Nerve-like Cells Research Articles

Nerve Regeneration Through Differentiation of Endometrial-Derived Mesenchymal Stem Cells into Nerve-Like Cells Using Polyacrylonitrile/Chitosan Conduit and Berberine in a Rat Sciatic Nerve Injury Model.

Nervous injuries are common in humans. One of the most advanced treatment methods is neural tissue engineering. This research aims to utilize nerve-like cells (NLCs) derived from endometrial mesenchymal stem cells (EnMSCs) on a polyacrylonitrile/chitosan (PAN/CS) scaffold, along with berberine, for the reconstruction of a rat sciatic nerve injury model. In this experimental study, EnMSCs were obtained through enzymatic digestion and identified using flow cytometry and their differentiation into adipocyte and osteoblast. PAN nanofiber scaffolds were produced through electrospinning, and EnMSCs were neurally differentiated on these scaffolds for grafting into an animal model. The expression of Nestin, Map-2, Tuj-1, and NF genes in NLCs was confirmed through RT-PCR and immunocytochemistry. Twenty-five adult male rats were used in this study, divided into 5 groups: (1) Scaffold/Cells/Berberine, (2) Scaffold/Cells, (3) Scaffold, (4) Berberine, and (5) Control. The animals were maintained for 8 weeks, and their sciatic nerve function (SFI) was assessed. Additionally, histological examinations were performed using hematoxylin/eosin, luxol fast blue staining, and immunohistochemistry. According to the results, extraction, identification, and differentiation of EnMSCs and fabrication of PAN conduit and its transplantation were successfully performed. The best behavioral performance and histology were observed in the Scaffold/Cells/Berberine group. The SFI test results were -24.08 for the Scaffold/Cells/Berberine group and -39.27 for the control group. The nerve diameter in these two groups was 591 µm and 80 µm, respectively, and the percentage of new nerve formation was 18.5% in the Scaffold/Cells/Berberine group and 0.2% in the control group. The immunohistochemistry results demonstrated that the intensity of the green color was higher in the groups with cells compared to the groups without cells. Furthermore, in the luxol staining results, all groups showed a significant improvement compared to the control group. In the Scaffold/Cells/Berberine group, fibers, and axons appeared denser, more organized, and displayed a higher intensity of blue staining. According to the results of this study, EnMSCs demonstrated efficient differentiation into NLCs. With the assistance of PAN/CS scaffolds and simultaneous administration of berberine, EnMSCs have the potential for nerve regeneration and recovery from sciatic nerve injury in the rat animal model.

Application and advance in repair of spinal cord injury by transplantation of bone marrow mesenchymal stem cells

Objectives: To summarize retrospectively the application and advance of bone marrow mesenchymal stem cells (BMSCs) in the recovery of spinal cord injury (SCI). Methods: An online search at Pubmed between 2023 and 1967 was conducted to identify the related articles with the keywords “bone marrow mesenchymal stem cells, spinal cord injury”, and the language was limited to English. The identified articles were extensively reviewed, focusing on these aspects: the biological characteristics of BMSCs, the various experimental models and clinical studies on the repair of SCI by transplantation of BMSCs, the mechanisms of immigration and therapy, and the problems and prospects. Results: The various experimental models and clinical studies demonstrated that great advances were made in the repair of SCI by transplantation of BMSCs. After transplantation, BMSCs could immigrate to the position of the injured spinal cord, and partially differentiate into nerve-like cells and secrete neurotrophic factors, so as to promote the repair and regeneration of nervous tissue and recovery of neurological function. Conclusions: With the profound researches of transgenic treatment and associated cell transplantation, BMSCs can extend their application on the recovery of SCI owing to the self-renewing and multi-directional differentiation.

Expression of Opsins of the Box Jellyfish Tripedalia cystophora Reveals the First Photopigment in Cnidarian Ocelli and Supports the Presence of Photoisomerases.

