Enhanced photodynamic therapy of TiO2/N-succinyl-chitosan composite for killing cancer cells

Abstract The aim of this study was to investigate the effect of TiO2/N-succinyl-chitosan composite (TiO2/ NSCS) photodynamic therapy (PDT), while considering the effects of various light sources on the activation of photosensitizer. The methyl thiazolyl tetrazolium assay was used to examine the cell survival rate of the cells. The results showed that glioma cell strain (U251) was the most sensitive cancer cell strain to TiO2/NSCS. When the concentration of TiO2/NSCS was between 0 and 800 μg·mL-1, there was no obvious cytotoxicity to normal liver cells (HL-7702) and U251 cells. During the PDT process, the photokilling effect of TiO2/NSCS on U251 cells under ultraviolet-A (UVA) light irradiation was stronger than that of pure TiO2, and its killing effects were positively correlated with concentration and irradiation time. In addition, both UVA and visible light could excite TiO2/ NSCS, which had significant killing effect on U251 cells. The results of acridine orange/ethidium bromide fluorescent double staining and Annexin V/propidium iodide double staining indicated that TiO2/NSCS under UVA and visible light irradiation could kill U251 cells by inducing apoptosis, and the apoptosis rate of TiO2/NSCS treatment groups was higher than that of TiO2 treatment groups. Therefore, TiO2/NSCS might be used as a potential photosensitizer in PDT.

Antibacterial and Cytotoxic Effects of Cyclodextrin-Triazole-Titanium Based Nanocomposite

Abstract In this paper, the antibacterial activity of triazole functionalized cyclodextrin (CD.Click) and cyclodextrin-triazole-titanium based nanocomposite (CD.COM) was evaluated. The results indicated that CD.Click and CD.COM perform a wide range of antibacterial activity against both gram positive (Staphylococcus aureus and Bacillus subtilis) and gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The cytotoxic effect of CD.COM was investigated in vitro on cancerous cell lines (cervical cancer, breast carcinoma and sarcoma osteogenic) and fibroblast cells by MTT assay. The cell viability evaluation confirmed that the growth of cancerous cells is inhibited in a dose and time dependent way without any significant effect on the normal fibroblast cells.

Study on inhibitory effect of Ag +-loaded TiO 2 on the biofilm of Staphylococcus aureus / 中华危重病急救医学

Objective:To observe the antibacterial effect of Ag +-loaded TiO 2 (Ag -TiO 2) and Ag -TiO 2 coated endotracheal tube (ETT) on the bacterial biofilm (BF) of Staphylococcus aureus. Methods:2, 3-bis-(2-methoxy- 4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) colorimetric method was used to detect minimal inhibitory concertation (MIC) of Ag-TiO 2 for inhibition of BF of Staphylococcus aureus. The Ag -TiO 2 coated ETT were prepared, and divided into 11 mg/L, 8 mg/L, 5 mg/L, 2 mg/L and 0 mg/L ETT group, according to the concentration gradient, then impregnated in the liquid with Staphylococcus aureus at a concentration of 1.0×10 9cfu/L. The influence of antibacterial coated ETT on the formation of Staphylococcus aureus BF was determined by detecting the colonies of bacteria and BF on the ETT. Results:Ag-TiO 2 had a significant inhibitory effect on Staphylococcus aureus BF in a concentration -dependent manner, and its MIC was 10 mg/L. Ag -TiO 2 coated ETT has significant anti -Staphylococcus aureus BF effect, and the higher the concentration, the stronger the effect. The absorbance ( A) values of Ag -TiO 2 5 mg/L, 8 mg/L, 11 mg/L ETT groups were significantly lower than that in control group (0.176±0.004, 0.147±0.002, 0.094±0.002 vs. 0.267±0.045, all P < 0.05). The inhibitory rates of Ag -TiO 2 2 mg/L, 5 mg/L, 8 mg/L ETT groups were increased gradually, and 11 mg/L Ag -TiO 2 coated ETT group had the highest inhibitory rate for BF, the inhibitory rates were 6.4%, 34.1%, 44.9% and 64.8%, respectively. Conclusion:Both Ag-TiO 2 and Ag-TiO 2 coated ETT have significant inhibitory effects on Staphylococcus aureus BF.

A novel biomimetic micro/nano hierarchical interface of titanium enhances adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal cells / 口腔疾病防治

Objective @#To design a novel biomimetic micro/nano hierarchical interface on endosseous titanium implants and investigate its effect on the biological activity of bone marrow mesenchymal cells.@*Methods@#Electrochemical anodization and spark plasma sintering were used to modify smooth titanium (untreated Ti group) with a microporous trabecular bone-like architecture (micro-Ti group) and TiO2 nanotube architecture (nano-TiO2 group). Additionally, electrochemical anodization was employed to prepare TiO2 nanotubes on microporous trabecular bone-like architectures, which formed a novel biomimetic hierarchical interface (micro/nano-TiO2 group). Four groups of titanium samples were characterized by field emission scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle (CA). Bone marrow mesenchymal cells (BMMCs) were seeded on four groups of titanium samples. Scanning electron microscopy (SEM) was employed to observe cell morphology. Cell proliferation was determined by MTT assay. The expression of focal adhesion proteins (F-actin; vinculin; osteocalcin, OCN; osteopontin, OPN) were observed under a confocal laser scanning microscope (CLSM). The mRNA expression levels of osteogenic factors (runt-related transcription factor 2, RUNX2; osteocalcin, OCN; osteopontin, OPN; collagen I, COL I) were assessed by qRT-PCR.@*Results@# The micro/nano- TiO2 group featured a hydrophilic surface (CA=9° ± 2.1°). The results of the MTT assay indicated that the relative cell proliferation rates for the nano- TiO2 and micro/nano-TiO2 samples were significantly increased compared with those for the untreated-Ti and micro-Ti samples (P＜0.001) after 5-9 days. The ALP results indicated that the micro/nano-TiO2 sample gained the highest value at 14 days. After 72 h of incubation, the expression of osteocalcin (OCN) and osteopontin (OPN) on micro/nano-TiO2 was the strongest. After 24 h incubation, the expression of F-actin on micro/nano-TiO2 was the strongest. In comparison with untreated-Ti and micro-Ti samples,the mRNA expression levels of all the osteogenic factors (runt-related transcription factor 2, RUNX2; osteocalcin, OCN; osteopontin, OPN; Collagen I, COL I) were markedly increased on the nano-TiO2 and micro/nano-TiO2 samples, the mRNA expression levels of collagen I (COL I) were significantly different between the nano-TiO2 and micro/nano-TiO2 samples versus the untreated-Ti and micro-Ti samples (P＜0.001). @* Conclusion@#The novel biomimetic micro/nano hierarchical interface has a positive effect on cell attachment, viability and osteogenic differentiation of bone marrow mesenchymal cells.

