Orexin and cannabinoid systems modulate long-term potentiation of the hippocampus CA1 area in anesthetized rats.

Objectives: Long-term potentiation (LTP) is a kind of synaptic plasticity and has a key role in learning and memory. Endocannabinoids and orexins are the endogenous systems that can modulate synaptic plasticity. Given that new studies have shown an interaction between cannabinoid and orexin systems in the brain, we decided to examine this interaction between the two systems on LTP induction in rat's hippocampus. Materials and Methods: Twenty-eight male Wistar rats were used for evaluating the effects of co-administrating of cannabinoid-1 receptor (CB1R) antagonist (AM251) and orexin-2 receptor (OX2R) antagonist (TCS OX2 29) on the induction of LTP in the Schaffer collateral-CA1 synapses of rat hippocampus. The drugs were microinjected into the CA1 area of rat hippocampus 30 min before inducing of LTP. Results: Results showed that sole administration of the antagonists inhibited LTP, with respect to the control group. Also, co-administrating of them reduced LTP as compared to the control group, but not significantly more than that when the antagonists were solely microinjected into the CA1. Nonetheless, the inhibitory effect of concurrent administration of the antagonists on LTP lasted until the end of the recording. Conclusion: These results propose that endogenous cannabinoids and orexins play a role in the expression of LTP, at least by CA1-CB1Rs and CA1-OX2Rs, respectively. Finally, there is no interaction between CB1R and OX2R on the induction of LTP in the Schaffer collateral-CA1 synapses; therefore, these two systems possibly act through common signaling pathways in the hippocampus's CA1 region.

Biological study of skin wound treated with Alginate/Carboxymethyl cellulose/chorion membrane, diopside nanoparticles, and Botox A.

A hydrogel-based wound dressing with desirable properties is necessary for achieving functional skin integrity post-injury. This study focuses on preparing a hydrogel using Alginate/Carboxymethyl cellulose (Alg/CMC) as a base material. To evaluate its regenerative effects on full-thickness wounds, diopside nanoparticles and Botulinum toxin A (BTX-A) were incorporated into the hydrogel along with chorion membrane. The diopside nanoparticles (DNPs) act as a proangiogenic factor, promoting proliferation and regulating inflammation, while the chorion membrane facilitates these processes. Additionally, BTX-A prevents scar formation and aids in wound closure. The nanoparticles and hydrogel were characterized using various techniques, and their cytocompatibility was assessed. In vivo studies and quantitative polymerase chain reaction analysis showed that wound area reduction was significant after two weeks of treatment with the Alg/CMC/ChNPs/DNPs/BTX-A hydrogel. Overall, this scaffold demonstrated potential for promoting tissue regeneration and new epithelization formation, making it a promising candidate for enhancing skin restoration in wound treatments.

Anti-inflammatory and collagenation effects of zinc oxide-based nanocomposites biosynthesised with Mentha longifolia leaf extract.

OBJECTIVE: The integration of nanomaterials and herbal medicine has led to the design of new nanocomposites, which are therapeutically more effective. The purpose of this study was to prepare different zinc oxide (ZnO)-based nanoparticles (NPs) via Mentha longifolia extract based on gauze linen fibre and study its effects on wound healing. METHODS: The textural properties, morphology, thermal stability, purity, spectroscopic and phase structure of nanoparticles were investigated. Subsequently, male Wistar rats were subjected to wounds in six different treatment groups: Group I: control; group II: ZnO/W prepared in water (W); group III: ZnO/M synthesised with Mentha longifolia (M) extract; group IV: ZnO/copper(II) oxide (CuO)/M nanocomposite synthesised with M extract; group IV: treated with ZnO/silver (Ag)/M nanocomposite; group V: treated with ZnO/Ag/M nanocomposite; and finally, group VI: treated with ZnO/CuO/Ag/M nanocomposite. In all groups, the wounds were treated for 21 days with prepared samples. Every seven days, after measuring the decreasing rate of the wound size, tissue samples from each group were taken for histopathological analysis. The prepared tissue sections were assessed by haematoxylin and eosin staining for the formation of the epidermis, dermis and muscular tissue, and Masson's Trichrome staining for the formation of collagen fibres. RESULTS: The results showed that the ZnO/CuO/Ag/M nanocomposite was a significantly more effective wound healing material in comparison with other samples (p<0.05). CONCLUSION: In this study, the integration of ZnO/CuO/Ag nanocomposites with secondary metabolites of Mentha longifolia gave rise to a superior combination, which could support different phases of wound healing via the regulation of cytokines and growth factors in the course of healing.

