Proliferation of human spermatogonial stem cells on optimized PCL/Gelatin nanofibrous scaffolds

Improvement of culture system and increasing the proliferation of spermatogonia stem cells under in vitro condition are the essential treatment options for infertility before autologous transplantation. Therefore, the present study aimed to evaluate the proliferation of human spermatogonia stem cells on the electrospun polycaprolactone/gelatin nanocomposite. Therefore, for this purpose, nanofiber porous scaffolds were prepared using the electrospinning method and their structures were then confirmed by SEM. After performing swelling, biodegradability and cell adhesion tests, human spermatogonia stem cells were cultured on scaffolds. In addition, both cell viability and proliferation were assessed using immunocytochemistry, flow cytometry and real-time PCR techniques in culturing during a 3-week period. SEM images indicated the presence of fibres with suitable diameters and arrangement as well as a sufficient porosity in nanocomposite scaffolds, showing good biocompatibility and biodegradability. The results show a significant increase in the number of spermatogonia stem cells in the cultured group on scaffold compared with the control group (p ≤ 0.05). As well, the results show that the expressions of integrin ɑ6 and β1 and Plzf genes estimated using real-time PCR in nanofiber scaffolds were significantly higher than those of the control group (p ≤ 0.05). However, the expression of c-Kit gene in the 3D group showed a significant decrease compared with the 2D group. Flow cytometry analysis also showed that the number of Plzf-positive cells was significantly higher in nanofiber porous scaffolds compared with the control group (p ≤ 0.05). Additionally, immunocytochemistry findings confirmed the presence of human spermatogonia stem cell colonies. In general, it seems that the designed nanocomposite scaffold could provide a suitable capacity for self-renewal of human spermatogonia stem cells, which can have a good application potential in research and reconstructive medicine related to the field of male infertility.

Augmenting Peripheral Nerve Regeneration Using Hair Follicle Stem Cells in Rats

Introduction

Cell therapy is the most advanced treatment of peripheral nerve injury. This study aimed to determine the effects of transplantation of hair follicle stem cells on the regeneration of the sciatic nerve injury in rats.

Methods

The bulge region of the rat whisker were isolated and cultured. Morphological and biological features of the cultured bulge cells were observed by light microscopy and immunocytochemistry methods. Percentages of CD34, K15, and nestin cell markers expression were demonstrated by flow cytometry. Rats were randomly divided into 3 groups of injury, epineurium, and epineurium with cells in which rat Hair Follicular Stem Cells (rHFSCs) were injected into the site of the nerve cut. HFSCs were labeled with Bromodeoxyuridine (BrdU), and double-labeling immunofluorescence was performed to study the survival and differentiation of the grafted cells. After 8 weeks, electrophysiological, histological, and immunocytochemical analysis assessments were performed.

Results

Rat hair follicle stem cells are suitable for cell culture, proliferation, and differentiation. The results suggest that transplantation of rat hair follicle stem cells can regenerate sciatic nerve injury; moreover, electrophysiology and histology examinations show that sciatic nerve repair was more effective in the epineurium with cell group than in the other experimental group (P<0.05).

Conclusion

The achieved results propose that hair follicle stem cells improve axonal growth and functional recovery after peripheral nerve injury.

Highlights

This study showed that rat hair follicle stem cells are suitable for cell culture, proliferation and differentiationThe results suggested that transplantation of rat hair follicle stem cells had the potential capability of regenerating sciatic nerve injuryEvidence of electrophysiology and histology showed Concomitant use of epineurium with hair follicle stem cell was more effective repairment.

Plain Language Summary

Although repairing damaged peripheral nerves has always been a medical challenge, but peripheral nerve injury has been successfully repaired using various procedures such as nerve auto-graft or stem cell therapy. The functional reconstruction is the most important after therapy because of that primary nerve repair or use of nerve autograft, are still accepted as golden standard methods for treatment. Considerable recent interest has been focused on adult stem cells for both research and clinical applications. A highly promising source of relatively abundant and accessible, active, multipotent adult stem cells are obtained from hair follicles. In research the hair follicle stem cells implanted into the gap region of a severed sciatic nerve injury greatly enhanced the rate of nerve regeneration and the restoration of nerve function. Time is one of the several aspects require specific attention in the clinical treatment of peripheral nerve injury. Because delay of nerve injury treatment may cause neurobiological alterations in neurons and Schwann cells, impairing nerve functional recovery and affect neuron survival. In this study, concluded that stem cell injection 2 weeks after injury in the damaged nerve epineurium repairs nerve fibers, while electrophysiology of the leg muscles showed that muscle function was significantly improved. It indicates the repair of muscular innervation and nerve repair. The results pave the way for further research on this topic.