Effect of titanium dioxide nanoparticles on the stereological parameters of the dentate gyrus and the morphology of granular hippocampal neurons in mice / Efecto de las nanopartículas de dióxido de titanio sobre los parámetros estereológicos del giro dentado y morfología de las neuronas granulares del hipocampo en ratones

SUMMARY: This study aims to investigate the Effects of Titanium dioxide nanoparticles (TiO2 NPs) on the stereological parameters in the dentate gyrus and the morphology of granular hippocampal neurons in adult mice. Adult male mice (n=20, weight average: 45 g) were randomly divided into four groups including: group receiving saline (controls), low-dose (LD) 2.5 mg/kg TiO TiO2 NPs, medium-dose (MD) 5 mg/kg TiO2 NPs and high-dose (HD) 10 mg/kg TiO2 NPs, daily using gavage for 35 days. To estimate the volume of the hippocampus, dentate gyrus, and sub-layers of dentate gyrus the Cavalieri principle was used. The physical dissector was used to determine the numerical density of dentate gyrus granular cells. For analyzing the morphology of dentate gyrus granular cells the qualitative Golgi staining was used. Our data showed that the total volume of the hippocampus, dentate gyrus and its sublayers including molecular, granular and polymorph in TiO2 treated mice decreased significantly compared to the control group. Moreover, the total number and numerical density of dentate gyrus granular sub layer cells showed a significant reduction in all three experimental groups compared to the control group. The granular cells of the dentate gyrus had shorter dendritic length and decreased dendritic branches in the TiO2-treated in comparison with the control mice. These data can justify the disorders related to memory, learning and hippocampus neurons damages due to using of TiO2 NPs.

RESUMEN: En este estudio se analizaron los efectos de las nanopartículas de dióxido de titanio (TiO2 NP) sobre los parámetros estereológicos en el giro dentado y la morfología de las neuronas granulares del hipocampo en ratones adultos. Se dividieron aleatoriamente ratones machos adultos (n = 20, promedio de peso: 45 g) en cuatro grupos: grupo que recibió solución salina (controles), dosis baja (LD) 2,5 mg/kg NP de TiO2, dosis media (MD) 5 mg/kg de NP de TiO2 y dosis altas (HD) de 10 mg/kg de NP de TiO2, por vía utilizando sonda durante 35 días. Para estimar el volumen del hipocampo, el giro dentado y las subcapas del giro dentado se utilizó el principio de Cavalieri. Se utilizó el disector físico para determinar la densidad numérica de las células granulares del giro dentado. Para analizar la morfología de las células granulares del giro dentado se usó la tinción cualitativa de Golgi. Nuestros datos mostraron que el volumen total del hipocampo, el giro dentado y sus subcapas, incluyendo la molecular, granular y polimorfos, en ratones tratados con TiO2, disminuyó significativamente en comparación con el grupo de control. Además, el número total y la densidad numérica de las células de la subcapa granular del giro dentado mostró una reducción significativa en los tres grupos experimentales en comparación con el grupo control. Las células granulares del giro dentado tenían una longitud dendrítica menor y ramas dendríticas disminuidas en los ratones tratados con TiO2 en comparación con los ratones del grupo control. Estos datos pueden justificar los trastornos relacionados con la memoria, el aprendizaje y los daños en las neuronas del hipocampo debido al uso de NP de TiO2.

Biological behaviors of fibroblasts on the surface of TiO2 nanotubes with different diameters after annealing treatment / 中国组织工程研究

BACKGROUND: Previous studies have shown that titanium nanotubes with different diameters affect the adhesion and growth of cells on the implant surface. OBJECTIVE: To investigate the effects of annealing treatment on the biological behaviors of fibroblasts on the surface of TiO2 nanotubes with different diameters. METHODS: TiO2 nanotubes were prepared by polishing pure titanium samples through anodizing at 5 V and 20 V respectively, and then annealed. The pure titanium samples were divided into six groups: P (polishing titanium), NT5 (TiO2 nanotubes prepared at 5 V), NT20 (TiO2 nanotubes prepared at 20 V), A-P (annealing treatment and polishing titanium), A-NT5 (TiO2 nanotubes prepared at 5V and annealed) and A-NT20 (TiO2 nanotubes formed at 20 V and annealed). Field emission scanning electron microscopy was used to obsesrve the surface topography. Fibroblasts were inoculated on the surface of each group of samples. After 60 and 120 minutes of culture, the number of cells adhering to titanium sample surface was counted using cell nucleus staining method. On day 1 of culture, cell morphology was observed using scanning electron microscopy. On days 1, 3 and 5 of culture, cell proliferation was detected by MTT method. On day 3 of culture, the secretion of collagen fiber was detected by picro-sirius red staining method. RESULTS AND CONCLUSION: (1) The annealing treatment had no significant effect on the morphology and diameter of the nanotubes. (2) The number of adherent cells in the NT5 and NT20 groups was significantly lower than that in the P group. The annealing treatment increased the number of fibroblasts on the surface of polished pure titanium and decreased the number of fibroblasts in the NT5 and NT20 groups. (3) Annealing enhanced the viability of fibroblasts on the surface of polished pure titanium and decreased the viability of cells on the surface of nanotubes prepared at 5 and 20 V. (4) Cell viability in the NT5 and NT20 groups was lower than that in the P group. Annealing treatment increased the viability of cells on the surface of polished pure titanium and decreased the viability of cells on the surface of nanotubes prepared at 5 and 20 V. (5) The level of collagen on the surface of nanotubes in the NT5 and NT20 groups was higher than that in the P group. Annealing treatment increased the level of collagen on the surface of polished pure titanium and decreased the level of collagen in the NT5 and NT20 groups. These findings suggest that TiO2 nanotubes inhibit the adhesion, spreading and proliferation of fibroblasts to different degrees; annealing treatment can enhance this inhibitory effect; TiO2 nanotubes enhance collagen secretion by fibroblasts to different degrees, and annealing treatment inhibits the enhancement.

