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Background: Growing incidences of chronic wounds recommend the development of optimal therapeutic wound dressings. Electrospun nanofibers have been considered to show potential wound healing properties when accompanied by other wound dressing materials. This study aimed to explore the potential role of Chitosan (CS) nanofibrous mats coated with resveratrol (RS) as an antioxidant and pro‐angiogenic agent in rat models of skin wound healing. Methods: Electrospun chitosan/polyethylene oxide (PEO) nanofibers were prepared using electrospinning technology and coated by 0.05 and 0.1 mg.ml resveratrol named as (CS/RS 0.05) and (CS/RS 0.1), respectively. The scaffolds were characterized physiochemically such as in vitro release study, TGA, FTIR spectroscopy analysis, biodegradability, and human dermal fibroblast seeding assay. The scaffold was subsequently used in vivo as a skin substitute on a rat skin wound model. Results: In vitro tests revealed that all scaffolds promoted cell adhesion and proliferation. However, more cell viability was observed in CS/RS 0.1 scaffold. The biocompatibility of the scaffolds was validated by MTT assay, and the results did not show any toxic effects on human dermal fibroblasts. It was observed that RS‐coated scaffolds had the ability to release RS in a controlled manner. In in vivo tests CS/RS 0.1 scaffold had the greatest impact on the healing process by improving the neodermis formation and modulated inflammation in wound granulation tissue. Histological analysis revealed enhanced vascular endothelial growth factor expression, epithelialization and increased depth of wound granulation tissue. Conclusions: The RS‐coated CS/PEO nanofibrous scaffold accelerates wound healing and may be useful as a dressing for cell transfer and clinical skin regeneration. [ABSTRACT FROM AUTHOR]

Objective Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, bio- sensors, food additives, pigments, manufacture of rubber products, and electronic materi- als. There are several studies about the effects of NPs on dermal fibroblast or keratino- cytes, but very little attention has been directed towards adipose-derived mesenchymal stem cells (ASCs). A previous study has revealed that ZnO-NPs restricted the migration capability of ASCs. However, the potential toxicity of these NPs on ASCs is not well un- derstood. This study intends to evaluate the effects of ZnO-NPs on subcutaneous ASCs. Materials and Methods In this experimental study, In order to assess toxicity, we ex- posed rat ASCs to ZnO-NPs at concentrations of 10, 50, and 100 µg/ml for 48 hours. Tox- icity was evaluated by cell morphology changes, cell viability assay, as well as apoptosis and necrosis detection. Results ZnO-NPs concentration dependently reduced the survival rates of ASCs as re- vealed by the trypan blue exclusion and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazo- lium-bromide (MTT) tests. ZnO-NPs, at concentrations of 10 and 50 µg/ml, induced a significant increase in apoptotic indices as shown by the annexin V test. The concentration of 10 µg/ml of ZnO-NPs was more toxic. Conclusion Lower concentrations of ZnO-NPs have toxic and apoptotic effects on subcutaneous ASCs. We recommend that ZnO-NPs be used with caution if there is a dermatological problem.

Exposure to glucocorticoids (GCs) leads to numerous changes in various biological systems including the reproductive system. The aim of the present study was to find out whether dexamethasone (Dex), a widely used GC, would influence the apoptosis and expression of Bax, an important proapoptotic protein, in the mouse testicular germ cells. Experimental groups of 8 male NMRI mice received one of the following treatments daily for 7 days: 4, 7 and 10 mg/kg Dex. Control groups were treated with equivalent volumes of saline. Experimental and control animals were sacrificed 24 h after the last injection. Immunohistochemical procedure was used to evaluation of Bax expression and the deoxyuridine nick-end labeling (TUNEL) was applied to assessment of the apoptotic germ cells. Bax expression was upregulated mainly at stages VII-VIII of spermatogenic cycle (p

