Guiding the Differentiation Direction of Pancreatic Islet-Derived Stem Cells by Glycated Collagen

Tailoring the Heterogeneous Structure of Macro-Fibers Assembled by Bacterial Cellulose Nanofibrils for Tissue Engineering Scaffolds

Bacterial cellulose/oxidized bacterial cellulose nanofibrils (BC/oxBCNFs) macro-fibers are developed as a novel scaffold for vascular tissue engineering. Utilizing a low-speed rotary coagulation spinning technique and precise solvent control, macro-fibers with a unique heterogeneous structure with dense surface and porous core are created. Enhanced by a polydopamine (PDA) coating, these macro-fibers offer robust mechanical integrity, high biocompatibility, and excellent cell adhesion. When cultured with endothelial cells (ECs) and smooth muscle cells (SMCs), the macro-fibers support healthy cell proliferation and exhibit a unique spiral SMC alignment, demonstrating their vascular suitability. This innovative strategy opens new avenues for advances in tissue engineering.

Investigation of the effect of pancreatic decellularized matrix on encapsulated Islets of Langerhans with mesenchymal stem cells

OBJECTIVE

In this study, it was aimed to provide a therapeutic approach for T1DM by encapsulating the pancreatic islets with mesenchymal stem cells and decellularized pancreatic extracellular matrix to support the survival of islets while maintaining their cellular activity.

METHOD

Pancreatic extracellular matrix was decellularized using different concentrations of detergent series. After the preparation of the protein-based tissue extracellular matrix was shown to be free of cells or any genetic material by molecular, immunofluorescence and histochemical techniques. Following the homogenization of the decellularized pancreatic extracellular matrix and the analysis of its protein composition by LC-MS, the matrix proteins were incorporated with pancreatic islets and rat adipose tissue-derived MSCs (rAT-MSCs) in alginate microcapsules. Glucose-stimulated insulin secretion property of the islet cells in the microbeads was evaluated by insulin ELISA. The gene expression profile of the encapsulated cells was analyzed by Real-Time PCR.

RESULTS

Unlike the protein composition of whole pancreatic tissue, the decellularized pancreas matrix was free of histone proteins or proteins originated from mitochondria. The protein matrix derived from pancreatic tissue was shown to support the growth and maintenance of the islet cells. When compared to the non-encapsulated pancreatic islet, the encapsulated cells demonstrate to be more efficient in terms of insulin expression.

CONCLUSION

The extracellular pancreatic matrix obtained in this study was directly used as supplementary in the alginate-based microcapsule enhancing the cell survival. The tissue matrix protein and alginate had a synergistic effect on total insulin secretion, which might have the potential to overcome the insulin deficiency. Despite the improvement in the cell viability and the number, the efficiency of the insulin secretion in response to glucose stimulation from the alginate microcapsules did not meet the expectation when compared with the non-encapsulated pancreatic islets.

The therapeutical effects of damage-specific stress induced exosomes on the cisplatin nephrotoxicity IN VIVO

Cisplatin is one of the metal containing drugs for the solid cancer treatments. However, its side-effects limit its application in the cancer treatment. Stem cell therapy is a promising treatment for the tissue damage caused by the chemotherapeutic agents, like cisplatin. Exosomes secreted by mesenchymal stem cells (MSCs) could be used for cell-free regenerative treatment, but their potency and reproducibility are questionable. In this study, the microenvironment of the renal tubular epithelial cells was mimicked by coculture of endothelial-, renal proximal tubule epithelial- and fibroblast cells. Cisplatin was applied to this tricell culture model, and the secreted rescue signals were collected and used to induce MSCs. From these stress-induced MSCs, the (stress-induced) exosomes were collected and used for the cell-free therapeutic treatment of cisplatin-treated rats with acute kidney injury. The composition of the stress-induces exosomes was compared with the non-induced exosomes and found that the expression of some critical factors for cell proliferation, repair mechanism and oxidative stress was improved. The cisplatin-damaged renal tissue showed substantial recovery after the treatment with stress-induced exosomes compared to the treatment with non-induced exosomes. Although, the non-induced exosomes showed their activity mostly as cytoprotective, the induced exosomes further involved actively in the tissue regeneration, like MSCs. It was shown that the exosomes could be reprogrammed to improve their therapeutic effect to be used in cell-free regenerative medicine. Further, cisplatin-induced tissue damage in the kidney might be effectively prevented and used for tissue regeneration by use of induced exosomes generated for a particular damage.

Comparative study of three types of mesenchymal stem cell to differentiate into pancreatic β-like cells in vitro

Type 1 diabetes (TID) is a chronic metabolic disease where the body produces insufficient or no insulin. Stem cells with multi-directional differentiation potential are transplanted and differentiate into β-like cells in vivo to replace pancreatic β cells, which has become a novel treatment strategy. The aim of the present study was to investigate the ability of three types of adult mesenchymal stem cell (MSC) to differentiate into pancreatic β-like cells in vitro in order to identify suitable sources for the treatment of diabetes. The three MSC types were menstrual blood-derived MSCs (MENSCs), umbilical cord-derived MSCs (UCMSCs) and dental pulp MSCs (DPSCs). The differentiation method used in the present study was divided into three steps and the MSCs were differentiated into pancreatic β-like cells in vitro. Among these MSCs, MENSCs had a greater ability to differentiate into islet β-like cells in vitro, while UCMSCs and DPSCs exhibited a similar differentiation potency, which was relatively lower compared with that of MENSCs. The present results indicated that MENSCs may be a suitable cell source for the curative treatment of TID.

The Impact of Advanced Glycation End-Products (AGEs) on Proliferation and Apoptosis of Primary Stem Cells: A Systematic Review

Stem cell-based regenerative therapies hold great promises to treat a wide spectrum of diseases. However, stem cell engraftment and survival are still challenging due to an unfavorable transplantation environment. Advanced glycation end-products (AGEs) can contribute to the generation of these harmful conditions. AGEs are a heterogeneous group of glycated products, nonenzymatically formed when proteins and/or lipids become glycated and oxidized. Our typical Western diet as well as cigarettes contain high AGEs content. AGEs are also endogenously formed in our body and accumulate with senescence and in pathological situations. Whether AGEs have an impact on stem cell viability in regenerative medicine remains unclear, and research on the effect of AGEs on stem cell proliferation and apoptosis is still ongoing. Therefore, this systematic review provides a clear overview of the effects of glycated proteins on cell viability in various types of primary isolated stem cells used in regenerative medicine.

Improvement of the insulin secretion from beta cells encapsulated in alginate/poly-L- histidine/alginate microbeads by platelet-rich plasma

Type 1 diabetes is clinically characterized as the loss of control of glucose homeostasis due to the reduced number of insulinproducing cells. Long-term glycemic control after implantation could be maintained by preserving the cell viability and tissue-specific functions during the process of microencapsulation. In this study, alginate solution was supplemented with platelet-rich plasma (PRP) to improve the viability and preserve the cell functions during the encapsulation of a beta cell line (BRIN-BD11). Cell viability was assessed and insulin secretion and insulin stimulation index were evaluated. eTh polymerization of alginate with PRP enhanced the viability up to 61% in the alginate microbeads. PRP supplementation to the alginate composition not only increased the number of viable cells by 1.95-fold, but the insulin secretion also improved by about 66%. eTh stimulation index, however, was not affected by the PRP supplementation.