scholarly journals Retained particle surface area dose drives inflammation in rat lungs following acute, subacute, and subchronic inhalation of nanomaterials

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Frédéric Cosnier ◽  
Carole Seidel ◽  
Sarah Valentino ◽  
Otmar Schmid ◽  
Sébastien Bau ◽  
...  
Keyword(s):  
Chronic Inflammation ◽  
Surface Area ◽  
Dose Response ◽  
Particle Surface ◽  
Adverse Outcomes ◽  
Polymorphonuclear Neutrophil ◽  
Published Data ◽  
Post Exposure ◽  
Titanium Dioxides ◽  
Acute And Chronic Inflammation

Abstract Background An important aspect of nanomaterial (NM) risk assessment is establishing relationships between physicochemical properties and key events governing the toxicological pathway leading to adverse outcomes. The difficulty of NM grouping can be simplified if the most toxicologically relevant dose metric is used to assess the toxicological dose-response. Here, we thoroughly investigated the relationship between acute and chronic inflammation (based on polymorphonuclear neutrophil influx (% PMN) in lung bronchoalveolar lavage) and the retained surface area in the lung. Inhalation studies were performed in rats with three classes of NMs: titanium dioxides (TiO2) and carbon blacks (CB) as poorly soluble particles of low toxicity (PSLT), and multiwall carbon nanotubes (MWCNTs). We compared our results to published data from nearly 30 rigorously selected articles. Results This analysis combined data specially generated for this work on three benchmark materials - TiO2 P25, the CB Printex-90 and the MWCNT MWNT-7 - following subacute (4-week) inhalation with published data relating to acute (1-week) to subchronic (13-week) inhalation exposure to the classes of NMs considered. Short and long post-exposure recovery times (immediately after exposure up to more than 6 months) allowed us to examine both acute and chronic inflammation. A dose-response relationship across short-term and long-term studies was revealed linking pulmonary retained surface area dose (measured or estimated) and % PMN. This relationship takes the form of sigmoid curves, and is independent of the post-exposure time. Curve fitting equations depended on the class of NM considered, and sometimes on the duration of exposure. Based on retained surface area, long and thick MWCNTs (few hundred nm long with an aspect ratio greater than 25) had a higher inflammatory potency with 5 cm2/g lung sufficient to trigger an inflammatory response (at 6% PMN), whereas retained surfaces greater than 150 cm2/g lung were required for PSLT. Conclusions Retained surface area is a useful metric for hazard grouping purposes. This metric would apply to both micrometric and nanometric materials, and could obviate the need for direct measurement in the lung. Indeed, it could alternatively be estimated from dosimetry models using the aerosol parameters (rigorously determined following a well-defined aerosol characterization strategy).

Effect of Nectaroscordum koelzi Methanolic Extract on Acute and Chronic Inflammation in Male Mice

2020 ◽  
Vol 20 ◽  
Author(s):  
Karam Hossein Hasanvand ◽  
Mojtaba Khaksarian ◽  
Maryam Alipour ◽  
Hormoz Mahmoudvand ◽  
Massumeh Naizi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Chronic Inflammation ◽  
Acute Inflammation ◽  
Methanol Extract ◽  
Significant Activity ◽  
Paw Edema ◽  
Ear Edema ◽  
Edema Volume ◽  
Cotton Pellet ◽  
Acute And Chronic Inflammation

Introduction: The present study deals with the effect of Nectaroscordum koelzi fruit extract on acute and chronic inflammation. Methods: Totally, 84 NMRI mice were used in this study. The extract effect on acute inflammation was analyzed by increasing vascular permeability via acetic acid and xylene induced ear edema among mice. The extract was evaluated in terms of effects on chronic inflammation by means of the cotton pellet test among mice. For the assessment of inflammation degree, the mice paw edema volume was measured by the plethysmometric test. Results: The findings showed that the extract was effective on acute inflammation induced by acetic acid in mice. In the xylene ear edema, N. koelzi extract indicated the significant activity in mice. In the cotton pellet method, the methanol extract produced a significant reduction in comparison with the control and dexamethasone. Mice paw edema volume decreased with the extract. Conclusion: In general, the data from the experiments indicated that the methanol extract of N. koelzi has an anti-inflammatory effect on acute and chronic inflammation. However, the exact contributing mechanisms have not been investigated for the pharmacological effects.

scholarly journals Farnesol-Loaded Liposomes Protect the Epidermis and Dermis from PM2.5-Induced Cutaneous Injury

