A step forward to overcome the cytotoxicity of graphene oxide through decoration with tragacanth gum polysaccharide.

Hybridization of nanomaterials (NMs) with natural polymers is one of the best techniques to promote their exciting properties. In this way, the main objective of this work was to investigate the efficiency of decoration of the graphene oxide (GO) nano-sheets with tragacanth gum (TG) polysaccharide. To aim this, different approaches were used (with and without ultrasonic treatment) and various tests (XRD, FTIR, Raman, UV-Vis, DLS, Zeta potential, contact angle, AFM, FE-SEM, TEM, and MTT assay) were conducted. Test results indicated that the nano-hybrids were successfully synthesized. Furthermore, our findings represented that, the TG hybridized GO (TG-GO) appreciably enhanced the biocompatibility of GO. Moreover, it was demonstrated that the ultrasonic treatment of TG solution put a remarkable impact on the microstructure, wettability, and also surface charge characteristic of fabricated nano-hybrids and consequently improved the biocompatibility against L929-fibroblast cells.

Poly (vinyl alcohol)/chitosan/polyethylene glycol-assembled graphene oxide bio-nanocomposites as a prosperous candidate for biomedical applications and drug/food packaging industry.

The graphene oxide (GO) nanoplates and polyethylene glycol-decorated GO (GO-PEG nano-hybrid) were synthesized and characterized by FTIR, Raman, XRD, AFM, FE-SEM-EDAX and MTT assay. Obtained results confirmed the graphite oxidation and also assembly of PEG upon GO plates. The MTT assay indicated that GO-PEG nanohybrid enhanced biocompatibility to cells compared to the GO. The GO-PEG nanohybrid was introduced to the polyvinyl alcohol/chitosan carbohydrate (PVA/CS) blends. The bio-nanocomposite were prepared by simple casting method. The GO-PEG nanohybrids demonstrated a significant role in improving thermal, mechanical and antibacterial properties. Accordingly, bio-nanocomposites containing modified GO (PVA/CS/GO-PEG) exhibited higher glass transition temperature (Tg), Young's modulus, tensile strength, elongation at break and antibacterial properties than nanocomposites containing pure GO (PVA/CS/GO). The biodegradation outcomes indicated that the highest weight loss and degradability is related to the bio-nanocomposite containing modified GO (PVA/CS/GO-PEG), which was also confirmed by FE-SEM micrographs. Therefore, PVA/CS/GO-PEG bio-nanocomposites can be a suitable candidate for biomedical applications (tissue engineering, wound dressing) and food-drug packaging industry.

Fabrication of nano-decorated ZnO-fibrillar chitosan exhibiting a superior performance as a promising replacement for conventional ZnO.

In this research, bioactive nano-hybrids based on the nano-fibrillar chitosan-ZnO (NF-CS-ZnO) were synthesized to diminish the toxicity of ZnO-NPs. The successful formation of nano-hybrids was confirmed by FT-IR, UV-Vis, and FE-SEM analyses, showing a uniform spherical ZnO-NPs with an average diameter of 20-30 nm, homogeneously dispersed on NF-CS. The obtained results demonstrated a remarkable antibacterial activity of NF-CS-ZnO-0.6 nano-hybrid against E. coli and S. aureus and, interestingly, no cytotoxic on normal cells (even at a high concentration of 100 µg/mL). Furthermore, NF-CS hybridization efficiently decreased the up-regulation in Cas3, Cas9, and Il6 of inspected fishes compared to the ZnO-NPs. Histopathological examination revealed hepatocyte necrosis in the fish exposed to ZnO-NPs and hyperemia exposed to NF-CS-ZnO-0.6 nano-hybrid. Finally, NF-CS efficiently improved the bio-safety and bactericidal activity of ZnO-NPs; therefore, NF-CS-ZnO nano-hybrid is prominently recommended as a talented low-toxicity antibacterial agent replacement of conventional ZnO-NPs for use in different applications.

Enhanced radiotherapy efficacy of breast cancer multi cellular tumor spheroids through in-situ fabricated chitosan-zinc oxide bio-nanocomposites as radio-sensitizing agents.