Photocatalytic Degradation of Textile dye Orange-122 Via Electrospray Mass Spectrometry

Abstract This work reports the study of the potential application of Zn/TiO2 catalysts, obtained by the sol-gel method, in processes of environmental decontamination through the reactions of photodegradation of textile dye, followed by electrospray mass spectrometry. The catalysts synthesis was performed according to a 2² factorial design with repetition at the central point. The characterization techniques used were: N2 adsorption measurements (BET method), scanning electron microscopy with energy dispersive X-ray (MEV/EDS), X-ray diffraction and point of zero charge (PZC). The photocatalytic tests were performed in batch in the presence of sunlight, and to evaluate the degradation kinetics study, a rapid direct injection electrospray mass spectrometry (DI-ESI-MS) method has been developed. By the photocatalytic tests, the calcination temperature of 400 °C has shown the best results of discoloration for the reactive Orange-122 dye (99.76%) in a reaction time of 2h. The discoloration kinetics were a pseudo-first order, and a statistical analysis was performed to investigate the effects of the variables and to optimize the conditions of discoloration to the dye. After the reactional time of 2 h, an ion of m/z 441.5 was detected by ESI-MS, indicating that the photocatalytic process was effective for the degradation of the dye to secondary compounds.

Evaluación de un reactor para la degradación fotocatalítica de glifosato empleando un catalizador de TiO2-Mn / Evaluation of a reactor for the photocatalytic degradation of glyphosate with a catalyst TiO2-Mn / Avaliação de reator para a degradação fotocatalítica do glifosato usando um catalisador de TiO2-Mn

Resumen En el presente trabajo se evaluó la degradación fotocatalítica del herbicida glifosato en solución acuosa con un catalizador comercial (TiO2 Degussa P25) y un catalizador sintetizado a partir de TiO2 dopado con manganeso (TiO2-Mn), soportados en anillos de borosilicato de diámetro interno y externo de 6,52 mm y 7,59 mm, respectivamente, y una longitud aproximada de 9,43 mm, mediante el uso de un reactor continuo de lecho empacado. El catalizador fue caracterizado por FTIR, SEM-EDS y AFM, con lo cual se determinaron algunas propiedades físicas y químicas del mismo. Las condiciones de operación del reactor fueron un caudal de alimentación de 4,25 mL min-1 de una solución de glifosato de pH natural de 4,45 y un tiempo de retención de 1 h y 25 min, en el cual se llevaron a cabo ensayos de fotocatálisis heterogénea, fotólisis y adsorción por un tiempo de 150 min. De lo anterior, se obtuvieron los porcentajes de remoción y el orden de la reacción fotocatalítica para el catalizador soportado en los anillos. A partir de los estudios de degradación realizados, con el TiO2-Mn soportado en los anillos, se logró un porcentaje máximo de degradación de 39.19%, mientras que, con el catalizador comercial TiO2 Degussa P25, se alcanzó un 28.6% de remoción. El modelo de reacción que sigue la degradación del glifosato es de difusión intrapartícula, debido a los procesos difusivos en los que la molécula de glifosato es adsorbida en los poros del catalizador para luego ser degradada.

Abstract In this work, the photocatalytic degradation of the herbicide glyphosate in aqueous solution was evaluated. Assays were performed on a commercial catalyst (TiO2 Degussa P25) and a catalyst synthesized from TiO2 doped with manganese (TiO2-Mn) supported on borosilicate rings, with an internal and external diameter of 6.52 mm and 7.59 mm respectively, and an approximate length of 9.43 mm, using a continuous packed bed reactor. The synthesized catalyst was characterized with techniques as FTIR, SEM-EDS, and AFM, which allowed to evaluating its chemical and physical properties. The reactor operating conditions were a feed flow rate of 4.25 mL min-1 of a pH 4.45 glyphosate solution and retention time of 1 h and 25 min. In such experiments, heterogeneous photocatalysis, photolysis, and adsorption test were carried out for 150 min, obtaining results of degradation percentages and the order of photocatalytic reaction for the catalyst supported in the rings and the powder in suspension. From the removal studies, a maximum degradation percentage of 39.19% was reached with TiO2-Mn supported in the rings. In contrast, the commercial catalyst TiO2 Degussa P25 had a 28.6% of removal. The glyphosate degradation follows an intraparticle diffusion model due to a diffusive process, where the glyphosate molecule is adsorbed in the catalyst pores and then degraded.

Resumo Neste trabalho, a degradação fotocatalítica de glifosato em solução aquosa foi avaliada com um catalisador comercial (TiO2 Degussa P25) e sintetizado a partir de TiO2 dopado com manganês (Mn-TiO2) com suporte em anéis de borosilicato de diâmetro interno e externo de catalisador 6,52 mm e 7,59 mm, respectivamente e um comprimento de aproximadamente 9,43 mm, usando um leito empacotado reator contínuo. O catalisador sintetizado foi caracterizado com FTIR, SEM-EDS and AFM, o que permitiu a sua morfologia e composição. As condições de operação do reactor foi alimentada à velocidade de 4,25 mL min-1 de uma solução de pH natural de 4,45 glifosato e um tempo de retenção de 1 hora e 25 minutos; em que foram realizados ensaios de fotocatálise heterogénea, fotólise, tempo de adsorção de 150 minutos, obtendo-se como percentagens resultados de remoção e com a reação fotocatalítica para o catalisador suportado em anéis. A partir dos estudos, foi obtido uma taxa máxima de degradação com TiO2-Mn suportado em anéis de 39,19% em comparação com o catalisador comercial de TiO2 Degussa P25 com os quais obtiveram porcentagens de degradação de 28,6%. A degradação do glifosato segue um modelo de difusão intrapartícula devido ao processo difusivo em que a molécula de glifosato é adsorvida no catalisador poros logo a ser degradada.

