Ectomesenchymal Cells Research Articles

Electrospun PCL/Alginate/Nanoclay Nerve Conduit with Olfactory Ectomesenchymal Stem Cells for Nerve Regeneration.

Biocompatible and biodegradable nerve growth conduits (NGCs) provide a promising alternative to conventional nerve grafting for peripheral nerve regeneration. Incorporating nanoclay (NC) has been shown to increase the hydrophilicity and flexibility of polymeric scaffolds. In the present study, poly caprolactone-alginate (PCL-ALG) conduits with varying percentages of NC (0.1%, 0.2%, and 0.5%) were fabricated using the electrospinning technique. The conduit containing 0.5% NC showed a greater increase in elongation (33%) and porosity, reaching 95% with the lowest contact angle (10°). For in vitro, human olfactory ectomesenchymal stem cells (OE-MSCs) were used as a favorable choice for neuronal differentiation owing to the origin from the neural crest. The viability and proliferation of OE-MSCs were maintained after 5 days on scaffolds with 0.5% NC, as confirmed by the MTT assay, cell adhesion analysis, and live/dead staining. Furthermore, the impact of 0.5% PCL-ALG-NC on the paracrine activity of OE-MSCs was studied for a period of 7 days. Our results indicated that human OE-MSCs, when cocultured with PC12 cells on NGC, have the capability to release nerve growth factor levels of up to 1392.83 pg/mL. In summary, the electrospun PCL-ALG conduit containing an optimal NC dosage (0.5%) and seeded with human OE-MSCs shows promising outcomes as NGC scaffold for peripheral nerve regeneration.

Organotypic 3D cellular models mimicking the epithelio-ectomesenchymal bi-layer during odontogenesis.

Odontogenesis, the intricate process of tooth development, involves complex interactions between oral ectoderm epithelial cells and ectomesenchymal cells derived from the cephalic neural crest, regulated by major signaling pathways. Dental developmental anomalies provide valuable insights for clinical diagnosis of rare diseases. More than 30% of rare diseases patients who undergo molecular analysis suffer from diagnostic errancy. In the search for up-to-date technologies and methods to study the pathophysiology of new candidate genetic variants, causing tooth mineralized tissues anomalies, we have developed an original model of tooth organoids with human or mouse cell lines of ameloblast-like cells and odontoblasts derived from the pulp. This in vitro 3D cellular model reproducing the two main compartments of the bell stage of tooth development between ameloblasts and odontoblasts, specific to enamel and dentin morphogenesis, respectively, mimics the epithelio-mesenchymal interactions during the dental bell stage of tooth morphogenesis and will facilitate the study of enamel and dentin genetic anomalies, allowing the functional validation of newly identified mutations (variants of uncertain significance -VUS- or new candidate genes).

Evaluation of the Composite Skin Patch Loaded with Bioactive Functional Factors Derived from Multicellular Spheres of EMSCs for Regeneration of Full-thickness Skin Defects in Rats.

Transplantation of stem cells/scaffold is an efficient approach for treating tissue injury including full-thickness skin defects. However, the application of stem cells is limited by preservation issues, ethical restriction, low viability, and immune rejection in vivo. The mesenchymal stem cell conditioned medium is abundant in bioactive functional factors, making it a viable alternative to living cells in regeneration medicine. Nasal mucosa-derived ecto-mesenchymal stem cells (EMSCs) of rats were identified and grown in suspension sphere-forming 3D culture. The EMSCs-conditioned medium (EMSCs-CM) was collected, lyophilized, and analyzed for its bioactive components. Next, fibrinogen and chitosan were further mixed and cross-linked with the lyophilized powder to obtain functional skin patches. Their capacity to gradually release bioactive substances and biocompatibility with epidermal cells were assessed in vitro. Finally, a full-thickness skin defect model was established to evaluate the therapeutic efficacy of the skin patch. The EMSCs-CM contains abundant bioactive proteins including VEGF, KGF, EGF, bFGF, SHH, IL-10, and fibronectin. The bioactive functional composite skin patch containing EMSCs-CM lyophilized powder showed the network-like microstructure could continuously release the bioactive proteins, and possessed ideal biocompatibility with rat epidermal cells in vitro. Transplantation of the composite skin patch could expedite the healing of the full-thickness skin defect by promoting endogenous epidermal stem cell proliferation and skin appendage regeneration in rats. In summary, the bioactive functional composite skin patch containing EMSCs-CM lyophilized powder can effectively accelerate skin repair, which has promising application prospects in the treatment of skin defects.

