Search

Introduction: Strategies of Schwann cell (SC) transplantation for regeneration of peripheral nerve injury involve many limitations. Stem cells can be used as alternative cell source for differentiation into Schwann cells. Given the high potential of neural crest-derived stem cells for the generation of multiple cell lineages, in this research, we considered whether olfactory ectomesenchymal stem cells (OE-MSCs) derived from neural crest can spontaneously differentiate into SC lineage Methods: OE-MSCs were isolated from human nasal mucosa and characterized by the mesenchymal and neural crest markers. The cells were cultured in glial growth factors-free medium and further investigated in terms of the phenotypic and functional properties. Results: Immunocytochemical staining and real-time PCR analysis indicated that the cultured OE-MSCs expressed SCs markers, SOX10, p75, S100, GFAP and MBP, differentiation indicative. It was found that the cells could secrete neurotrophic factors, including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Furthermore, after co-cultured with PC12, the mean neurite length was enhanced by OE-MSCs. Conclusion: The findings indicated that OE-MSCs could be differentiated spontaneously into SC-like phenotypes, suggesting their applications for transplantation in peripheral nerve injuries.

Introduction: Maintenance of neurogenesis depends on the function of some histone-modifying enzymes; including Enhancer of zeste homolog 2 (EZH2) and histone acetyltransferases (P300). The mechanism of epigenetic regulation and gene expression underlying the transition of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) into MNs has not been fully clarified. Methods: Two morphogens; sonic hedgehog (Shh: 100 ng/mL) and retinoic acid (RA: 0.01 mM) were involved in the specification of hUCB-MSCs into MNs after MSC characterization using Flow cytometry. Real time-quantitative PCR and immunocytochemistry were performed to find the expression of the genes at the level of mRNA and protein. Results: The expression of MN-related markers was confirmed at the level of mRNA and protein by induction of differentiation. The results were confirmed by immunocytochemistry and showed those mean cell percentages of 55.33%±15.885% and 49.67%±13.796% could express Islet-1 and ChAT, respectively. The gene expression level of Islet-1 and ChAT was significantly increased in the first and second week of exposure, respectively. After two weeks, the expression level of P300 and EZH-2 genes increased remarkably. No significant expression of Mnx-1 was detected when compared to the control sample. Conclusion: MN-related markers, Islet-1 and ChAT, were detected in differentiated cells of hUCB-MSCs, supporting the potency of cord blood cells in the regeneration of MN-related disorders. Assessing these epigenetic regulatory genes at the protein level can be suggested to confirm their functional epigenetic modifying effects during motor neuron differentiation.

The pressing demand for a creative method to effectively model human drug responses in preclinical research has prompted the advancement of organ-on-a-chip (OoC) systems.

Peripheral nerve injury is a common medical condition that has a great impact on patient quality of life. Currently, surgical management is considered to be a gold standard first-line treatment; however, is often not successful and requires further surgical procedures. Commercially available FDA- and CE-approved decellularized nerve conduits offer considerable benefits to patients suffering from a completely transected nerve but they fail to support neural regeneration in gaps > 30 mm. To address this unmet clinical need, current research is focused on biomaterial-based therapies to regenerate dysfunctional neural tissues, specifically damaged peripheral nerve, and spinal cord. Recently, attention has been paid to the capability of graphene-based materials (GBMs) to develop bifunctional scaffolds for promoting nerve regeneration, often via supporting enhanced neural differentiation. The unique features of GBMs have been applied to fabricate an electroactive conductive surface in order to direct stem cells and improve neural proliferation and differentiation. The use of GBMs for nerve tissue engineering (NTE) is considered an emerging technology bringing hope to peripheral nerve injury repair, with some products already in preclinical stages. This review assesses the last six years of research in the field of GBMs application in NTE, focusing on the fabrication and effects of GBMs for neurogenesis in various scaffold forms, including electrospun fibres, films, hydrogels, foams, 3D printing, and bioprinting.

The occurrence of anosmia, the loss or change in sense of smell, is one of the most common symptoms of COVID-19 experienced by almost 53% of those affected. Several hypotheses explain the mechanism of anosmia in patients suffering from COVID-19. This study aims to review the related mechanisms and answer the questions regarding COVID-19-related anosmia as well as propose a new strategy for treatment of long-term anosmia as a result of COVID-19 infection. This paper covers all of the studies investigating olfactory disorders following COVID-19 infection and explains the possible reasons for the correlated anosmia, including olfactory cleft syndrome, local inflammation in the nasal epithelium, early apoptosis of olfactory cells, changes in olfactory cilia and odor transmission, damage to microglial cells, effect on olfactory bulbs, epithelial olfactory injury, and impairment of olfactory neurons and stem cells. The key questions that arise in this field have been discussed, such as why prevalent anosmia is varied among the age categories and among sexes and the correlation of anosmia with mild or severe COVID-19 infection. The angiotensin-converting enzyme 2 receptor is a significant player in the mechanism of anosmia in COVID-19 patients. Based on current studies, a novel approach to treat long-COVID-19 with ongoing anosmia has been proposed. The fields of smart drug delivery, tissue engineering, and cell therapy provide a hypothesized strategy that can minimize the side effects of current treatments and support efficient recovery of the olfactory system.

