scholarly journals Osteoblast Attachment Compromised by High and Low Temperature of Titanium and Its Restoration by UV Photofunctionalization

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5493
Author(s):  
Takayuki Ikeda ◽  
Takahisa Okubo ◽  
Juri Saruta ◽  
Makoto Hirota ◽  
Hiroaki Kitajima ◽  
...  

Titanium implants undergo temperature fluctuations during manufacturing, transport, and storage. However, it is unknown how this affects their bioactivity. Herein, we explored how storage (six months, dark conditions) and temperature fluctuations (5–50 °C) affected the bioactivity of titanium implants. Stored and fresh acid-etched titanium disks were exposed to different temperatures for 30 min under wet or dry conditions, and their hydrophilicity/hydrophobicity and bioactivity (using osteoblasts derived from rat bone marrow) were evaluated. Ultraviolet (UV) treatment was evaluated as a method of restoring the bioactivity. The fresh samples were superhydrophilic after holding at 5 or 25 °C under wet or dry conditions, and hydrophilic after holding at 50 °C. In contrast, all the stored samples were hydrophobic. For both fresh and stored samples, exposure to 5 or 50 °C reduced osteoblast attachment compared to holding at 25 °C under both wet and dry conditions. Regression analysis indicated that holding at 31 °C would maximize cell attachment (p < 0.05). After UV treatment, cell attachment was the same or better than that before temperature fluctuations. Overall, titanium surfaces may have lower bioactivity when the temperature fluctuates by ≥20 °C (particularly toward lower temperatures), independent of the hydrophilicity/hydrophobicity. UV treatment was effective in restoring the temperature-compromised bioactivity.

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 622
Author(s):  
Fei Sun ◽  
Shao-Jie Li ◽  
Xin-Chang Li ◽  
Lei Wang ◽  
De-Chun Ba ◽  
...  

Plasma oxidation could produce an oxidized surface, resulting in a graded TiO2−x film layer and significantly improving dental implant hydrophilicity and biocompatibility. Unfortunately, these features are gradually lost by the influence of the environment. In this study, alkali storage was used to improve these characteristics at room temperature. Titanium samples were divided into sandblasting acid-etching (SLA), oxidation (SLA samples that were oxidized), and storage (SLA samples that were oxidized and stored in 0.1 mol/L NaOH solution) groups. We measured the surface properties of each group, including the roughness, chemical composition, and hydrophilicity of these materials. We investigated the effects of titanium storage on cell responses, including cell attachment, proliferation, differentiation. We also investigated the osseointegration of the stored titanium implants. The results showed that the storage process maintains the superhydrophilic properties of oxidation treatment. Oxidized samples promoted cell responses. The descending order of biocompatibility was storage > oxidation > SLA. Furthermore, oxidation and alkali storage had significant effects on bone growth at the early stage of the implant. These results suggested that alkali storage can suitably maintain the surface characteristics of plasma oxidation, and the combination of oxidation and storage treatment can improve the primary implant stability.


2020 ◽  
Vol 21 ◽  
Author(s):  
Tatiana Almeida Pignataro ◽  
Jessica Maresch de Araújo ◽  
Aline Batista Silva Silva ◽  
Mariane Leão Freitas ◽  
Heitor Castro Alves Teixeira ◽  
...  

Abstract This study aimed to compare the effects a commercial milk-based extender and a self-made egg yolk extender had on the quality of canine semen stored at two different temperatures, 5ºC or 15ºC. The ejaculate obtained was split into two aliquots of equal volume and diluted with the milk or egg yolk extender. The final concentration was 100×106 spermatozoa/mL. Diluted semen was placed in transport containers and maintained at final storage temperatures of 5ºC and 15ºC. The quality of the chilled semen was assessed 12, 24, and 36 hours after storage. Semen diluted with the milk extender had higher motility, vigour, and plasma membrane integrity (p<0.05) of the spermatozoa than that diluted with the egg yolk extender. No difference in the semen quality was observed between the stored temperatures in both the groups. The difference observed between the extenders could be due to the standard formulation of the commercial milk extender and the presence of glucose in the mixture. In conclusion, the milk extender was better than the egg yolk extender at preserving the motility, viability, and membrane integrity of chilled canine semen for up to 36 hours. The storage temperature did not seem to affect the semen quality, suggesting that canine semen can be refrigerated at 15ºC.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3946
Author(s):  
Takahisa Okubo ◽  
Takayuki Ikeda ◽  
Juri Saruta ◽  
Naoki Tsukimura ◽  
Makoto Hirota ◽  
...  