Overwhelming evidence has shown that three-dimensional multicellular tumor spheroids (MCTSs) as a mimic of in-vivo tumor can accurately exhibit cellular responses to treatments. So, we compared the capability of pure zinc oxide nanoparticles (ZnO-NPs) and chitosan-ZnO bio-nanocomposites (CS-ZnO BNCs) for enhancing the radiosensitization of MDA-MB-231 breast cancer cells (BCCs) in the 3D-MCTSs model. ZnO-NPs and CS-ZnO BNCs were synthesized by a facile co-precipitation method. FE-SEM images revealed that the uniform spherical ZnO-NPs with an average diameter of 35 nm were successfully dispersed on chitosan. MDA-MB-231 MCTSs which were formed in a non-adherent culture plate, possessed functional features of in-vivo tumor. The priority of such culture method to conventionally used 2D monolayer (or parental) cell culture is the mimicking of tumor microenvironment. The toxicity of CS-ZnO BNCs and ZnO-NPs against the MDA-M-231 BCCs was evaluated using MTT-colorimetric assay, which demonstrated superior biocompatibility of CS-ZnO BNCs compared to pure ZnO-NPs (even at high concentration of 100 µg/mL). Survival fraction analysis of cells under clinical X-ray irradiation (6 MV) showed that MCTSs had a higher radioresistance compared to parental cells. Besides, the clonogenic potential of irradiated MCTSs was significantly decreased by the addition of CS-ZnO BNCs similar to that of monolayer cells. The sensitivity enhancement ratios (SER) for MCTSs and monolayer cells were calculated 1.5 and 1.63, respectively. Further, tracking of radiobiological properties and apoptosis induction of MCTSs showed that CS-ZnO BNCs not only could lead to the creation of higher radiation-induced complex DNA break and apoptosis death in MCTSs, but also weakened DNA repair mechanisms. It was found that non-toxic concentration of CS-ZnO BNCs has promising potential to enhance radiosensitivity of resistant-MCTSs as a superior in-vitro tumor model. So, CS-ZnO BNCs can be a prominent candidate for overcoming the resistance of BCCs to radiotherapy.

Fabrication and characterization of graphene oxide-chitosan-zinc oxide ternary nano-hybrids for the corrosion inhibition of mild steel.

In this study, graphene oxide-chitosan (GO-CS) and graphene oxide-chitosan-ZnO (GO-CS-ZnO) hybrids were synthesized in order to examine the effectiveness of hybridization in enhancing the corrosion inhibition activity of graphene oxide (GO). In this way, the synthesized GO and nano-hybrids were firstly characterized by using FTIR, UV-Vis, FE-SEM, AFM, TEM and subsequently were studied in term of corrosion inhibition. Our primary results indicated that, single-layer GO, GO-CS hybrids and also GO-CS-ZnO ternary nano-hybrids were appropriately synthesized. The corrosion inhibition results demonstrated superior performance of GO-CS hybrids than pure GO. In addition, GO-CS-ZnO ternary nano-hybrids revealed the highest corrosion inhibition activity compared with all nano-materials studied here. The corrosion inhibition efficiency of GO (η = 42.35%) was enhanced to 83.81% and 85.61% for GO-CS and GO-CS-ZnO nanocomposites in 500 ppm conc., respectively. Generally, our results demonstrated that hybridization strategy successfully promoted the corrosion inhibition efficiency of GO. Furthermore, Langmuir isotherm was used in three methods (PDP, EIS and LPR) to study the adsorption of synthesized nano-materials on mild steel.

Investigating the best strategy to diminish the toxicity and enhance the antibacterial activity of graphene oxide by chitosan addition.