Renal histological alterations induced by acute exposure of titanium dioxide nanoparticles / Alteraciones histológicas renales inducidas por la exposición aguda de nanopartículas de dióxido de titanio

SUMMARY: Titanium dioxide nanoparticles (TiO2 NPs) are widely used in many commercial products, nanomedicine, agriculture, personal care products, different industries and pharmaceutical preparations with potential risk in human health and the environment. The current work was conducted to investigate the renal damage that might be induced by the acute toxicity TiO2 NPs. A total of 40 healthy male adult Wistar albino rats (Rattus norvegicus) were exposed to TiO2 NPs (126, 252, 378 mg/kg bw) for 24 and 48 h. Fresh portions of the kidneys from each rat were processed for histological and histochemical alterations. In comparison with respective control rats, exposure to TiO2 NPs has marked the following glomerular, tubular and interstitial alterations including the followings: glomerular congestion, Bowman's capsule swelling and dilatation, inflamed glomeruli, renal tubules cloudy swelling, karyorrhexis, karyolysis, infiltration of inflammatory cells, congestion, necrosis, hydropic degeneration, dilatation and congestion of blood vessels, hyaline droplets and hyaline casts precipitation, interstitial edema and fibrosis. From the findings of the current work one may conclude that TiO2 NPs are capable of inducing kidney damage with more insulation in the cortex and the proximal convoluted tubules than the medulla and the distal ones respectively. In addition, it might be concluded that renal damage induced by these nanomaterials is dose and duration of exposure dependent. Further hematological, biochemical, immunohistochemical, and ultra-structural studies are recommended.

RESUMEN: Las nanopartículas de dióxido de titanio (TiO2 NP) se usan ampliamente en muchos productos comerciales, nanomedicina, agricultura, productos para el cuidado personal, diferentes industrias y preparaciones farmacéuticas con riesgo potencial para la salud humana y el medio ambiente. El trabajo actual se realizó para investigar el daño renal que podría ser inducido por la toxicidad aguda NP de TiO2. Un total de 40 ratas Wistar albinas adultas sanas (Rattus norvegicus) fueron expuestas a TiO2 NP (126, 252, 378 mg / kg de peso corporal) durante 24 y 48 h. Las muestras de los riñones de las ratas se procesaron para estudios histológicos e histoquímicos. En comparación con las ratas control, la exposición de las ratas a TiO2 NP presentaron las siguientes alteraciones glomerulares, tubulares e intersticiales: congestión glomerular, dilatación de la cápsula de Bowman, inflamación glomerular, túbulos renales aumentados, cariorrexis, cariólisis, infiltración de células inflamatorias, congestión, necrosis, degeneración hidrópica, dilatación y congestión de vasos sanguíneos, gotas y precipitaciones hialina, edema intersticial y fibrosis. A partir de los hallazgos del trabajo actual, se puede concluir que las NP de TiO 2 son capaces de inducir daño renal con más aislamiento en la corteza y en los túbulos contorneados proximales que en la médula y los túbulos contorneados distales, respectivamente. Además, se podría concluir que el daño renal inducido por estos nanomateriales depende de la dosis y la duración de la exposición. Se recomiendan estudios adicionales hematológicos, bioquímicos, inmunohistoquímicos y ultraestructurales.

Preparation of Adriamycin Hydrochloride Magnetic Thermosensitive Liposome Based on TiO 2@Fe3O4 and Its Physicochemical Properties，Magnetic Effect and Photothermal Effect Study / 中国药房

OBJECTIVE： To prepare Adriamycin hydrochloride （DOX） magnetic thermosensitive liposome （MTSL）， investigate its physicochemical properties， magnetic effect and photothermal effect， so as to provide reference for tumor chemo- therapy and photodynamic/photothermal therapy. METHODS： Using DOX as model drug， TiO2@Fe3O4 as photosensitizers and magnetic materials， DOX-TiO2@Fe3O4-MTSL was prepared with membrane dispersion method. The morphology and dispersibility were observed； particle size and Zeta potential were detected； encapsulation efficiency of the liposome were determined by centrifugal ultrafiltration and HPLC. Its paramagnetism property was also detected by magnetometer. Compared with DOX solution， in vitro release behavior of the liposome was investigated by dialysis method， and the release curves at different temperatures （at 37， 43 ℃） were compared. The photothermal conversion effect of the liposome and the production of reactive oxygen species （ROS） in human breast cancer MCF-7 cells were investigated by near infrared laser irradiation at 808 nm. RESULTS： Prepared DOX-TiO2@Fe3O4-MTSL was brown-black with good water dispersion， and was spherical in shape and uniform in size under electron microscopy. Average particle size was 250.6 nm； polydispersity index was 0.107； Zeta potential was （－7.76±3.41）mV； encapsulation efficiency was （92.3±3.2）％. Under the external magnetic field， the liposome could move in a directional direction and had obvious paramagnetism. Compared with DOX solution， the liposomes released slowly and showed obvious sustained- release characteristics. Compared with at 37 ℃， the drug release of liposome speeded up significantly at 43 ℃.With the increase of laser （808 nm） irradiation time， the temperature of the liposome kept rising， which had obvious photothermal conversion effect and could induce the increase of ROS in MCF-7 cells. CONCLUSIONS： DOX-TiO2@Fe3O4-MTSL is prepared succe- ssfully， which has uniform appearance， good physical and chemical properties. It has obvious paramagnetism sustained release effect and photothermal conversion efficiency， and can promote ROS production in MCF-7 cells under near infrared laser irradiation at 808 nm.

