Integrated In Situ Fabrication of CuO Nanorod-Decorated Polymer Membranes for the Catalytic Flow-Through Reduction of p-Nitrophenol.

We developed a novel method to fabricate copper nanorods in situ in a poly(ether sulfone) (15 wt %) casting solution by a sonochemical reduction of Cu2+ ions with NaBH4. The main twist is the addition of ethanol to remove excess NaBH4 through Cu(0) catalyzed ethanolysis. This enabled the direct use of the resulting copper-containing casting dispersions for membrane preparation by liquid nonsolvent-induced phase separation and led to full utilization of the copper source, generating zero metal waste. We characterized the copper nanorods as presented in the membranes via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV/vis spectroscopy. We could demonstrate that the rapid immobilization from reducing conditions led to the membrane incorporation of copper nanorods in a state of high reactivity, which also promoted the complete oxidation to CuO after fabrication. We further observed a large aspect ratio and crystal straining of the nanorods, likely resulting from growth around the matrix polymer. The entanglement with poly(ether sulfone) further facilitated a selective presentation at the pore surface of the final CuO-decorated membranes. The membranes also exhibit high water permeances of up to 2800 L/m2hbar. Our catalytic membranes achieved exceptionally high activities in the aqueous flow-through reduction of p-nitrophenol (p-NP), with turnover frequencies of up to 115 h-1, even surpassing those of other state-of-the-art catalytic membranes that incorporate Pd or Ag. Additionally, we demonstrated that catalytic hydrolysis of the reducing agent in water can lead to hydrogen gas formation and blocking of active sites during continuous catalytic p-NP hydrogenation. We illustrated that the accompanying conversion loss can be mitigated by facilitated gas transport in the water-filled pores, which is dependent on the orientation of the pore size gradient and the flow direction.

L-Theanine Improves Locomotor Function in a Model of Multiple Sclerosis Mice.

This study designed to investigate the protective effects of L-theanine on experimental Multiple sclerosis in mice. Frothy Male C57BL/6 mice were allocated into 4 experimental groups: control no treatment received a regular chew pellet, and the cuprizone (CPZ) group received a standard chew pellet containing 0.2% (w/w) CPZ. In group 3, mice were fed a regular diet and administered p.o. with L-theanine (50mg/kg). In group 4, mice received a diet containing CPZ and were administered p.o. with L-theanine (50mg/kg). Finally, reflexive motor behavior and serum antioxidant levels were determined. Based on findings, CPZ significantly decreased ambulation score, hind-limb suspension, front limb suspension, and grip strength (P<0.05). The CPZ + L-theanine reduced the adverse effect of the CPZ on ambulation score, hind-limb foot angle, surface righting, and negative geotaxis (P<0.05). The CPZ + L-theanine increased front and hind-limb suspension, grip strength, number of the cross, and duration of a stay on the rotarod compared to the control animal (P<0.05). CPZ administration significantly elevated serum malondialdehyde (MDA) while superoxide dismutase (SOD) and glutathione peroxidase (GPx) and total antioxidant status (TAS) levels decreased compared to control mice (P<0.05). The CPZ + L-theanine leads to the cessation of MDA production while increasing SOD, GPx, and TAS levels (P<0.05). These results suggested L-theanine has a protective effect against CPZ-induced MS in mice.

Controlled release of a non-steroidal anti-inflammatory drug from a photocurable polymeric calcium phosphate cement.

In this research, a photocurable composite based on tetracalcuim phosphate ceramic and, hydroxyethyl methacrylate-modified poly(acrylic-maleic acid) was developed and studied as a potential drug delivery system for bone defects. Different concentrations (5, 10 and 20 wt. %) of a non-steroidal anti-inflammatory drug, Indomethacin, were loaded on to the composite and its release behavior was investigated in phosphate buffered solution during 504 h. The obtained release data were fitted by both power law (Peppas) and Weibull equations. The composites were also characterized after different soaking periods using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and Fourier transforming infrared spectroscopy. The results of XRD and SEM analyses revealed the formation of nanosized needle/flake-like apatite crystals on the composites surfaces; however, better apatite formation was observed for the composites loaded with higher amounts of Indomethacin. The morphological observations and quantitative estimations revealed that the loaded composites were gradually degraded in the phosphate-buffered saline. Moreover, a controlled release of Indomethacin was found from the composites in which a higher drug concentration led to a more drug level as well as sustained release profile. In drug release modeling, better regression coefficient was obtained from the Weibull equation, compared to the power law, meaning that the Weibull equation suggests a better description of the indomethacin release from the composites during the whole period of the test. In conclusion, the photocurable composite with apatite formation ability can be successfully used for the controlled release of indomethacin as an anti-inflammatory drug in bone defects.

