Application of a novel bioreactor for in vivo engineering of pancreas tissue

Decellularized tracheal scaffold as a promising 3D scaffold for tissue engineering applications

Tissue engineering is a science that uses the combination of scaffolds, cells, and active biomolecules to make tissue in order to restore or maintain its function and improve the damaged tissue or even an organ in the laboratory. The purpose of this research was to study the characteristics and biocompatibility of decellularized sheep tracheal scaffolds and also to investigate the differentiation of Adipose-derived stem cells (AD-MSCs) into tracheal cells. After the decellularization of sheep tracheas through the detergent-enzyme method, histological evaluations, measurement of biochemical factors, measurement of DNA amount, and photographing the ultrastructure of the samples by scanning electron microscopy (SEM), they were also evaluated mechanically. Further, In order to check the viability and adhesion of stem cells to the decellularized scaffolds, adipose mesenchymal stem cells were cultured on the scaffolds, and the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay was performed. The expression analysis of the intended genes for the differentiation of mesenchymal stem cells into tracheal cells was evaluated by the real-time PCR method. These results show that the prepared scaffolds are an ideal model for engineering applications, have high biocompatibility, and that the tracheal scaffold provides a suitable environment for the differentiation of ADMSCs. This review provides a basis for future research on tracheal decellularization scaffolds, serves as a suitable model for organ regeneration, and paves the way for their use in clinical medicine.

The differentiation and generation of glucose-sensitive beta like-cells from menstrual blood-derived stem cells using an optimized differentiation medium with platelet-rich plasma (PRP)

Regarding their reversible damage of insulin-producing cells (IPCs) and the inefficiency of treatment methods for type 1 diabetes mellitus (T1DM), scientists decided to produce IPCs from an unlimited source of cells. But the production of these cells is constantly faced with problems such as low differentiation efficiency in cell therapy and regenerative medicine. This study provided an ideal differentiation medium enriched with plasma-rich platelet (PRP) delivery to produce IPCs from menstrual blood-derived stem cells (MenSCs). We compared them with and without PRP differentiation medium. MenSCs were then cultured in two experimental groups: with/without PRP differentiation medium and a control group (undifferentiated MenSCs). After 18 days, differentiated cells were analyzed for expression of pancreatic gene markers by real-time PCR. Immunocytochemical staining was used to detect the presence of insulin and Pdx-1 in the differentiated cells, and insulin and C-peptide secretion response to glucose were tested by ELISA. Finally, the morphology of differentiated cells was examined by an inverted microscope. In vitro studies showed that MenSCs differentiated in the PRP differentiation medium had strong properties of IPCs such as pancreatic islet-like structure. The expression of pancreatic markers at both RNA and protein levels showed that the differentiation efficiency was higher in the PRP differentiation medium. In both experimental groups, the differentiated cells were functional and secreted C-peptide and insulin on glucose stimulation, but the secretion of C-peptide and insulin in the PRP group was higher than those cultured in the without PRP differentiation medium. Our findings showed that using of PRP enriched differentiation medium can promote the differentiation of MenSCs into IPCs compared to the without PRP culture group. Therefore, the use of PRP into differentiation media can be proposed as a new approach to producing IPCs from MenSCs and used in cell-based therapies for T1DM.

Generation of glucose sensitive insulin-secreting cells from human induced pluripotent stem cells on optimized polyethersulfone hybrid nanofibrous scaffold

BACKGROUND

In the realm of diabetes treatment, various strategies have been tried, including islet transplantation and common drug therapies, but the limitations of these procedures and lack of responsive to the high number of patients have prompted researchers to develop a new method. In recent decades, the use of stem cells and three-dimonsional (3D) scaffold to produce insulin-secreting cells is one of the most promising new approaches. Meanwhile, human-induced pluripotent stem cells (iPSCs) propose due to advantages such as autologousness and high pluripotency in cell therapy. This study aimed to evaluate the differentiation of iPSCs into pancreatic islet insuli-producing cells (IPCs) on Silk/PES (polyethersulfone) nanofibers as a 3D scaffold and compare it with a two-dimonsional (2D) cultured group.