Cubomedusae, or box jellyfish, have a complex visual system comprising 24 eyes of four types. Like other cnidarians, their photoreceptor cells are ciliary in morphology, and a range of different techniques together show that at least two of the eye types—the image-forming upper and lower lens eyes—express opsin as the photopigment. The photoreceptors of these two eye types express the same opsin (Tc LEO), which belongs to the cnidarian-specific clade cnidops. Interestingly, molecular work has found a high number of opsin genes in box jellyfish, especially in the Caribbean species Tripedalia cystophora, most of which are of unknown function. In the current study, we raised antibodies against three out of five opsins identified from transcriptomic data from T. cystophora and used them to map the expression patterns. These expression patterns suggest one opsin as the photopigment in the slit eyes and another as a putative photoisomerase found in photoreceptors of all four eyes types. The last antibody stained nerve-like cells in the tentacles, in connection with nematocytes, and the radial nerve, in connection with the gonads. This is the first time photopigment expression has been localized to the outer segments of the photoreceptors in a cnidarian ocellus (simple eye). The potential presence of a photoisomerase could be another interesting convergence between box jellyfish and vertebrate photoreceptors, but it awaits final experimental proof.

Neuronal differentiation of mesenchymal stem cells by polyvinyl alcohol/Gelatin/crocin and beta-carotene.

Nerve tissues are important in coordinating the motions and movements of the body. Nerve tissue repair and regeneration is a slow process that might take a long time and cost a lot of money. As a result, tissue engineering was employed to treat nerve tissue lesions. The aim of this study was to investigate the proliferation of C6 cells and human mesenchymal stem cells derived bone marrow (hBMMSCs) differentiate into neuronal-like cells on the polyvinyl alcohol/gelatin/crocin (PVA/Gel/Cro) nanofiber scaffolds in vitro. PVA/Gel scaffolds containing crocin in three concentrations (1%, 3%, and 5%) were prepared by the electrospinning method. The human bone marrow-derived mesenchymal stem cells (hBMSCs) differentiation on the PVA/Gel/Cro 5% that induced by beta-carotene (βC), was analyzed during 10days. Morphology of differentiated cells on the scaffolds was taken by scanning electron microscope (SEM). The expression of the neural cell markers was studied by quantitative reverse transcription- polymerase chain reaction (qRT-PCR) and immunocytochemistry (ICC). MTT results of C6 cells culture on the scaffolds showed that proliferation and metabolic activity on PVA/Gel scaffold containing crocin 5% (PVA/Gel/Cro 5%) are significantly more than the other concentrations (P = 0.01). MSC differentiation to nerve-like cells was approved by MAP-2 expression at the mRNA level and NESTIN and MAP-2 at the protein level. These results suggested that PVA/Gel/Cro 5% and βC could lead to hBMSCs differentiation to neural cells.

Phenolic-rich extract of avocado Persea americana (var. Colinred) peel blunts paraquat/maneb-induced apoptosis through blocking phosphorylation of LRRK2 kinase in human nerve-like cells.