Histopathology and Histomorphological Study of Wound Healing Using Clove Extract Nanofibers (Eugenol) Compared to Zinc Oxide Nanofibers on the Skin of Rats.

In order to evaluate the healing effect of eugenol and other nanofibers, 100 male Wistar rats (200&plusmn;10 g) were used with 14-15 weeks of age in this study. All of the male rats were transferred in the standard cages under controlled exposure conditions in a 12:12 h light/dark cycle with a constant temperature about 22&plusmn;2 oC. In addition, the male rats were fed with pellets. Firstly, anesthesia process was performed by 2% xylazine hydrochloride (10mg/Kg/IP) and 10% ketamine hydrochloride (100mg/Kg/IP), and then the rats were placed on the operating table. Then the dorsal surfaces of the rats&rsquo; skin to ileum were scrubbed and prepared as the next step. A circular wound (with a 7 mm diameter) was created by a 7 mm sterile biopsy punch. All 100 rats were divided into four groups (n=25) randomly named as control, nano zinc oxide (ZnO), eugenol nanofibers, and polycaprolactone groups. After that, they were divided into five groups regarding the wound closure rate in days 3, 5, 7, 14, and 21. Then, the wound dressings were placed on the wounds and renewed every 24 h. At the end of days 3, 5, 7, 14, and 21, the relevant tests, such as histopathology, were conducted by removing the tissue volume using a biopsy punch, and then decapitation process was performed on the rats. It was obvious that eugenol nanofiber showed the best granulation tissue by the production of collagen. Further studies are being performed on wound healing by eugenol nanofiber.

Effect of N-acetyl-cysteine nanoparticles on intra-abdominal adhesion after laparotomy in rats.

Postoperative adhesion (POA) is a common and well-known complication with an estimated risk of 50-100%. The antioxidant effect of n-acetyl-cysteine (NAC) can increase intracellular glutathione levels, thereby reducing adhesion. This study was conducted to compare the outcomes of NAC nanoparticles (Nano-NAC) on intra-abdominal adhesion (IAA) after laparotomy in rat. A total of 25 male Wistar rats were randomized into five groups: 50 mg/kg Nano-NAC, 75 mg/kg Nano-NAC, 150 mg/kg Nano-NAC, NAC and control. During the surgical procedure, some sections (2×2cm) were collected through abdominal midline incision to ensure the infliction of peritoneal damage by a standard adhesion. Macroscopic evaluation was performed on the 14th and 28th day and blood samples were collected to evaluate the inflammatory factor (C-reactive protein) on days 0, 14 and 28. According to the serologic results (CRP test), C-reactive protein was at highest level in 150 mg/kg Nano-NAC and control groups and at lowest level in 50 mg/kg Nano-NAC and 75 mg/kg Nano-NAC groups (p⟨0.001). The macroscopic evaluation results showed that frequency of adhesion bands was significantly lower in 50 mg/kg Nano-NAC group than the control at the intervals. Results showed that the intraperitoneal administration of lower Nano-NAC dosages (50 and 75 mg/kg) had a major role in the management of postoperative inflammation. Nano-NAC administration was proved feasible, safe and effective in reduction of the C-reactive protein level.

The physical, mechanical, and biological properties of silk fibroin/chitosan/reduced graphene oxide composite membranes for guided bone regeneration.