Strontium doped bioglass incorporated hydrogel-based scaffold for amplified bone tissue regeneration.

Repairing of large bone injuries is an important problem in bone regeneration field. Thus, developing new therapeutic approaches such as tissue engineering using 3D scaffolds is necessary. Incorporation of some bioactive materials and trace elements can improve scaffold properties. We made chitosan/alginate/strontium-doped bioglass composite scaffolds with optimized properties for bone tissue engineering. Bioglass (BG) and Sr-doped bioglasses (Sr-BG) were synthesized using Sol-Gel method. Alginate-Chitosan (Alg/Cs) scaffold and scaffolds containing different ratio (10%, 20% and 30%) of BG (Alg/Cs/BG10, 20, 30) or Sr-BG (Alg/Cs/Sr-BG10, 20, 30) were fabricated using freeze drying method. Characterization of bioglasses/scaffolds was done using zeta sizer, FTIR, XRD, (FE) SEM and EDS. Also, mechanical strength, antibacterial effect degradation and swelling profile of scaffolds were evaluated. Bone differentiation efficiency and viability of MSCs on scaffolds were determined by Alizarin Red, ALP and MTT methods. Cell toxicity and antibacterial effect of bioglasses were determined using MTT, MIC and MBC methods. Incorporation of BG into Alg/Cs scaffolds amplified biomineralization and mechanical properties along with improved swelling ratio, degradation profile and cell differentiation. Mechanical strength and cell differentiation efficiency of Alg/Cs/BG20 scaffold was considerably higher than scaffolds with lower or higher BG concentrations. Alg/Cs/Sr-BG scaffolds had higher mechanical stability and more differentiation efficiency in comparison with Alg/Cs and Alg/Cs/BG scaffolds. Also, Mechanical strength and cell differentiation efficiency of Alg/Cs/Sr-BG20 scaffold was considerably higher than scaffolds with various Sr-BG concentrations. Biomineralization of Alg/Cs/BG scaffolds slightly was higher than Alg/Cs/Sr-BG scaffolds. Overall, we concluded that Alg/Cs/Sr-BG20 scaffolds are more suitable for repairing bone major injuries.

Use of bioactive glass doped with magnesium or strontium for bone regeneration: A rabbit critical-size calvarial defects study.

Background: This study aimed to evaluate the amount of bone regeneration in critical defects of rabbit calvaria filled with magnesium- and strontium-doped bioactive glasses. Materials and Methods: In this rabbit critical-size calvarial defects study, 12 male New Zealand white rabbits were randomly divided into two groups. On the calvaria of each rabbit, four lesions (two lesions in the frontal bone and two lesions in the peritoneal bone) were created with a diameter of 8 mm spaced apart. Each lesion was filled in with (1) strontium-doped bioactive glass, (2) magnesium-doped bioactive glass, (3) 45S5 bioactive glass, and (4) empty lesion (control). Six rabbits were sacrificed at the end of 4 weeks, and six rabbits were randomly sacrificed at the end of 8 weeks. Bone sections with a 5-µ thickness of rabbit calvary bone were prepared, and the percentage of new bone, connective tissue, and residual material were calculated in microscopic images. Statistical analysis was performed by two-way ANOVA and Bonferroni additional tests, and the level of significance was set at P < 0.05 in all categories. Results: At 4 weeks, magnesium-doped bioactive glass showed the highest new bone formation with a mean of 11.66 ± 2.64, followed by the strontium-doped bioactive glass with the mean of 11.10 ± 1.69 (P = 0.0001). While at week 8, the highest amount of new bone observed in the strontium-doped group with a mean of 28.22 ± 3.19, and then, the magnesium-doped bioactive glass with a mean of 22.55 ± 3.43 (P = 0.0001). Conclusion: Doping strontium and magnesium in the structure of bioactive glasses increases new bone regeneration in comparison with 45S5 bioactive glass.

