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@#Traditional titanium implants do not completely meet the clinical requirements because they are bioinert. The surface of titanium implants, modified by strontium ions, can enhance osseointegration and reduce peri-implantitis. In this paper, the biological properties of titanium implant surfaces modified by strontium ions were reviewed. Strontium ions can be coated on the implant surface by hydrothermal treatment, electrochemical deposition, phosphate chemical conversion, flame-spraying, supramolecular self-assembly, magnetron sputtering, laser deposition and alkali etching. Implant surfaces modified by strontium ions can not only promote osteogenesis and early osseointegration but also inhibit bacterial growth and reduce postoperative infections. Even better osseointegration and antibacterial effects can be achieved when strontium ions are incorporated with other elements, such as silver, zinc, gallium, and calcium. However, most of the studies on the use of strontium ion-modified titanium implants are animal experiments and in vitro experiments, and the observation time is short compared with the actual service life of the implants. Thus, the conclusions obtained may be different from the actual clinical application, and the long-term effects need to be studied. In addition, the osteogenic effects of various modification methods also need to be compared. Future research can focus on the following points: ① to find efficient modification methods that can be widely used in the clinic; ②to study how to control the concentration of strontium ions near the implant to exert their biological function and reduce their toxic side effects; and ③ to conduct long-term follow-up clinical trials to observe their osteogenic and antibacterial effects.
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BACKGROUND: For more than a decade, water-soluble, eco-friendly, biocompatible, and low-toxicity fluorescent nanomaterials have received considerable attention for their numerous in vivo and in vitro applications in biomedical imaging, disease diagnostics, and environmental monitoring. Owing to their tunable photoluminescence properties, carbon-based luminescent nanomaterials have shown great potential in bioimaging, photocatalysis, and biosensing among other applications. RESULTS: Marine environments provide excellent resources for the fabrication of these nanomaterials, because many marine organisms contain interesting trigger organic compounds that can be used as precursors. Herein, we synthesize multi-color emissive carbon dots (CDs) with an intrinsic photoluminescence quantum yield of 20.46%. These nanostructures were achieved through the one-step hydrothermal treatment of marine polysaccharide chondroitin sulfate, obtained from shark cartilage, in aqueous solution. CONCLUSIONS: We successfully demonstrate the low toxicity of our marine resource-derived CDs in zebrafish, and provide an initial assessment of their possible use as a bioimaging agent. Notably, the newly synthesized CDs localize in the intestines of zebrafish larvae, thereby indicating their biocompatibility and potential use as in vivo dyes.
Subject(s)
Animals , Polysaccharides/chemistry , Sharks , Carbon/chemistry , Quantum Dots/chemistry , Zebrafish , Carbon/toxicity , Cartilage , Quantum Dots/toxicity , Luminescence , Nanostructures , Coloring Agents/toxicity , Coloring Agents/chemistryABSTRACT
It is difficult to get sufficient roughness on titanium implant surface using traditional electrochemical treatments. In this study, we have developed a new method which provides a hybrid structured titanium surface having micro/nano roughness using electrochemical treatment in NaCl electrolyte and hydrothermal treatment. Titanium disks were anodically oxidized (ANO) in 0.15M NaCl electrolyte by applying positive electric pulses. The oxide compounds loosely attached to the surface were removed by ultrasonic cleaning (ANO group). These specimens were hydrothermally (HT) treated in an alkaline solution (ANO-HT group). ANO group showed the dimpled grain surfaces with a diameter of approximately 30 µm, and its roughness (Ra) was about 2.4 µm. The nano-sized crystallites which had an anatase TiO₂ crystalline structure were uniformly distributed on the surface of ANO-HT group. This group still retained high roughness (~2.7 µm) similar to ANO group and showed high hydrophilicity. Titanium surface with high roughness and hydrophilicity was fabricated using new electrochemical treating method and hydrothermal treatment. This surface modification method could be used for enhancing the osteoconductivity of the titanium implants.
Subject(s)
Crystallins , Hydrophobic and Hydrophilic Interactions , Methods , Titanium , UltrasonicsABSTRACT
In order to study the influence of the hydrothermal treatment technology (HTT) on macro/micro nutrients extraction from two types of chicken manure (broiler chicken manure (BCM) and laying hen chicken manure (LCM)), hydrothermal treatment followed by the solid/liquid separation of the HTT product was performed with a fixed feedstock to water mass ratio (1:3), 30 min reaction time and three different reaction temperatures (160ºC, 180ºC, 200ºC). More than 50% of N can be extracted from solid to liquid after HTT for both BCM and LCM. Moreover, the organic N content was more than 80% in all liquid samples and it was increasing with the increase of HTT temperature. According to all the results, 180ºC is the optimum temperature for both types of chicken manure and the pH value of the liquid extracted at the optimum temperature was close to 7 for both types of chicken manure. The heavy metal contents in the liquid obtained from BCM and LCM were not detected. It was observed that macro nutrients and micro-nutrients were dissolved in the liquid after HTT.
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The objective of this study is to evaluate the possibility of recycling the liquid product obtained from sewage sludge by the hydrothermal treatment as a kind of organic fertilizer and its effect on the plant growth. A small scale hydrothermal treatment experiment was performed and proved that the liquid product contains high content of nitrogen and low content of micronutrients. Therefore, the liquid product has the potential to be used as a kind of liquid fertilizer. In a seed germination test, the liquid product indicated low phytotoxicity. Moreover, in a Komatsuna cultivation experiment, the liquid product showed accelerate effect to the crop yield which is not lower than the chemical fertilizer. Through the low-temperature hydrothermal treatment, the sewage sludge was converted into liquid organic material that could be used as a delayed-release nitrogen fertilizer for the growth of Komatsuna. These results indicated the possibility of establishing a comprehensive system for recycling sewage sludge into a kind of organic fertilizer.