Introduction: Cholinergic-associated diseases currently constitute a significant cause of neurological and neurodegenerative disabilities. As the drugs are not efficient in improving the suffered tissues, stem cell treatment is considered an effective strategy for substituting the lost cells. Methods: In the current study, we set out to investigate the differentiation properties of human Adipose-Derived Mesenchymal Stem Cells (AD-MSCs) into cholinergic-like cells by two morphogens of Retinoic Acid (RA) and Sonic Hedgehog (Shh) using a three-step in vitro procedure. The results were evaluated using real-time PCR, flow cytometry, and immunocytochemistry for two weeks. Results: Our data showed that the cells could express cholinergic specific markers, including Islet-1, Acetylcholinesterase (AChE), SMI-32, and Nestin, at mRNA and protein levels. We could also quantitatively evaluate the expression of Islet-1, AChE, and Nestin at 14 days post-induction using flow cytometry. Conclusion: Human AD-MSCs are potent cells to differentiate into cholinergic-like cells in the presence of RA and Shh through a three-step protocol. Thus, they could be a suitable cell candidate for the regeneration of cholinergic-associated diseases. However, more functional and electrophysiological analyses are needed in this regard.

Bioactive glasses are highly reactive surface materials synthesized by melting or sol-gel techniques. In this study, mesoporous bioactive glass-ceramics doped with different amounts of vanadium and iron ((60-(

Among the various therapeutic procedures used for improving PD, stem cell-based therapy has been shown to be a promising method. Olfactory ectomesenchymal stem cells (OE-MSCs) are a great source of stem cells for PD. Also, the intranasal administration (INA) of stem cells to the neural lesion has several advantages over the other approaches to cellular injections. However, improving the efficacy of INA to produce the highest number of cells at the lesion site has always been a controversial issue. For this purpose, this study was designed to apply the magnetically targeted cell delivery (MTCD) approach to OE-MSCs in the injured striatum area through the IN route in order to explore their outcomes in rat models of PD. Animals were randomly classified into four groups including control, PD model, treatment-NTC (treated with INA of non-target cells), and treatment-TC (treated with INA of target cells). The Alg-SPIONs-labeled OE-MSCs were stained successfully using the Prussian blue method with an intracellular iron concentration of 2.73 pg/cell. It was able to reduce signal intensity in the striatum region by increasing the number of these cells, as shown by the magnetic resonance imaging (MRI). Behavioral evaluation revealed that the administration of OE-MSCs with this novel advanced stem cell therapy alleviated Parkinson's motor dysfunction. Further, histological evaluations confirmed the functional enhancement of dopaminergic neuron cells by the expression of Nurr1, Dopamine transporter (DAT), and paired-like homeodomain transcription factor 3 (TH). Overall, this study showed that INA of OE-MSCs in the MTCD approach enhanced stem cells' therapeutic effects in PD models.

Objective: Animal-free scaffolds have emerged as a potential foundation for consistent, chemically defined, and low-cost materials. Because of its good potential for high biocompatibility with reproductive tissues and well-characterized scaffold design, we investigated whether polyglycolic acid (PGA) could be used as an animal-free scaffold instead of natural fibrin-agarose, which has been used successfully for three-dimensional human endometrial cell culture.Methods: Isolated primary endometrial cells was cultured on fibrin-agarose and PGA polymers and evaluated various design parameters, such as scaffold porosity and mean fiber diameter. Cytotoxicity, scanning electron microscopy (SEM), and immunostaining experiments were conducted to examine cell activity on fabricated scaffolds.Results: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and SEM results showed that endometrial cells grew and proliferated on both scaffolds. Immunostaining showed cytokeratin and vimentin expression in seeded cells after 7 days of culture. On both scaffolds, an epithelial arrangement of cultured cells was found on the top layer and stromal arrangement matrix on the bottom layer of the scaffolds. Therefore, fibrin-agarose and PGA scaffolds successfully mimicked the human endometrium in a way suitable for in vitro analysis.Conclusion: Both fibrin-agarose and PGA scaffolds could be used to simulate endometrial structures. However, because of environmental and ethical concerns and the low cost of synthetic polymers, we recommend using PGA as a synthetic polymer for scaffolding in research instead of natural biomaterials.

Current hyaluronic acid-based hydrogels often cause cytotoxicity to encapsulated cells and lack the adhesive property required for effective biomedical and tissue engineering applications. Provision of the cell-adhesive surface is an important requirement to improve its biocompatibility. An aqueous solution of hyaluronic acid possessing phenolic hydroxyl (HA-Ph) moieties is gellable via a horseradish peroxidase (HRP)-catalyzed oxidative cross-linking reaction. This study evaluates the effect of different degrees of cross-linked Ph moieties on cellular adhesiveness and proliferation on the resultant enzymatically cross-linked HA-Ph hydrogels. Mechanical characterization demonstrated that the compression force of engineered hydrogels could be tuned in the range of 0.05-35 N by changing conjugated Ph moieties in the precursor formulation. The water contact angle and water content show hydrophobicity of hydrogels increased with increasing content of cross-linked Ph groups. The seeded mouse embryo fibroblast-like cell line and human cervical cancer cell line, on the HA-Ph hydrogel, proved cell attachment and spreading with a high content of cross-linked Ph groups. The HA-Ph with a higher degree of Ph moieties shows the maximum degree of cell adhesion, spreading, and proliferation which presents this hydrogel as a suitable biomaterial for biomedical and tissue engineering applications.