METHODS

Investigating the functional, morphological, molecular, and cellular characteristics of differentiated iPSCs on control cultures (without differentiation medium), 2D and 3D were measured by various methods such as electron microscopy, Q-PCR, immunofluorescence, western blot, and ELISA.

RESULTS

This investigation revealed that differentiated cells on the 3D Silk/PES scaffold expressed pancreatic specific-markers such as insulin and pdx1 at higher levels than the control and 2D groups, with a significant difference between the two groups. All results of Q-PCR, immunocytochemistry, and western blot showed that IPCs in the silk/PES 3D group was more efficient than in the 2D group. In the face of these cases, the release of insulin and C-peptide in response to several concentrations of glucose in the 3D group was significantly higher than in the 2D culture.

CONCLUSION

Finally, our findings displayed that optimized Silk/PES 3D scaffolds can enhance the differentiation of IPCs from iPSCs compared to the 2D culture group.

Angiogenesis and Re-endothelialization in decellularized scaffolds: Recent advances and current challenges in tissue engineering

Decellularization of tissues and organs has recently become a promising approach in tissue engineering and regenerative medicine to circumvent the challenges of organ donation and complications of transplantations. However, one main obstacle to reaching this goal is acellular vasculature angiogenesis and endothelialization. Achieving an intact and functional vascular structure as a vital pathway for supplying oxygen and nutrients remains the decisive challenge in the decellularization/re-endothelialization procedure. In order to better understand and overcome this issue, complete and appropriate knowledge of endothelialization and its determining variables is required. Decellularization methods and their effectiveness, biological and mechanical characteristics of acellular scaffolds, artificial and biological bioreactors, and their possible applications, extracellular matrix surface modification, and different types of utilized cells are factors affecting endothelialization consequences. This review focuses on the characteristics of endothelialization and how to optimize them, as well as discussing recent developments in the process of re-endothelialization.

Tissue engineering approaches and generation of insulin-producing cells to treat type 1 diabetes

Tissue engineering (TE) has become a new effective solution to a variety of medical problems, including diabetes. Mesenchymal stem cells (MSCs), which have the ability to differentiate into endodermal and mesodermal cells, appear to be appropriate for this function. The purpose of this review was to evaluate the outcomes of various researches on the insulin-producing cells (IPCs) generation from MSCs with TE approaches to increase efficacy of type 1 diabetes treatments. The search was performed in PubMed/Medline, Scopus and Embase databases until 2021. Studies revealed that MSCs could also differentiate into IPCs under certain conditions. Therefore, a wide range of protocols have been used for this differentiation, but their effectiveness is very different. Scaffolds can provide a microenvironment that enhances the MSCs to IPCs differentiation, improves their metabolic activity and up-regulate pancreatic-specific transcription factors. They also preserve IPCs architecture and enhance insulin production as well as protect against cell death. This systematic review offers a framework for prospective research based on data. In vitro and in vivo evidence suggests that scaffold-based TE can improve the viability and function of IPCs.

The microenvironment of silk/gelatin nanofibrous scaffold improves proliferation and differentiation of Wharton's jelly-derived mesenchymal cells into islet-like cells

The use of umbilical cord-derived mesenchymal stem cells along with three-dimensional (3D) scaffolds in pancreatic tissue engineering can be considered as a treatment for diabetes. This study aimed to investigate the differentiation of Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) into pancreatic islet-insulin producing cells (IPCs) on silk/gelatin nanofibers as a 3D scaffold. Mesenchymal markers were evaluated at the mesenchymal stem cells (MSCs) level by flow cytometry. WJ-MSCs were then cultured on 3D scaffolds and treated with a differential medium. Immunocytochemical assays showed efficient differentiation of WJ-MSCs into IPCs. Also, Real-time PCR results showed a significant increase in the expression of pancreatic genes in the 3D culture group compared to the two-dimensional (2D) culture group. Despite these cases, the secretion of insulin and C-peptide in response to different concentrations of glucose in the 3D group was significantly higher than in the 2D culture. The results of our study showed that silk/gelatin scaffold with WJ-MSCs could be a good option in the production of IPCs in regenerative medicine and pancreatic tissue engineering.