Preparation and antibacterial properties of La-doped TiO2 films on 3Y-TZP ceramic surface / 口腔疾病防治

Objective @#To prepare the La-doped TiO2 film on the surface of 3Y-TZP ceramics in order to observe its antibacterial properties, providing an experimental basis for the application of antibacterial zirconia ceramics in the clinic.@*Method@# A cylindrical 3Y-TZP specimen with a diameter of 20 mm and a height of 3 mm was prepared. The sol-gel method was used to prepare 1% lanthanum (La)-doped TiO2 sol, and the La-TiO2 film-3Y-TZP ceramic was prepared by dip coating on the surface of 3Y-TZP. The TiO2 thin film-3Y-TZP ceramic was prepared by adding no lanthanum nitrate solution in the same way. The surface morphology of 3Y-TZP ceramic specimens (3Y-TZP group), TiO2 thin film-3Y-TZP ceramic specimens (TiO2 film group), and La-TiO2 thin film-3Y-TZP ceramic specimens (La-TiO2 film group) was observed by scanning electron microscopy, and photocatalysis, antibacterial and cytotoxicity experiments were carried out. For the photocatalytic experiment, four specimens were randomly selected from the La-TiO2 film group and TiO2 film group to observe the degradation rate of methylene blue at different time points under sunlight. In the antimicrobial experiment, five specimens were randomly selected from the La-TiO2 film group, TiO2 film group and 3Y-TZP group. The antimicrobial activity of each group was tested using the bacteriostatic circle method, and the bacteriostatic distance of each group was compared. In the cytotoxicity experiment, three samples were randomly selected from the La-TiO2 film group, TiO2 film group and 3Y-TZP group (negative control group), and the extracts were prepared. Here, 0.064% phenol solution were served as the positive control group. Morphological observation of L-929 cells in four groups was performed after 3 d of culture. Cell viability and relative cell proliferation were measured by MTT assay.@*Results@#La-TiO2 films with uniform distribution can be prepared on a 3Y-TZP surface by the dipping-drawing method. Photocatalytic experiments showed that the degradation rate of methylene blue in the La-TiO2 film group was (41.2 ± 1.5)% in daylight for 2 hours, which was higher than that in TiO2 film group (36.5 ± 2.4)%. A significant difference was noted between the two groups (t=3.321, P=0.016). The antimicrobial experiment showed that the antimicrobial distance of La-TiO2 group was (0.34 ± 0.08) mm, which was larger than that of TiO2 group (0.12 ± 0.02) mm. No obvious antimicrobial circle was noted in 3Y-TZP group, and the antimicrobial distance of the La-TiO2 film group was larger than that of TiO2 film group (F=63.798, P < 0.001). Cytotoxicity test showed that the relative proliferation rate of cells in La-TiO2 film group was (89.5 ± 1.3)%, and the cytotoxicity rating was grade 1. Significant differences were noted among the four groups (F=68.250, P < 0.001).@*Conclusion @#The La-doped TiO2 film can improve its photocatalytic activity and enhance the antibacterial activity of 3Y-TZP without obvious cytotoxicity.

Evaluation of bioactivity and osseointegration for ti-6al-4v alloy implant modified by anodic oxidation and cyclic precalcification treatments / 대한치과재료학회지

The aim of this study was to examine the bioactivity and osseointegration of Ti-6Al-4V alloy implant which was modified by an anodic oxidation and a cyclic precalcification treatments. After blasting treatment using HAp (Hydroxyapatitie; HAp) powder which is resorbable blasting media (RBM) on the surface of Ti-6Al-4V alloy implants, the anodic oxidation treatment and the cyclic precalcification treatment were conducted to form nanotube TiO2 layer and HAp precipitation respectively. The surface morphology of the surface-treated Ti-6Al-4V alloy implant was investigated after immersion in the simulated body fluid(SBF) for 3 days to investigate the bioactivity. To investigate the effect of surface treatment on bonding between the implant and bone, RBM treated implant and RBM-anodization-cyclic precalcification(RACP) treated implant were placed on the distal side of both tibia diaphysis of rats, and then the removal torque of the implant was measured after 4 weeks. On the surface of RACP treated group, bone-like apatite precipitation was observed after immersion in SBF for 3 days. The removal torque was significantly higher in the RACP treated group than in the RBM treated group. The interfacial fracture between the implant and the new bone was observed in the RBM treated group, but both the cohesive fracture at the new bone and the interfacial fractures between the implant and the new bone were observed in the RACP treated group.

Bleaching of stained resin using nitrogen doped-TiO₂ nanoparticles / 대한치과재료학회지

There has been increasing use of the H₂O₂-based teeth bleaching agents. The purpose of this study was to evaluate the bleaching effectiveness of the laser irradiation combined with nitrogen doped-TiO₂ nanoparticles (NPs) on the stained resin. Nitrogen (N) doped-TiO₂ NPs were prepared under sol-gel method. Light absorbance, X-ray diffraction patterns of NPs, and bleaching of methylene blue and stained resins were evaluated. For bleaching of stained resin, NPs-containing gel was used. For irradiation, light of two different wavelengths was used. Unlike TiO₂, N-TiO₂ showed high absorbance after 400 nm. N-TiO₂, which have used TiN as a precursor, showed a new rutile phase at the TiN structure. For methylene blue solution, N-TiO₂ with 3% H₂O₂ resulted in the greatest absorbance decrease after laser irradiation regardless of wavelength. For stained resin test, N-TiO₂ with 3% H₂O₂ resulted in the greatest color difference after laser irradiation, followed by group that used N-TiO₂ without 3% H₂O₂.

A novel textile wastewater treatment using ligninolytic co-culture and photocatalysis with TiO2 / Un novedoso tratamiento de aguas residuales de la industria textil usando co-cultivos ligninolíticos y fotocatálisis con TiO2 / Um novo tratamento para águas residuais têxtis usando co-cultura ligninolítica e fotocatálise com TiO2

Abstract Textile industries produce effluent wastewater that, if discharged, exerts a negative impact on the environment. Thus, it is necessary to design and implement novel wastewater treatment solutions. A sequential treatment consisting of ligninolytic co-culture with the fungi Pleurotus ostreatus and Phanerochaete crhysosporium (secondary treatment) coupled to TiO2 /UV photocatalysis (tertiary treatment) was evaluated in the laboratory in order to discolor, detoxify, and reuse textile effluent wastewater in subsequent textile dyeing cycles. After 48 h of secondary treatment, up to 80% of the color in the wastewater was removed and its chemical and biochemical oxygen demands (COD, and BOD5) were abated in 92% and 76%, respectively. Laccase and MnP activities were central to color removal and COD and BOD5 abatement, exhibiting activity values of 410 U L-1 and 1 428 U L-1, respectively. Subjecting wastewater samples to 12 h of tertiary treatment led to an 86% color removal and 73% and 86% COD and BOD5 abatement, respectively. The application of a sequential treatment for 18 h improved the effectiveness of the wastewater treatment, resulting in 89% of color removal, along with 81% and 89% COD and BOD5 abatement, respectively. With this sequential treatment a bacterial inactivation of 55% was observed. TiO2 films were reused continuously during two consecutive treatment cycles without thermic reactivation. Removal percentages greater than 50% were attained. Acute toxicity tests performed with untreated wastewater led to a lethality level of 100% at 50% in Hydra attenuata and to a growth inhibition of 54% at 50% in Lactuca sativa. Whereas sequentially treated wastewater excreted a 13% lethality at 6.25% and an inhibition of 12% at 75% for H. attenuata and L. sativa, respectively. Finally, sequentially treated wastewater was reused on dyeing experiments in which 0.86 mg g-1 adsorbed dye per g of fabric, that is equivalent to 80% of dye adsorption.

