Goethite and Hematite Nanoparticles Show Promising Anti-Toxoplasma Properties.

Toxoplasma gondii is an intracellular parasitic protozoan with a high infection rate in mammals, including humans, and birds. There is no effective vaccine, and treatment relies on antiparasitic drugs. However, existing antiprotozoal drugs have strong side effects and other problems; therefore, new treatment approaches are needed. Metal nanoparticles have attracted increased interest in the biomedical community in recent years because of their extremely high surface area to volume ratio and their unique reactivity that could be exploited for medicinal purposes. Previously, we confirmed the anti-Toxoplasma effects of gold, silver, and platinum nanoparticles, in a growth inhibition test. Here, we asked whether the anti-Toxoplasma effect could be confirmed with less expensive metal nanoparticles, specifically iron oxide nanoparticles (goethite and hematite). To improve the selective action of the nanoparticles, we modified the surface with l-tryptophan as our previous findings showed that the bio-modification of nanoparticles enhances their selectivity against T. gondii. Fourier-Transform Infrared Spectroscopy (FTIR) analysis confirmed the successful coating of the iron oxide nanoparticles with l-tryptophan. Subsequently, cytotoxicity and growth inhibition assays were performed. L-tryptophan-modified nanoparticles showed superior anti-Toxoplasma action compared to their naked nanoparticle counterparts. L-tryptophan enhanced the selective toxicity of the iron oxide nanoparticles toward T. gondii. The bio-modified nanoparticles did not exhibit detectable host cell toxicity in the effective anti-Toxoplasma doses. To elucidate whether reactive oxygen species contribute to the anti-Toxoplasma action of the bio-modified nanoparticles, we added Trolox antioxidant to the assay medium and found that Trolox appreciably reduced the nanoparticle-induced growth inhibition.

Proliferation and differentiation of MC3T3-E1 cells on polymethyl methacrylate cements containing Fe3O4 and TiO2 for hyperthermic treatment of metastatic bone tumors.

Polymethyl methacrylate (PMMA) bone cement is widely used to relieve pain caused by metastatic bone tumors. We previously found that PMMA bone cement containing 15 mass% or more of TiO2 showed good apatite-forming ability, and 25 mass% or more of Fe3O4 generated sufficient heat for hyperthermia under an alternating current (AC) magnetic field. In this study, the cytocompatibility of PMMA bone cement with Fe3O4:TiO2 weight ratios of 25:15 (F25T15-3/2-42) and 30:15 (F30T15-3/2-42) was evaluated using osteoblastic cells (MC3T3-E1). The proliferation and differentiation of MC3T3-E1 cells were suppressed for F25T15-3/2-42 and F30T15-3/2-42 compared to PMMA bone cement without Fe3O4 and TiO2 (F0T0-3/2-42). The release of methyl methacrylate (MMA) monomers from F25T15-3/2-42 and F30T15-3/2-42 at 7 days was about 33 and 50 times higher than that from F0T0-3/2-42, respectively. The remarkable release of MMA monomers from F25T15-3/2-42 and F30T15-3/2-42 may be responsible for the suppressed proliferation and differentiation of MC3T3-E1 cells. The release of MMA monomers was not reduced when the MMA/PMMA weight ratio was decreased from 3/2 to 1/1, however, it was significantly reduced by increasing the content of benzoyl peroxide (BPO) and N, N-dimethyl-p-toluidine (DMPT) to 8 and 4 mass% against MMA, respectively. Proliferation and differentiation of MC3T3-E1 cells on PMMA-type cements containing Fe3O4 and TiO2 with increased BPO and DMPT contents need to be investigated in the future; however, our findings will be useful for designing PMMA cements for the hyperthermic treatment of metastatic bone tumors.

Underwater analysis of the reproductive behaviour and egg development of the jawfish Opistognathus iyonis.