About 2.8% of trauma patients suffer from peripheral nerve injury and it becomes a serious challenge in the world. Therefore, various methods and materials have been used for regenerating periphera...

One of the most effective approaches for treatment of cartilage involves the use of porous three-dimensional scaffolds, which are useful for improving not only cellular adhesion but also mechanical properties of the treated tissues. In this study, we manufactured a composite scaffold with optimum properties to imitate nasal cartilage attributes. Cartilage extracellular matrix (ECM) was used in order to improve the cellular properties of the scaffolds; while, chitosan and agarose were main materials that are used to boost the mechanical and rheological properties of the scaffolds. Furthermore, we explored the effect of the various weight ratios of chitosan, agarose, and ECM on the mechanical and biomedical properties of the composite scaffolds using the Taguchi method. The resulting composites display a range of advantages, including good mechanical strength, porous morphology, partial crystallinity, high swelling ratio, controlled biodegradability rate, and rheological characteristics. Additionally, we performed the cytotoxicity tests to confirm the improvement of the structure and better cell attachments on the scaffolds. Our findings illustrate that the presence of the ECM in chitosan/agarose structure improves the biomedical characteristics of the final scaffold. In addition, we were able to control the mechanical properties and microstructure of the scaffolds by optimizing the polymers' concentration and their resulting interactions. These results present a novel scaffold with simultaneously enhanced mechanical and cellular attributes comparing to the scaffolds without ECM for nasal cartilage tissue engineering applications.

Regenerative medicine offers the potential to repair or substitute defective tissues by constructing active tissues to address the scarcity and demands for transplantation. The method of forming 3D constructs made up of biomaterials, cells, and biomolecules is called bioprinting. Bioprinting of stem cells provides the ability to reliably recreate tissues, organs, and microenvironments to be used in regenerative medicine. 3D bioprinting is a technique that uses several biomaterials and cells to tailor a structure with clinically relevant geometries and sizes. This technique's promise is demonstrated by 3D bioprinted tissues, including skin, bone, cartilage, and cardiovascular, corneal, hepatic, and adipose tissues. Several bioprinting methods have been combined with stem cells to effectively produce tissue models, including adult stem cells, embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and differentiation techniques. In this review, technological challenges of printed stem cells using prevalent naturally derived bioinks (e.g., carbohydrate polymers and protein-based polymers, peptides, and decellularized extracellular matrix), recent advancements, leading companies, and clinical trials in the field of 3D bioprinting are delineated.

Various composite scaffolds with different fabrication techniques have been applied in cartilage tissue engineering. In this study, poly ɛ-caprolactone (PCL) was printed by fused deposition modeling method, and the prepared scaffold was filled with Alginate (Alg): Alginate-Sulfate (Alg-Sul) hydrogel to provide a better biomimetic environment and emulate the structure of glycosaminoglycans properly. Furthermore, to enhance chondrogenesis, different concentrations of decellularized extracellular matrix (dECM) were added to the hydrogel. For cellular analyses, the adipose-derived mesenchymal stem cells were seeded on the hydrogel and the results of MTT assay, live/dead staining, and SEM images revealed that the scaffold with 1% dECM had better viscosity, cell viability, and proliferation. The study was conducted on the optimized scaffold (1% dECM) to determine mechanical characteristics, chondrogenic differentiation, and results demonstrated that the scaffold showed mechanical similarity to the native nasal cartilage tissue along with possessing appropriate biochemical features, which makes this new formulation based on PCL/dECM/Alg:Alg-Sul a promising candidate for further in-vivo studies.

Implantation of a suitable nerve guide conduit (NGC) seeded with sufficient Schwann cells (SCs) is required to improve peripheral nerve regeneration efficiently. Given the limitations of isolating and culturing SCs, using various sources of stem cells, including mesenchymal stem cells (MSCs) obtained from nasal olfactory mucosa, can be desirable. Olfactory ecto-MSCs (OE-MSCs) are a new population of neural crest-derived stem cells that can proliferate and differentiate into SCs and can be considered a promising autologous alternative to produce SCs. Regardless, a biomimetic physicochemical microenvironment in NGC such as electroconductive substrate can affect the fate of transplanted stem cells, including differentiation toward SCs and nerve regeneration. Therefore, in this study, the effect of 3D printed polycaprolactone (PCL)/polypyrrole (PPy) conductive scaffolds on differentiation of human OE-MSCS into functional SC-like phenotypes was investigated. Biological evaluation of 3D printed scaffolds was examined by in vitro culturing the OE-MSCs on samples surfaces, and conductivity showed no effect on increased cell attachment, proliferation rate, viability, and distribution. In contrast, immunocytochemical staining and real-time polymerase chain reaction analysis indicated that 3D structures coated with PPy could provide a favorable microenvironment for OE-MSCs differentiation. In addition, it was found that differentiated OE-MSCs within PCL/PPy could secrete the highest amounts of nerve growth factor and brain-derived neurotrophic factor neurotrophic factors compared to pure PCL and 2D culture. After co-culturing with PC12 cells, a significant increase in neurite outgrowth on PCL/PPy conductive scaffold seeded with differentiated OE-MSCs. These findings indicated that 3D printed PCL/PPy conductive scaffold could support differentiation of OE-MSCs into SC-like phenotypes to promote neurite outgrowth, suggesting their potential for neural tissue engineering applications.