It is increasingly evident that LRRK2 kinase activity is involved in oxidative stress (OS)-induced apoptosis-a type of regulated cell death and neurodegeneration, suggesting LRRK2 inhibition as a potential therapeutic target. We report that a phenolic-rich extract of avocado Persea americana var. Colinred peel (CRE, 0.01 mg/ml) restricts environmental neurotoxins paraquat (1 mM)/maneb (0.05 mM)-induced apoptosis process through blocking reactive oxygen species (ROS) signaling and concomitant inhibition of phosphorylation of LRRK2 in nerve-like cells (NLCs). Indeed, PQ + MB at 6 h exposure significantly increased ROS (57 ± 5%), oxidation of protein DJ-1cys106SOH into DJ-1Cys106SO3 ([~3.7 f(old)-(i)ncrease]), augmented p-(S935)-LRRK2 kinase (~20-f(old) (i)ncrease), induced nuclei condensation/fragmentation (28 ± 6%), increased the expression of PUMA (~6.2-fi), and activated CASPASE-3 (CASP-3, ~4-fi) proteins; but significantly decreased mitochondrial membrane potential (ΔΨm, ~48 ± 4%), all markers indicative of apoptosis compared to untreated cells. Remarkably, CRE significantly diminished both OS-signals (i.e., DCF+ cells, DJ-1Cys106SO3) as well as apoptosis markers (e.g., PUMA, CASP-3, loss of ΔΨm, p-LRRK2 kinase) in NLCs exposed to PQ + MB. Furthermore, CRE dramatically reestablishes the transient intracellular Ca2+ flow (~300%) triggered by dopamine (DA) in neuronal cells exposed to PQ + MB. We conclude that PQ + MB-induced apoptosis in NLCs through OS-mechanism, involving DJ-1, PUMA, CASP-3, LRRK2 kinase, mitochondria damage, DNA fragmentation, and alteration of DA-receptors. Our findings imply that CRE protects NLCs directly via antioxidant mechanism and indirectly by blocking LRRK2 kinase against PQ + MB stress stimuli. These data suggest that CRE might be a potential natural antioxidant.

Augmentation of Neurotoxicity of Anticancer Drugs by X-Ray Irradiation

In order to investigate the combination effect of anticancer drugs and X-ray irradiation on neurotoxic side-effects (neurotoxicity), a method that provides homogeneously X-ray-irradiated cells was newly established. PC12 cell suspension was irradiated by X-ray (0.5 Gy) in serum-supplemented medium, immediately inoculated into 96-microwell plates and incubated overnight. The medium was replaced with fresh serum-depleted medium containing 50 ng/ml nerve growth factor to induce differentiation toward nerve-like cells with characteristic neurites according to the overlay method without changing the medium. The differentiated cells were treated by anticancer drugs as well as antioxidants, oxaliplatin or bortezomib, and the viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Antioxidants and anticancer drugs were cytotoxic to differentiating PC12 cells. Combination of anticancer drugs and X-ray irradiation slightly reduced cell viability. The present 'population irradiation method' may be useful for the investigation of the combination effect of X-ray irradiation and any pharmaceutical drug.

Role of a novel (−)-epigallocatechin-3-gallate delivery system on the prevention against oxidative stress damage in vitro and in vivo model of Parkinson's disease

Epigallocatechin-3-gallate (EGCG) is an antioxidant molecule that is studied, in this work, to evaluate its attenuating effect of the oxidative stress (OS) damage involved with the Parkinson disease (PD). To optimize the EGCG antioxidant effect, an appropriate deliver system is proposed that protects its stability and bioactivity and allows having a controlled delivery at the level of concentration required for obtaining such effect.The preparation of the novel core shell nanoparticles system for EGCG delivery starts from the formation of mixed micelles of the triblock copolymer Pluronic® F127 and sodium dodecyl sulfate surfactant followed by covering with chitosan and in situ EGCG encapsulation. The nanoparticles, after being purified by ultrafiltration, with average size around 35 nm, with encapsulation efficiency (%EE) of EGCG (~83%) and exhibiting colloidal stability and an in vitro EGCG sustained release, were chosen to evaluate the antioxidant effects of EGCG in vitro on nerve-like cells (NLCs) and in vivo in OS model of PD. They protected NLCs against OS generated by rotenone (ROT) by reducing levels of H2O2, and oxidation of DJ-1 protein. They also maintained the mitochondrial membrane potential (ΔΨm) and reduced the activation of cell death markers (CASPASE 3). In in vivo studies these nanoparticles prevented to the knockdown parkin Drosophila melanogaster, exposed to paraquat, against induced locomotor impairment, lipid peroxidation, and life span diminution. This study reaffirms the beneficial use of EGCG as an antioxidant agent and shows, through in vivo OS model of PD, the importance of its controlled delivery from an appropriate system to attain optimum results.