Titanium-based implant abutments and tissue bars are polished during the finalization. We hypothesized that polishing degrades the bioactivity of titanium, and, if this is the case, photofunctionalization-grade UV treatment can alleviate the adverse effect. Three groups of titanium disks were prepared; machined surface, polished surface and polished surface followed by UV treatment (polished/UV surface). Polishing was performed by the sequential use of greenstone and silicon rubber burs. UV treatment was performed using a UV device for 12 min. Hydrophobicity/hydrophilicity was examined by the contact angle of ddH2O. The surface morphology and chemistry of titanium were examined by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Human epithelium cells were seeded on titanium disks. The number of cells attached, the spreading behavior of cells and the retention on titanium surfaces were examined. The polished surfaces were smooth with only minor scratches, while the machined surfaces showed traces and metal flashes made by machine-turning. The polished surfaces showed a significantly increased percentage of surface carbon compared to machined surfaces. The carbon percentage on polished/UV surfaces was even lower than that on machined surfaces. A silicon element was detected on polished surfaces but not on polished/UV surfaces. Both machined and polished surfaces were hydrophobic, whereas polished/UV surfaces were hydrophilic. The number of attached cells after 24 h of incubation was 60% lower on polished surfaces than on machined surfaces. The number of attached cells on polished/UV surfaces was even higher than that on machined surfaces. The size and perimeter of cells, which was significantly reduced on polished surfaces, were fully restored on polished/UV surfaces. The number of cells remained adherent after mechanical detachment was reduced to half on polished surfaces compared to machined surfaces. The number of adherent cells on polished/UV surfaces was two times higher than on machined surfaces. In conclusion, polishing titanium causes chemical contamination, while smoothing its surface significantly compromised the attachment and retention of human epithelial cells. The UV treatment of polished titanium surfaces reversed these adverse effects and even outperformed the inherent bioactivity of the original titanium.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 134
Author(s):  
Ana Isabel Galván ◽  
Alicia Rodríguez ◽  
Alberto Martín ◽  
Manuel Joaquín Serradilla ◽  
Ana Martínez-Dorado ◽  
...  

Dried fig is susceptible to infection by Aspergillus flavus, the major producer of the carcinogenic mycotoxins. This fruit may be contaminated by the fungus throughout the entire chain production, especially during natural sun-drying, post-harvest, industrial processing, storage, and fruit retailing. Correct management of such critical stages is necessary to prevent mould growth and mycotoxin accumulation, with temperature being one of the main factors associated with these problems. The effect of different temperatures (5, 16, 25, 30, and 37 °C) related to dried-fig processing on growth, one of the regulatory genes of aflatoxin pathway (aflR) and mycotoxin production by A. flavus, was assessed. Firstly, growth and aflatoxin production of 11 A. flavus strains were checked before selecting two strains (M30 and M144) for in-depth studies. Findings showed that there were enormous differences in aflatoxin amounts and related-gene expression between the two selected strains. Based on the results, mild temperatures, and changes in temperature during drying and storage of dried figs should be avoided. Drying should be conducted at temperatures >30 °C and close to 37 °C, while industry processing, storage, and retailing of dried figs are advisable to perform at refrigeration temperatures (<10 °C) to avoid mycotoxin production.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.


2013 ◽  
Vol 641-642 ◽  
pp. 574-577 ◽  
Author(s):  
Ying Tao Li ◽  
Ling Zhou ◽  
Mao Jiang ◽  
Yu Zhang ◽  
Jun Shao

In this paper, the mechanical property experiments of concrete based on the seawater and sea sand have been carried in different raw materials preparation and different conservation environments. The results show that the early strength and late strength of concrete based on seawater and sea sand are better than concrete based on freshwater and sand. There is no significant strength decreased for concrete based on seawater and sea sand under accelerated alternating wet and dry conditions. For concrete based on seawater and sea sand mixed with admixture, the downward trend of late strength is significantly delayed, the late strength of concrete based on the seawater and sea sand mixed with slag gets the most obvious growth trend, while the late strength of seawater and sea sand concrete mixed with fly ash gets the largest increment.


Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1284 ◽  
Author(s):  
Bo Wang ◽  
Fu-hua Lin ◽  
Xiang-yang Li ◽  
Zhong-wei Zhang ◽  
Xiao-rong Xue ◽  
...  