The modification of poly (

For bone tissue engineering, stem cell-based therapy has become a promising option. Recently, cell transplantation supported by polymeric carriers has been increasingly evaluated. Herein, we encapsulated human olfactory ectomesenchymal stem cells (OE-MSC) in the collagen hydrogel system, and their osteogenic potential was assessed in vitro and in vivo conditions. Collagen type I was composed of four different concentrations of (4 mg/mL, 5 mg/mL, 6 mg/mL, 7 mg/mL). SDS-Page, FTIR, rheologic test, resazurin assay, live/dead assay, and SEM were used to characterize collagen hydrogels. OE-MSCs encapsulated in the optimum concentration of collagen hydrogel and transplanted in rat calvarial defects. The tissue samples were harvested after 4- and 8-weeks post-transplantation and assessed by optical imaging, micro CT, and H&amp, E staining methods. The highest porosity and biocompatibility were confirmed in all scaffolds. The collagen hydrogel with 7 mg/mL concentration was presented as optimal mechanical properties close to the naïve bone. Furthermore, the same concentration illustrated high osteogenic differentiation confirmed by real-time PCR and alizarin red S methods. Bone healing has significantly occurred in defects treated with OE-MSCs encapsulated hydrogels in vivo. As a result, OE-MSCs with suitable carriers could be used as an appropriate cell source to address clinical bone complications.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders, which is caused by the loss of dopaminergic (DAergic) neurons. Thus, cell replacement therapy (CRT) might be regarded as an alternative therapy to effectively treat motor functional defects in PD patients. Human olfactory ectomesenchymal stem cells (OE-MSCs) are a novel type of mesenchymal stem cells (MSCs) with a strong tendency to differentiate into DAergic neurons. However, there are various barriers to successful CRT including the proliferation capacity of stem cells at higher passage numbers as well as the route of stem cell delivery. In this regard, we aimed to explore the efficacy of late passage OE-MSC administration through the intranasal (IN) route in PD rat models. Herein, the proliferation capacity of OE-MSCs was compared at early and late passage numbers; then, the results were validated via RNA sequencing analysis. Subsequently, the efficacy of IN injection of late passage OE-MSC in PD models was evaluated. The results manifested the absence of noticeable differences in proliferation capacity and signaling pathways in OE-MSCs at early and late passage numbers. Moreover, it was found that the IN administration of OE-MSCs with a high passage number substantially increased the levels of DAergic markers and improved the motor function in rat models of PD. Overall, our findings suggested that OE-MSCs with a high passage number are a promising CRT candidate due to their fundamental potential to provide a large number of cells with an enormous proliferation capacity. Moreover, they exhibit the high efficiency of IN administration as a noninvasive route of late-passage OE-MSC delivery for CRT, particularly for PD.

Mutations in NARS2 (MIM: 612803) are associated with combined oxidative phosphorylation deficiency 24 (COXPD24; MIM: 616239) that is a rare mitochondrial and a multisystem autosomal recessive disorder. We aimed to detect the underlying genetic factors in two siblings with progressive ataxia, epilepsy, and severe-to-profound hearing impairment. After doing medical assessments and pertinent tests (i.e., auditory brainstem responses, pure tone otoacoustic emission test, cardiac examinations, computed tomography, and electroencephalogram), because of the clinical and probable genetic heterogeneity, whole-exome sequencing was performed, and co-segregation analysis was confirmed by Sanger sequencing. Biological impacts of the novel variant were evaluated using sequence-to-function bioinformatics tools. A novel homozygous missense variant, NM_024678.6:c.545 T > A; p.(Ile182Lys), in exon 5 of NARS2 was identified in both patients and verified by Sanger sequencing. In silico analyses introduced this variant as pathogenic. Mitral valve prolapses with mild regurgitation, brachymetatarsia, severe hallux valgus, and clubbed fingers were reported as novel manifestations in association with NARS2 gene. By doing a literature review, we also underscored the high heterogeneity of disease phenotype. Herein, we report some novel phenotype and genotype features of two female patients in an Iranian consanguineous family with COXPD24, caused by a variant in NARS2—NM_024678.6: c.545 T > A; p.(Ile182Lys). Moreover, our data expanded the phenotype and genotype spectrum of NARS2-related disorder and confirmed an unpredictable nature of genotype–phenotype correlation in COXPD24.