Hyaluronic acid methacrylate/pancreatic extracellular matrix as a potential 3D printing bioink for constructing islet organoids

Islet transplantation has poor long-term efficacy because of the lack of extracellular matrix support and neovascularization; this limits its wide application in diabetes research. In this study, we develop a 3D-printed islet organoid by combining a pancreatic extracellular matrix (pECM) and hyaluronic acid methacrylate (HAMA) as specific bioinks. The HAMA/pECM hydrogel was validated in vitro to maintain islet cell adhesion and morphology through the Rac1/ROCK/MLCK signaling pathway, which helps improve islet function and activity. Further, in vivo experiments confirmed that the 3D-printed islet-encapsulated HAMA/pECM hydrogel increases insulin levels in diabetic mice, maintains blood glucose levels within a normal range for 90 days, and rapidly secretes insulin in response to blood glucose stimulation. In addition, the HAMA/pECM hydrogel can facilitate the attachment and growth of new blood vessels and increase the density of new vessels. Meanwhile, the designed 3D-printed structure was conducive to the formation of vascular networks and it promoted the construction of 3D-printed islet organoids. In conclusion, our experiments optimized the HAMA/pECM bioink composition and 3D-printed structure of islet organoids with promising therapeutic effects compared with the HAMA hydrogel group that can be potentially used in clinical applications to improve the effectiveness and safety of islet transplantation in vivo. STATEMENT OF SIGNIFICANCE: The extraction process of pancreatic islets can easily cause damage to the extracellular matrix and vascular system, resulting in poor islet transplantation efficiency. We developed a new tissue-specific bioink by combining pancreatic extracellular matrix (pECM) and hyaluronic acid methacrylate (HAMA). The islet organoids constructed by 3D printing can mimic the microenvironment of the pancreas and maintain islet cell adhesion and morphology through the Rac1/ROCK/MLCK signaling pathway, thereby improving islet function and activity. In addition, the 3D-printed structures we designed are favorable for the formation of new blood vessel networks, bringing hope for the long-term efficacy of islet transplantation.

Whole-organ decellularization of the human uterus and in vivo application of the bio-scaffolds in animal models

PURPOSE

The aim of this investigation was to design a perfusion-based decellularization protocol to provide whole human uterine bio-scaffolds with preserved structural and componential characteristics and to investigate the in vivo properties of the decellularized tissues.

METHODS

Eight human uteri, donated by brain-dead patients, were decellularized by perfusion of sodium dodecyl sulfate (SDS) through the uterine arteries using a peristaltic pump. The bio-scaffolds were evaluated and compared with native human uterus regarding histological, immunohistochemical, structural, and bio-mechanical properties, in addition to CT angiographies to examine the preservation of the vascular networks. Subsequently, we obtained acellular patches and implanted them on uterine defects of female Wistar rats to investigate the bio-compatibility and regenerative potential of the bio-scaffolds. Finally, we performed immunostaining to investigate the potential role of circulating stem cells in recellularization of the implanted bio-scaffolds.

RESULTS

The outcomes of this investigation confirmed the efficacy of the proposed protocol to provide whole human uterine scaffolds with characteristics and extra-cellular matrix components similar to the native human uterus. Subsequent in vivo studies demonstrated the bio-compatibility and the regenerative potential of the scaffolds and suggested a signaling pathway as an underlying mechanism for the regenerative process.

CONCLUSIONS

To the best of our knowledge, this investigation provides the first efficient perfusion-based decellularization protocol for the human uterus to obtain whole-organ scaffolds. The outcomes of this investigation could be employed in future human uterus tissue engineering studies which could ultimately result in the development of novel treatments for female infertile patients.