Fishes of the jawfish family Opistognathidae are cryptobenthic and distributed in subtropical seas, and new species are still being reported. Opistognathus spp. live alone in burrows and males orally brood their egg clutches. The life cycle of jawfish, including their reproductive behaviour, is poorly understood. Here we describe the natural reproduction and embryonic development of Opistognathus iyonis in Yamaguchi, Japan, based on underwater surveys for 3 years. Spawning was observed as female jawfish came into the male's burrow ~30 min before sunrise. The jawfish had a mean number of 4.4 egg clutches in the burrow through 48.2 days, and the egg took 12 days to hatching. The mean temperature for developmental days was 20.8°C. The mean and cumulative water temperature during development significantly correlated with the number of developmental days. During egg development, male jawfish took care of eggs by holding them for part of the time in their mouths. Hatching was observed ~20 min after sunset. When hatching occurred orally, eggs were pushed out and back repeatedly using the lower jaw; consequently, the egg clutches were let out in an upward direction. To our best knowledge, this is the first report of the reproductive behaviour of O. iyonis in the natural environment in the same area for several years.

Spinodal Decomposition in the Mg-Al-Fe-O System.

A supersaturated spinel solid solution having a nominal compositional ratio of Mg/Al/Fe = 0.5:1.0:1.5 was prepared using a conventional solid-state reaction at 1573 K in air followed by quenching in ice water. The formula of the resulting spinel structure compound (the spinel) was determined to be (Mg0.50AlFe0.262+Fe1.243+)0.97O4 based on a Rietveld refinement and thermogravimetry, indicating a cation-deficient spinel structure having mixed valences of Fe. This spinel was found to decompose to γ-Fe2O3 and a modified, Fe-poor spinel structure compound via a spinodal decomposition below 855 K. The spinodal temperature was estimated using the sidebands appearing in X-ray diffraction patterns in addition to the temperature dependence of magnetization values. This spinodal decomposition was accompanied by the oxidation of Fe2+ to Fe3+ and produced a unique grid-like microstructure (with a grid width of approximately 25 nm) along with enhancement of the saturated magnetization of the material. A sample cooled to room temperature in a furnace after heating at 1573 K in air had a lamella structure having a width of approximately 0.1 µm and comprised particles with a mixture of γ-Fe2O3 and the Fe-poor spinel compound on their surfaces. Subsequent heating of this same material to 1373 K in air formed ε-Fe2O3 in the particles. The crystallographic relationship between ε-Fe2O3 and the modified spinel structure compound was aε // [112̅]s, bε // [1̅10]s, and cε // [111]s (where ε and s indicate the ε-Fe2O3 and spinel, respectively).

Studying and Utilizing Traditional Technologies: Microstructure and Formation Mechanism of ε-Fe2O3 on Traditional Japanese Bizen Stoneware.

Traditional Japanese Bizen stoneware is produced by firing a specific type of green clay in a wood-fired kiln at approximately 1200 °C. During this process, single crystalline branched dendrite-like particles of Al-substituted ε-Fe2O3 (ε-Fe1.7Al0.3O3) with widths and lengths of approximately 15 and 30 µm, respectively, are formed on the surface of the ceramic. Composite particles consisting of ε-Fe2O3 epitaxially connected to spinel structure compounds [comprising the Fe-substituted spinel (Mg,Fe)(Al,Fe)2O4 and γ-Fe2O3)] with lengths of approximately 3 µm are also generated. The present work clarified the crystallographic relationship between ε-Fe2O3 and the spinel structure compounds. In addition, brown-colored samples similar to Bizen pottery and with surface Al-substituted ε-Fe2O3 particles were prepared by heating clay with K2CO3 under a 10 vol % CO gas and 90 vol % Ar gas mixture using an electric furnace instead of a firewood kiln. Hence, a traditional method was adapted to achieve the industrial production of ε-Fe2O3 crystals.

Direct Visualization of Nearly Free Electron States Formed by Superatom Molecular Orbitals in a Li@C60 Monolayer.