In this study, blends of chitosan (CS)/silk fibroin (SF) and reduced graphene oxide (rGO) as guided bone regeneration membranes were fabricated by solvent casting method and their architectural features, hydrophilicity, porosity, swelling, degradation, and mechanical properties were investigated. The influence of CS, SF, and rGO on osteoblasts spreading and attachment was also determined by scanning electron microscopy (SEM) images and DAPI (4', 6-diamidoino-2-phenylindole) staining assay. The osteogenic differentiation was determined by the alizarin red staining and alkaline phosphatase activity. The results demonstrated that, the hydrophilicity, swelling and degradability decreases with the increase of SF content, whereas tensile strength increases accordingly. It was confirmed that with increasing the rGO concentration, the porosity and tensile strength decreased but the hydrophilicity was improved. The cell behaviors of G-292 cells were enhanced by increasing the CS content. According to the results, it can be concluded that, SF/CS/rGO blended membranes are promising candidates for bone tissue engineering and optimum results were obtained for the membrane composed of SF:CS: rGO with 84:7:9 weight ratio. It should be noted that the optimized membranes should be further studied for clinical applications.

Investigation of the Effects of Spinal Dexamethasone Injection as a Premedication in Rabbit Anesthesia.

Anesthesia and analgesia are important in human and veterinary medicine, especially in surgical procedures. Rodents, avians, and exotic species are required to be anesthetized using an appropriate anesthetic regimen. This study aimed to suggest a new anesthetic drug and method in order to facilitate anesthesia as well as analgesia among rabbits, laboratory animals, and humans. Spinal injection of dexamethasone combined with intramuscular ketamine among rabbits can play the role of premedication agents. A total of 24 healthy white adult rabbits from New-Zealand were equally assigned into four groups. Groups 1, 2, 3, and 4 were subjected to spinal xylazine (5mg/kg) with ketamine (35mg/kg,IM), spinal dexamethasone (0.37mg/kg-four times diluted) with ketamine (35mg/kg,IM), dexamethasone (4mg/kg,IM) with ketamine (35mg/kg,IM), and spinal dexamethasone (0.37mg/kg-four times diluted), respectively. The results showed that there was a significant difference in terms of clinical reflexes recorded for group 2, compared to groups 1 and 3. A significant difference was also observed regarding clinical reflexes between group 2 and the other groups. Furthermore, no abnormality was observed in terms of histological sections within groups 2 and 4. Spinal dexamethasone can be used as a premedication combined with ketamine in rabbit anesthesia.

Evaluation of Influence of Zeolite/Collagen Nanocomposite (ZC) and Hydroxyapatite (HA) on Bone Healing: A Study on Rabbits.

Bone healing is still a great challenge in orthopedic surgery and clinical practice. There is a dearth of research investigating the effect of Zeolite/Collagen (ZC) nanocomposite on bone regeneration. In the present study, a critical segmental defect of the rabbit femur was repaired using defects in femurs repaired by ZC nanocomposite, and the effects were examined histologically. In total, 45 rabbits at seven months of age weighing 3.5 kilograms were utilized in this study. After making the bone defects, all animals were randomized into three groups (n=15). In a normal control group (NC), a defect was created, no intervention was made, and the skin incision was sutured. On the other hand, in the ZC group, the nanocomposite of ZC was placed into the created defect. In the hydroxyapatite group (HA), the hydroxyapatite was placed into the created defect. The samples were collected on days 15, 30, and 45 postoperatively and assessed histopathologically. The mean scores of the index of the union were compared and considerable alterations were observed in this regard in the experimental groups (P&lt;0.05). The values of the index of spongiosa demonstrated that on day 15, it was the highest in the ZC group (2.2) and lowest in the HA and NC groups (0.6). Moreover, the values of the index of bone marrow demonstrated no noticeable alteration among the values of the index of bone marrow in the experimental groups (P&gt;0.05). The findings of this study demonstrated that ZC nanocomposite might be considered for reconstruction in bone damages. It seems the ZC nanocomposite bears a crucial capability in the reconstruction of bone damages and might be used as a biological frame in bone damages.

Comparative Evaluation of the Biochemical Effects of Ketamine plus Ketoprofen and Midazolam in the Premedication of Pigeons.