The main objective of this work was to find a way to increase the bio-applicability of graphene oxide (GO) nanoparticles. In this way, various kinds of graphene oxide-chitosan (GO-CS) nano-hybrids were synthesized through attachment of different kinds of chitosan (CS) structures with GO. Subsequently, they were assessed in terms of structural characterization, antibacterial activity and cytotoxicity to obtain a hybrid structure representing the highest bactericidal and biocompatibility performance. Our results revealed that the single-layer GO and also three different kinds of GO-CS nano-hybrid structures (pristine powder, spherical and nano-fibrilar network structures) were successfully synthesized. Antibacterial activity results indicated superior antibacterial activity of nano-hybrids compared to the pure GO. In addition, it was observed that the attachment of CS to GO interestingly reduced the cytotoxicity effect of GO and even caused cell proliferation in some samples. Furthermore, the antibacterial and bio-safety properties of different hybrids were compared and suggestive mechanisms for their particular performances were proposed.

Intelligent superabsorbents based on a xanthan gum/poly (acrylic acid) semi-interpenetrating polymer network for application in drug delivery systems.

In the present study, semi-interpenetrating polymer networks (semi-IPNs) were synthesized based on crosslinked acrylic acid (AA)/xanthan gum (XG) biopolymer in the presence of N, N'-hexane-1, 6-dilbisprop-2-enamide (MS) or 1,4-butandioldimethacrylate (BDOD) as the cross-linking agent. MS is a novel acrylic-urethane diene monomer prepared through the condensation reaction between AA and hexamethylene diisocyanate (HDI). Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), X-ray diffraction (XRD) and thermogravimetric (TGA) analyses were used to study the morphology, structure and thermal stability of MS and semi-IPNs. The effect of crosslinking agent type on different behaviors such as morphology, stability, swelling, and water-retention capabilities of the synthesized hydrogels were investigated. XG-PAA semi-IPNs exhibited a very high adsorption potential and stability. Hydrogel biocompatibility was confirmed by the outcomes of MTT assay and cell staining. We recommend XG-PAA semi-IPNs as an environmentally benign and readily non-toxic material with an excellent adsorption capacity for application in drug delivery systems, wound healing and dye removal.

Schimke Immuno-osseous Dysplasia: A Case Report.

Schimke immuno-osseous dysplasia (SIOD) is a rare inherited disease characterized by steroid resistant nephrotic syndrome, spondyloepiphyseal dysplasia, and T-cell immunodeficiency. Focal segmental glomerulosclerosis (FSGS) is the most frequent renal pathological finding associated with proteinuria in SIOD. In this case report, we describe a 4.5-year-old boy who presented with nephrotic syndrome and ventricular septal defect followed by tremor in the limbs after-cerebral infarction. It is emphasized that SIOD should be considered in children with wide range of presentation, from growth retardation, steroid resistant nephrotic syndrome, and bone, cardiac, and neurological abnormalities in the late childhood or even adolescence.

Facile and rapid in-situ synthesis of chitosan-ZnO nano-hybrids applicable in medical purposes; a novel combination of biomineralization, ultrasound, and bio-safe morphology-conducting agent.

In this study, zinc oxide nanoparticle (ZnO-NPs) and also chitosan­zinc oxide (CS-ZnO-NPs) nano-hybrid were synthesized by a rapid ultrasound assisted co-precipitation method. The morphology, chemical bonding, crystal structure, UV absorption, toxicity and antibacterial properties of the CS-ZnO-NPs and ZnO-NPs were characterized. The FE-SEM (field emission scanning electron microscopy) micrographs and XRD (X-ray diffraction) analysis revealed that the used technique led to the preparation of homogeneous, ultra-thin (thickness of 20-30 nm) and highly pure ZnO sheets for the both kinds of nanoparticles. The obtained results also demonstrated a superior performance of CS-ZnO-NPs hybrid rather than ZnO-NPs in terms of antibacterial activity, cell viability and UV absorption. It was deduced that the designed biomineralization technique was a very fast and successful strategy to provide a ZnO hybrid with elevated bacterial growth inhibition and bio-safety. Furthermore, the experimental data of antibacterial analyses were compared with the curves obtained from modified Gompertz model and good accordance was observed.

Early Onset Cerebral Infarction in Schimke Immuno-Osseous Dysplasia.