Olfactory Ecto-Mesenchymal Stem Cells in Modeling and Treating Alzheimer's Disease.

Alzheimer's disease (AD) is a condition in the brain that is marked by a gradual and ongoing reduction in memory, thought, and the ability to perform simple tasks. AD has a poor prognosis but no cure yet. Therefore, the need for novel models to study its pathogenesis and therapeutic strategies is evident, as the brain poorly recovers after injury and neurodegenerative diseases and can neither replace dead neurons nor reinnervate target structures. Recently, mesenchymal stem cells (MSCs), particularly those from the human olfactory mucous membrane referred to as the olfactory ecto-MSCs (OE-MSCs), have emerged as a potential avenue to explore in modeling AD and developing therapeutics for the disease due to their lifelong regeneration potency and facile accessibility. This review provides a comprehensive summary of the current literature on isolating OE-MSCs and delves into whether they could be reliable models for studying AD pathogenesis. It also explores whether healthy individual-derived OE-MSCs could be therapeutic agents for the disease. Despite being a promising tool in modeling and developing therapies for AD, some significant issues remain, which are also discussed in the review.

Olfactory Ectomesenchymal Stem Cells as a Potential Source in Nerve Tissue Engineering: A Letter

Olfactory Ectomesenchymal Stem Cells as a Potential Source in Nerve Tissue Engineering: A Letter

Konjac glucomannan-fibrin composite hydrogel as a model for ideal scaffolds for cell-culture meat

In this study, composite gel was prepared from konjac glucomannan (KGM) and fibrin (FN). Composite gels with different concentration ratios were compared in terms of their mechanical properties, rheological properties, water retention, degradation rate, microstructure and biocompatibility. The results showed that the composite gels had better gel strength and other properties than non-composite gels. In particular, composite hydrogels with low Young's modulus formed when the KGM concentration was 0.8% and the FN concentration was 1.2%. The two components were cross linked through hydrogen-bond interaction, which formed a more stable gel structure with excellent water retention and in-vitro degradation rates, which were conducive to myogenic differentiation of ectomesenchymal stem cells (EMSCs). KGM-FN composite gel was applied to the preparation of cell-culture meat, which had similar texture properties and main nutrients to animal meat as well as higher content of dry base protein and dry base carbohydrate.

Plant-derived exosomes extracted from Lycium barbarum L. loaded with isoliquiritigenin to promote spinal cord injury repair based on 3D printed bionic scaffold.

Plant-derived exosomes (PEs) possess an array of therapeutic properties, including antitumor, antiviral, and anti-inflammatory capabilities. They are also implicated in defensive responses to pathogenic attacks. Spinal cord injuries (SCIs) regeneration represents a global medical challenge, with appropriate research concentration on three pivotal domains: neural regeneration promotion, inflammation inhibition, and innovation and application of regenerative scaffolds. Unfortunately, the utilization of PE in SCI therapy remains unexplored. Herein, we isolated PE from the traditional Chinese medicinal herb, Lycium barbarum L. and discovered their inflammatory inhibition and neuronal differentiation promotion capabilities. Compared with exosomes derived from ectomesenchymal stem cells (EMSCs), PE demonstrated a substantial enhancement in neural differentiation. We encapsulated isoliquiritigenin (ISL)-loaded plant-derived exosomes (ISL@PE) from L. barbarum L. within a 3D-printed bionic scaffold. The intricate construct modulated the inflammatory response following SCI, facilitating the restoration of damaged axons and culminating in ameliorated neurological function. This pioneering investigation proposes a novel potential route for insoluble drug delivery via plant exosomes, as well as SCI repair. The institutional animal care and use committee number is UJS-IACUC-2020121602.