2021 ◽  
Vol 22 (11) ◽  
pp. 6076
Author(s):  
Yu-Chiuan Wu ◽  
Wei-Yun Chen ◽  
Chun-Yin Chen ◽  
Sheng I. Lee ◽  
Yu-Wen Wang ◽  
...  
Keyword(s):  
Chronic Inflammation ◽  
Water Solubility ◽  
Antibacterial Properties ◽  
Hair Follicles ◽  
Protective Effects ◽  
Cutaneous Injury ◽  
Anti Inflammatory ◽  
High Concentrations ◽  
Acute And Chronic Inflammation

Particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5) increases oxidative stress through free radical generation and incomplete volatilization. In addition to affecting the respiratory system, PM2.5 causes aging- and inflammation-related damage to skin. Farnesol (Farn), a natural benzyl semiterpene, possesses anti-inflammatory, antioxidative, and antibacterial properties. However, because of its poor water solubility and cytotoxicity at high concentrations, the biomedical applications of Farn have been limited. This study examined the deleterious effects of PM2.5 on the epidermis and dermis. In addition, Farn-encapsulated liposomes (Lipo-Farn) and gelatin/HA/xanthan gel containing Lipo-Farn were prepared and applied in vivo to repair and alleviate PM2.5-induced damage and inflammation in skin. The prepared Lipo-Farn was 342 ± 90 nm in diameter with an encapsulation rate of 69%; the encapsulation significantly reduced the cytotoxicity of Farn. Lipo-Farn exhibited a slow-release rate of 35% after 192 h of incubation. The half-maximal inhibitory concentration of PM2.5 was approximately 850 μg/mL, and ≥400 μg/mL PM2.5 significantly increased IL-6 production in skin fibroblasts. Severe impairment in the epidermis and hair follicles and moderate impairment in the dermis were found in the groups treated with post-PM2.5 and continuous subcutaneous injection of PM2.5. Acute and chronic inflammation was observed in the skin in both experimental categories in vivo. Treatment with 4 mM Lipo-Farn largely repaired PM2.5-induced injury in the epidermis and dermis, restored injured hair follicles, and alleviated acute and chronic inflammation induced by PM2.5 in rat skin. In addition, treatment with 4 mM pure Farn and 2 mM Lipo-Farn exerted moderate reparative and anti-inflammatory effects on impaired skin. The findings of the current study indicate the therapeutic and protective effects of Lipo-Farn against various injuries caused by PM2.5 in the pilosebaceous units, epidermis, and dermis of skin.

Enhancement on Stability of Nanosized Titanium Dioxide in Silicone Suspension Using Diblock Copolymer: Influence of Dispersant Structure

2013 ◽  
Vol 747 ◽  
pp. 599-602
Author(s):  
Surachet Toommee ◽  
Nisanart Traiphol
Keyword(s):  
Titanium Dioxide ◽  
Surface Area ◽  
Diblock Copolymer ◽  
High Efficiency ◽  
Particle Surface ◽  
Ethyl Acrylate ◽  
Polymer Structure ◽  
Particle Agglomeration ◽  
Nanosized Titanium Dioxide ◽  
Enhanced Adsorption

This research investigates using of poly (dimethylsiloxane-b-hydroxy ethyl acrylate) (PDMS-b-PHEA) diblock copolymer to stabilized TiO2nanoparticles in silicone fluid. The polar PHEA segment is expected to anchor on TiO2surface while the non-polar PDMS segment extends into silicone medium. To study effects of polymer structure on its stabilizing efficiency, PDMS-b-PHEA of structures 5-b-0.3, 5-b-1.1 and 8-b-1.0 are used. Results show that suspensions of particle with surface area ~40 and ~200 m2/g can be stabilized for longer than 1 and 7 hrs, respectively. The copolymer with relatively long PHEA and PDMS segments is highly effective as a dispersant. This is due to enhanced adsorption on particle surface and steric stabilization. However, in the system of 40 m2/g-TiO2, excess amounts could lead to polymer entanglement and particle agglomeration. The copolymer dispersant exhibits high efficiency for the 200 m2/g-TiO2suspension as well. In the latter system, higher concentration is required to effectively cover particle surface.