Novel injectable thermosensitive PNIPAM/hyaluronic acid hydrogels containing various amounts of chitosan-g-acrylic acid coated PLGA (ACH-PLGA) micro/nanoparticles were synthesized and designed to facilitate the regeneration of cartilage tissue. The ACH-PLGA particles were used in the hydrogels to play a triple role: first, the allyl groups on the chitosan-g-acrylic acid shell act as crosslinkers for PNIPAM and improved the mechanical properties of the hydrogel to mimic the natural cartilage tissue. Second, PLGA core acts as a carrier for the controlled release of chondrogenic small molecule melatonin. Third, they could reduce the syneresis of the thermosensitive hydrogel during gelation. The optimum hydrogel with the minimum syneresis and the maximum compression modulus was chosen for further evaluations. This hydrogel showed a great integration with the natural cartilage during the adhesion test, and also, presented an interconnected porous structure in scanning electron microscopy images. Eventually, to evaluate the cytotoxicity, mesenchymal stem cells were encapsulated inside the hydrogel. MTT and Live/Dead assay showed that the hydrogel improved the cells growth and proliferation as compared to the tissue culture polystyrene. Histological study of glycosaminoglycan (GAG) showed that melatonin treatment has the ability to increase the GAG synthesis. Overall, due to the improved mechanical properties, low syneresis, the ability of sustained drug release and also high bioactivity, this injectable hydrogel is a promising material system for cartilage tissue engineering.

Background: Hearing impairment (HI) is a heterogeneous disorder. GJB2 and GJB6 genes are typically the first line of genetic screening before proceeding to any massive parallel sequencing. ...

Introduction: Aging is a natural phenomenon that is caused by changes in the cells of the body. Theoretically, aging starts from birth and lasts throughout life. These changes affect the function of the cells. Also, in old tissues, the capacity for homeostasis and tissue repair is decline due to destructive changes in specific tissue stem cells, niche of stem cells and systemic factors that regulate stem cell activity. Understanding molecular pathways that disrupt stem cell function during aging is crucial for the development of new treatments for aging-associated diseases. In this article, the symptoms of stem cell aging and the key molecular pathways that are commonly used for the aging of stem cells were discussed. We will consider experimental evidence for all of the mechanisms and evaluate the way that can slow down or even stop the aging process. Finally, we will look at the aging process of three types of stem cells.

Regeneration and functional recovery after peripheral nerve damage still remain a significant clinical problem. In this study, alginate/chitosan (alg/chit) hydrogel was used for the transplantation of olfactory ectomesenchymal stem cells (OE-MSCs) to promote peripheral nerve regeneration. The OE-MSCs were isolated from olfactory mucosa biopsies and evaluated by different cell surface markers and differentiation capacity. After creating sciatic nerve injury in a rat model, OE-MSCs were transplanted to the injured area with alg/chit hydrogel which was prepared and well-characterized. The prepared hydrogel had the porosity of 91.3 ± 1.27%, the swelling ratio of 379% after 240 min, weight loss percentages of 80 ± 5.56% after 14 days, and good blood compatibility. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, 4',6-diamidino-2-phenylindole, and LIVE/DEAD staining were done to assay the behavior of OE-MSCs on alg/chit hydrogel and the results confirmed that the hydrogel can provide a suitable substrate for cell survival. For functional analysis, alg/chit hydrogel with and without OE- MSCs was injected into a 3-mm sciatic nerve defect of Wistar rats. The results of the sciatic functional index, hot plate latency, electrophysiological assessment, weight-loss percentage of wet gastrocnemius muscle, and histopathological examination using hematoxylin-eosin and Luxol fast blue staining showed that utilizing alg/chit hydrogel with OE-MSCs to the sciatic nerve defect enhance regeneration compared to the control group and hydrogel without cells.

Desirable carbon allotropes such as graphene oxide (GO) have entered the field with several biomedical applications, owing to their exceptional physicochemical and biological features, including extreme strength, found to be 200 times stronger than steel; remarkable light weight; large surface-to-volume ratio; chemical stability; unparalleled thermal and electrical conductivity; and enhanced cell adhesion, proliferation, and differentiation properties. The presence of functional groups on graphene oxide (GO) enhances further interactions with other molecules. Therefore, recent studies have focused on GO-based materials (GOBMs) rather than graphene. The aim of this research was to highlight the physicochemical and biological properties of GOBMs, especially their significance to biomedical applications. The latest studies of GOBMs in biomedical applications are critically reviewed, and in vitro and preclinical studies are assessed. Furthermore, the challenges likely to be faced and prospective future potential are addressed. GOBMs, a high potential emerging material, will dominate the materials of choice in the repair and development of human organs and medical devices. There is already great interest among academics as well as in pharmaceutical and biomedical industries.