The present study was conducted with the aim of comparing the effects of premedication with ketoprofen and midazolam in birds. A total of 24 male pigeons with an approximate weight of 300 g were divided into four equal groups. The control group (Group I) was injected with ketamine alone. Groups II-IV were injected with ketoprofen alone, ketoprofen+ketamine, and midazolam+ketamine, respectively. The biochemical changes in the four groups were evaluated after intramuscular drug injections at different anesthetic levels. A record of biochemical changes was maintained for each group. Blood samples were taken before and after the administration of the medications in order to measure the levels of serum alkaline phosphatase (ALP), oxaloacetate transaminase (OT), prothrombin time (PT), glucose (GLU), lactate dehydrogenase (LDH), albumin (Alb), total protein (TP), and gamma-glutamyl transferase (GGTF). The results showed significant differences in the mean levels of ALP, OT, PT, GLU, LDH, Alb, and TP after anesthesia, compared to that before anesthesia. Therefore, ketoprofen+ketamine can be used for the induction of anesthesia in birds.The present study was conducted with the aim of comparing the effects of premedication with ketoprofen and midazolam in birds. A total of 24 male pigeons with an approximate weight of 300 g were divided into four equal groups. The control group (Group I) was injected with ketamine alone. Groups II-IV were injected with ketoprofen alone, ketoprofen+ketamine, and midazolam+ketamine, respectively. The biochemical changes in the four groups were evaluated after intramuscular drug injections at different anesthetic levels. A record of biochemical changes was maintained for each group. Blood samples were taken before and after the administration of the medications in order to measure the levels of serum alkaline phosphatase (ALP), oxaloacetate transaminase (OT), prothrombin time (PT), glucose (GLU), lactate dehydrogenase (LDH), albumin (Alb), total protein (TP), and gamma-glutamyl transferase (GGTF). The results showed significant differences in the mean levels of ALP, OT, PT, GLU, LDH, Alb, and TP after anesthesia, compared to that before anesthesia. Therefore, ketoprofen+ketamine can be used for the induction of anesthesia in birds.

Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass.

This paper reports on strong and bioactive bone cement based on ternary bioactive SiO2-CaO-P2O5 glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption.

Development of strong and bioactive calcium phosphate cement as a light-cure organic-inorganic hybrid.

In this research, light cured calcium phosphate cements (LCCPCs) were developed by mixing a powder phase (P) consisting of tetracalcium phosphate and dicalcium phosphate and a photo-curable resin phase (L), mixture of hydroxyethylmethacrylate (HEMA)/poly acrylic-maleic acid at various P/L ratios of 2.0, 2.4 and 2.8 g/mL. Mechanical strength, phase composition, chemical groups and microstructure of the cured cements were evaluated at pre-set times, i.e. before and after soaking in simulated body fluid (SBF). The proliferation of Rat-derived osteoblastic cells onto the LCCPCs as well as cytotoxicity of cement extracts were determined by cell counting and 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyl-2H-tetrazolium bromide assay after different culture times. It was estimated from Fourier transforming infrared spectra of cured cements that the setting process is ruled by polymerization of HEMA monomers as well as formation of calcium poly-carboxylate salts. Microstructure of the cured cements consisted of calcium phosphate particles surrounded by polymerized resin phase. Formation of nano-sized needlelike calcium phosphate phase on surfaces of cements with P/L ratios of 2.4 and 2.8 g/mL was confirmed by scanning electron microscope images and X-ray diffractometry (XRD) of the cured specimen soaked in SBF for 21 days. Also, XRD patterns revealed that the formed calcium phosphate layer was apatite phase in a poor crystalline form. Biodegradation of the cements was confirmed by weight loss, change in molecular weight of polymer and morphology of the samples after different soaking periods. The maximum compressive strength of LCCPCs governed by resin polymerization and calcium polycarboxylate salts formation was about 80 MPa for cement with P/L ratio of 2.8 g/mL, after incubation for 24 h. The strength of all cements decreased by decreasing P/L ratio as well as increasing soaking time. The preliminary cell studies revealed that LCCPCs could support proliferation of osteoblasts cultured on their surfaces and no cytotoxic effect was observed for the extracts of them.