Schimke Immuno-osseous Dysplasia (SIOD) is a rare autosomal recessive disease caused by a biallelic mutation in SMARCAL1 gene. Typical findings in SIOD include spondylo-epiphyseal dysplasia, steroid resistance nephrotic syndrome, progressive renal failure, T-cell immunodeficiency, bone marrow failure, and cerebral infarction. In this case report, we describe a 9-yr-old girl who presented with failure to thrive in infancy. Nephrotic syndrome was diagnosed at the age of four years. She had three episodes of admission with cerebral stroke due to moyamoya syndrome. In the last admission at Namazi Hospital, Shiraz, southern Iran, in October 2016, she had new cerebral ischemia, developed seizure, and finally died.

The effect of zinc on healing of renal damage in rats.

BACKGROUND: Several studies have previously been performed to promote kidney healing after injuries. Objectives: The aim of this study was to investigate the effect of zinc on renal healing after traumatic injury in rats. MATERIALS AND METHODS: Forty healthy female rats were selected and one of their kidneys was incised. Half of the incisions were limited only to the cortex (renal injury type I) and the other ones reached the pelvocalyceal system of the kidney (renal injury type II). All the rats in the zinc treated group (case group) received 36.3 mg zinc sulfate (contained 8.25 mg zinc) orally. After 28 days, the damaged kidneys were removed for histopathological studies. RESULTS: In the rats with type I injury, kidney inflammation of the case group was significantly lower than that of the control group. However, the result was not significant in rats with type II injury. Tissue loss and granulation tissue formation were significantly lower in the case group than the control group in both type I and II kidney injuries. CONCLUSIONS: Overall, Zinc can contribute to better healing of the rat's kidneys after a traumatic injury.

High aspect ratio phospho-calcified rock candy-like cellulose nanowhiskers of wastepaper applicable in osteogenic differentiation of hMSCs.

The aim of this study was to prepare cellulose nanowhiskers (CNWs) from wastepaper powder (WPP), as an environmentally friendly approach for obtaining the source material, which is a highly available and low-cost precursor for cellulose nanomaterial processing. Acid hydrolysis and calcification treatments were employed for extraction of CNWs and preparation of novel phospho-calcified cellulose nanowhiskers (PCCNWs). CNWs and PCCNWs were analyzed through optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transformed infrared spectra (FTIR) and X-ray diffraction analysis (XRD). Cell behaviors in the presence of CNWs and PCCNWs were studied by MTT assay and live-dead staining. Finally, the effect of these particles on osteogenic differentiation of stem cells was evaluated based on alkaline phosphatase activity (ALP), calcium mineralization as well as von Kossa and alizarin red staining. Based on the results, PCCNWs had a positive effect on osteogenic differentiation of human mesenchymal stem cells (hMSCs) and can be used for developing new approaches for bone tissue engineering.

Preparation and evaluation of polyurethane/cellulose nanowhisker bimodal foam nanocomposites for osteogenic differentiation of hMSCs.

Biocompatible and biodegradable polyurethanes (PUs) based on polycaprolactone diol (PCL) were prepared and filled with cellulose nanowhiskers (CNWs) obtained from wastepaper. The incorporated polyurethane nanocomposites were used to prepare foamed scaffolds with bimodal cell sizes through solvent casting/particulate leaching method. Sodium chloride and sugar porogens were also prepared to fabricate the scaffolds. The mechanical and thermal properties of PU/CNW nanocomposites were investigated. Incorporation of different CNWs resulted in various structures with tunable mechanical properties and biodegradability. All bimodal foam nanocomposites were biodegradable and also non-cytotoxic as revealed by MTT assay using SNL fibroblast cell line. PU/CNW foam scaffolds were used for osteogenic differentiation of human mesenchymal stem cells (hMSCs). Based on the results, such PU/CNW nanocomposites could support proliferation and osteogenic differentiation of hMSCs in three-dimensional synthetic extracellular matrix (ECM).

A Simple Method for Closure of Urethrocutaneous Fistula after Tubularized Incised Plate Repair: Preliminary Results.