Cellular growth of enclosed cells in core-shell microcapsules is a key element for the practical use of the device in tissue engineering and biopharmaceutical fields. We developed alginate derivative microcapsules with a liquid core template by horseradish peroxidase crosslinking using an integrated coaxial microfluidic device by electrospray system. The cells and gelatin solution were extruded from the inner channel of coaxial microfluidic device and alginate possessing phenolic moieties (Alg-Ph) and horseradish peroxidase (HRP) flowed from the outer channel. In open electric filed, concentric drops of the two coaxial fluids broken up into microdrops and sprayed into the gelling bath containing hydrogen peroxide to instantly gel alginate in the shell fluid before the two fluids got mixed or gelatin dispersed in a gelling bath. The core-shell structure of about 350 μm in diameter and gel membrane of 42 μm was developed by optimization of operational parameters including electrical voltage, flow rate and concentration of polymers. The physical properties of microcapsules including swelling and mechanical resistance proved the applicability of fabricated vehicles for cell culture systems in vitro and in vivo. The viability of enclosed fibroblast cells in generated core-shell microcapsule was more than 90% which is sufficiently high compared with it before encapsulation. The growth profile and behavior of cells in microcapsules showed appropriate cell growth and the possibility of fabrication of spherical tissue was confirmed through degradation of hydrogel membrane. These results validate the significant potential of coaxial electrospray system and HRP-mediated hydrogelation in the fabrication of cell-laden core-shell microcapsule for tissue engineering and regenerative medicine.

Background Therapy based stem cells have offered a novel therapeutic approach for the improvement of neurodegenerative diseases, specially Parkinson. Hence, developing a well-established culture model with appropriate stem cells is extremely crucial in regenerative engineering to provide efficient targeted cells. Human adult mesenchymal stem cells derived from adipose tissue (hADSCs) have emerged as a promising source of stem cells due to their unique potentials of self-renewal and differentiation into other stem cells. The purpose of this study was to investigate the differentiation capacity of hADSCs into dopaminergic and neuron-like cells in the 3D culture plate (Matrigel). Methods and materials hADSCs were obtained from adipose tissues of patients and then characterized morphologically with flowcytometry. Isolated cells were harvested to perform differentiation on Matrigel and tissue culture plate (TCP) supplemented with induction factors. The survival rate of cells during neural induction was monitored by MTT. The expression of specific cell markers was analyzed by QRT-PCR and immunocytochemistry on days 2, 8 and 14. The level of released dopamine was measured using HPLC technique. Results Matrigel had a positive effect on maintaining cell growth compared to those on TCP. Moreover, the number of TH and MAPII positive cells is substantially higher in Matrigel than in TCP. Sox2 and Nestin had a prominent expression in hADSCs within the first days of differentiation. The gene expression of neural markers such as TH, Nurr1, LMX1A and DAT was detected and increased after day 8. Moreover, the dopamine released in the cell harvested on Matrigel was greater than those seeded on TCP. Conclusions Overall, hADSCs could generate dopaminergic cells, which suggest its strong capability to serve as a tool for Parkinson disease model in the regenerative medicine.

The tympanic membrane (TM), more commonly known as the eardrum, consists of a thin layer of tissue in the human ear that receives sound vibrations from outside of the body and transmits them to the auditory ossicles. The TM perforations (TMPs) are a common ontological condition, which in some cases can result in permanent hearing loss. Despite the spontaneous healing capacity of the TM to regenerate in the majority of cases of acute perforation, chronic perforations require surgical interventions. However, the disadvantages of the surgical procedure include infection, anesthetic risks, and high failure of graft patency. The tissue engineering strategy, which includes the applications of a three-dimensional (3D) scaffold, cells, and biomolecules or a combination of them for the closure of chronic perforation, has been considered as an emerging treatment. Using this approach, emerging products are currently under development to regenerate the TM structure and its properties. This research aimed to highlight the problems with the current methods of TMP treatment, and critically evaluate the tissue engineering approaches, which may overcome these drawbacks. The focus of this review is on recent literature to critically discuss the emerging advanced materials used as a 3D scaffold in the development of a TM with cellular engineering, biomolecules, cells, and the fabrications of the TM and its pathway to the clinical application. In this review, we discuss the properties of TM and the advantages and disadvantages of the current clinical products for repair and replacement of the TM. Furthermore, we provide an overview of the in vitro and preclinical studies of emerging products over the past 5 years. The results of recent preclinical studies suggest that the tissue engineering field holds significant promise.

The design of 3D hydrogel constructs to elicit highly controlled cell response is a major field of interest in developing tissue engineering. The bioactivity of encapsulated cells inside pure alginate hydrogel is limited by its relatively inertness. Combining short nanofibers within a hydrogel serves as a promising method to develop a cell friendly environment mimicking the extracellular matrix. In this paper, we fabricated alginate hydrogels incorporating different magnetic short nanofibers (M.SNFs) content for olfactory ecto-mesenchymal stem cells (OE-MSCs) encapsulation. Wet-electrospun gelatin and superparamagnetic iron oxide nanoparticles (SPIONs) nanocomposite nanofibers were chopped using sonication under optimized conditions and subsequently embedded in alginate hydrogels. The storage modulus of hydrogel without M.SNFs as well as with 1 and 5 mg/mL of M.SNFs were in the range of nerve tissue. For cell encapsulation, OE-MSCs were used as a new hope for neuronal regeneration due to their neural crest origin. Resazurin analyses and LIVE/DEAD staining confirmed that the composite hydrogels containing M.SNFs can preserve the cell viability after 7 days. Moreover, the proliferation rate was enhanced in M.SNF/hydrogels compared to alginate hydrogel. The presence of SPIONs in the short nanofibers can accelerate neural-like differentiation of OE-MSCs rather than the sample without SPIONs.