Novel electrospun conduit based on polyurethane/collagen enhanced by nanobioglass for peripheral nerve tissue engineering.

Peripheral nerve injury can significantly affect the daily life of individuals with impaired nerve function and permanent nerve deformity. One of the most common treatments is autograft transplantation. Tissue engineering is one of the efficient methods to regenerate injured nerves using scaffolds, cells, and growth factors. Conduits, which are produced by a variety of techniques, could be used as an alternative treatment for patients with damaged nerves. The electrospinning technique is one of the most important and widely used methods for generating nanofiber conduits from biocompatible polymers. In this study, using the electrospinning method, three different conduits, including polyurethane (PU), polyurethane/collagen (PU/C), and a new conduit based on polyurethane + collagen + nanobioglass (PU/C/NBG), were prepared. The characteristics of these three types of conduits were evaluated by SEM, XRD, and various experiments, including porosity, degradation, contact angle, DMTA, FTIR, MTT, and DAPI staining. The results of MTT and DAPI assays revealed the safety of conduits and proper cell attachment. Overall, the results obtained from various experiments showed that the novel PU/C/NBG conduit has better mechanical properties in terms of porosity, hydrophilicity, and biocompatibility in comparison with PU and PU/C conduits and could be a suitable candidate for peripheral nerve regeneration and axonal growth due to its repair potential.

Nanobioglass enhanced polyurethane/collagen conduit in sciatic nerve regeneration.

The main purpose of neural tissue engineering and regenerative medicine is the development of biological substitutions to preserve, improve, and regenerate the damaged functions of tissues and organs. Three novel conduits, including polyurethane (PU), polyurethane/collagen (PU/C), and polyurethane/collagen/nano-bio glass (PU/C/NBG), were fabricated by the electrospinning technique. After confirming the suitability of conduits in the in-vitro environment, conduits were surgically sutured in a 10-mm gap in the sciatic nerve of a rat to evaluate their role in sciatic nerve reconstruction. After 4, 8, and 12 weeks of surgery, nerve regeneration was assessed by the hot plate test, sciatic functional index, electromyography, histology, and immunohistochemistry against S100, NF200, and CD31 antibodies. The results of various examinations revealed that the PU/C/NBG conduit is significantly more suitable than PU and PU/C conduits in terms of nerve regeneration. However, all three groups of conduits had the potential to be used for nerve regeneration. Overall, this study discovered that the PU/C/NBG conduit is a biocompatible neural conduit, which is a favorable candidate for peripheral nerve regeneration and axonal growth.

Investigating the Impact of Collagen-Chitosan Derived from Scomberomorus Guttatus and Shrimp Skin on Second-Degree Burn in Rats Model.

BACKGROUND: The present study focused on burning as one of the main causes of mortality with detrimental economic and social effects in the world. The purpose of this study was to investigate the impact of collagen-chitosan gel extracted from Scomberomorus guttatus and shrimp skin in the treatment of second degree burn healing among rats. MATERIALS & METHOD: To fulfill the purpose of the study, chitosan and collagen were extracted respectively from shrimp and Scomberomorus guttatus skin waste by the acid-based method and were evaluated by using Pico Tag, SDS-PAGE. The burn wound healing efficiency of marine collagen-chitosan gel was examined in vivo using rats. Three different ratios of collagen and chitosan blend (Col-CH, 1:3, 1:1 and 3:1) were prepared to obtain the most effective Col-CH gel for burn wound healing and were compared to the animals treated with silver sulfadiazine ointment. Healing burn wound was studied by measuring wound surface area with Image J and histopathologic examination was carried out based on the mean of epithelialization, fibroblastic cells, acute and chronic inflammatory cells, angiogenesis, structure collagen and the amount of collagen on days 15 and 25 post-burn. RESULTS: The results of SDS-PAGE indicated that the extracted collagen was type I and it was composed of two α (α1 and α2) chains. Amino acid analysis showed a much higher glaycin content in extracted collagen which amounted to one-third of the total amino. The wound surface measurement showed a significant reduction in wound size in the group treated with Col-CH (3:1) compared to silver-sulfadiazine treated group on 15th and 25th days. Histopathological findings represented a high score in epithelialization, collagen, collagen structure, fibroblast cell and a decrease in inflammatory cells infiltration in Col-CH (3:1) treated group on 25th day. The most obvious finding of the present study is that chitosan-collagen gel (3:1) represented a better efficacy compared to sulfadiazine in burn wound healing on day 25 post-burn.

