support the islets’ survival and insulin-producing function when injected in a streptozotocin-induced diabetic rat model. The developed decellularization protocol allows us to obtain a scaffold with a low DNA content (33 [26; 38] ng/mg of tissue, p < 0.05) and with the preservation of GAGs (0.92 [0.84; 1.16] µg/mg, p < 0.05) and fibrillar collagen (273.7 [241.2; 303.0] µg/mg, p < 0.05). Rat islets of Langerhans were seeded in the obtained scaffolds. The rats with stable T1DM were treated by intraperitoneal injections of rat islets alone and islets seeded on the DP scaffold. The blood glucose level was determined for 10 weeks with a histological examination of experimental animals’ pancreas. A more pronounced decrease in the recipient rats’ glycemia was detected after comparing the islets seeded on the DP scaffold with the control injection (by 71.4% and 51.2%, respectively). It has been shown that the DP scaffold facilitates a longer survival and the efficient function of pancreatic islets in vivo and can be used to engineer a pancreas. 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