A novel hybrid polymer of PCL/Fish gelatin nanofibrous scaffold improves proliferation and differentiation of wharton's jelly-derived mesenchymal cells into islet-like cells

BACKGROUND

Using a different source of stem cells to compensate for the lost beta cells is a promising way to cure diabetic patients. Besides The best efficiency of insulin-producing cells (IPCs) will appear when we culture them in an environment similar to inside the body. Hence, three-dimensional (3D) culture ameliorates the differentiation of diverse kinds of stem cells into IPCs compared to those differentiated in two-dimensional (2D) culture. In this study, we aim to create an ideal differentiation environment by using PCL/Fish gelatin nanofibrous scaffolds to differentiate wharton's jelly-derived mesenchymal cells (WJ-MSCs) to IPCs and compare them with a 2D cultured group.

METHODS

The evaluation of cellular, molecular, and functional properties of differentiated cells on the 3D and 2D cultures were investigated by several assay such as electron microscopy, quantitative PCR, immunochemistry, western blotting, and ELISA.

RESULTS

The in vitro studies showed, WJ-MSCs that differentiated in the 3D culture have strong properties of IPCs such as islet-like cells. The expression of pancreatic-specific genes at both RNA and protein levels showed higher differentiation efficacy of 3D culture. Besides, the results of the elisa tests demonstrates that in both groups the differentiated cells are functional and secreted C-peptide and insulin in glucose stimulation, but the secretion of C-peptide and insulin in the 3D culture group was higher than those cultured in 2D groups.

CONCLUSION

Our findings showed the use of PCL/Fish gelatin nanofibrous scaffolds with optimized differentiation protocols can promote the differentiation of IPCs from WJ-MSCs compared to the 2D culture group.

Recent advancements in decellularized matrix technology for bone tissue engineering

The native extracellular matrix (ECM) provides a matrix to hold tissue/organ, defines the cellular fate and function, and retains growth factors. Such a matrix is considered as a most biomimetic scaffold for tissue engineering due to the biochemical and biological components, 3D hierarchical structure, and physicomechanical properties. Several attempts have been performed to decellularize allo- or xeno-graft tissues and used them for bone repairing and regeneration. Decellularized ECM (dECM) technology has been developed to create an in vivo-like microenvironment to promote cell adhesion, growth, and differentiation for tissue repair and regeneration. Decellularization is mediated through physical, chemical, and enzymatic methods. In this review, we describe the recent progress in bone decellularization and their applications as a scaffold, hydrogel, bioink, or particles in bone tissue engineering. Furthermore, we address the native dECM limitations and the potential of non-bone dECM, cell-based ECM, and engineered ECM (eECM) for in vitro osteogenic differentiation and in vivo bone regeneration.

Decellularized Matrix Bioscaffolds: Implementation of Native Microenvironment in Pancreatic Tissue Engineering

ABSTRACT

Type 1 diabetes is an autoimmune disease, and its incidence is usually estimated in the range of 5% to 10%. Currently, the administration of exogenous insulin is the standard of care therapy. However, this therapy is not effective in some patients who may develop some chronic complications. Islet transplantation into the liver is another therapy with promising outcomes; however, the long-term efficacy of this therapeutic option is limited to a small number of patients. Because native extracellular matrix (ECM) components provide a suitable microenvironment for islet functions, engineering a 3-dimensional construct that recapitulates the native pancreatic environment could address these obstacles. Many attempts have been conducted to mimic an in vivo microenvironment to increase the survival of islets or islet-like clusters. With the advent of decellularization technology, it is possible to use a native ECM in organ engineering. Pancreatic decellularized bioscaffold provides proper cell-cell and cell-ECM interactions and retains growth factors that are critical in the determination of cell fate within a native organ. This review summarizes the current knowledge of decellularized matrix technology and addresses its possible limitations before use in the clinic.