Using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we directly determine the spatial and energetic distributions of superatom molecular orbitals (SAMOs) of an Li@C60 monolayer adsorbed on a Cu(111) surface. Utilizing a weakly bonded [Li+@C60] NTf2- (NTf2-: bis(trifluoromethanesulfonyl)imide) salt makes it possible to produce a Li@C60 monolayer with high concentration of Li@C60 molecules. Because of the very uniform adsorption geometry of Li@C60 on Cu(111), the pz-SAMO, populated above the upper hemisphere of the molecule, exhibits an isotropic and delocalized nature, with an energy that is significantly lower compared to that of C60. The isotropic overlapping of pz-SAMOs in the condensed monolayer of Li@C60 results in a laterally homogeneous STM image contributing to the formation of a free-electron-like states. These findings make an important step toward further basic research and applicative utilization of Li@C60 SAMOs.

Ultra-high-molecular-weight Polyethylene (UHMWPE) Wing Method for Strong Cranioplasty.

We developed a new cranioplasty method that utilizes artificial bone made of ultra-high-molecular-weight polyethylene, with a wedge-shaped edge (UHMWPE Wing). This study shows the methods and data of case series and finite element analyses with the UHMWPE Wing. A circumferential wing was preoperatively designed for a custom-made artificial bone made of UHMWPE to achieve high fixed power and to minimize the usage of cranial implants. Here, we present 4 years of follow-up data and finite element analyses for patients treated with the UHMWPE Wing between February 2015 and February 2019. Eighteen consecutive patients underwent cranioplasty using our UHMWPE Wing design. There were no postoperative adverse events in 17 of the patients for at least 18 months. One case of hydrocephalus experienced screw loosening and graft uplift due to shunt malfunction. Placement of a ventriculo-peritoneal shunt immediately returned the artificial bone to normal position. Finite element analyses revealed that a model using the UHMWPE Wing had the highest withstand load and lowest deformation. This is the first report on the UHMWPE Wing method. This method may enable clinicians to minimize dead space and achieve high strength in cranioplasty.

Cytotoxicity evaluation of iron nitride nanoparticles for biomedical applications.

Magnetic nanoparticles are widely studied for their use in various therapeutic and diagnostic purposes. As biomaterials, their biocompatibility is as important as their magnetic properties. Iron nitride (Fex Ny ) has excellent magnetic properties, and thus Fex Ny nanoparticles could be useful as potential biomaterials. However, the biocompatibility of Fex Ny nanoparticles is yet to be investigated. In this study, we assessed the biocompatibility of Fex Ny nanoparticles by evaluating their direct-contact cytotoxicity compared with that of magnetite nanoparticles (MNPs). Rat fibroblasts were incubated with the nanoparticle samples dispersed in culture medium at concentrations of 10, 50, and 100 µg/ml. The DNA concentration measurement, MTT assay, and trypan blue exclusion test were conducted after days 1 and 3 of incubation. After day 1, the cell viability decreased, and cell death increased with increasing sample concentration when compared with the control. However, after day 3, there were no significant differences when compared with the control, irrespective of the sample concentrations. Further, there were no significant differences between the Fex Ny nanoparticles and MNPs at the same concentrations in all the cytotoxicity evaluation tests. Therefore, it is suggested that Fex Ny nanoparticles might be as cytocompatible as the conventional MNPs.

Pharmacological evaluation of novel (6-aminopyridin-3-yl)(4-(pyridin-2-yl)piperazin-1-yl) methanone derivatives as TRPV4 antagonists for the treatment of pain.

A novel series of (6-aminopyridin-3-yl)(4-(pyridin-2-yl)piperazin-1-yl) methanone derivatives were identified as selective transient receptor potential vanilloid 4 (TRPV4) channel antagonist and showed analgesic effect in Freund's Complete Adjuvant (FCA) induced mechanical hyperalgesia model in guinea pig and rat. Modification of right part based on the compound 16d which was disclosed in our previous communication led to the identification of compound 26i as a flagship compound. In this paper, we described the details about design, synthesis and structure-activity relationship (SAR) analysis at right and left part of these derivatives (Fig. 1).