Objective(s): Type 1 diabetes mellitus is a common autoimmune and multifactorial disorder. Researchers have been interested in making a favorable islet-like tissue model for the treatment of diabetes. The main objective of this study was to determine the effects of the spleen extracellular matrix (S-ECM) on the function of the MIN6 cell line (a β-cell model). Materials and Methods: In this experimental research, Wistar rat spleens were decellularized by sodium dodecyl sulfate (SDS) and Triton X-100. S-ECM was characterized by histological assessments, scanning electron microscopy, determination of residua DNA, and examination of the mechanical tensile property. Then, MIN6 cells were seeded on S-ECM scaffold. Glucose-stimulated insulin secretion and mRNA expression of insulin-related genes were examined to confirm the function of the cells. Results: The main components of S-ECM such as collagen and glycosaminoglycan remained after decellularization. Furthermore, very low residual DNA and appropriate mechanical behavior of S-ECM provided an ideal extracellular microenvironment for the MIN6 cells. GSIS results showed that the seeded cells in S-ECM secreted more insulin than the traditional two-dimensional (2D) culture. The expression of specific insulin-related genes such as PDX-1, insulin, Maf-A, and Glut-2 in the recellularized scaffold was more significant than in the 2D traditional cultured cells. Also, MTT assay results showed that S-ECM were no cytotoxic effects on the MIN6 cells. Conclusion: These results collectively have evidenced that S-ECM is a suitable scaffold for stabilizing artificial pancreatic islands. [ABSTRACT FROM AUTHOR]

The wounds caused by either burning or trauma are recognised potentially dangerous. Hydrogels are perceived as promising materials in wounds care applications. In the first step, various compounds were fabricated to obtain the optimal composition and then characterised using several techniques, including a water vapour passage test, antibacterial test, scanning electron microscopy, water absorption, tensile strength, biodegradability, and Fourier transform infrared spectroscopy. Next, silver nanoparticles (AgNPs) plus sildenafil citrate as a well-known angiogenesis stimulant were added to the compound. The prepared wound dressings with different compounds were applied to three Wistar rat groups. Haematoxylin and eosin, and silver staining methods were used. The results revealed the optimised sample and the sample possessing the AgNPs outperformed the others in antibacterial activity. The angiogenesis was significantly triggered by the sildenafil citrate-treated group, and the better recovery was observed for rats treated with the optimised sample encompassing AgNPs and sildenafil citrate. [ABSTRACT FROM AUTHOR]

Fabrication of nanofibrous biomaterials composed of natural and synthetic materials that incorporated with antibiotic and growth factors with controlled release manner is an attractive topic in wound healing. The purpose of this study was to prepare optimal composite of materials as biomimetic nanofibrous mats for application in wound healing. The mat was prepared of polycaprolactone (PCL) in the bottom, chitosan/poly ethylene oxide (Cs/PEO) in the middle, and PCL/collagen (PCL/Coll) in the top layer. A panel of standard characterization tests of nanofibrous mat was performed and its compatibilities in strength and integration were confirmed. Middle layer was loaded with epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), and silver sulfadiazine (SSD) was incorporated in the bottom layer as an anti‐infection factor. Then, on the dorsum of rats, a 400‐mm2 wound was created and surrounded by a silicone ring to control the usual tissue contractions. Nanofibrous mats with or without growth factors were applied as wound dressings and at day 14, the healing process was evaluated. At day 14, the treated group by designed mat showed faster epithelialization and angiogenesis. Silicone ring in the test group was desirable in wound closure compared to the control group. Reformation of skin tissue was manifested in a shorter time. This composite nanofibrous mat could be introduced as a dynamic and effective candidate for wound dressing. [ABSTRACT FROM AUTHOR]