Biologically-synthesised ZnO/CuO/Ag nanocomposite using propolis extract and coated on the gauze for wound healing applications.

Wound healing has long been recognised as a major clinical challenge for which stablishing more effective wound therapies is necessary. The generation of metallic nanocomposites using biological compounds is emerging as a new promising strategy for this purpose. In this study, four metallic nanoparticles (NPs) with propolis extract (Ext) and one without propolis including ZnO/Ext, ZnO/Ag/Ext, ZnO/CuO/Ext, ZnO/Ag/CuO/Ext and ZnO/W were prepared by microwave method and assessed for their wound healing activity on excision experimental model of wounds in rats. The developed nanocomposites have been characterised by physico-chemical methods such as X-ray diffraction, scanning electron microscopy, diffuse reflectance UV-vis spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and Brunauer-Emmett-Teller analyses. The wounded animals treated with the NPs/Ext in five groups for 18 days. Every 6 days, for measuring wound closure rate, three samples of each group were examined for histopathological analysis. The prepared tissue sections were investigated by haematoxylin and Eosin stainings for the formation of epidermis, dermis and muscular and Masson's trichrome staining for the formation of collagen fibres. These findings toughly support the probability of using this new ZnO/Ag/Ext materials dressing for a wound care performance with significant effect compared to other NPs.

How preparation and preservation procedures affect the properties of amniotic membrane? How safe are the procedures?

Human amniotic membrane (AM) has been widely used for tissue engineering and regenerative medicine applications. AM has many favorable characteristics such as high biocompatibility, antibacterial activity, anti-scarring property, immunomodulatory effects, anti-cancer behavior and contains several growth factors that make it an excellent natural candidate for wound healing. To date, various methods have been developed to prepare, preserve, cross-link and sterilize the AM. These methods remarkably affect the morphological, physico-chemical and biological properties of AM. Optimization of an effective and safe method for preparation and preservation of AM for a specific application is critical. In this review, the isolation, different methods of preparation, preservation, cross-linking and sterilization as well as their effects on properties of AM are well discussed. For each section, at least one effective and safe protocol is described in detail.

Extraction and Characterization of Collagen with Cost-Effective Method from Human Placenta for Biomedical Applications.

BACKGROUND: Collagen is the main product in pharmaceutics and food industry with a high demand. Collagen can be extracted from several tissues such as skin, bone and tendon, etc. Collagen can be used in tissue engineering researches as a substrate of wound healing and nerve regeneration. Extraction methods of collagen are various with different purities. In this research, we aimed to extract collagen from human placenta with a modified method. METHODS: This modified approach was used for extracting of collagen from human placenta with acetic acid and NaCl treatment using different concentrations. RESULTS: SDS page showed three different bands that reflected two alpha-chains and one beta-chain with molecular weights of 102, 118 and 220 kDa, respectively. There was no significant difference between extracted collagen from human placenta and standard collagen in western blot analysis. CONCLUSION: It was concluded that human placenta can be an alternative source of collagen with high purity for biomedical applications such as tissue engineering, stem cell therapy and research.

Lung tissue engineering: An update.