Discovery of novel 2',4'-dimethyl-[4,5'-bithiazol]-2-yl amino derivatives as orally bioavailable TRPV4 antagonists for the treatment of pain: Part 2.

A series of 2',4'-dimethyl-[4,5'-bithiazol]-2-yl amino derivatives have been identified as selective TRPV4 antagonists that display inhibition potencies against 4α-phorbol 12,13-didecanoate (4αPDD), well known as a TRPV4 selective agonist and/or a hypotonicity. In particular, 9-(6-((2',4'-dimethyl-[4,5'-bithiazol]-2-yl)amino)nicotinoyl)-3-oxa-9-azabicyclo[3.3.1]nonan-7-one showed an analgesic effect in Freund's Complete Adjuvant (FCA) induced mechanical hyperalgesia model in guinea pig (reported in Part 1). However, there are some concerns such as species differences and the need for higher plasma exposure to achieve target efficacy for evaluation by an in vivo pain model. In this Letter, we report the resolution of some of the problems by further optimizing the chemical scaffold.

Stability of α''-Fe16N2 in hydrogenous atmospheres.

We revealed the inherent instability of α''-Fe16N2 in hydrogenous atmospheres due to the denitrification toward α-Fe by forming NH3 at the particle surface. Coating the particle surface with SiO2 to suppress the formation of NH3 has proven to be a simple yet powerful method to enhance the stability of α''-Fe16N2 in hydrogenous atmospheres.

Magnetic ordered states induced by interparticle magnetostatic interaction in α-Fe/Au mixed nanoparticle assembly.

The magnetic behavior of α-Fe/Au nanoparticle (NP) assemblies is studied over a very wide range of dipolar interactions among α-Fe NPs, by changing the volume density of the α-Fe NP. The assembly whose α-Fe NP density is lower than 0.1% exhibits typical superparamagnetic behavior. When Fe NP density exceeds 8.6% the magnetic dynamics changes to that resembling superspin glass. Moreover, NP assembly with highest Fe concentration (43%), whose dipolar interaction is enormously strong compared with previous studies, exhibits a two-stage magnetic transition, i.e., ferromagnetic and spin glass-like transitions at 385 K and around 150 K, respectively. Therefore, we first observed the reentrant spin glass-like magnetism at the limit of strong interaction in a close-packed NP assembly. Based on these observations, the magnetic phase diagram of the interacting α-Fe NP assembly is determined over a very wide range of interaction.

Quantitative understanding of thermal stability of α''-Fe16N2.

The thermal stability of α''-Fe16N2, which attracts much interest because of its superior magnetic properties featuring a large magnetocrystalline anisotropy (Ku ~ 1 × 10(7) erg cm(-3)) and a large saturation magnetization (Ms ~ 234 emu g(-1)), though unfortunately thermally unstable, has been quantitatively studied.

Treatment of experimental cerebral vasospasm by protein transduction of heme oxygenase 1 (HO-1) conjugated to a residue of 11 arginines.

BACKGROUND: Many kinds of proteins can be transduced into various cells by conjugation with 10-20 amino acid peptides. A sequence of 11 consecutive arginine groups (11R) is one of the most efficient protein transduction domains (PTD). We used the 32-kDa heat shock protein heme oxygenase-1 (HO-1) as a therapeutic protein for experimental cerebral vasospasm. This protein is an enzyme of the heme-catabolism and cleaves heme to form biliverdin and carbon monoxide (CO). HO-1 has known vascular relaxing properties. We examined the transduction efficacy and antispastic therapeutic effect of 11R fused HO-1 protein in cerebral arteries. METHODS: 11R fused HO-1 protein was expressed purified. An MTT assay was used to evaluate the cytotoxicity of 11R-HO-1. An antispastic effect was investigated in a rat model of experimental subarachnoid hemorrhage by measuring basilar artery diameters 4 h after the injection of 11R-HO-1 into the cisterna. FINDINGS: Expression and purification of 11R-HO-1 could be successfully effected. Transduction into the basilar artery was also successful. 11R-HO-1 protein has the positive effect of attenuating cerebral vasospasm. CONCLUSION: These results suggest that the 11R-HO-1 protein transduction method has a potential to treat cerebral vasospasm.

