Transdifferentiation of Human Dental Pulp Stem Cells Into Oligoprogenitor Cells

Introduction: The nerve fibers in central nervous system are surrounded by myelin sheet which is formed by oligodendrocytes. Cell therapy based on oligodendrocytes and their precursors transplantation can hold a promising alternative treatment for myelin sheet repair in demyelinating diseases. Methods: Human Dental Pulp Stem Cells (hDPSCs) are noninvasive, autologous and easy available source with multipotency characteristics, so they are in focus of interest in regenerative medicine. In the present study, hDPSCs were differentiated into oligoprogenitor using glial induction media, containing Retinoic Acid (RA), basic Fibroblast Growth Factor (bFGF), Platelet- Derived Growth Factor (PDGF), N2 and B27. The differentiated Oligoprogenitor Cells (OPCs) were evaluated for nestin, Olig2, NG2 and O4 using immunocytochemistry. Also, the expression of nestin, Olig2 and PDGFR-alpha gens (neuroprogenitor and oligoprogenitor markers) were investigated via RT-PCR technique. Results: The results indicate that glial differentiation medium induces the generation of oligoprogenitor cells as revealed via exhibition of specific glial markers, including Olig2, NG2 and O4. The expersion of nestin gene (neuroprogenitor marker) and Olig2 and PDGFR-alpha genes (oligoprogentor markers) were detected in treated hDPSCs at the end of the induction stage. Conclusion: hDPSCs can be induced to transdifferentiate into oligoprogenitor cells and respond to the routinely applied regents for glial differentiation of mesanchymal stem cells. These data suggest the hDPSCs as a valuable source for cell therapy in neurodegenerative diseases

Reserach Paper: Trans-differentiation of human dental pulp stem cells into cholinergic-like neurons via nerve growth factor

Introduction: Cell therapy has been widely considered as a therapeutic approach for neurodegenerative diseases and nervous system damage. Cholinergic neurons as one of the most important neurons that play a significant role in controlling emotions, mobility, and autonomic systems. In this study, Human Dental Pulp Stem Cells (hDPSCs) were differentiated into the cholinergic neurons by β-mercaptoethanol in the preinduction phase and also by the nerve growth factor (NGF) in the induction phase. Methods: The hDPSCs were evaluated for CD73, CD31, CD34, and Oct-4. Concentration-time relationships for NGF were assessed by evaluating the viability rate of cells and the immune response to nestin, neurofilament 160, microtubule-associated protein-2, and choline acetyltransferase. Results: The hDPSCs had a negative response to CD34 and CD31. The optimal dose for the NGF was 50 ng/mL seven days after the induction when the highest percentage of expressing markers for the Cholinergic neurons (ChAT) was detected. Conclusion: The results of this study provided a method for producing cholinergic neurons by hDPSCs, which can be used in cytotherapy for degenerative diseases of the nervous system and also spinal cord injury

In vitro and in vivo evaluations of three-dimensional hydroxyapatite/silk fibroin nanocomposite scaffolds

In this study, three-dimensional hydroxyapatite/silk fibroin (HAp/SF) nanocomposite scaffolds were successfully prepared through layer solvent casting combined with the freeze-drying technique for tissue engineering applications. Various SF aqueous concentrations, ranging from 2.5 to 10, were used to control the physicochemical properties of the prepared scaffolds. Biologic responses of the rat bone marrow stromal cells (rBMSCs) to the HAp/SF scaffolds were examined by culturing the cells within them. In addition, biodegradation and biocompatibility of the scaffolds were evaluated in vitro and in vivo, respectively. Among the prepared scaffolds, HAp/SF-2.5 was the most brittle sample and showed porous structure with lowest mechanical properties. The average pore diameters were 350 ± 67 and 112 ± 89 μm and decreased with the increase in the SF concentration from 5 to 10, respectively. The pores formed in the scaffolds, made up of the 5 SF, were more uniform and regular than those of the scaffolds made up of 5 and 10 SF. The HAp/SF scaffolds did not change the rBMSCs viability and were not cytotoxic compared with the control sample. The scanning electron microscopy micrographs showed that the cells migrated into the pores and well attached to the scaffolds and their cytoplasm was extended in all directions, indicating a promising cell adhesion, high biocompatibility, and no cytotoxicity of the HAp/SF-5 nanocomposite scaffolds. Subcutaneous implantation of the HAp/SF-5 scaffolds in rat models suggested an excellent biocompatibility. All data obtained from this study suggest the potential use of the HAp/SF-5 for hard tissue engineering. © 2014 International Union of Biochemistry and Molecular Biology, Inc

Transdifferentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells in Dopaminergic Neurons in a Three-Dimensional Culture

Introduction: The induction of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) toward dopaminergic neurons is a major challenge in tissue engineering and experimental and clinical treatments of various neurodegenerative diseases, including Parkinson disease. This study aims to differentiate HUC-MSCs into dopaminergic neuron-like cells. Methods: Following the isolation and characterization of HUC-MSCs, they were transferred to Matrigel-coated plates and incubated with a cocktail of dopaminergic neuronal differentiation factors. The capacity of differentiation into dopaminergic neuronlike cells in 2-dimensional culture and on Matrigel was assessed by real-time polymerase chain reaction, immunocytochemistry, and high-performance liquid chromatography. Results: Our results showed that dopaminergic neuronal markers' transcript and protein levels were significantly increased on the Matrigel differentiated cells compared to 2D culture plates. Conclusion: Overall, the results of this study suggest that HUC-MSCs can successfully differentiate toward dopaminergic neuron-like cells on Matrigel, having great potential for the treatment of dopaminergic neuron-related diseases. © 2022 Iran University of Medical Sciences. All rights reserved

Antimicrobial peptides-loaded smart chitosan hydrogel: Release behavior and antibacterial potential against antibiotic resistant clinical isolates

In this study, we synthesized thermo-responsive chitosan (TCTS) hydrogels, and loaded with different concentrations of antimicrobial peptide (AMP) (0, 4, 8 and 16 μg·ml−1) to fabricate an antibacterial wound dressing against resistant clinical isolates. Physico-chemical properties, release behavior, cytobiocompatibility and antibacterial activity of the AMP-TCTS hydrogels against standard strain and resistant Acinetobacter baumannii were fully determined in vitro. The TCTS-40% β-glycerolphosphate hydrogels showed a gelation time of 15 min at 37 °C. 80% weight loss at day 35 with no changes in pH value was observed. AMP-TCTS hydrogels showed a burst release of AMP (around 40%) at day 1, and a controlled release up to day 7. A dramatic water uptake was observed at first 4 h, and then continued for 10 h in a steady manner. All the AMP-TCTS hydrogels showed excellent cytobiocompatibility for human fibroblasts. The TCTS showed no antibacterial activity against both standard strain and clinical isolates. All the AMP-TCTS hydrogels had strong antibacterial activity against standard strains, but only 16 μg·ml−1 showed antibacterial behavior against resistant A. baumannii. Our results strongly suggest the 16 μg·ml−1 AMP-TCTS hydrogel as an excellent antibacterial wound dressing against resistant A. baumannii, and now promises to proceed with pre-clinical investigations