BACKGROUND: Urethrocutaneous fistula (UCF) is the most prevalent complication after hypospadias repair surgery. Many methods have been developed for UCF correction, and the best technique for UCF repair is determined based on the size, location, and number of fistulas, as well as the status of the surrounding skin. OBJECTIVES: In this study, we introduced and evaluated a simple method for UCF correction after tubularized incised plate (TIP) repair. METHODS: This clinical study was conducted on children with UCFs ≤ 4 mm that developed after TIP surgery for hypospadias repair. The skin was incised around the fistula and the tract was released from the surrounding tissues and the dartos fascia, then ligated with 5 - 0 polydioxanone (PDS) sutures. The dartos fascia, as the second layer, was covered on the fistula tract with PDS thread (gauge 5 - 0) by the continuous suture method. The skin was closed with 6 - 0 Vicryl sutures. After six months of follow-up, surgical outcomes were evaluated based on fistula relapse and other complications. RESULTS: After six months, relapse occurred in only one patient, a six-year-old boy with a single 4-mm distal opening, who had undergone no previous fistula repairs. Therefore, in 97.5% of the cases, relapse was non-existent. Other complications, such as urethral stenosis, intraurethral obstruction, and epidermal inclusion cysts, were not seen in the other patients during the six-month follow-up period. CONCLUSIONS: This repair method, which is simple, rapid, and easily learned, is highly applicable, with a high success rate for the closure of UCFs measuring up to 4 mm in any location.

Autoantibodies in a Three-Year-Old Girl with Visceral Leishmaniasis: A Potential Diagnostic Pitfall.

Visceral leishmaniasis (VL), a life-threatening parasitic infection, is endemic in the Mediterranean region. Diagnosis of VL is based on epidemiologic, clinical, and laboratory findings. However, sometimes, clinical features and laboratory findings overlap with those of autoimmune diseases. In some cases, autoantibodies are detected in patients with VL and this could be a potential diagnostic pitfall. In this study, we have reported on a three-year-old girl from a VL-endemic area in Iran, who presented with prolonged fever and splenomegaly. Bone marrow examination, serologic tests, and the molecular PCR assay were performed; however, results were inconclusive. The levels of anti-double stranded DNA, cytoplasmic antineutrophil cytoplasmic autoantibody, and perinuclear antineutrophil cytoplasmic autoantibody were elevated and, at the end, splenic biopsy was performed. The splenic tissue PCR test detected the DNA of Leishmania infantum. The patient's condition improved with anti-Leishmania therapy, and the autoantibodies disappeared within the following four months. Clinical presentations and laboratory findings of VL and autoimmune diseases may overlap in some patients.

A randomized comparison of vitamin B6 and dimenhydrinate in the treatment of nausea and vomiting in early pregnancy.

BACKGROUND: Nausea and vomiting are the common symptoms of early pregnancy. Without treatment, vomiting can complicate the pregnancy, so it must be reduced. Wide varieties of treatment have been used for nausea and vomiting in pregnancy. This study compared the effectiveness of vitamin B6 and dimenhydrinate for gestational nausea and vomiting. MATERIALS AND METHODS: One hundred and forty pregnant women with a gestational age of <16 weeks who had symptoms of nausea and vomiting were selected. They were randomly allocated into group A (n = 70) and group B (n = 70). The patients in group A received a vitamin B6 tablet, while the patients in group B received a dimenhydrinate tablet daily; the tablets were identical in appearance. The degree of nausea and vomiting was assessed by physical symptoms of Rhodes score. RESULTS: One hundred and thirty-five women returned to follow-up. Dimenhydrinate and vitamin B6 significantly reduced nausea and vomiting scores from 8.3 (7.4) to 2.8 (2.0) and from 8.6 (2.9) to 3.8 (2.3), respectively. The mean score change after treatment with dimenhydrinate was greater than with vitamin B6. CONCLUSION: Both dimenhydrinate and vitamin B6 were effective in the treatment of nausea and vomiting in early pregnancy. Dimenhydrinate was more effective than vitamin B6.