One of the most effective approaches for treatment of chronic rhinosinusitis is the use of hydrogel scaffolds with the sustained release of a given required drug. With this in mind, first, we synthesized and characterized poly (lactide-co-glycolide) (PLGA) micro and nano particles loaded with dexamethasone (DEX). We observed a 7-day release of DEX from nanoparticles, while the microparticles showed a 22-day release profile. Due to their slower rate of release, the PLGA microparticles loaded with DEX (PLGADEX microparticles) were specifically chosen for this study. As a second step, chitosan/polyvinylpyrrolidone (PVP) based hydrogels were prepared in various weight ratios and the PLGADEX microparticles were optimized in their structure based on variable gelation times. The morphological studies showed PLGADEX microparticles homogenously dispersed in the hydrogels. Moreover, the effect of weight ratio in the presence and absence of optimum percentage of PLGADEX microparticles was studied. The resultant hydrogels demonstrated a range of advantages, including good mechanical strength, porous morphology, amorphous structure, high swelling ratio, controlled biodegradability rate, and antibacterial activity. Additionally, a cytotoxicity analysis confirmed that the hydrogel scaffolds do not have adverse effects on the cells; our release studies in the hydrogel with the highest PVP content also showed 80 release after 30 days. Based on these results we were able to predict and control some of the mechanical properties, including the microstructure of the scaffolds, as well as the drug release, by optimizing the polymers - microparticle concentration, plus their resulting interactions. This optimized hydrogel can become part of a suitable alternative for treatment of allergic rhinitis and chronic sinusitis. © 2020 Elsevier B.V.

Background Motor neuron- related disorders such as Spinal Cord Injuries and Amyotrophic Lateral Sclerosis are extremely common around the world. Many efforts have been made to use stem cells to modulate regeneration of spinal cord damages. Human umbilical cord blood mesenchymal stem cells (CB-MSCs) cover a class of cells with self-renewal feature and multilineage differentiation capacity. Retinoic acid(RA) and sonic hedgehog(Shh) are two morphogens responsible in motorneuron commitment during development. This study aims to explore the effect of Shh and RA on differentiation of CB-MSCs into motor neuron- like cells and to determine the related microRNA profile. To do that, human MSCs were isolated and then characterized using flowcytometry. The cells were induced using RA and Shh and the outcomes were assessed by immunocytochemistry, real-time- PCR, and flowcytometry. MicroRNA analysis was performed using Solexa system at three libraries, including Test 1 (with RA and Shh), Test 2 (After removing RA and Shh) and the Control. Results The isolated cells were spindle shape and could express MSC markers confirmed by flowcytometry. The cells could express motorneuron- related markers including Islet-1, Hb-9, SMI-32 and ChAT at the level of mRNA and protein, when treated with RA and Shh. Two weeks after induction, the expression of Neun and Islet-1 declined. The analysis of miRNA sequencing revealed a significant expression of mir-let-7b, mir-137 and mir-324-5p, which were responsible for neuron/motor neuron differentiation and suppression of neural progenitor cell proliferation. Moreover, some novel microRNAs involved in cholinergic, Jak- Stat, Hedgehog and Map kinase signaling pathways were revealed. Conclusion CB-MSC represents a type of cells with convenient accessibility, which can be differentiated into motor neuron- like cells in the presence of RA and Shh. We could also detect the expression of candid microRNAs responsible in motor neuron differentiation and some novel microRNAs involved in cholinergic, Jak- Stat, Hedgehog and Map kinase signaling pathways that must be functionally evaluated in further studies.

Electrospun nanofiber matrices sufficiently mimic the structural morphology of natural extracellular matrix. In this study, we aimed to examine the effects of agar/polyvinyl alcohol nanofiber (PVA) scaffold on the proliferation efficiency and differentiation potential of neonate mouse spermatogonial stem cells (SCCs). Testicular cells were isolated from testes of 40 mouse pups and were seeded in: 1) 2D cell culture plates in the absence (2D/−GF) or presence (2D/+GF) of growth factors and 2) onto agar/PVA scaffold in the absence (3D/−GF) or presence (3D/+GF) of growth factors. The cells were subsequently cultured for 4 weeks. First 2 weeks were dedicated to proliferative phase, whereas the next 2 weeks emphasized the differentiation phase. The identity of the SCCs was investigated at different time-points by flow cytometry and quantitative reverse transcription PCR (qRT-PCR) analyses against the germ cell markers, including PLZF, Id-4, Gfrα-1, Tekt-1, and Sycp-3. After 2 weeks of culture, the 3D/+GF group showed the highest percentage of PLZF-positive cells among culture systems (P Id-4 and Gfrα-1) decreased significantly in all groups, particularly in 3D/+GF group after 28 days of culture. Additionally, the cells in the 3D/+GF group displayed the highest expression of meiotic (Sycp-3) and post-meiotic markers (Tekt-1) 14 days after differentiation induction. Seemingly, the combination of the agar/PVA scaffold and growth factor-supplemented medium synergistically increased the differentiation rate of mouse SSCs into meiotic and post-meiotic cells. Thus, agar/PVA nanofiber scaffolds may have the potential for applications in the restoration of infertility, especially in azoospermic males. 2D: two dimentional; 3D: three dimentional; bFGF: basic fibroblast growth factor; BMP-4: bone morphogenetic protein 4; DMEM: Dulbecco’s modified Eagle’s medium; ECM: extracellular matrix; FCS: fetal calf serum; FTIR: Fourier-transform infrared spectroscopy; GDNF: glial cell line-derived neurotrophic factor; GF: growth factors; Gfrα-1, GDNF family co-receptor α1; Id-4, Inhibitor of DNA Binding 4; MTT: methylthiazoltetrazolium; PLZF: promyelocytic leukemia zinc finger; PVA: polyvinyl alcohol; qRT-PCR: quantitative reverse transcription PCR; RA: retinoic acid; SACS: soft agar culture system; SD: standard deviation; SEM: scanning electron microscope; SSCs: spermatogonial stem cells; Sycp-3, Synaptonemal complex protein 3; Tekt-1, Tektin 1.