IPSCs-derived nerve-like cells from familial Alzheimer’s disease PSEN 1 E280A reveal increased amyloid-beta levels and loss of the Y chromosome

Alzheimer’s disease (AD) is a progressive, degenerative disorder that mainly results in memory loss and a cognitive disorder. Although the cause of AD is still unknown, a minor percentage of AD cases are produced by genetic mutations in the presenilin-1 (PSEN1) gene. Differentiated neuronal cells derived from induced pluripotent stem cells (iPSCs) of patients can recapitulate key pathological features of AD in vitro; however, iPSCs studies focused on the p.E280 A mutation, which afflicts the largest family in the world with familial AD, have not been carried out yet. Although a link between the loss of the Y (LOY) chromosome in peripheral blood cells and risk for AD has been reported, LOY-associated phenotype has not been previously studied in PSEN1 E280 A carriers. Here, we report the reprogramming of fibroblast cells into iPSCs from a familial AD patient with the PSEN1 E280 A mutation, followed by neuronal differentiation into neural precursor cells (NPCs), and the differentiation of NPCs into differentiated neurons that lacked a Y chromosome. Although the PSEN1 E280 A iPSCs and NPCs were successfully obtained, after 8 days of differentiation, PSEN1 E280 A differentiated neurons massively died reflected by release and/ or activation of death markers, and failed to reach complete neural differentiation compared to PSEN 1 wild type cells.

PCL/gelatin nanofibrous scaffolds with human endometrial stem cells/Schwann cells facilitate axon regeneration in spinal cord injury.

The significant consequences of spinal cord injury (SCI) include sensory and motor disability resulting from the death of neuronal cells and axon degeneration. In this respect, overcoming the consequences of SCI including the recovery of sensory and motor functions is considered to be a difficult tasks that requires attention to multiple aspects of treatment. The breakthrough in tissue engineering through the integration of biomaterial scaffolds and stem cells has brought a new hope for the treatment of SCI. In the present study, human endometrial stem cells (hEnSCs) were cultured with human Schwann cells (hSC) in transwells, their differentiation into nerve-like cells was confirmed by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and immunocytochemistry techniques. The differentiated cells (co-hEnSC) were then seeded on the poly ε-caprolactone (PCL)/gelatin scaffolds. The SEM images displayed the favorable seeding and survival of the cells on the scaffolds. The seeded scaffolds were then transplanted into hemisected SCI rats. The growth of neuronal cells was confirmed with immunohistochemical study using NF-H as a neuronal marker. Finally, the Basso, Beattie, and Bresnahan (BBB) test confirmed the recovery of sensory and motor functions. The results suggested that combination therapy using the differentiated hEnSC seeded on PCL/gelatin scaffolds has the potential to heal the injured spinal cord and to limit the secondary damage.

Design of epigallocatechin gallate loaded PLGA/PF127 nanoparticles and their effect upon an oxidative stress model

The epigallocatechin gallate (EGCG) is the most abundant and powerful antioxidant found in green tea. This polyphenol has been proven to have great therapeutic potential in different diseases such as cancer, diabetes, and neurodegenerative diseases. However, the limitations imposed by their low stability and rapid systemic elimination lessen their bioavailability and therapeutic efficacy. To overcome the above problems, EGCG was incorporated into poly(lactic-co-glycolic acid) and Pluronic® F127 based nanoparticles (PLGA/PF127). Nanoparticles were prepared using the emulsion/solvent evaporation method resulting in particles with a mean size around 100 nm, low polydispersity index ≤0.1, high drug encapsulation efficiency (∼86%) and in vitro sustained release. The antioxidant efficacy of the EGCG nanoparticulate formulation was evaluated upon an in vitro oxidative stress model. Remarkably, we found for the first time that EGCG encapsulated in PLGA/PF127 nanoparticles prevent the rotenone-induced ROS generation, loss of mitochondrial membrane potential and DNA fragmentation in nerve-like cells. Therefore, our findings suggest the use of these nanoparticles system might be a great opportunity to test EGCG delivery as a potential therapeutic strategy in in vivo models of neurodegenerative diseases.