Resumen Las industrias textiles producen un efluente que, si es descargado, ejerce un impacto negativo en el ambiente. Así, es necesario diseñar e implementar soluciones novedosas para el tratamiento de estos desechos. Con el fin de decolorar, detoxificar y reutilizar aguas residuales producidas en la industria textil en ciclos de tinturado subsecuentes, se evaluó en laboratorio un tratamiento secuencial, consistente en un cultivo ligninolítico con los hongos Pleurotus ostreatus y Phanerochaete crhysosporium (tratamiento secundario) acoplado con fotocatálisis TiO2/UV (tratamiento terciario). Después de 48 horas de tratamiento secundario, se removió hasta un 80% del color del agua residual y las Demandas Química y Bioquímica de Oxígeno (DQO y DBO5) fueron reducidas en 92 y 76% respectivamente. Las actividades Lacasa y MnP (410 U L-1 y 1428 U L-1, respectivamente) fueron centrales en la remoción de color y en la reducción de DQO y DBO5. Someter muestras de agua residual a 12 horas de tratamiento terciario resultó en una remoción de 86% de color, 73% de DQO y 86% de DBO. La aplicación de un tratamiento secuencial por 18 h incrementó su efectividad, lo cual resultó en 89% de remoción de color, además de 81% y 89% de remoción de DQO y DBO5 respectivamente. Con este tratamiento secuencial se observó una inactivación bacteriana del 55%. Las películas de TiO2 se reutilizaron continuamente durante 2 ciclos de tratamiento consecutivos sin reactivación térmica. Se alcanzaron porcentajes de remoción mayores al 50%. Las pruebas de toxicidad aguda llevadas a cabo con agua residual cruda produjeron un nivel de letalidad del 100% a 50% en Hydra attenuata y una inhibición de crecimiento del 54% a 50% en Lactuca sativa. El agua residual tratada secuencialmente produjo una letalidad del 13% a 6.25% y una inhibición del 12% a 75% para H. attenuata y L. sativa, respectivamente. Finalmente, el agua residual tratada secuencialmente fue reutilizada en experimentos de tinturado en los que la cantidad de colorante absorbido fue de 0.86 mg g-1 por g de tela, lo cual es equivalente a 80% de adsorción.

Resumo A indústria têxtil produz águas residuais que causam um impacto negativo ao meio ambiente quando são descartadas. Portanto, é necessário projetar e implementar novas soluções para seu tratamento. Um tratamento sequencial que consiste na co-cultura ligninolítica com os fungos Pleurotus ostreatus e Phanerochaete crhysosporium (tratamento secundário) acoplada à fotocatálise com TiO2/UV foi avaliado no laboratório para descolorir, desintoxicar e reutilizar água residual têxtil em ciclos subsequentes de tintura. Após 48 h de tratamento secundário, aproximadamente 80% da cor foi removida da água residual e sua demanda química e bioquímica de oxigênio (COD, e BOD5) foram diminuídas em 92% e 76%, respectivamente. A atividade de Laccase e MnP foram centrais na remoção da cor e diminuição de COD e BOD5, mostrando valores de atividade de 410 U L-1 e 1428 U L-1, respectivamente. Submeter as amostras de água residual a 12 h de tratamento terciário levou a uma remoção de 86% da cor e uma diminuição de 73% e 86% de COD e BOD5 respectivamente. A aplicação do tratamento sequencial por 18 h melhorou a efetividade do tratamento de águas residuais, resultando em 89% de remoção de cor e uma diminuição de 81% e 89% de COD e BOD5, respectivamente. Com este tratamento sequencial, observamos uma inativação bacteriana de 55%. As películas de TiO2 foram reutilizadas continuamente durante dois tratamentos consecutivos sem reativação térmica. Atingimos porcentagens de remoção acima de 50%. Os testes de toxicidade aguda feitos em água residual sem tratar causaram níveis de letalidades de 100% a 50% em Hydra attenuata e uma inibição do crescimento de 54% a 50% em Lactuca sativa. Enquanto água residual tratada sequencialmente causou uma letalidade de 13% a 6.25% e uma inibição de 12% a 75% para H. attenuata e L. sativa, respectivamente. Finalmente, a água residual tratada sequencialmente foi reutilizada em experimentos de tintura nos quais absorveu 0.86 mg g-1 por g de tecido, o que é equivalente a uma absorção de 80%.

Decolorization of Reactive Black 5 Dye by Heterogeneous Photocatalysis with TiO 2 /UV / Decoloración del tinte Negro Remazol B mediante fotocatálisis heterogénea con TiO 2 /UV / Descoloração do corante sintético Negro Remazol B por fotocatálise heterogênea com TiO 2 /UV

Abstract Reactive Black 5 (RB5) is an azo dye widely used in the textile industry because of its high chemical stability. Since it does not entirely fix on the fabrics, it pollutes water sources. In this work, the decolorization of aqueous solutions with RB5 was performed by heterogeneous photocatalysis with TiO2/UV. The reaction was carried out in an aluminum photoreactor equipped with five lamps. The effect of TiO2 (0.1, 0.175, and 0.25 g L-1), RB5 concentration (50, 75, and 100 mg L-1), and pH (3, 7, and 11) was evaluated for 14 h, using a Box-Behnken experimental statistical design. Complete decolorization of RB5 was obtained at 14 h, employing 0.175 g L-1 TiO2, 50 mg L-1 RB5, and pH 3. A 98.44% of decolorization was achieved in 10 h (0.25 g L-1 of TiO2, 50 mg L-1 of RB5, and pH 7). The highest decolorization percentage of RB5 (99.51%) was obtained at 10 h of exposure to UV light, using 0.5 g L-1 of TiO2, 50 mg L-1 of the dye, and a pH of 3. Cytotoxicity tests on the HepG2 cell line indicated that photocatalytic degradation of RB5 did not generate cytotoxic byproducts.