Developmental Anomalies in Human Teeth: Odontoblastic Differentiation in Hamartomatous Calcifying Hyperplastic Dental Follicles Presenting with DSP, Nestin, and HES1.

Hyperplastic dental follicles (HDFs) represent odontogenic hamartomatous lesions originating from the pericoronal tissues and are often associated with impacted or embedded teeth. These lesions may occasionally feature unique calcifying bodies, known as calcifying whorled nodules (CWNs), characterized by stromal cells arranged in a whorled or spiral fashion. CWNs are typically observed in multiple calcifying hyperplastic dental follicles or regional odontodysplasia. In our study, we examined 40 cases of HDFs, including nine instances with characteristics of CWNs, referred to as calcifying hyperplastic dental follicles (CHDFs), which are infrequently accompanied by odontodysplasia. The median ages of the HDFs and CHDFs were 16 (ranging from 3 to 66) and 15 (ranging from 11 to 50) years, respectively. The lower third molars were the most frequently affected by HDSFs and CHDFs, followed by the upper canines. A histological examination was conducted on all 40 cases, with an immunohistochemical analysis performed on 21 of them. Among the cases with CWN, nine affected a single embedded tooth, with one exception. CWNs exhibited diverse calcifications featuring sparse or entirely deposited psammoma bodies, and some displayed dentinoid formation. Immunohistochemically, the stromal cells of HDFs were frequently positive for CD56 and nestin. By contrast, CWNs were negative for CD56 but positive for nestin as well as hairy and enhancer split 1 (HES1), with a few dentin sialoprotein (DSP)-positive calcified bodies. Our results revealed that hamartomatous CHDFs can impact multiple and single-embedded teeth. CWNs composed of nestin and HES1-positive ectomesenchymal cells demonstrated the potential to differentiate into odontoblasts and contribute to dentin matrix formation under the influence of HES1. This study is the first report documenting odontoblastic differentiation in HDFs. The rare occurrence of HDFs and CHDFs contributes to limited comprehension. To prevent misdiagnosis, a better understanding of these conditions is necessary.

Single-cell RNA-seq of in vitro expanded cells from cranial neural crest reveals a rare odontogenic sub-population.

Ecto-mesenchymal cells of mammalian tooth germ develops from cranial neural crest cells. These cells are recognised as a promising source for tooth development and regeneration. Despite the high heterogeneity of the neural crest, the cellular landscape of in vitro cultured cranial neural crest cells (CNCCs) for odontogenesis remains unclear. In this study, we used large-scale single-cell RNA sequencing to analyse the cellular landscape of in vitro cultured mouse CNCCs for odontogenesis. We revealed distinct cell trajectories from primary cells to passage 5 and identified a rare Alx3+/Barx1+ sub-population in primary CNCCs that differentiated into two odontogenic clusters characterised by the up-regulation of Pax9/Bmp3 and Lhx6/Dmp1. We successfully induced whole tooth-like structures containing enamel, dentin, and pulp under the mouse renal capsule using in vitro cultured cells from both cranial and trunk neural crests with induction rates of 26.7% and 22.1%, respectively. Importantly, we confirmed only cells sorted from odontogenic path can induce tooth-like structures. Cell cycle and DNA replication genes were concomitantly upregulated in the cultured NCCs of the tooth induction groups. Our data provide valuable insights into the cell heterogeneity of in vitro cultured CNCCs and their potential as a source for tooth regeneration.