Neurogenic Differentiation of Bone Marrow Mesenchymal-Like Stem Cell Induced by Delonix regia Flowers Extract

Stem cell technology has great potential in the effort to cure degenerative diseases. This study was done to determine optimum dose of flamboyant (Delonix regia) flower extract to induce proliferation and differentiation of mice (Mus musculus) bone marrow mesenchymal-like stem cell. Bone marrow cells were collected from mice by aspiration. Cells suspension (1 x 106) were poured into petri dishes containing 2 ml of modified Dulbecco's Modified Eagle's Media (mDMEM) and incubated overnight at 37 °C in a 5% CO2 incubator and microscopically observed. In quadriplicate, MSC were cultured in mDMEM containing D. regia flower extract of 0.0 (control), 0.4, 0.6, 0.8, and 1.0 mg/ml and incubated at 37 °C for 9 days. Population doubling time (PDT) and differentiated cell type were microscopically observed using HE staining on day 1 and 10. Data obtained were analyzed by ANOVA and Tukey test. The results showed that the addition of D regia flowers extracts 0.8 and 1.0 mg/ml significantly reduced PDT compared to that of 0.4, 0.6 and control. The extract, at 0.4 and 0.6 mg/ml, were able to induce MSC differentiation into fibroblast-like and nerve-like cells. In conclusion, D. regia flower extracts of 0.6, 0.8 and 1.0 mg/ml were able to stimulate MSC proliferation, but optimum dose for neurogenic differentiation was 0.6 mg/ml. This is the first to show potential of D. regia flower extract as neurogenic differentiatian inducer on mice MSC. These findings can be used as preliminary information for using the extract as cellular differentian inducer in basic and applicative reseach using stem cells.

Polymeric nanoparticles of (-)-epigallocatechin gallate: A new formulation for the treatment of ocular diseases

The epigallocatechin gallate (EGCG) is the most abundant and powerful antioxidant found in green tea. This polyphenol has been proven to have great therapeutic potential in different diseases such as cancer, diabetes, and neurodegenerative diseases. However, the limitations imposed by their low stability and rapid systemic elimination lessen their bioavailability and therapeutic efficacy. To overcome the above problems, EGCG was incorporated into poly(lactic-co-glycolic acid) and Pluronic® F127 based nanoparticles (PLGA/PF127). Nanoparticles were prepared using the emulsion/solvent evaporation method resulting in particles with a mean size around 100 nm, low polydispersity index ≤0.1, high drug encapsulation efficiency (∼86%) and in vitro sustained release. The antioxidant efficacy of the EGCG nanoparticulate formulation was evaluated upon an in vitro oxidative stress model. Remarkably, we found for the first time that EGCG encapsulated in PLGA/PF127 nanoparticles prevent the rotenone-induced ROS generation, loss of mitochondrial membrane potential and DNA fragmentation in nerve-like cells. Therefore, our findings suggest the use of these nanoparticles system might be a great opportunity to test EGCG delivery as a potential therapeutic strategy in in vivo models of neurodegenerative diseases.