Pancreatic Extracellular Matrix/Alginate Hydrogels Provide a Supportive Microenvironment for Insulin-Producing Cells

Type 1 diabetes mellitus (T1DM), as an autoimmune deficiency disease, is associated with an absolute deficiency of insulin subject to islet β-cell destruction. Insulin-producing cells (IPCs) differentiated from induced pluripotent stem cells are an ideal replacement origin of β-cells, which can be applied for cell transplantation therapies in T1DM. At present, more strategies focus on inducing and differentiating to obtain IPCs; however, the unsatisfactory differentiation efficiency and the lack of ideal carriers for in vivo transplantation limited their application. It is necessary to consider the cell microenvironment by constructing a biomimetic niche to improve the differentiation and transplantation efficiency. The main components of the extracellular matrix derived from pancreatic (the niche of β-cells) decellularization were retained, which could provide the ideal extracellular microenvironment for IPCs. In this research, a hydrogel prepared with alginate (Alg) and the pancreatic extracellular matrix (pECM) was assessed for the beneficial outcomes on encapsulated IPCs. The results showed that pECM/Alg improved the differentiation efficiency and promoted insulin secretion and the expression of insulin-related genes as well. Besides, pECM/Alg-encapsulated IPCs exhibited obvious biocompatibility in vivo, which can prolong the transplantation effect and hypoglycemic function by reducing the inflammatory reaction. RNA-seq indicated that the PI3K/Akt pathway may be related to the improvement of the differentiation efficiency and function of IPCs. In general, the pECM/Alg hydrogel provides an ideal biomimetic microenvironment for IPCs and is suitable for in vivo transplantation.

The Role of MicroRNAs in the Induction of Pancreatic Differentiation

Stem cell-based therapy is one of the therapeutic options with promising results in the treatment of diabetes. Stem cells from various sources are expanded and induced to generate the cells capable of secreting insulin. These insulin-producing cells [IPCs] could be used as an alternative to islets in the treatment of patients with diabetes. Soluble growth factors, small molecules, geneencoding transcription factors, and microRNAs [miRNAs] are commonly used for the induction of stem cell differentiation. MiRNAs are small non-coding RNAs with 21-23 nucleotides that are involved in the regulation of gene expression by targeting multiple mRNA targets. Studies have shown the dynamic expression of miRNAs during pancreatic development and stem cell differentiation. MiR- 7 and miR-375 are the most abundant miRNAs in pancreatic islet cells and play key roles in pancreatic development as well as islet cell functions. Some studies have tried to use these small RNAs for the induction of pancreatic differentiation. This review focuses on the miRNAs used in the induction of stem cells into IPCs and discusses their functions in pancreatic β-cells.

PHBV nanofibers promotes insulin-producing cells differentiation of human induced pluripotent stem cells

Tissue-engineering associated techniques have long been employed to improve the various elements of the therapeutic approaches toward the more efficient ones in diabetic states. The resultant constructs comprise of the polymeric scaffolds with proper degradation rates that produce bodily compatible components, and the pluripotent cells that are highly capable of generating islet-like cells. In this study, Poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers were fabricated by the Electrospinning. After validation of its 3-D structure, fibers size and non-toxicity, insulin-producing cells (IPC) differentiation potential of the induced pluripotent stem cells (iPSCs) were evaluated during growing on the PHBV nanofibers in comparison with tissue culture polystyrene (TCPS). SEM analyses confirmed the 3-D and nanofibrous structure of the fabricated scaffold. The survival rate of the iPSCs cultured on the PHBV nanofibers was increased significantly compared to the cells cultured on the TCPS, which is an evidence for the non-toxicity of the nanofibers. Insulin and C-peptide secretion levels significantly increased in the differentiated iPSCs on PHBV nanofibers compared to those cells cultured on TCPS. Moreover, levels of the gene transcription and translation results revealed that insulin, Glut-2, and Pdx-1 genes and insulin protein, in IPC-differentiated iPSCs grown on PHBV nanofibers are significantly higher than those cells grown on TCPS. Taken together, these results go beyond previous reports, showing thatiPSCs-PHBV as a promising cell-copolymer construct, could potentially be applied in the pancreatic tissue engineering applications to diabetic patient treatment.