P75NTR promotes tooth rhythmic mineralization via upregulation of BMAL1/CLOCK.

The circadian clock plays a critical role in dentomaxillofacial development. Tooth biomineralization is characterized by the circadian clock; however, the mechanisms underlying the coordination of circadian rhythms with tooth development and biomineralization remain unclear. The p75 neurotrophin receptor (p75NTR) is a clock factor that regulates the oscillatory components of the circadian rhythm. This study aims to investigate the impact of p75NTR on the rhythmic mineralization of teeth and elucidate its underlying molecular mechanisms. We generated p75NTR knockout mice to examine the effects of p75NTR deficiency on tooth mineralization. Ectomesenchymal stem cells (EMSCs), derived from mouse tooth germs, were used for in vitro experiments. Results showed a reduction in tooth mineral density and daily mineralization rate in p75NTR knockout mice. Deletion of p75NTR decreased the expression of DMP1, DSPP, RUNX2, and ALP in tooth germ. Odontogenic differentiation and mineralization of EMSCs were activated by p75NTR. Histological results demonstrated predominant detection of p75NTR protein in odontoblasts and stratum intermedium cells during rapid formation phases of dental hard tissue. The mRNA expression of p75NTR exhibited circadian variations in tooth germs and EMSCs, consistent with the expression patterns of the core clock genes Bmal1 and Clock. The upregulation of BMAL1/CLOCK expression by p75NTR positively regulated the mineralization ability of EMSCs, whereas BMAL1 and CLOCK exerted a negative feedback regulation on p75NTR by inhibiting its promoter activity. Our findings suggest that p75NTR is necessary to maintain normal tooth biomineralization. Odontogenic differentiation and mineralization of EMSCs is regulated by the p75NTR-BMAL1/CLOCK signaling axis. These findings offer valuable insights into the associations between circadian rhythms, tooth development, and biomineralization.

The Proteome Profile of Olfactory Ecto-Mesenchymal Stem Cells-Derived from Patients with Familial Alzheimer's Disease Reveals New Insights for AD Study.

Alzheimer's disease (AD), the most common neurodegenerative disease and the first cause of dementia worldwide, has no effective treatment, and its pathological mechanisms are not yet fully understood. We conducted this study to explore the proteomic differences associated with Familial Alzheimer's Disease (FAD) in olfactory ecto-mesenchymal stem cells (MSCs) derived from PSEN1 (A431E) mutation carriers compared with healthy donors paired by age and gender through two label-free liquid chromatography-mass spectrometry approaches. The first analysis compared carrier 1 (patient with symptoms, P1) and its control (healthy donor, C1), and the second compared carrier 2 (patient with pre-symptoms, P2) with its respective control cells (C2) to evaluate whether the protein alterations presented in the symptomatic carrier were also present in the pre-symptom stages. Finally, we analyzed the differentially expressed proteins (DEPs) for biological and functional enrichment. These proteins showed impaired expression in a stage-dependent manner and are involved in energy metabolism, vesicle transport, actin cytoskeleton, cell proliferation, and proteostasis pathways, in line with previous AD reports. Our study is the first to conduct a proteomic analysis of MSCs from the Jalisco FAD patients in two stages of the disease (symptomatic and presymptomatic), showing these cells as a new and excellent in vitro model for future AD studies.

A multifunctional polydopamine/genipin/alendronate nanoparticle licences fibrin hydrogels osteoinductive and immunomodulatory potencies for repairing bone defects

Here, we fabricated a hybrid nanoparticle composed of polydopamine nanoparticles (pNPs), alendronate (Al) and genipin (GP) for cranial bone defect repair. Al was crosslinked into pNPs via GP (Al@pNPs), after which hybrid nanoparticles were obtained. By embedding these Al@pNPs into the fibrin hydrogels, a multifunctional bone repair scaffold was fabricated (Al@pNPs/Fg). The Al@pNPs/Fg exhibited three synergistic effects on the bone microenvironment: i) enhanced ectomesenchymal stem cell (EMSC) osteogenic differentiation by activating the piezo 1 channel; ii) inhibited the formation and function of osteoclasts related to the NF-κB signaling pathways; and iii) promoted M2 polarization and anti-inflammatory factor expression under normal and simulated inflammatory conditions. Al@pNPs/Fg ultimately promoted cranial bone defect regeneration in an SD rat model. This simple and low-cost technology provides a new approach to constructing an efficient delivery system and has desirable biological properties, providing a tissue-committed niche for the repair of bone defects.