Human olfactory ecto-mesenchymal stem cells (hOE-MSCs) derived from the human olfactory mucosa (OM) can be easily isolated and expanded in cultures while their immense plasticity is maintained. To mitigate ethical concerns, the hOE-MSCs can be also transplanted across allogeneic barriers, making them desirable cells for clinical applications. The main purpose of this study was to evaluate the effects of administering the hOE-MSCs on a spinal cord injury (SCI) model of rats. These cells were accordingly isolated and cultured, and then treated in the neurobasal medium containing serum-free Dulbecco’s Modified Essential Medium (DMEM) and Ham’s F-12 Medium (DMEM/F12) with 2% B27 for two days. Afterwards, the pre-induced cells were incubated in N2B27 with basic fibroblast growth factor (bFGF), fibroblast growth factor 8b (FGF8b), sonic hedgehog (SHH), and ascorbic acid (vitamin C) for six days. The efficacy of the induced cells was additionally evaluated using immunocytochemistry (ICC) and real-time polymerase chain reaction (RT-PCR). The differentiated cells were similarly transplanted into the SC contusions. Functional recovery was further conducted on a weekly basis for eight consecutive weeks. Moreover, cell integration was assessed via conventional histology and ICC, whose results revealed the expression of choline acetyltransferase (ChAT) marker at the induction stage. According to the RT-PCR findings, the highest expression level of insulin gene-enhancer protein (islet-1), oligodendrocyte transcription factor (Olig2), and homeobox protein HB9 was observed at the induction stage. The number of engraftment cells also rose (approximately by 2.5 % ± 0.1) in the motor neuron-like cells derived from the hOE-MSCs-grafted group compared with the OE-MSCs-grafted one. The functional analysis correspondingly revealed that locomotor and sensory scores considerably improved in the rats in the treatment group. These findings suggested that motor neuron-like cells derived from the hOE-MSCs could be utilized as an alternative cell-based therapeutic strategy for SCI.

The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore, in vitro degradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal stem cell viability. It is worth mentioning that this is the first report investigating the conductivity of PLLA/PAMAM nanofiber. The results revealed that by increasing the amount of PAMAM, the ionic conductivity of scaffolds was enhanced by about nine times. Moreover, the outcomes indicated that the presence of PAMAM could improve the limitations of PLLA like hydrophobicity, lack of active group, and poor cell adhesion.

There is a growing research interest on designing a tissue regenerative matrix that can be injected and forms an anisotropic network for effective nerve injury repair. Here, an injectable alginate hydrogel composed of magnetic polycaprolactone (PCL) short nanofibers were fabricated. Nanocomposite PCL centrifugal spun fibers containing superparamagnetic iron oxide nanoparticles (SPIONs) were cut into short nanofibers (SFs) through micro-cutting technique and subsequently incorporated into alginate hydrogels. Doping SPION into short PCL fibers allows the SFs alignment by external magnetic fields in the millitesla (mT) order within the hydrogel. The effect of SFs lengths (5, 25 and 50 µm) as well as magnetic short fibers (M.SFs) concentration (0.5, 1, 2.5, 5 and 10 mg / ml) inside alginate hydrogel on fiber orientation under external magnetic field were investigated by measuring angular deflection of nanofibers. The results revealed that 5 and 25 µm M.SFs with 5 mg/ml concentration have the lowest angular deflection of 1.1⁰ and 6.8⁰, respectively. The mechanical properties of prepared hydrogels revealed that both oriented 5 and 25 µm M.SFs, have higher storage modulus (G’) and loss modulus (G”) values than the random ones and by increasing M.SFs length from 5 µm to 25 µm, G’ and G” values displayed descending trend. The fluorescence microscopy of olfactory ecto-mesenchymal stem cells (OE-MSCs) encapsulated in hybrid hydrogels containing oriented M.SFs showed the possibility of preserving cell viability after 7 days. Following 14-day of induction, the oriented 25 µm M.SF led to the acceleration of neural differentiation of OE-MSCs versus the random one. Therefore, it was expected that ordered injectable alginate/M.SFs hybrid hydrogels function as a minimal invasive constructs for the regeneration of neural tissues.