Antibiotic tetracycline enhanced the toxic potential of photo catalytically active P25 titanium dioxide nanoparticles towards freshwater algae Scenedesmus obliquus

The effects of the photocatalytic toxicity of titanium dioxide nanoparticle (nano-TiO2) on phytoplankton are well understood. However, as UV light intensity decreases sharply with the depth of the water column, the effects of nano-TiO2 itself on deeper water phytoplankton, such as green algae, need further research. In this research, we investigated the effects of three sizes of TiO2 (10, 50 and 200 nm) on the photosynthetic and antioxidative processes of Scenedesmus obliquus in the absence of UV light. We found that 50 nm and 10 nm TiO2 (10 mg/L) inhibited growth rates and the maximal photosystem II quantum yield compared to the control in Scenedesmus obliquus. The minimal and maximal fluorescence yields, and the contents of reactive oxygen species and lipid peroxidation, increased, indicating that photosynthetic energy/electrons transferred to oxygen and induced oxidative stress in nano-TiO2-treated samples. In addition, we found that aggregations of algae and 10 nm TiO2 were present, which could induce cell membrane disruption, and vacuoles were induced to cope with nano-TiO2 stress in Scenedesmus obliquus. These results enhance our understanding of the effects of nano-TiO2 on the photosynthetic and antioxidative processes of green algae, and provide basic information for evaluating the ecotoxicity of nano-TiO2 in freshwater ecosystems.

Download Full-text

Systemic Effects of Metals Released from Arthroplasty Implants – a Brief Summary

Zeitschrift für Orthopädie und Unfallchirurgie ◽

10.1055/a-1187-1751 ◽

2020 ◽

Vol 158 (05) ◽

pp. 501-507

Author(s):

Anastasia Rakow ◽

Janosch Schoon

Keyword(s):

Titanium Dioxide ◽

Titanium Dioxide Nanoparticles ◽

Systemic Effects ◽

Human Organ ◽

Systemic Complications ◽

Specific Effects ◽

Organ Systems ◽

Accumulation Of Metals ◽

Cobalt Exposure ◽

Toxic Potential

AbstractIn recent years, increasing concern has been raised regarding potential systemic toxicity of metals released from arthroplasty implants. A lack of valid metal thresholds for human (organ) toxicity and the prospect of multi-decade survival of modern hip and knee replacements pose special challenges. Indeed, evidence of systemic effects of metals released from such implants is largely missing. Systemic cobalt exposure has repeatedly been associated with cardiotoxic and neurotoxic effects, and also with thyroid dysfunction. The toxic potential of chromium is considered less pronounced. Yet, in arthroplasty there is usually a co-exposure to chromium and cobalt which complicates evaluation of element-specific effects. Toxicity of titanium dioxide nanoparticles has been subject to debate among international regulatory authorities. Their wide use in a variety of products in everyday life, such as toothpaste, cosmetics and food colorants, hampers the assessment of an arthroplasty-induced systemic titanium exposure. To date there is no clear evidence for systemic complications due to titanium dioxide released from arthroplasty implants. Release of further metals such as tantalum, niobium, nickel, vanadium and zirconium from hip and knee replacement implants has been described occasionally, but systemic effects of respective long-term exposure scenarios are unknown. Generally, the characterization of all released metals regarding their chemical and physical specifications is critical for the evaluation of potential systemic risks. Systematic studies investigating the accumulation of metals relevant in arthroplasty in different organs/organ systems and the biological consequences of such accumulations are urgently needed.

Download Full-text

Methods of determining titanium dioxide nanoparticles enhance inorganic arsenic bioavailability and methylation in two freshwater algae species

MethodsX ◽

10.1016/j.mex.2018.06.004 ◽

2018 ◽

Vol 5 ◽

pp. 620-625

Author(s):

Zhuanxi Luo ◽

Zhenhong Wang ◽

Yameng Yan ◽

Jinli Li ◽

Changzhou Yan ◽

...

Keyword(s):

Titanium Dioxide ◽

Titanium Dioxide Nanoparticles ◽

Inorganic Arsenic ◽

Freshwater Algae

Download Full-text

Genotoxicity Studies of Titanium Dioxide Nanoparticles (TiO2NPs) in the Brain of Mice

Scientifica ◽

10.1155/2016/6710840 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Hanan R. H. Mohamed ◽

Nahed A. Hussien

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Titanium Dioxide ◽

Brain Tissue ◽

Titanium Dioxide Nanoparticles ◽

Direct Sequencing ◽

Disease Incidence ◽

Dependent Manner ◽

Toxic Potential ◽

The Brain

Titanium dioxide nanoparticles (TiO2NPs) are excessively used and represent one of the top five most commonly used nanoparticles worldwide. Recently, various studies referred to their toxic potential on various organs using different treatment route. Male Swiss Webster mice were orally administrated TiO2NPs (500 mg/kg b.w.) daily for five consecutive days and then animals were sacrificed at 24 h, 7 days, or 14 days after the last treatment. The present results report that exposure to TiO2NPs produces mild to moderate changes in the cytoarchitecture of brain tissue in a time dependent manner. Moreover, Comet assay revealed the apoptotic DNA fragmentation, while PCR-SSCP pattern and direct sequencing showed point mutation of Presenilin 1 gene at exon 5, gene linked to inherited forms of the Alzheimer’s disease. Therefore, from these findings, the present study concluded that TiO2NPs is genotoxic and mutagenic to brain tissue which in turn might lead to Alzheimer’s disease incidence.

Download Full-text

The Effect of silver and titanium dioxide nanoparticles on Klebsiella pneumoniae isolates multi resistant to antibiotics and observed by Scanning electron microscopy

10.24086/bios17.26 ◽

2017 ◽

Author(s):

Payman Kareem ◽

Essra Alsammak

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Titanium Dioxide ◽

Klebsiella Pneumoniae ◽

Titanium Dioxide Nanoparticles ◽

Scanning Electron

Download Full-text