Protein therapy using heme-oxygenase-1 fused to a polyarginine transduction domain attenuates cerebral vasospasm after experimental subarachnoid hemorrhage.

A sequence of 11 consecutive arginine residues (11R) is one of the best protein transduction domains for introducing proteins into cell membranes. Heme-oxygenase-1 (HO-1) is involved in heme catabolism and reduces the contractile effect of hemoglobin after subarachnoid hemorrhage (SAH). Therefore, we constructed 11R-fused HO-1 protein to achieve successful transduction of the protein into the cerebral arteries and examined the therapeutic effect of the 11R-HO-1 protein for cerebral vasospasm (CV) after SAH. We injected the 11R-HO-1 protein into the cisterna magna of male rats and, several hours after the injection, performed immunofluorescence staining and western blotting analysis of the rat basilar arteries (BAs) to determine transduction efficacy. We also assessed intraarterial HO-1 activity as cGMP (cyclic guanosine 3', 5'-cyclic monophosphate) accumulation in SAH and determined whether protein transduction of 11R-HO-1 quantified the therapeutic effect in a rat double-hemorrhage model of SAH. The BAs expressed significantly more HO-1 in the group injected with 11R-HO-1 (3.56±0.54 (11R-HO-1) versus control (saline)), and transduction of 11R-HO-1 resulted in higher activity (>3.25-fold) in rat BAs with SAH. Moreover, the results of the rat double-hemorrhage model showed that the 11R-HO-1 protein significantly attenuated CV after SAH (317.59±23.48 µm (11R-HO-1) versus 270.08±14.66 µm (11R-fused enhanced green fluorescent protein), 252.05±13.95 µm (saline), P<0.01).

Size control and characterization of wustite (core)/spinel (shell) nanocubes obtained by decomposition of iron oleate complex.

Monodisperse wustite (core)/spinel (shell) nanocubes with controllable size from 9 to 22 nm were synthesized by the decomposition of iron oleate complex at high temperature. The composition of the nanocubes was confirmed by X-ray diffraction and magnetic analysis, meanwhile the distributions of wustite and spinel phases within the nanocubes were directly observed by high resolution transmission electron microscopy using the dark-field image technique. The core/shell structure is quite unique, in which spinel phase is distributed not only preferentially on the surface, but also in the interior, while almost all of the wustite phase is located in the core of the nanocubes. The formation of wustite is inherent in the decomposition of the iron oleate complex, as indirectly inferred through the detection of a huge quantity of carbon monoxide generated from the reactor.

Facile synthesis of Fe3O4 nanoparticles by reduction phase transformation from gamma-Fe2O3 nanoparticles in organic solvent.

A phase transformation induced by the reduction of as-synthesized gamma-maghemite (gamma-Fe(2)O(3)) nanoparticles was performed in solution by exploiting the reservoir of reduction gas (CO) generated from the incomplete combustion reaction of organic substances in the reactor. Results from X-ray diffraction, color indicator, and magnetic analysis using a SQUID strongly support this phase transformation. Based on this route, monodisperse magnetite (Fe(3)O(4)) nanoparticles were simply produced in the range from 260 to 300 degrees C. Almost all aspects of the original gamma-Fe(2)O(3) nanoparticles, such as shape, size, and monodispersity, were maintained in the produced Fe(3)O(4) nanoparticles.

Protein transduction method for cerebrovascular disorders.

Many studies have shown that a motif of 11 consecutive arginines (11R) is one of the most effective protein transduction domains (PTD) for introducing proteins into the cell membrane. By conjugating this "11R", all sorts of proteins can effectively and harmlessly be transferred into any kind of cell. We therefore examined the transduction efficiency of 11R in cerebral arteries and obtained results showing that 11R fused enhanced green fluorescent protein (11R-EGFP) immediately and effectively penetrated all layers of the rat basilar artery (BA), especially the tunica media. This method provides a revolutionary approach to cerebral arteries and ours is the first study to demonstrate the successful transductionof a PTD fused protein into the cerebral arteries. In this review, we present an outline of our studies and other key studies related to cerebral vasospasm and 11R, problems to be overcome, and predictions regarding future use of the 11R protein transduction method for cerebral vasospasm (CV).