Bacterial cellulose (BC) is a new kind of cellulose with great potential in enhancing preparation of isotactic Polypropylene (iPP) composites, which have been found with excellent performance. However, the interface compatibility between BC and iPP is poor. In this study, iPP/BC composites were prepared by solution mixing. Esterification modified BC (CO) and Maleic anhydride grafted polypropylene (MAPP) added as a compatibilizer was both used to improve the interfacial compatibility of the iPP/BC composites. The rheology and isothermal crystallization behavior of the composites was tested and discussed. The result shows that the complex viscosity and storage modulus of the composite significantly increase in the rule iPP, iPP/BC2, iPP/CO2, and M-iPP/BC3, which indicates that the compatibility of the composite increases as this rule. According to the isothermal crystallization kinetics result, the crystal growth mode of iPP was not affected by the addition of BC and the interfacial compatibility. The spherulite growth rate of the iPP/BC composite increases with increasing crystallization temperature. Especially, the value decreases as the same rule with the complex viscosity and storage modulus of the composite at the same isothermal crystallization temperature. These results suggest that the interface compatibility of iPP/BC composites is greatly improved and the interface compatibility of the M-iPP/BC3 is better than the iPP/CO2.


The abundant availability of demolition waste from construction industry is leading towards a significant problem of disposal, land and air pollution. The natural aggregate resources are also depleting due to development of construction activities. An attempt is made in this study to convert this waste into wealth by substituting the recycled brick from demolition waste to granite aggregate in production of the concrete. The granite aggregate (GA) is replaced with recycled brick aggregate (RBA) by 25% of its weight to produce M15 and M20 grades of concrete. The granite aggregate concrete (GAC) and recycled brick aggregate concrete (RBAC) were subjected to different temperatures between 100 to 1000oC for a duration of 3 hours and the mechanical properties such as compressive strength and flexural strength were examined to assess its fire performance. The response of RBAC is better than GAC at each temperature. The study revealed that the residual strength increases with the increase in grade of concrete at all temperatures.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 461
Author(s):  
Paula Navarro ◽  
Alberto Olmo ◽  
Mercè Giner ◽  
Marleny Rodríguez-Albelo ◽  
Ángel Rodríguez ◽  
...  

The chemical composition and surface topography of titanium implants are essential to improve implant osseointegration. The present work studies a non-invasive alternative of electrical impedance spectroscopy for the characterization of the macroporosity inherent to the manufacturing process and the effect of the surface treatment with femtosecond laser of titanium discs. Osteoblasts cell culture growths on the titanium surfaces of the laser-treated discs were also studied with this method. The measurements obtained showed that the femtosecond laser treatment of the samples and cell culture produced a significant increase (around 50%) in the absolute value of the electrical impedance module, which could be characterized in a wide range of frequencies (being more relevant at 500 MHz). Results have revealed the potential of this measurement technique, in terms of advantages, in comparison to tiresome and expensive techniques, allowing semi-quantitatively relating impedance measurements to porosity content, as well as detecting the effect of surface modification, generated by laser treatment and cell culture.


1999 ◽  
Vol 65 (4) ◽  
pp. 1435-1443 ◽  
Author(s):  
M. Wilson ◽  
S. S. Hirano ◽  
S. E. Lindow

ABSTRACT The growth and survival of pathogenic and nonpathogenicPseudomonas syringae strains and of the nonpathogenic species Pantoea agglomerans, Stenotrophomonas maltophilia, and Methylobacterium organophilum were compared in the phyllosphere of bean. In general, the plant pathogens survived better than the nonpathogens on leaves under environmental stress. The sizes of the total leaf-associated populations of the pathogenic P. syringae strains were greater than the sizes of the total leaf-associated populations of the nonpathogens under dry conditions but not under moist conditions. In these studies the surface sterilants hydrogen peroxide and UV irradiation were used to differentiate cells that were fully exposed on the surface from nonexposed cells that were in “protected sites” that were inaccessible to these agents. In general, the population sizes in protected sites increased with time after inoculation of plants. The proportion of bacteria on leaves that were in protected sites was generally greater for pathogens than for nonpathogens and was greater under dry conditions than under moist conditions. When organisms were vacuum infiltrated into leaves, the sizes of the nonexposed “internal” populations were greater for pathogenic P. syringae strains than for nonpathogenic P. syringaestrains. The sizes of the populations of the nonpathogenic species failed to increase or even decreased. The sizes of nonexposed populations following spray inoculation were correlated with the sizes of nonexposed, internal populations which developed after vacuum infiltration and incubation. While the sizes of the populations of the pathogenic P. syringae strains increased on leaves under dry conditions, the sizes of the populations of the nonpathogenic strains of P. syringae, P. agglomerans, andS. maltophilia decreased when the organisms were applied to plants. The sizes of the populations on dry leaves were also correlated with the sizes of the nonexposed populations that developed following vacuum infiltration. Although pathogenicity was not required for growth in the phyllosphere under high-relative-humidity conditions, pathogenicity apparently was involved in the ability to access and/or multiply in certain protected sites in the phyllosphere and in growth on dry leaves.


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