Developmental origin of the mammalian premaxilla

The evolution of jaws has played a major role in the success of vertebrate expansion into a wide variety of ecological niches. A fundamental, yet unresolved, question in craniofacial biology is about the origin of the premaxilla, the most distal bone present in the upper jaw of all amniotes. Recent reports have suggested that the mammalian premaxilla is derived from embryonic maxillary prominences rather than the frontonasal ectomesenchyme as previously shown in studies of chicken embryos. However, whether mammalian embryonic frontonasal ectomesenchyme contributes to the premaxillary bone has not been investigated and a tool to trace the contributions of the frontonasal ectomesenchyme to facial structures in mammals is lacking. The expression of the Alx3 gene is activated highly specifically in the frontonasal ectomesenchyme, but not in the maxillary mesenchyme, from the beginning of facial morphogenesis in mice. Here, we report the generation and characterization of a novel Alx3CreERT2 knock-in mouse line that express tamoxifen-inducible Cre DNA recombinase from the Alx3 locus. Tamoxifen treatment of Alx3CreERT2/+;Rosa26mTmG/+ embryos at E7.5, E8.5, E9.5, and E10.5, each induced specific labeling of the embryonic medial nasal and lateral nasal mesenchyme but not the maxillary mesenchyme. Lineage tracing of Alx3CreERT2-labeled frontonasal mesenchyme from E9.5 to E16.5 clearly showed that the frontonasal mesenchyme cells give rise to the osteoblasts generating the premaxillary bone. Furthermore, we characterize a Dlx1-Cre BAC transgenic mouse line that expresses Cre activity in the embryonic maxillary but not the frontonasal mesenchyme and show that the Dlx1-Cre labeled embryonic maxillary mesenchyme cells contribute to the maxillary bone as well as the soft tissues lateral to both the premaxillary and maxillary bones but not to the premaxillary bone. These results clearly demonstrate the developmental origin of the premaxillary bone from embryonic frontonasal ectomesenchyme cells in mice and confirm the evolutionary homology of the premaxilla across amniotes.

Human nasal mucosa ectomesenchymal stem cells derived extracellular vesicles loaded omentum/chitosan composite scaffolds enhance skull defects regeneration

Engineered bone tissue that can promote osteogenic differentiation is considered an ideal substitute for materials to heal bone defects. Extracellular vesicle (EV)-based cell-free regenerative therapies represent an emerging promising alternative for bone tissue engineering. We hypothesized that EVs derived from human nasal mucosa-derived ectomesenchymal stem cells (hEMSCs) can promote bone tissue regeneration. Herein, hEMSCs were cultured with osteogenic induction medium or normal medium to generate two types of EVs. We first demonstrated that the two EVs exhibited strong potential to promote rat suture mesenchymal stem cell (SMSC) osteogenesis by transferring TG2 to SMSCs and regulating extracellular matrix (ECM) synthesis. Next, we developed a composite hydrogel made of porcine omentum and chitosan into which EVs were adsorbed to enable the effective delivery of EVs with sustained release kinetics. Implantation of the EV-loaded hydrogels in a critical-size rat cranial defect model significantly promoted bone regeneration. Therefore, we suggest that our hEMSC-derived EV-loading system can serve as a new therapeutic paradigm for promoting bone tissue regeneration in the clinic.