Effects of deferoxamine-activated hypoxia-inducible factor-1 on the brainstem after subarachnoid hemorrhage in rats.

OBJECTIVE: Hypoxia-inducible factor (HIF)-1 is a transcription factor that regulates the expression of various neuroprotective genes. The goal of this study was to clarify the relationship between HIF-1 expression and subarachnoid hemorrhage (SAH) and to characterize the effects of deferoxamine (DFO)-induced increases in HIF-1 protein levels on the brainstem and the basilar artery (BA) after experimental SAH. METHODS: Rat single- and double-hemorrhage models (injected on Days 0 and 2) of SAH were used. We assessed the time courses for HIF-1 protein levels in the brainstems and the BA diameters within 10 minutes and 6 hours on Days 1 and 2 in the single-SAH model, and also on Day 7 in the double-SAH model. After induction of double hemorrhage in rats, DFO was injected intraperitoneally. We then evaluated HIF-1 protein expression and brainstem activity, BA diameter, and brainstem blood flow. RESULTS: After the rats experienced SAH, HIF-1 protein expression was significantly greater at 10 minutes in the single-injection model and at 7 days in the double-injection model than at similar time points in the control group, and these increases correlated with degrees of cerebral vasospasm. DFO injection resulted in significant increases in HIF-1 protein expression and activity in the brainstems of rats with SAH, compared with the rats with SAH that were given placebos, and the rats without SAH in the double-hemorrhage model. Cerebral vasospasm and reduction of brainstem blood flow were significantly attenuated in the rats that were administered DFO. CONCLUSION: These results show that a DFO-induced increase in HIF-1 protein level and activity exerts significant attenuation of BA vasospasm and reduction of brainstem blood flow in the rat model of SAH. DFO may be a promising agent for treating clinical SAH.

Submucous turbinectomy combined with posterior nasal neurectomy in the management of severe allergic rhinitis: clinical outcomes and local cytokine changes.

OBJECTIVES: Submucous resection of the inferior turbinate is one of the recommended methods to alleviate nasal symptoms in patients with severe allergic rhinitis patients in terms of postoperative results and preservation of nasal function. Posterior nasal neurectomy, recently developed by Kikawada, is a novel method to selectively cut the neural bundles out from the sphenopalatine foramen and to diminish the complaints of hypersecretion. This study was carried to examine the clinical effectiveness and changes in local cytokine levels of this combined surgical procedure. METHODS: Twenty-three patients with severe perennial allergic rhinitis underwent submucous turbinectomy combined with posterior nasal neurectomy under general anesthesia. The patients' subjective nasal symptoms were examined at each visit. The levels of interleukin-5 (IL-5), eotaxin and regulated on activation, normal T cell expressed and secreted (RANTES) in nasal lavages were measured before and 6 month after surgery. Nasal mucosa of the inferior turbinate was also obtained for histopathological examination in some cases. RESULTS: The mean symptom scores for sneeze, rhinorrhea, nasal obstruction, and total severity were all statistically decreased after surgery. Therapeutic effects continued to be apparent as long as 3 years after surgery. The mean levels of both IL-5 and eotaxin significantly decreased after surgery, but that of RANTES remained unchanged. Histopathological examination revealed that the number of inflammatory cells and nasal glands markedly reduced in lamina propria and the epithelial layer became covered with stratified columnar cells. CONCLUSION: Submucosal turbinectomy with posterior nasal neurectomy has remarkably improved subjective nasal symptoms in patients with severe allergic rhinitis on a long-term follow-up basis. The present study also demonstrates that the clinical effectiveness of the procedure is accompanied by decreases in local inflammatory cell infiltration and the related cytokine production.