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Considerable research efforts have been made in recent years towards the development of silica mesoporous nanocomposite as drug delivery system. Numerous reports are available in literature for the synthesis of mesoporous nano materials. In present work two distinct mesoporous MCM-41 nanocomposite (MCM-41-A and MCM-41-B) were synthesized and characterized by different instrumental techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, FTIR and nitrogen adsorption desorption analyses. Both the mesoporous nanocomposite was synthesized with different hydrothermal treatment and effect on mesoporosity was determined. Evaluation data revealed MCM-41-A MSNs with regular spherical shape with high degree of mesoporosity whereas MCM-41-B MSNs were lack of mesoporous characteristics. For instance, hydrothermal treatment significantly affects the physical properties like surface area, pore volume and pore diameter of the MSNs.
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El catalizador de FCC está constituido por partículas de composición compleja donde el componente activo es una zeolita Y. En este trabajo se presentan los resultados texturales y estructurales de una zeolita USY comercial lixiviada, de una serie de catalizadores con 7, 15, 25, 35 y 45% de material activo y los de estos materiales desactivados hidrotérmicamente. Las muestras se caracterizaron por fluorescencia de rayos X (FRX), difracción de rayos X (DRX), resonancia magnética nuclear de silicio (29Si RMN) y fisiadsorción de nitrógeno a 77 K. A partir de estos resultados se hallaron correlaciones entre el volumen de microporo y el contenido de zeolita y entre el grado de cristalinidad y el porcentaje de zeolita. Además, se encontró que un tratamiento con sólo 20% de vapor de agua a 1033 K durante 16 horas destruye los grupos estructurales Si(2Al) y Si(3Al) como reflejo de la dealuminización drástica que sufre el material.
FCC catalyst is made up of particles of complex composition where the main active component is a Y zeolite. This work presents the textural and structural results of a commercial USY zeolite which had been previously prepared from a set of catalysts with 7, 15, 25, 35 y 45% of active material and of the hydrothermally deactivated materials zeolite. The samples have been characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), 29Si NMR spectroscopy and nitrogen adsorption at 77K. From these results was found correlations between micropore volume and zeolite content and degree crystallinity and %zeolite. Also, it was found that an hydrothermal treatment at 1033 K with only 20% steam during 16 hours destroys the structural groups Si(2Al) and Si(3Al) as a reflection of the strongly dealumination of the zeolite component of the catalyst.
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STATEMENT OF PROBLEM: HA has been used as a coating material on Ti implants to improve osteoconductivity. However, it is difficult to form uniform HA coatings on implants with complex surface geometries using a plasma spraying technique. PURPOSE: To determine if Ti6Al4V sintered porous-surfaced implants coated with HA solgel coated and hydrothermal treated would accelerate osseointegration. MATERIALS AND METHODS: Porous implants which were made by electric discharge were used in this study. Implants were anodized and hydrothermal treatment or HA sol-gel coating was performed. Hydrothermal treatment was conducted by high pressure steam at 300 degrees C for 2 hours using a autoclave. To make a HA sol, triethyl phosphite and calcium nitrate were diluted and dissolved in anhydrous ethanol and mixed. Then anodized implant were spin-coated with the prepared HA sols and heat treated. Samples were soaked in the Hanks' solution with pH 7.4 at 37 degrees C for 6 weeks. The microstructure of the specimens was observed with a scanning electron microscope (SEM), and the composition of the surface layer was analyzed with an energy dispersive spectroscope (EDS). RESULTS: The scanning electron micrographs of HA sol-gel coated and hydrothermal treated surface did not show any significant change in the size or shape of the pores. After immersion in Hanks' solution, the precipitated HA crystals covered macro- and micro-pores. The precipitated Ca and P increased in Hanks' solution that surface treatment caused increased activity. CONCLUSION: This study shows that sol-gel coated HA and hydrothermal treatment significantly enhance the rate of HA formation due to the altered surface chemistry.
Subject(s)
Calcium , Chemistry , Dental Implants , Ethanol , Hot Temperature , Hydrogen-Ion Concentration , Immersion , Osseointegration , Plasma , SteamABSTRACT
STATEMENT OF PROBLEM: Ti-6Al-7Nb alloy is used instead of Ti-6Al-4V alloy that was known to have toxicity. PURPOSE: This study was performed to investigate the effect of electrolyte concentration on the surface characteristics of anodized and hydrothermally-treated Ti-6Al-7Nb alloy. MATERIALS AND METHODS: Discs of Ti-6Al-7Nb alloy of 20 mm in diameter and 2 mm in thickness were polished sequentially from 300 to 1,000 SiC paper, ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at 50 degrees C for 24 hours. Anodizing was performed at current density 30 mA/cm2 up to 300 V in electrolyte solutions containing beta-glycerophosphate disodium salt hydrate (beta-GP) and calcium acetate (CA). Hydrothermal treatment was conducted by high pressure steam at 300 degrees C for 2 hours using a autoclave. All samples were soaked in the Hanks' solution with pH 7.4 at 36.5 degrees C for 30 days. RESULTS AND CONCLUSION: The results obtained were summarized as follows; 1. After hydrothermal treatment, the precipitated HA crystals showed the dense fine needle shape. However, with increasing the concentration of electrolyte they showed the shape of thick and short rod. 2. When the dense fine needle shape crystals was appeared after hydrothermal treatment, the precipitation of HA crystals in Hanks' solution was highly accelerated. 3. The crystal structures of TiO2 in anodic oxide film were composed of strong anatase peak and weak rutile peak as analyzed with thin-film X-ray diffractometery. 4. The Ca/P ratio of the precipitated HA layer was equivalent to that of HA crystal in Hanks' solution.