Evaluation of a bioceramic-based nanocomposite material for controlled delivery of a non-steroidal anti-inflammatory drug.

In this study, nanocomposite of 50wt% calcium sulfate and 50wt% nanocrystalline apatite was produced and its biocompatibility, physical and structural properties were compared with pure calcium sulfate (CS) cement. Indomethacin (IM), a non-steroidal anti-inflammatory drug, was also loaded on both CS and nanocomposite cements and its in vitro release was evaluated over a period of time. The effect of the loaded IM on basic properties of the cements was also investigated. Biocompatibility tests showed a partial cytotoxicity in CS cement due to the reduced number of viable mouse fibroblast L929 cells in contact with the samples as well as spherical morphologies of the cells. However, no cytotoxic effect was observed for nanocomposite cement and no significant difference was found between the number of the cells seeded in contact with this specimens and culture plate as control. Other results showed that the setting time and injectability of the nanocomposite cement was much higher than those of CS cement, whereas reverse result obtained for compressive strength. In addition, incorporation of IM into compositions slightly increased the initial setting time and injectability of the cements and did not change their compressive strength. While a fast IM release was observed from CS cement in which about 97% of the loaded drug was released during 48h, nanocomposite cement showed a sustained release behavior in which 80% of the loaded IM was liberated after 144h. Thus, the nanocomposite can be a more appropriate carrier than CS for controlled release of IM in bone defect treatments.

Effect of adding sodium hexametaphosphate liquefier on basic properties of calcium phosphate cements.

Sodium hexametaphosphate (Na-HMP) is a common liquefying agent widely used in the ceramics industry for modifying the rheological behavior of ceramic slurries. The objective of this study was to investigate the influence of Na-HMP on several properties of calcium phosphate cements (CPCs). Various types of CPCs were prepared by mixing the same powder, namely, a mixture of tetracalcium phosphate and dicalcium phosphate anhydrate, with various liquids, namely, distilled water, Na(2)HPO(4) solutions, and Na-HMP solutions. The setting time, mechanical strength, rheological properties, and injectability of the cement pastes were examined in this work. Also, X-ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques were employed for phase analysis and morphological evaluations, respectively. The results showed that, compared to CPCs made with water and Na(2)HPO(4) solutions, the CPC pastes made with Na-HMP solutions had improved stability and injectability but prolonged setting times. The XRD and SEM studies showed that Na-HMP inhibited the growth of apatite crystals during soaking of the cements in Ringer's solution. Thus, the CPC made with Na-HMP solution had lower compressive strength than those made with water or Na(2)HPO(4) solutions. Although Na-HMP could improve the injectability and stability of the CPC paste, it impaired other basic properties of the cement. Thus, it is not an appropriate liquefier additive.

Formation of interconnected macropores in apatitic calcium phosphate bone cement with the use of an effervescent additive.

Calcium phosphate cements (CPCs) can be considered as good candidate for bone tissue engineering because they can be resorbed and take part in the bone remodeling process. Several efforts have been made into improve the resorption rate of the calcium phosphate cement by introducing macropores to the cement matrix. In this investigation a simple and effective method has been presented based on the addition of various amounts of an effervescent agent to the calcium phosphate cement components. The effervescent agent was a mixture of sodium hydrogen carbonate, NaHCO(3) (that was added to the powder phase), and citric acid monohydrate, C(6)H(8)O(7).H(2)O (that was dissolved in the liquid phase). The obtained macroporous samples were characterized by Fourier transform infrared spectrometer, X-ray diffraction, and scanning electron microscopy techniques at 4 h after setting and 3 days after soaking in a special simulated body fluid solution named Hank's balanced salt solution. Mercury intrusion porosimetry was also employed for characterizing the pore volume and pore size distribution in the cement structure. Results showed that the rate of conversion of staring reactant to the apatite phase and the apatite chemistry were significantly changed by using the additive in the cement components. Also both the pore volume and pore size were changed by varying both the amount of effervescent additive and the powder to liquid ratio.