Fast transdifferentiation of human Wharton’s jelly mesenchymal stem cells into neurospheres and nerve-like cells

BackgroundThe human mesenchymal stem cells derived from Wharton’s jelly tissue (hWJ-MSCs) represent a tool for cell-based therapies and regenerative medicine. hWJ-MSCs form neurospheres (NSs) within 3–7 days. No data is available to establish the neuro-phenotypic markers and time of formation of nerve-like (NLCs) and glial cells from NSs derived from hWJ-MSCs. New methodhWJ-MSCs were incubated with Fast-N-Spheres medium for 24 and 72h. The new formed NSs were in turn incubated with forskolin in neurogenic NeuroForsk medium for 1–7days. ResultshWJ-MSCs cultured with Fast-N-Spheres medium trans-differentiated into NSs in just 24h compared to 72h for hWJ-MSCs cultured with classic growth factor medium. The NSs generated from the Fast-N-Spheres medium expressed reduced levels SOX2, OCT4 and NANOG, as markers of pluripotency compared to undifferentiated hWJ-MSCs. The formed NSs exposed to NeuroForsk medium differentiated into NLCs in 4days as evidenced by high levels of protein expression of the neuronal markers, and no expression of the glial marker GFAP. Comparison with existing method(s)Currently, the formation and harvest of NSs is expensive and time consuming. Published protocols require 3–7days to form NSs from whole human umbilical cord MSCs. We report for the first time, to our knowledge, the differentiation of NSs-derived from hWJ-MSCs into NLCs. ConclusionsThe fastest method to obtain NSs and NLCs from hWJ-MSCs takes only five days using the two-step incubation media Fast-N-Spheres and NeuroForsk.

Nano Secondary Ion Mass Spectrometry Imaging of Dopamine Distribution Across Nanometer Vesicles.

We report an approach to spatially resolve the content across nanometer neuroendocrine vesicles in nerve-like cells by correlating super high-resolution mass spectrometry imaging, NanoSIMS, with transmission electron microscopy (TEM). Furthermore, intracellular electrochemical cytometry at nanotip electrodes is used to count the number of molecules in individual vesicles to compare to imaged amounts in vesicles. Correlation between the NanoSIMS and TEM provides nanometer resolution of the inner structure of these organelles. Moreover, correlation with electrochemical methods provides a means to quantify and relate vesicle neurotransmitter content and release, which is used to explain the slow transfer of dopamine between vesicular compartments. These nanoanalytical tools reveal that dopamine loading/unloading between vesicular compartments, dense core and halo solution, is a kinetically limited process. The combination of NanoSIMS and TEM has been used to show the distribution profile of newly synthesized dopamine across individual vesicles. Our findings suggest that the vesicle inner morphology might regulate the neurotransmitter release event during open and closed exocytosis from dense core vesicles with hours of equilibrium needed to move significant amounts of catecholamine from the protein dense core despite its nanometer size.

Ninjin'yoeito and ginseng extract prevent oxaliplatin-induced neurodegeneration in PC12 cells.

Ninjin'yoeito (NYT) is a formula of Japanese traditional kampo medicine composed of 12 crude drugs, and is designed to improve the decline in constitution after recovery from disease, fatigue, anemia, anorexia, perspiration during sleep, cold limbs, slight fever, chills, persistent cough, malaise, mental disequilibrium, insomnia, and constipation. Oxaliplatin (L-OHP) is a platinum-based anticancer drug used to treat colorectal, pancreatic, and stomach cancers. However, it often causes acute and chronic peripheral neuropathies including cold allodynia and mechanical hyperalgesia. In this study, we investigated the preventive effects of NYT on neuronal degeneration caused by L-OHP using PC12 cells, which are derived from the rat adrenal medulla and differentiate into nerve-like cells after exposure to nerve growth factor. L-OHP treatment decreased the elongation of neurite-like projection outgrowths in differentiated PC12 cells. When PC12 cells were treated with NYT hot water extract, neurodegeneration caused by L-OHP was significantly prevented in a concentration-dependent manner. Among the 12 crude drugs composing NYT, the extract of Ginseng (theroot of Panax ginseng) exhibited the strongest preventive effects on neurodegeneration in differentiated PC12 cells. By activity-guided fractionation, we found that the fraction containing ginsenosides displayed preventive activity and, among several ginsenosides, ginsenoside F2 exhibited significant preventive effects on L-OHP-induced decreases in neurite-like outgrowths in differentiated PC12 cells. These results suggest that NYT and ginseng are promising agents for preventing L-OHP-induced neuropathies and present ginsenoside F2 as one of the active ingredients in ginseng.