Pulmonary disease is a worldwide public health problem that reduces the life quality and increases the need for hospital admissions as well as the risk of premature death. A common problem is the significant shortage of lungs for transplantation as well as patients must also take immunosuppressive drugs for the rest of their lives to keep the immune system from attacking transplanted organs. Recently, a new strategy has been proposed in the cellular engineering of lung tissue as decellularization approaches. The main components for the lung tissue engineering are: (1) A suitable biological or synthetic three-dimensional (3D) scaffold, (2) source of stem cells or cells, (3) growth factors required to drive cell differentiation and proliferation, and (4) bioreactor, a system that supports a 3D composite biologically active. Although a number of synthetic as well biological 3D scaffold suggested for lung tissue engineering, the current favorite scaffold is decellularized extracellular matrix scaffold. There are a large number of commercial and academic made bioreactors, the favor has been, the one easy to sterilize, physiologically stimuli and support active cell growth as well as clinically translational. The challenges would be to develop a functional lung will depend on the endothelialized microvascular network and alveolar-capillary surface area to exchange gas. A critical review of the each components of lung tissue engineering is presented, following an appraisal of the literature in the last 5 years. This is a multibillion dollar industry and consider unmet clinical need.

Effects of collagen/ß-tricalcium phosphate bone graft to regenerate bone in critically sized rabbit calvarial defects.

Bone defects remain a significant health issue and a major cause of morbidity in elderly patients. Composites based on collagen/calcium phosphate have been widely used for bone repair in clinical applications, owing to their comparability to bone extracellular matrix. This study aimed to evaluate the effects of a scaffold of collagen/calcium phosphate (COL/ß-TCP) on bone formation to assess its potential use as a bone substitute to repair bone defects. Bilateral full-thickness critically sized calvarial defects (8 mm in diameter) were created in New Zealand white rabbits and treated with COL/ß-TCP or COL scaffolds. One defect was also left unfilled as a control. Bone regeneration was assessed through histological evaluation using hematoxylin and eosin and Masson's trichrome staining after 4 and 8 weeks. Alizarin Red staining was also utilized to observe the mineralization process. Our findings indicated that COL/ß-TCP implantation could better enhance bone regeneration than COL and exhibited both new bone growth and scaffold material degradation.

Improvement of post-thawed sperm quality in broiler breeder roosters by ellagic acid-loaded liposomes.

Liposomes could improve the delivery of substances to sperm. This study was conducted to investigate the effect of the antioxidant ellagic acid and ellagic acid-loaded liposomes on post-thawed sperm quality in broiler breeder roosters. Semen was diluted in Beltsville extender containing ellagic acid or ellagic acid-loaded liposomes (ellagic acid at 0 (control), 0.5, 1, and 2 mM) and cryopreserved. Sperm quality was evaluated post-thawing: motility characteristics (Computer-Assisted Semen Analysis), membrane functionality (HOS test), abnormal morphology, mitochondrial activity (Rhodamine 123), apoptotic status (Annexin V/Propidium iodide), malondialdehyde, and antioxidant activities (glutathione peroxidase (GPx), superoxide dismutase (SOD), and total antioxidant capacity (TAC)). The results showed that 1 mM ellagic acid-loaded liposomes improved total motility, membrane functionality, and viability comparing to 0.5 and 2 mM ellagic acid, 2 mM ellagic acid-loaded liposomes, and control group. Mitochondrial activity was significantly higher for 1 mM ellagic acid-loaded liposomes compared to the rest of the treatments, except 1 mM ellagic acid. Ellagic acid at 1 mM in both forms significantly increased GPx and TAC after freeze-thawing (no significant variation for SOD), and also yielded the lower proportion of apoptotic and dead cells. In conclusion, ellagic acid improved post-thawed sperm quality in broiler breeder roosters. The use of liposomes could further enhance the effects of ellagic acid.

CdS nanocrystals/graphene oxide-AuNPs based electrochemiluminescence immunosensor in sensitive quantification of a cancer biomarker: p53.