Ultrasonic irradiation to modify the functionalized bionanocomposite in sulfonated polybenzimidazole membrane for fuel cells applications and antibacterial activity

In this article the new proton exchange membranes were prepared from sulfonated polybenzimidazole (s-PBI) and various amounts of sulfonated titania/cellulose nanohybrids (titania/cellulose-SO₃H) via ultrasonic waves. The ultrasonic irradiation effectively changes the rheology and the glass transition temperature and the crystallinity of the composite polymer. Ultrasonic irradiation has a very strong mixing and dispersion effect, much stronger than conventional stirring, which can improve the dispersion of titania/cellulose-SO₃H nanoparticles in the polymer matrix. The strong -SO₃H/-SO₃H interaction between s-PBI chains and titania/cellulose-SO₃H hybrids leads to ionic cross-linking in the membrane structure, which increases both the thermal stability and methanol resistance of the membranes. After acid doping with phosphoric acid, s-PBI/titania/cellulose-SO₃H nanocomposite membranes exhibit depressions on methanol permeability and enhancements on proton conductivity comparing to the pristine s-PBI membrane. The chemical structure of the functionlized titania was characterized with FTIR, and energy-dispersive X-ray. Imidazole and sulfonated groups on the surface of modified nanoparticles forming linkages with s-PBI chains, improved the compatibility between s-PBI and nanoparticles, and enhanced the mechanical strength of the prepared nanocomposite membranes. From SEM and TEM analysis could explain the homogeneous dispersion of titania/cellulose-SO₃H in nanocomposite membranes. Moreover, the membranes exhibited excellent antibacterial activities against S. aureus and E. coli. A.

Hair follicle stem cells: In vitro and in vivo neural differentiation

Hair follicle stem cells (HFSCs) normally give rise to keratinocytes, sebocytes, and transient amplifying progenitor cells. Along with the capacity to proliferate rapidly, HFSCs provide the basis for establishing a putative source of stem cells for cell therapy. HFSCs are multipotent stem cells originating from the bulge area. The importance of these cells arises from two important characteristics, distinguishing them from all other adult stem cells. First, they are accessible and proliferate for long periods. Second, they are multipotent, possessing the ability to differentiate into mesodermal and ectodermal cell types. In addition to a developmental capacity in vitro, HFSCs display an ability to form differentiated cells in vivo. During the last two decades, numerous studies have led to the development of an appropriate culture condition for producing various cell lineages from HFSCs. Therefore, these stem cells are considered as a novel source for cell therapy of a broad spectrum of neurodegenerative disorders. This review presents the current status of human, rat, and mouse HFSCs from both the cellular and molecular biology and cell therapy perspectives. The first section of this review highlights the importance of HFSCs and in vitro differentiation, while the final section emphasizes the significance of cell differentiation in vivo.

Neuronal differentiation of rat hair follicle stem cells: the involvement of the neuroprotective factor Seladin-1 (DHCR24)

Background: The seladin-1 (selective Alzheimer disease indicator-1), also known as DHCR24, is a gene found to be down-regulated in brain region affected by Alzheimer disease (AD). Whereas, hair follicle stem cells (HFSC), which are affected in with neurogenic potential, it might to hypothesize that this multipotent cell compartment is the predominant source of seladin-1. Our aim was to evaluate seladin-1 gene expression in hair follicle stem cells. Methods: In this study, bulge area of male Wistar rat HFSC were cultured and then characterized with Seladin-1 immunocytochemistry and flow cytometry on days 8 to 14. Next, 9-11-day cells were evaluated for seladin-1 gene expression by real-time PCR. Results: Our results indicated that expression of the seladin-1 gene (DHCR24) on days 9, 10, and 11 may contribute to the development of HFSC. However, the expression of this gene on day 11 was more than day 10 and on 10^th day was more than day 9. Also, we assessed HFSC on day 14 and demonstrated these cells were positive for β-ш tubulin, and seladin-1 was not expressed in this day. Conclusion: HFSC express seladin-1 and this result demonstrates that these cells might be used to cell therapy for AD in future.

Delivery of epidermal neural crest stem cells (EPI-NCSC) to hippocamp in Alzheimer's disease rat model

BACKGROUND

Alzheimer's disease (AD) is characterized by progressive neuronal loss in hippocamp. Epidermal neural crest stem cells (EPI-NCSC) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the effects of transplanting EPI-NCSC into AD rat model.

METHODS

Two weeks after induction of AD by injection of Amyloid-β1-40 into CA1 area of rat hippocamp, Y-maze and single-trial passive avoidance tests were used to show deficit of learning and memory abilities. EPI-NCSC were obtained from the vibrissa hair follicle of rat, cultured and labeled with bromodeoxyuridine. When Alzheimer was proved by behavioral tests, EPI-NCSC was transplanted into CA3 area of hippocamp in AD rat model. The staining of EPI-NCSC markers (nestin and SOX10) was done in vitro. Double-labeling immunofluorescence was performed to study survival and differentiation of the grafted cells.

RESULTS

We showed that transplanted EPI-NCSC survive and produce many neurons and a few glial cells, presenting glial fibrillary acidic protein. Total number of granule cells in hippocamp was estimated to be more in the AD rat model with transplanted cells as compared to AD control group. We observed that rats with hippocampal damage made more errors than control rats on the Y-maze, when reward locations were reversed.

CONCLUSION

Transplanted cells were migrated to all areas of hippocamp and the total number of granule cell in treatment group was equal compared to control group. Transplantation of EPI-NCSC into hippocamp might differentiate into cholinergic neurons and could cure impairment of memory in AD rat model.