Pancreatic and duodenal homeobox 1 (Pdx1) and Sonic hedgehog (Shh) are the key regulators of beta‐cell function. In vitro experiments have shown that there is significant cooperation between Pdx1 and Shh with regard to the production and maintenance of insulin‐producing cells (IPCs). In this study, the combined effect of Pdx1 overexpression and Shh manipulation on the function of adipose tissue‐derived IPCs was determined. A eukaryotic expression vector (Pdx1‐pCDNA3.1(+)) was constructed and transfected into a Chinese hamster ovary (CHO) cell line. Adipose tissue‐derived mesenchymal stem cells (ADMSCs) obtained from rats were assigned to two groups [control (C) and manipulated (M)] and differentiated into IPCs. Manipulated cells were treated with a mixture of FGF‐β and cyclopamine and recombinant Shh protein at days 3 and 11, respectively, and transfected with Pdx1‐pCDNA3.1(+) at day 10. The expression of multiple genes related to function of beta cells was analyzed using real‐time PCR. The functionality of IPCs in vitro was analyzed through dithizone (DTZ) staining and ELISA. IPCs were injected into the tail vein of diabetic rats, and blood glucose and insulin concentrations were measured. CHO cells transfected with Pdx1‐pCDNA3.1(+) showed a significantly higher expression of Pdx1 compared with nontransfected cells. Manipulated IPCs exhibited a significantly higher expression of MafA, Nkx2.2, Nkx6.1, Ngn3, insulin, and Isl1 and a higher insulin secretion in response to glucose challenge in relation to control cells. Rats that received manipulated IPCs exhibited a higher ability to normalize blood glucose and insulin secretion when compared to controls. Our protocol might be used for more efficient cell therapy of patients with diabetes in the future. [ABSTRACT FROM AUTHOR]

Many recent studies have demonstrated that most nanoparticles (NPs) have an adverse or toxic action on male germ cells. In present study, protective effect of quercetin (Que) on titanium dioxide nanoparticle (NTiO)-induced spermatogenesis defects in mice was investigated. Thirty-two Naval Medical Research Institute (NMRI) mice were randomly divided into four groups. Que group received 75 mg/kg of Que for 42 days. NTiO group received 300 mg/kg NTiO for 35 days. NTiO + Que group initially received 75 mg/kg Que for 7 days and was followed by concomitant administration of 300 mg/kg NTiO for 35 days. Control group received only normal saline for 42 days. Sperm parameters, testosterone concentration, histological criteria, and apoptotic index were assessed. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), and catalase (CAT) activities were also evaluated for oxidative stress in testicular tissue. Administration of NTiO significantly induced histological changes in testicular tissue; increased apoptotic index; and decreased testicular weight, testosterone concentration, and sperm quality ( p < 0.01). In the testis, NTiO increased oxidative stress through an increase in lipid peroxidation and a decrease in SOD and CAT activities ( p < 0.05). Que pretreatment could significantly attenuate testicular weight; apoptotic index; and histological criteria including vacuolization, detachment, and sloughing of germ cells in seminiferous tubules. Serum and tissue testosterone levels were significantly increased in Que-pretreated mice ( p < 0.01). Sperm parameters including sperm number, motility, and percentage of abnormality were also effectively improved by Que pretreatment ( p < 0.01). Pretreatment of Que significantly ameliorated oxidative stress and increased the activities of SOD and CAT in testicular tissue. These results indicate that sperm production can be increased by Que pretreatment in NTiO-intoxicated mice. The improved sperm quality and reverse testis histology by Que pretreatment may be a consequence of elevation testosterone concentration, reduction in germ cell apoptosis, and suppression of oxidative stress in testicular tissue. [ABSTRACT FROM AUTHOR]