An ultrahigh sensitive, simple and reliable Electrochemiluminescence (ECL) immunosensor for selective quantification of p53 protein was designed according to the enhancement effects of AuNPs on ECL emission of CdS nanocrystals (CdS NCs). CdS NCs were immobilized on the glassy carbon electrode and AuNPs introduced to the process through formation of a sandwich-type immunocomplex between first anti-p53/p53/ secondary anti-p53. ECL of CdS NCs firstly evoked the SPR of AuNPs which in return amplified the CdS NCs ECL intensity. By using graphene oxide in immunosensor fabrication procedure, and attaching more AuNPs on the surface of the electrode, the ECL intensity was further increased resulting in much higher sensitivity. After applying the optimum conditions, the linear range of the developed immunosensor was found between 20 and 1000 fg/ml with a calculated limit of detection of 4 fg/ml. Moreover, the interference, reproducibility and storage stability studies of the immunosensor were investigated. Finally, immunosensor's authenticity was evaluated by detecting the p53 protein in human spikes which offers it as a potential in early detection of cancer, monitoring the cancer progress and clinical prognosis.

Promotion of Cell-Based Therapy: Special Focus on the Cooperation of Mesenchymal Stem Cell Therapy and Gene Therapy for Clinical Trial Studies.

Regenerative medicine (RM) is a promising new field of medicine that has mobilized several new tools to repair or replace lost or damaged cells or tissues by stimulating natural regenerative mechanisms nearby cell and tissue-based therapy approaches. However, mesenchymal stem cell (MSC) based therapy has been shown to be safe and effective to a certain degree in multiple clinical trial studies (CTSs) of several diseases, in most MSC CTSs the efficacy of treatment has been reported low. Therefore, researchers have focused on efficacy enhancing of MSC to improve migratory and homing, survival, stemness, differentiation and other therapeutic applicable properties by using different approaches. Gene therapy is one of the experimental technique tools that uses genes to change cells for therapeutic and investigation purposes. In this study has been focused on genetically modified MSCs for use in RM with an emphasis on CTSs. We highlight the basic concept of genetic modifications and also discuss recent clinical studies aspects. Recently reviewed studies show that MSC therapy with assistant gene therapy can be used in cancer therapy, heart diseases, Fanconi anemia and several other diseases.

Use new poly (ε-caprolactone/collagen/NBG) nerve conduits along with NGF for promoting peripheral (sciatic) nerve regeneration in a rat.

Regeneration of peripheral nerve defects remained a remarkable clinical challenge. Engineered nerve conduits represent a promising strategy to improve functional recovery in peripheral nerve injury repair. However, nerve conduits require additional factors such as neurotrophic factors to create a more conducive microenvironment for nerve regeneration. Neurotrophic factors have well-demonstrated abilities to improve neurite outgrowth, making them great candidates for repairing of defected nerves. To this end, we examined the beneficial effects of repairing the transected rat sciatic nerve by loading of nerve growth factor (NGF) in nerve conduits. The PCL/Collagen/NBG conduits were interposed into the 10 mm right sciatic nerve defects. Twenty-four rats were randomly allocated into four groups: 1- nerve autograft group, 2- a nongrafted group with gap 10-mm, 3- conduit group and 4- the conduits loaded with NGF. Motor and sensory functional recovery, the evoked muscle action potential, and motor distal latency showed significant improvement in rats treated with NGF. The histology and immunohistochemistry studies revealed less fibrosis and a high level of expression of CD31 and NF-200 protein at the crush site in the Conduit + NGF group. In conclusion, the PCL/Collagen/NBG conduit loaded with NGF, which exhibited nanometer-scale features, neurotrophic activity, favorable mechanical properties and biocompatibility could improve sciatic nerve regeneration in rats.

Curcumin Mitigates Radiation-induced Lung Pneumonitis and Fibrosis in Rats.