Bone marrow-derived mesenchymal stem cells differentiate into nerve-like cells in vitro after transfection with brain-derived neurotrophic factor gene.

Bone marrow-derived mesenchymal stem cells can differentiate into a variety of adult cells. Brain-derived neurotrophic factor (BDNF) is briefly active during differentiation and induces mesenchymal stem cells to differentiate into nerve cells. In this study, we cloned human BDNF to generate a recombinant pcDNA3.1(−)-BDNF vector and transfected the vector into bone marrow-derived mesenchymal stem cells. We selected these cells with Geneticin-418 to obtain BDNF-BMSCs, which were induced with retinoic acid to obtain induced BDNF-BMSCs. The transfected cells displayed the typical morphology and surface antigen profile of fibroblasts and were observed to express clusters of differentiation 29, 44, and 90 (observed in matrix and stromal cells), but not clusters of differentiation 31, 34, and 45 (observed in red blood cells and endothelial cells), via flow cytometry. Enzyme-linked immunosorbent assays showed that transfected bone marrow-derived mesenchymal stem cells secreted more BDNF than non-transfected bone marrow-derived mesenchymal stem cells. Immunocytochemistry and real-time reverse transcription polymerase chain reaction analysis showed that non-induced BDNF-BMSCs maintained a higher proliferative capacity and expressed higher amounts of brain-derived neurotrophic factor, nestin, neuron-specific enolase, and glial fibrillary acid protein than non-transfected bone marrow-derived mesenchymal stem cells. An additional increase was observed in the induced BDNF-BMSCs compared to the non-induced BDNF-BMSCs. This expression profile is characteristic of neurocytes. Our data demonstrate that bone marrow-derived mesenchymal stem cells transfected with the BDNF gene can differentiate into nerve-like cells in vitro, which may enable the generation of sufficient quantities of nerve-like cells for treatment of neuronal diseases.

Tooth Regeneration with Stem Cell Sources

Introduction: During the last decade, advances in tissue engineering and stem cell-based tooth regeneration have provided realistic and attractive means of replacing lost or damaged teeth. The first adult stem cells isolated from dental tissues were dental pulp stem cells (DPSCs). When transplanted with hydroxyl apatite/tri calcium phosphate (HA/TCP) powder, they formed a dentin-like structure lined with odontoblast-like cells that surrounded a pulp-like interstitial tissue. DPSCs could differentiate in vitro into other mesenchymal cell derivatives such as odontoblasts, adipocytes, chondrocytes, and osteoblasts and could also differentiate into functionally active neurons. Mesenchymal stem cells (MSCs) have also been isolated from the dental pulp of human deciduous teeth. When these cells are transplanted mixed with HA/TCP in vivo, they can form dentin and bone but not dentin–pulp complexes. Stem cells from the apical papilla (SCAPs) are found in the papilla tissue in the apical part of the roots of developing teeth. The third molars and teeth with open apices are an important source of SCAPs. Transplantation of SCAPs and periodontal ligament stem cells (PDLSCs) into tooth sockets allowed the formation of dentin and periodontal ligament. Dental follicle stem cells (DFSCs) have also been isolated from the follicles of developing third molars. They can differentiate into osteoblasts, adipocytes, and nerve-like cells in vitro and form cementum and periodontal ligament in vivo. Results: Future therapeutic approaches for the restoration of damaged dentin, pulp, cementum, and periodontal ligaments may make use of autologous stem cells that have been stored after removal from the patient. Conclusion:With regard to clinical application, these stem cells share the common obstacles of ethical concern arising from their embryonic origin, the risk of tumorigenesis, and the possibility of immune rejection after allogeneic transplantation. Keywords: Tooth Regeneration, Stem Cell.