Background: Galectin-3 (Gal-3), a β-galactoside-binding lectin, is a multifunctional lectin that involves in a number of critical biological processes. Objective: The purpose of this study was to investigate the expression pattern of Gal-3 in mouse endometrium during estrus phase of estrous cycle and pre-implantation. Materials and Methods: In this experimental study 42 NMRI female mice were divided in seven different groups. Ovulation in NMRI female mice was stimulated by injecting hMG and hCG. Estrus phase was considered as stimulated and un-stimulated groups. The other groups of mice were mated, and the day of vaginal plug formation was considered as the day 1 of pregnancy. The mice of all groups were sacrificed on different days of pre-implantation period and their uterine horns were fixed and avidin-biotin complex method of immunohistochemistry (IHC) was applied. Results: In estrus group, Gal-3 immunoreactivity in luminal epithelium was strong, in stromal cells very strong, in glandular epithelium very weak and endothelial cells very strong. No identifiable difference was observed in un-stimulated and stimulated estrus phase. In test groups, days 1-2, insignificant difference of Gal-3 expression was observed. On day 3, luminal epithelium and stromal cells showed significant decrease in comparison to estrus and day 1 (p=0.001). On the 4th and 5th days, luminal epithelium and stromal cells showed significant decrease in comparison to estrus phase and days 1-3 (p=0.0001). Conclusion: The data suggested that successful implantation is probably associated with the downregulation of Gal-3 in the mouse endometrium at the beginning of pregnancy. [ABSTRACT FROM AUTHOR]

Context: Curcumin is a yellow-orange polyphenol derived from turmeric [ Curcuma longa L. (Zingiberaceaerhizomes)]. Turmeric is a main ingredient of Indian, Persian, and Thai dishes. Extensive studies within the last half a century have demonstrated the protective action of curcumin in many disorders of the body. Objective: This study evaluated the protective effect of curcumin on dexamethasone-induced spermatogenesis defects in mice. Materials and methods: Thirty-two NMRI mice were randomly divided into 4 groups. The first (control) group received 1 mL/day of distilled water by intraperitoneal (i.p.) injection for 7 days. The second group received 200 mg/kg/day of curcumin (Cur) for 10 days. Third group received 7 mg/kg/day of dexamethasone (Dex) for 7 days. Forth group received 200 mg/kg of curcumin for 10 days after dexamethasone treatment. Testicular histopathology, morphometric analysis, head sperm counting, and immunohistochemistry assessments were performed for evaluation of the dexamethasone and curcumin effects. Results: Expression of Bcl-2 was significantly increased in the curcumin + dexamethasone group compared with dexamethasone-treated animals ( p < 0.05). Dexamethasone induced spermatogenesis defects including epithelial vacuolizations, sloughing of germ cells, reduction of seminiferous tubule diameter, reduction in the number of sperm heads and significant maturation arrest ( p < 0.001). Curcumin + dexamethasone treatment significantly prevented these changes ( p < 0.05). Discussion and conclusion: The results of this study demonstrate that curcumin increases the expression of Bcl-2 protein, an important anti-apoptotic factor, and improves the spermatogenesis defects in dexamethasone treated mice. Curcumin has a potent protective effect against the testicular toxicity and might be clinically useful. [ABSTRACT FROM AUTHOR]

The aim of the present study was to develop a tissue-engineering approach through alginate gel molding to mimic cartilage tissue in a three-dimensional culture system. The perfusion biomimetic bioreactor was designed to mimic natural joint. The shear stresses exerting on the bioreactor chamber were calculated by Computational Fluid Dynamic (CFD). Several alginate/bovine chondrocyte constructs were prepared, and were cultured in the bioreactor. Histochemical and immunohistochemical staining methods for the presence of glycosaminoglycan(GAG), overall matrix production and type II collagen protein were performed, respectively. The dynamic mechanical device applied a linear mechanical displacement of 2 mm to 10 mm. The CFD modeling indicated peak velocity and maximum wall shear stress were 1.706×10-3 m/s and 0.02407 dyne/cm2, respectively. Histochemical and immunohistochemical analysis revealed evidence of cartilage-like tissue with lacunas similar to those of natural cartilage and the production of sulfated GAG of matrix by the chondrons, metachromatic territorial matrix-surrounded cells and accumulation of type II collagen around the cells. The present study indicated that when chondrocytes were seeded in alginate hydrogel and cultured in biomimetic cell culture system, cells survived well and secreted newly synthesized matrix led to improvement of chondrogenesis. [ABSTRACT FROM AUTHOR]