Radiation-induced lung injury is one of the most prominent factors that interfere with chest cancer radiotherapy, and poses a great threat to patients exposed to total body irradiation. Upregulation of pro-oxidant enzymes is one of the main mechanisms through which the late effects of ionizing radiation on lung injury can be exerted. Interleukin (IL)-4 and IL-13 are two important cytokines that have been proposed to be involved in this process. Through stimulation of dual oxidase 1 and 2 (DUOX 1 & 2), they induce chronic oxidative stress in irradiated tissues. In this study, we evaluated the effects of curcumin treatment on the regulation of IL-4 and IL-13, DUOX1 & 2 genes as well as the pathological changes developed by this treatment. Twenty male Wistar rats were divided into four groups: radiation only; curcumin only; radiation +curcumin; and control group with neither pharmacotherapy nor radiation. Curcumin was administered for 4 and 6 consecutive days before and after irradiation, respectively. Also, the chest area was irradiated with 15 Gy using a cobalt-60 gamma rays source. All rats were sacrificed 67 days after irradiation, followed by the assessment of the levels of IL-4 and IL-13; the expression of IL- 4 receptor-a1 (IL4Ra1), IL13Ra2, DUOX1 and DUOX2, and finally the histopathological changes were evaluated. Radiation led to the increased level of IL-4, while the level of IL-13 showed no change. QPCR results showed the upregulation of IL4Ra1, DUOX1 and DUOX2 following lung irradiation. Histopathological evaluation also showed a remarkable increase in pneumonitis and fibrosis. Treatment with curcumin downregulated the expression of IL-4, IL4Ra1, DUOX1 & 2. Furthermore, it could mitigate pneumonitis and fibrosis following lung irradiation. The late effects of radiation- induced lung injury may be due to the upregulation of DUOX1 & 2 genes. Curcumin, through modulation of these genes, may contribute to the protection against ionizing radiation.

Enhanced sciatic nerve regeneration by human endometrial stem cells in an electrospun poly (ε-caprolactone)/collagen/NBG nerve conduit in rat.

In recent years, for neurodegenerative diseases therapy, research has focused on the stem cells therapy. Due to promising findings in stem cell therapy, there are various sources of stem cells for transplantation in human. The aim of this study was to evaluate sciatic nerve regeneration in the rat after nerve transaction followed by human endometrial stem cells (hEnSCs) treatment into poly (e-caprolactone)/collagen/nanobioglass (PCL/collagen/NBG) nanofibrous conduits. After treatment of animals, the performance in motor and sensory tests, showed significant improvement in rats treated with hEnSCs as an autograft. H&E images provided from cross-sectional and, longitudinal-sections of the harvested regenerative nerve as well as immunohistochemistry results indicated that regenerative nerve fibres had been formed and accompanied with new blood vessels in the conduit cell group. Due to the advantage of high surface area for cell attachment, it is reported that this electrospun nerve conduit could find more application in cell therapy for nerve regeneration in future, to further improve the functional regeneration outcome, especially for longer nerve defect restoration. In conclusion, our results suggest that the PCL/collagen/NBG nanofibrous conduit filled with hEnSCs is a suitable strategy to improve nerve regeneration after a nerve transaction in rat.

Injectable natural polymer compound for tissue engineering of intervertebral disc: In vitro study.

Intervertebral disc degeneration is recognized to be the leading cause for chronic low-back pain. Injectable hydrogel is one of the great interests for tissue engineering and cell encapsulation specially for intervertebral (IVD) affecting rate of regeneration success, in this study we assessed viscoelastic properties of a Chitosan-ß glycerophosphate-hyaluronic acid, Chondroitin-6-sulfate, type 2 of Collagen, gelatin, fibroin silk (Ch-ß-GP-HA-CS-Col-Ge-FS) hydrogel which was named as NP hydrogel that is natural extracellular matrix of IVD. Chitosan-based hydrogel was made in the ratio of 1.5%: 7%: 1%:1%:1%-1.5%-1% (Ch: ß-GP: HA-CS-Col-Ge-FS). Gelation time and other rheological properties were studied using amplitude sweep and frequency sweep tests. Also, the cytotoxicity of the hydrogel invitro assessed by MTT and trypan blue tests. Morphology of the hydrogel and attachment of NP cells were evaluated by SEM. Our result showed that NP hydrogel in 4°C is an injectable transparent solution. It started gelation in 37°C after about 30min. Gelation temperature of NP hydrogel was 37°C. Storage modulus (G') of this hydrogel at 37°C was almost constant over a wide range of strain. MTT and trypan blue tests showed hydrogel was cytocompatible. The obtained results suggest that this hydrogel would be a natural and cytocompatible choice as an injectable scaffold for using in vivo study of IVD regeneration.