Resumen El Negro Remazol B (NRB) es un colorante azoico, usado en la industria textil por su estabilidad química. Este tinte no se fija al 100%, ocasionando contaminación en el agua. En este trabajo se evaluó la decoloración de soluciones acuosas con NRB mediante fotocatálisis heterogénea con TiO2/UV. La reacción se realizó en un fotorreactor de aluminio equipado con cinco lámparas. El efecto de la concentración de TiO2 (0,1; 0,175 y 0,25 g L-1), y NRB (50, 75 y 100 mg L-1) y el pH (3, 7 y 11) fue evaluado durante 14 h, tomando un diseño estadístico experimental Box-Behnken. La decoloración completa del NRB se obtuvo después de 14 h (0,175 g L-1 de TiO2, 50 mg L-1 de NRB, y pH 3). Se alcanzó un 98,44% de decoloración después de 10 h (0,25 g L-1 de TiO2, 50 mg L-1 de NRB, y pH 7). Se encontró que el mejor porcentaje de decoloración del NRB (99,51%) se obtuvo a las 10 h de exposición a luz UV, utilizando 0,5 g L-1 de TiO2, 50 mg L-1 del colorante y un pH de 3. Los ensayos de citotoxicidad sobre la línea celular HepG2 indicaron que la degradación fotocatalítica del NRB no generó subproductos citotóxicos.

Resumo O Negro Remazol B (RNB) é um corante azoico usado na indústria têxtil pela sua estabilidade química. O corante não é fixo no tecido em 100%, então contamina as fontes de água. Neste trabalho, avaliou-se a descoloração de soluções aquosas com RNB por meio de fotocatálise heterogênea com TiO2/UV. A reação foi feita no fotoreactor de alumínio com cinco lâmpadas. O efeito da concentração de TiO2 (0,1; 0,175 e 0,25 g L-1), RNB (50, 75 e 100 mg L-1) e pH (3, 7 e 11) foi avaliado durante 14 h utilizando o modelo estatístico Box-Behnken. Ás 14 h, foi atingida a descoloração completa do RNB (pH 3; 0,175 g L-1 de TiO2 e 50 mg L-1 de RNB). Utilizando 0,25 g L-1 de TiO2, 50 mg L-1 de RNB e pH 7, obteve-se descoloração de 98,44% em 10 h. Encontrou-se que a melhor porcentagem de descoloração do RNB (91,51%) foi obtida com 10 h de exposição à luz UV usando 0,5 g L-1 de TiO2, 50 mg L-1 do corante e pH de 3. Adicionalmente, os testes de citotoxicidade na linha celular HepG2 mostraram que a degradação fotocatalítica do RNB não gerou subprodutos citotóxicos.

Titanium Dioxide Nanoparticles and Sodium Nitroprusside Alleviate the Adverse Effects of Cadmium Stress on Germination and Seedling Growth of Wheat (Triticum aestivum L) / Nanopartículas de dióxido de titanio y nitroprusiato de sodio alivian los efectos adversos del estrés por cadmio en la germinación y el crecimiento de as plántulas de trigo (Triticum aestivum L) / Nanopartículas de dióxido de titânio e nitroprussiato de sódio aliviam os efeitos adversos do estresse por cádmio na germinação e no crescimento do trigo (Triticum aestivum L)

Abstract Effect of titanium dioxide nanoparticles (TiO2 NPs) (0, 500, 1 000 and 2 000 mg/L) and sodium nitroprusside (SNP) (0 and 100 μM) as nitric oxide (NO) donor, on wheat seed germination and seedling growth were investigated under cadmium (Cd) stress (0, 50 and 100 mM CdCl2). Concentration-dependent declining trends were observed in wheat germination indices upon seed exposure to CdCl2 suspensions which were more obvious under higher Cd stress. Exogenous sodium nitroprusside (SNP) and TiO2 nanoparticles (NPs) positively affected most germination indices under normal and stress conditions. In most cases, combined application of TiO2 NPs and SNP suspensions boosted stimulatory function of both compounds and moderated adverse effects of Cd treatments on wheat seed germination and seedling growth. 2 000 mg/L TiO2 + SNP (100 μM) treatment recorded the best results regarding most germination indices under lower and higher (50 and 100 mM CdCl2) Cd stress. Overall, it could be concluded that application of TiO2 NPs in combination with SNP might be a promising approach in counteracting the adverse effects of Cd stress on wheat seed germination and early growth.

Resumen Se investigó el efecto de nanopartículas de dióxido de titanio (TiO2 NPs) (0, 500, 1 000 and 2 000 mg/L) y nitroprusiato de sodio (SNP) (0 and 100 μM) como donador de óxido nítrico (NO), en la germinación de las semillas y el crecimiento de las plántulas de trigo bajo estrés por Cadmio (Cd) (0, 50 and 100 mM CdCl2). Se observaron tendencias decrecientes en los índices de germinación de las semillas de trigo expuestas a suspensiones de CdCl2. Estas tendencias fueron dependientes de la concentración, y más obvias ante alto estrés por Cd. El Nitroprusiato de Sodio exógeno (SNP) y las nanopartículas de TiO2 (NPs) afectaron positivamente la mayoría de los índices de germinación bajo condiciones normales y de estrés. En la mayoría de los casos, la aplicación combinada de suspensiones de TiO2 NPs y SNP incrementó la función estimulante de ambos componentes y moderó los efectos adversos de los tratamientos de Cd en la geminación de las semillas de trigo y el crecimiento de las plántulas. Con el tratamiento de 2000 mg/L TiO2 + SNP (100 μM) se registraron los mejores resultados en cuanto a los índices de germinación sometidos a bajo y alto estrés por Cd (50 and 100 mM CdCl2). En general, podría concluirse que la aplicación de TiO2 NPs en combinación con SNP podría ser una aproximación promisoria para contrarrestar los efectos adversos del estrés por Cd en la germinación de las semillas de trigo y en su crecimiento temprano.