Decellularised whole ovine testis as a potential bio-scaffold for tissue engineering

The aim of this study was to determine an efficient whole-organ decellularisation protocol of a human-sized testis by perfusion through the testicular arteries. In the first step of this study, we determined the most efficient detergent agent, whereas the second phase delineated the optimal time required for the decellularisation process. Initially sheep testes were decellularised by one of three different detergent agents: sodium dodecyl sulphate (SDS), Triton X-100 and trypsin-ethylenediamine tetraacetic acid (EDTA) solutions, each perfused for 6h. In the second phase, the selected detergent agent was applied for different time periods. A total number of 20 organs were processed during this investigation. The efficacy of the decellularisation process and the preservation of the extracellular matrix components and structure were evaluated by histopathological examinations, 4',6'-diamidino-2-phenylindole (DAPI) staining, DNA quantification, hydroxyproline measurement, magnetic resonance imaging and scanning electron microscopy. Organ perfusion with 1% SDS solution for 6 to 8h demonstrated the most desirable outcomes regarding decellularisation and extracellular matrix preservation. The 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay was used to determine the toxicity of the scaffold and its potential for further application in tissue-engineering investigations. This investigation introduces an efficient method to produce a three-dimensional testicular bio-scaffold resembling the properties of the native organ that could be employed in tissue-engineering studies.

In vivo application of decellularized rat colon and evaluation of the engineered scaffolds following 9 months of follow-up

The aim of this study was to investigate the rat small intestine mesentery and colon as natural bio-reactors for rat colon-derived scaffolds. We decellularized eight whole rat colons by a perfusion-based protocol using 0.1% sodium dodecyl sulfate for 24 hr. The provided bio-scaffolds were examined by histological staining, scanning electron microscopy, and collagen and sulfated glycosaminoglycan quantification. Subsequently, we implanted 4 cm segments of the provided bio-scaffolds into two groups of animal models comprising tissue grafting into the mesenteric tissue (n: 10) and end-to-end anastomosis (n: 10) to the colon of host rats. Following 9 months of follow-up, we harvested the grafts and performed histological and immunohistochemical studies as well as real-time PCR evaluation for telomerase activity of the samples. Histological staining, scanning electron microscopy and protein content evaluation of the acellular tissues confirmed the complete removal of the cellular components and preservation of the extracellular matrix. Histopathological assessment of the implanted scaffolds was suggestive of a regenerative process in both groups. Moreover, immunohistochemical analysis of the samples confirmed the presence of smooth muscle cells, endothelial progenitor cells, and neural elements in both groups of grafted scaffolds. Our data confirmed the recellularization of the acellular colon grafts in both groups after 9 months of follow up. Also, the implanted tissues demonstrated different characteristics based on their implantation location. The outcomes of this investigation illustrate the capability of acellular tissues for in vivo application and regeneration.

Whole Organ Engineering: Approaches, Challenges, and Future Directions

End-stage organ failure remains a leading cause of morbidity and mortality across the globe. The only curative treatment option currently available for patients diagnosed with end-stage organ failure is organ transplantation. However, due to a critical shortage of organs, only a fraction of these patients are able to receive a viable organ transplantation. Those patients fortunate enough to receive a transplant must then be subjected to a lifelong regimen of immunosuppressant drugs. The concept of whole organ engineering offers a promising alternative to organ transplantation that overcomes these limitations. Organ engineering is a discipline that merges developmental biology, anatomy, physiology, and cellular interactions with enabling technologies such as advanced biomaterials and biofabrication to create bioartificial organs that recapitulate native organs in vivo. There have been numerous developments in bioengineering of whole organs over the past two decades. Key technological advancements include (1) methods of whole organ decellularization and recellularization, (2) three-dimensional bioprinting, (3) advanced stem cell technologies, and (4) the ability to genetically modify tissues and cells. These advancements give hope that organ engineering will become a commercial reality in the next decade. In this review article, we describe the foundational principles of whole organ engineering, discuss key technological advances, and provide an overview of current limitations and future directions.