NPS-Crosslinked Fibrin Gels Load with EMSCs to Repair Peripheral Nerve Injury in Rats.

Neural tissue engineering has been introduced as a novel therapeutic strategy for trauma-induced sciatic nerve defects. Here, a neuropeptide S (NPS)-crosslinked fibrin scaffolds (NPS@Fg) loaded with an ectomesenchymal stem cell (EMSC) system to bridge an 8-mm sciatic nerve defect in rats are reported. The Schwann cell-like and neural differentiation of the EMSCs on the engineered fibrin scaffolds are also assessed in vitro. These results show that the NPS@Fg promotes the differentiation of EMSCs into neuronal lineage cells, which may also contribute to the therapeutic outcome of the NPS@Fg+EMSCs strategy. After transplantation NPS@Fg+EMSCs into sciatic nerve defects in rats, nerve recovery is assessed up to 12 weeks postinjury. In vivo experiments show that the combination of NPS crosslinked fibrin scaffolds with EMSCs can significantly accelerate nerve healing and improve morphological repair. In the study, NPS@Fg+EMSCs may represent a new potential strategy for peripheral nerve reconstruction.

Human Olfactory Ecto-mesenchymal Stem Cells Displaying Schwann-cell-like Phenotypes and Promoting Neurite Outgrowth in Vitro.

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. 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. 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. The findings indicated that OE-MSCs could be differentiated spontaneously into SC-like phenotypes, suggesting their applications for transplantation in peripheral nerve injuries.

Dynamic expression of Mage-D1 in rat dental germs and potential role in mineralization of ectomesenchymal stem cells

Mage-D1 (MAGE family member D1) is involved in a variety of cell biological effects. Recent studies have shown that Mage-D1 is closely related to tooth development, but its specific regulatory mechanism is unclear. The purpose of this study was to investigate the expression pattern of Mage-D1 in rat dental germ development and its differential mineralization ability to ectomesenchymal stem cells (EMSCs), and to explore its potential mechanism. Results showed that the expression of Mage-D1 during rat dental germ development was temporally and spatially specific. Mage-D1 promotes the proliferation ability of EMSCs but inhibits their migration ability. Under induction by mineralized culture medium, Mage-D1 promotes osteogenesis and tooth-forming ability. Furthermore, the expression pattern of Mage-D1 at E19.5 d rat dental germ is similar to p75 neurotrophin receptor (p75NTR), distal-less homeobox 1 (Dlx1) and msh homeobox 1 (Msx1). In addition, Mage-D1 is binding to p75NTR, Dlx1, and Msx1 in vitro. These findings indicate that Mage-D1 is play an important regulatory role in normal mineralization of teeth. p75NTR, Dlx1, and Msx1 seem to be closely related to the underlying mechanism of Mage-D1 action.

Human nasal olfactory stem cells, purified as advanced therapy medicinal products, improve neuronal differentiation.

Olfactory ecto-mesenchymal stem cells (OE-MSC) are mesenchymal stem cells derived from the lamina propria of the nasal mucosa. They display neurogenic and immunomodulatory properties and were shown to induce recovery in animal models of spinal cord trauma, hearing loss, Parkinsons's disease, amnesia, and peripheral nerve injury. As a step toward clinical practice, we sought to (i) devise a culture protocol that meets the requirements set by human health agencies and (ii) assess the efficacy of stem cells on neuron differentiation. Nasal olfactory mucosa biopsies from three donors were used to design and validate the good manufacturing process for purifying stem cells. All processes and procedures were performed by expert staff from the cell therapy laboratory of the public hospital of Marseille (AP-HM), according to aseptic handling manipulations. Premises, materials and air were kept clean at all times to avoid cross-contamination, accidents, or even fatalities. Purified stem cells were cultivated for 24 or 48 h and conditioned media were collected before being added to the culture medium of the neuroblastoma cell line Neuro2a. Compared to the explant culture-based protocol, enzymatic digestion provides higher cell numbers more rapidly and is less prone to contamination. The use of platelet lysate in place of fetal calf serum is effective in promoting higher cell proliferation (the percentage of CFU-F progenitors is 15.5%), with the optimal percentage of platelet lysate being 10%. Cultured OE-MSCs do not show chromosomal rearrangement and, as expected, express the usual phenotypic markers of mesenchymal stem cells. When incorporated in standard culture medium, the conditioned medium of purified OE-MSCs promotes cell differentiation of Neuro2a neuroblastoma cells. We developed a safer and more efficient manufacturing process for clinical grade olfactory stem cells. With this protocol, human OE-MSCs will soon be used in a Phase I clinical based on their autologous transplantation in digital nerves with a neglected injury. However, further studies are required to unveil the underlying mechanisms of action.