Preparation of growth factor-loaded biodegradable matrices consisting of poly(depsipeptide-co-lactide) and cell growth on the matrices

Biodegradable films and sponges of poly(depsipeptide-co-lactide)s with two reactive side-chain groups, poly[(Glc–Asp)-co-LA] and poly[(Glc–Lys)-co-LA], were prepared with entrapped growth factors (bFGF, EGF, and NGF) or models for these growth factors (lysozyme, insulin and lactoferrin) based on their physicochemical similarities. These films and sponges were prepared to evaluate the potential utility of these copolymers as biodegradable scaffolds for tissue engineering. Sustained release of the model proteins from the biodegradable matrices was observed. The cell growth rates on the growth factor-loaded matrices were higher than on those without growth factors and were at the same level as with the addition of native growth factors. The effective differentiation of PC12 cells into nerve-like cells were observed on NGF-loaded copolymer film. These results indicate that the released growth factors maintained their activity and that these copolymers would be good candidates for scaffolds for tissue engineering.

Spatial control of cell attachment, proliferation, and differentiation using ion-beam induced thin films

Abstract In this study, cellular films were fabricated by ion-beam irradiation into poly- l -lactic acid sheets and cell culture. The cellular film shapes can be controlled by pattern masks. We performed spatial cell patterning using three types of cells: fibroblasts, endothelial cells, and nerve-like cells. First, multi-layered cellular construct was fabricated by stacking fibroblast cellular films. When three cellular films were stacked and incubated, these films firmly attached to each other. Second, tubular constructs were fabricated by endothelial cell culture on linearly patterned surfaces with wide widths of 80, 120, 160, and 200 μm. The patterned cellular films were rounded into vessel-like structure. The diameters of the constructs depend upon the pattern widths. Finally, we controlled cell attachment and nerve growth of nerve-like cells by using linearly patterned surfaces with narrow widths of 10, 30, and 50 μm. Nerve growth direction was controlled by varying the pattern widths. In the case of 10 μm, the attached cells and nerve growth were straight on the patterned thin films. These cell patterning techniques are expected to have applications in tissue engineering, cell transplantation, and in vitro tissue modeling.

Construction of cytoskeleton modulated by phosphatase and tensin homolog deleted on chromosome ten/mammalian target of rapamycin during the differentiation of bone marrow stem cell-derived nerve cells

Objective To observe the construction of cytoskeleton modulated by phosphatase and tensin homolog deleted on chromosome ten (PTEN)/mammalian target of rapamycin (mTOR) during the nerve cell differentiation by human bone marrow stem cells in vitro,and to analyze the implication.Methods Adult bone marrow cells were isolated and induced into nerve-like cells by some cytokines in vitro after 2 weeks.The mRNA expression of mTOR which is the downstream molecule of PTEN was compared between un-treated and treated by the BPV (a type of PTEN inhibitor) using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).The construction patterns of cytoskeleton were indicated by Phalloidin-fluoresceine isothiocyanate (FITC),and observed by the fluorescence microscopy.Results Neuron specific enolase (NSE) and β-Ⅲ tubulin were expressed in these cells after the induction by adult human bone marrow stem cells.nestin,the marker of neural progenitors was expressed increasingly at the beginning,and decreasingly subsequently.The mRNA expression level of mTOR was increased and the lenth of the neurites was from (4.58 ± 1.21) μm to (9.09 ±2.68) μm after the cells were treated by BPV (P ＜ 0.05).Conclusion When the nerve cells derived from bone marrow stem cells obtain the mature differentiation,PTEN/mTOR may possess the the ability of cytoskeleton construction modulation in the neuritis of nerve cells in vitro. Key words: Nerve cell; Cell differentiation; Phosphatase and tensin homolog deleted in chromosome 10; Mammalian target of rapamycin; Cytoskeleton