Resumo Foram investigados os efeitos de nanopartículas de dióxido de titânio (TiO2 NPs) (0, 500, 1000 e 2000 mg/L) e nitroprussiato de sódio (SNP) (0 e 100 pM) como donadoras de óxido nítrico (NO) na germinação de sementes e no crescimento de plántulas de trigo sob estresse por cádmio (Cd) (0, 50 e 100 mM CdCl2). Se observaram tendências decrescentes nos índices de germinação de sementes de trigo expostas a suspensões de CdCl2. Essas tendências foram dependentes da concentração, sendo mais evidentes frente ao alto estresse por Cd. O nitroprussiato de sódio (SNP) e as nanopartículas de TiO2 (NPs) afetaram positivamente a maioria dos índices de germinação sob condições normais e de estresse. Na maioria dos casos, a aplicação combinada de suspensões de TiO2 NPs e SNP aumentou a função estimulante de ambos componentes e moderou os efeitos adversos dos tratamentos de Cd na germinação de semestres de trigo e no crescimento das plántulas. Com o tratamento de 2 000 mg/L TiO2 + SNP (100 μM) se registraram os melhores resultados em quanto aos índices de germinação submetidos a baixo e alto estresse por Cd (50 e 100 mM CdCl2). De modo geral, se pode concluir que a aplicação de TiO2 NPs em combinação com SNP poderia ser uma aproximação promissora para combater os efeitos adversos do estresse por Cd na germinação de sementes de trigo e no seu crescimento inicial.

Antibacterial activity of TiO2 nanotube arrays on periodontal pathogens before and after loaded with minocycline hydrochloride / 中国病理生理杂志

AIM:To investigate the effects of titanium dioxide(TiO2)nanotube arrays on the early adhesion behavior of Porphyromonas gingivalis(Pg),Tannerella forsythia(Tf)and Actinobacillus actinomycetemcomitans(Aa)be-fore and after loaded with minocycline hydrochloride(MN).METHODS: TiO2nanotube arrays were prepared by ano-dization and loaded with MN.Titanium slices were divided into 3 groups according to different treatment methods: pure polishing titanium(Ti)group,TiO2nanotube titanium(TiO2)group, and MN(120 μg)TiO2nanotube titanium(MN TiO2)group.The antibacterial properties of the titanium tablets were evaluated by the bacteriostasis test.RESULTS:The Ti had no antibacterial activity.The antibacterial activity of TiO 2to Aa,Pg and Tf was poor,with only about 20%of anti-bacterial rate after 4 h.After loaded with MN,its antibacterial activity was enhanced,and the antibacterial rate was up to 77%after 4 h.CONCLUSION: No antibacterial activity in the Ti group was observed.If TiO2nanotube arrays were formed on the surface and MN was loaded,the antibacterial activity on periodontal pathogens was stronger.

Overcoming Cancer Multidrug Resistance by Doxorubicin-TiO2 Nanoparticles / 中国药学杂志

OBJECTIVE To investigate the effect of TiO2 nanoparticles on overcoming cancer multidrug resistance(MDR). METHODS: Doxorubicin-TiO2 nanoparticles(DTN) were prepared, the K562/DOX cells were chosen as the model cells. And doxorubicin solution(F-DOX) and doxorubicin liposomes(DOX-L) were also prepared as the control. The MTT assay were measured, and the amount of doxorubicin in the K562/DOX cells at different time were determined by HPLC. The P-gp expression were detected by flow cytometry. RESULTS: The MTT assay shows that IC50 of group DTN were lower than that of group F-DOX. The uptake test shows that amount of doxorubicin in K562/DOX cells of group DTN was 1.23 times of group DOX-L when in 4 h, and the efflux test shows that amount of doxorubicin in K562/DOX cells was 1.18 times of group DOX-L. The flow cytometry result revealed that the effect of TiO2 nanoparticles on overcoming MDR maybe through down-regulating the expression of P-gp in K562/DOX cells. CONCLUSION: The TiO2 nanoparticles are a new inorganic materials-based nanoparticles which promising approach to overcome MDR.

Effects of modified hydrothermal nanotitania on the viability of Staphylococcus aureus

@#Staphylococcus aureus (S. aureus) is an important bacterium with significant pathological implications in the field of medicine. Attempting to cure bacterial infections at an advanced stage results in considerable waste of time, effort and expenditure. Thus, the prevention of such illnesses is paramount. Besides using chemical drugs to treat infections, several non-organic extracts have been tested in trials and been shown to impede the bacteria’s growth. This paper proposes that the modified hydrothermal nanotitania extract has great potential to combat this lethal organism. The viability of S. aureus was shown to be markedly reduced following the addition of nanotitania extract with 0.01%, 0.03% and 0.05% silver after 24, 48, and 72 hours. The ability of the nanotitania extract to inhibit the growth of S. aureus indicates its antimicrobial characteristics.

Effects of conditions for anodization and cyclic precalcification treatments on surface characteristics and bioactivity / 대한치과재료학회지

The purpose of this study was to investigate the effects of the anodization and cyclic calcification treatment on the surface characteristic and bioactivity of the titanium thin sheet in order to obtain basic data for the production of bioactive titanium membrane. A 30×20×0.08 mm titanium sheets were prepared, and then they were pickled for 10 seconds in the solution which was mixed with HNO₃: HF: H₂O in a ratio of 12: 7: 81. The TiO₂ nanotube layer was formed to increase the specific surface area of the titanium, and then the cyclic calcification treatment was performed to induce precipitation of hydroxiapatite by improvement of the bioactivity. The corrosion resistance test, wettability test and immersion test in simulated body solution were conducted to investigate the effect of these surface treatments. The nanotubes formed by the anodization treatment have a dense structure in which small diameter tubes are formed between relatively large diameter tubes, and their inside was hollow and the outer walls were coupled to each other. The hydroxyapatite precipitates were well combined on the nanotubes by the penetration into the nanotube layer by successive cyclic calcification treatment, and the precipitation of hydroxyapatite tended to increase proportionally after immersion in simulated body solution as the number of cycles increased. In conclusion, it was confirmed that induction of precipitation of hydroxyapatite by cyclic calcification treatment after forming the nanotube TiO₂ nanotube layer on the surface of the titanium membrane can contribute to improvement of bioactivity.