Stem Cell‐Niche Engineering via Multifunctional Hydrogel Potentiates Stem Cell Therapies for Inflammatory Bone Loss

AbstractEffective therapies capable of simultaneously inhibiting inflammation and promoting bone healing remain to be developed for inflammatory bone disease. Stem cell therapies hold great promise for a variety of diseases, but their translation is hampered by low cell survival, rapid clearance, and limited functional integration of transplanted stem cells in target tissues. Herein, a multifunctional hydrogel‐based stem cell niche engineering strategy is reported for the treatment of inflammatory bone loss. By rationally integrating different functional modules, an injectable hydrogel‐based stem niche is engineered, which possesses temperature‐triggered gelling performance, inflammation/oxidative stress‐resolving activity, stem‐cell binding and survival‐enhancing capacity, and osteogenesis‐promoting capability. Using ectomesenchymal stem cells (EMSCs), effectiveness of this functionally advanced synthetic stem cell niche is demonstrated in rats with periodontitis, a representative inflammatory bone loss disease. Synergistic effects of the multifunctional hydrogel and EMSCs are also confirmed, with respect to normalizing the pathological microenvironment and improving alveolar bone regeneration in the periodontal tissue. Mechanistically, inflammation/oxidative stress‐resolving and osteogenic differentiation promoting capacities of the synthetic stem cell niche are mainly achieved by an incorporated nanotherapy via the GDF15/Atf3/c‐Fos axis of the MAPK signaling pathway. Besides periodontitis, the newly engineered hydrogel‐stem cell therapies are promising for the treatment of other inflammatory bone defects.

Wet-electrospinning of nanofibrous magnetic composite 3-D scaffolds for enhanced stem cells neural differentiation

Electrospinning, as an interestingly popular method, generates fibrous scaffolds and mimics extracellular matrices. Low cellular penetration between fibers of electrospun scaffolds due to the high packing density and small interfibrillar pore size is a big challenge. This study represents a facile and versatile strategy for preparing a three-dimensional (3D) polycaprolactone (PCL)/gelatin/iron oxide nanofibrous scaffold using a magnetically assisted wet-electrospinning process. In this method, a non-contact magnetic force with various intensities (0, 250, 300, 350, and 500 mT) is utilized to assemble fibers so that the interconnectivity and mechanical integrity of the 3D scaffolds are preserved. The morphology of magnetic constructs, as well as pore structure, is verified by scanning electron microscopy. Both wet-electrospun 350 mT and 500 mT scaffolds show good mechanical stability, biodegradability, optimal porosity, and high phosphate buffer solution (PBS) absorption. The results of cell culture studies further reveal that wet-electrospun 350 mT scaffolds exhibit higher cell proliferation, attachment and infiltration than 500 mT scaffolds. Moreover, wet-electrospun 350 mT scaffolds accelerate neural differentiation of olfactory ecto-mesenchymal stem cells (OE-MSCs). These results show that the wet- electrospun 3D nanofibrous scaffold fabricated under an external magnetic field with desirable shape and tunable density can be readily fabricated for neural tissue engineering applications.