Insulin production from hiPSC-derived pancreatic cells in a novel wicking matrix bioreactor

Clinical use of pancreatic β islets for regenerative medicine applications requires mass production of functional cells. Current technologies are insufficient for large-scale production in a cost-efficient manner. Here, we evaluate advantages of a porous cellulose scaffold and demonstrate scale-up to a wicking matrix bioreactor as a platform for culture of human endocrine cells. Scaffold modifications were evaluated in a multiwell platform to find the optimum surface condition for pancreatic cell expansion followed by bioreactor culture to confirm suitability. Preceding scale-up, cell morphology, viability, and proliferation of primary pancreatic cells were evaluated. Two optimal surface modifications were chosen and evaluated further for insulin secretion, cell morphology, and viable cell density for human-induced pluripotent stem cell-derived pancreatic cells at different stages of differentiation. Scale-up was accomplished with uncoated, amine-modified cellulose in a miniature bioreactor, and insulin secretion and cell metabolic profiles were determined for 13 days. We achieved 10-fold cell expansion in the bioreactor along with a significant increase in insulin secretion compared with cultures on tissue culture plastic. Our findings define a new method for expansion of pancreatic cells a on wicking matrix cellulose platform to advance cell therapy biomanufacturing for diabetes.

Genistein improve nicotine toxicity on male mice pancreas

Nicotine is the most toxic factor of tobacco. Genistein is a phytoestrogen and antioxidant that has numerous health benefits. The aim of this study is to evaluate the effects of genistein against toxic properties of nicotine to the pancreas of mice. For this purpose, 48 male mice were randomly assigned into six groups (n=8): normal control, nicotine control (2.5 mg/kg), genistein (25 and 50 mg/kg), and nicotine+genistein (25 and 50 mg/kg) treated groups. Various doses of genistein and genistein+nicotine were administered intraperitoneally to animals for 4 weeks. The weight of pancreas, total antioxidant capacity and nitrite oxide of serum, insulin levels, and the number and diameter of islets of Langerhans were investigated. Nicotine administration reduced significantly total antioxidant capacity, insulin, pancreas weight, and the number and diameter of islets of Langerhans and increased nitrite oxide in serum compared to the control normal group (P<0.05). Conversely, genistein and genistein+nicotine increased significantly insulin, total antioxidant capacity, and the number and diameter islets of Langerhans and decreased serum nitrite oxide compared to the nicotine control group. It seems that the genistein can improve pancreas damage following the nicotine administration.

Development of an efficient perfusion-based protocol for whole-organ decellularization of the ovine uterus as a human-sized model and in vivo application of the bioscaffolds

PURPOSE

The main purpose of this investigation was to determine an efficient whole-organ decellularization protocol of a human-sized uterus and evaluate the in vivo properties of the bioscaffold.

METHODS

Twenty-four ovine uteri were included in this investigation and were decellularized by three different protocols (n 6). We performed histopathological and immunohistochemical evaluations, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA quantification, MTT assay, scanning electron microscopy, biomechanical studies, and CT angiography to characterize the scaffolds. The optimized protocol was determined, and patches were grafted into the uterine horns of eight female Wistar rats. The grafts were extracted after 10 days; the opposite horns were harvested to be evaluated as controls.

RESULTS

Protocol III (perfusion with 0.25% and 0.5% SDS solution and preservation in 10% formalin) was determined as the optimized method with efficient removal of the cellular components while preserving the extracellular matrix. Also, the bioscaffolds demonstrated native-like biomechanical, structural, and vascular properties. Histological and immunohistochemical evaluations of the harvested grafts confirmed the biocompatibility and recellularization potential of bioscaffolds. Also, the grafts demonstrated higher positive reaction for CD31 and Ki67 markers compared with the control samples which indicated eminent angiogenesis properties and proliferative capacity of the implanted tissues.

CONCLUSIONS

This investigation introduces an optimized protocol for whole-organ decellularization of the human-sized uterus with native-like characteristics and a prominent potential for regeneration and angiogenesis which could be employed in in vitro and in vivo studies. To the best of our knowledge, this is the first study to report biomechanical properties and angiographic evaluations of a large animal uterine scaffold.