Performance Impacts of Tailored Surface Geometry in Li-Ion Battery Cathodes

2013 ◽  
Author(s):  
George J. Nelson
Keyword(s):  
Surface Area ◽  
Solid Phase ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Analytical Models ◽  
Li Ion Battery ◽  
Fractal Structures ◽  
Surface Geometry ◽  
Trade Offs ◽  
Li Ion

Analytical models developed to investigate charge transfer in Li-ion battery cathodes reveal distinct transport regimes where performance may be limited by either microstructural surface characteristics or solid phase geometry. For several cathode materials, particularly those employing conductive additives, surface characteristics are expected to drive these performance limitations. For such electrodes gains in performance may be achieved by modifying surface geometry to increase surface area. However, added surface area may present a diminishing return if complex structures restrict access to electrochemically active interfaces. A series of parametric studies has been performed to better ascertain the merits of complex, tailored surfaces in Li-ion battery cathodes. The interaction between lithium transport and surface geometry is explored using a finite element model in which complex surfaces are simulated with fractal structures. Analysis of transport in these controlled structures permits assessment of scaling behavior related to surface complexity and provides insight into trade-offs in tailoring particle surface geometry.

Influence of particle surface area on the toxicity of insoluble manganese dioxide dusts

1997 ◽  
Vol 71 (12) ◽  
pp. 725-729 ◽  
Author(s):  
Dominique Lison ◽  
Cécile Lardot ◽  
François Huaux ◽  
Giovanna Zanetti ◽  
Bice Fubini
Keyword(s):  
Manganese Dioxide ◽  
Surface Area ◽  
Particle Surface ◽  
Particle Surface Area

scholarly journals Relationship between hospital or surgeon volume and outcomes in joint arthroplasty: protocol for a suite of systematic reviews and dose–response meta-analyses

BMJ Open ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. e022797 ◽  
Author(s):  
Xiang-Dong Wu ◽  
Meng-Meng Liu ◽  
Ya-Ying Sun ◽  
Zhi-Hu Zhao ◽  
Quan Zhou ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Dose Response ◽  
Data Extraction ◽  
Meta Analysis ◽  
High Volume ◽  
Joint Arthroplasty ◽  
Surgeon Volume ◽  
Published Data ◽  
Records Management ◽  
Meta Analyses

IntroductionJoint arthroplasty is a particularly complex orthopaedic surgical procedure performed on joints, including the hip, knee, shoulder, ankle, elbow, wrist and even digit joints. Increasing evidence from volume–outcomes research supports the finding that patients undergoing joint arthroplasty in high-volume hospitals or by high-volume surgeons achieve better outcomes, and minimum case load requirements have been established in some areas. However, the relationships between hospital/surgeon volume and outcomes in patients undergoing arthroplasty are not fully understood. Furthermore, whether elective arthroplasty should be restricted to high-volume hospitals or surgeons remains in dispute, and little is known regarding where the thresholds should be set for different types of joint arthroplasties.Methods and analysesThis is a protocol for a suite of systematic reviews and dose–response meta-analyses, which will be amended and updated in conjunction with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. Electronic databases, including PubMed and Embase, will be searched for observational studies examining the relationship between the hospital or surgeon volume and clinical outcomes in adult patients undergoing primary or revision of joint arthroplasty. We will use records management software for study selection and a predefined standardised file for data extraction and management. Quality will be assessed using the Newcastle-Ottawa Scale, and the meta-analysis, subgroup analysis and sensitivity analysis will be performed using Stata statistical software. Once the volume–outcome relationships are established, we will examine the potential non-linear relationships between hospital/surgeon volume and outcomes and detect whether thresholds or turning points exist.Ethics and disseminationEthical approval is not required, because these studies are based on aggregated published data. The results of this suite of systematic reviews and meta-analyses will be submitted to peer-reviewed journals for publication.PROSPERO registration numberCRD42017056639.

Malignant Pyoderma

1981 ◽  
Vol 89 (6) ◽  
pp. 917-922 ◽  
Author(s):  
John R. Salassa ◽  
R.K. Winkelmann ◽  
Thomas J. McDonald
Keyword(s):  
Chronic Inflammation ◽  
External Ear ◽  
Systemic Corticosteroids ◽  
The Face ◽  
Acute And Chronic Inflammation ◽  
Histopathologic Findings

Malignant pyoderma is a rare inflammatory pyoderma of unknown cause with characteristic destructive and necrotizing ulcers limited to the face, neck, and upper trunk. The typical lesions are small, purulent, periauricular ulcers. Enlargement and coalescence result in extensive lesions that may ultimately destroy portions of the external ear. The histopathologic findings are acute and chronic inflammation with necrosis. Treatment consists of long-term systemic corticosteroids. We present two new cases and alert otolaryngologists to the seriousness of this disease.

Hard-templating synthesis and enhanced photocatalysis of mesoporous titanium dioxides nanoparticles

2018 ◽  
Vol 11 (04) ◽  
pp. 1850077 ◽  
Author(s):  
K. L. Jin ◽  
X. J. Chen ◽  
J. C. Xu ◽  
Y. S. Huang ◽  
Y. B. Han ◽  
...  
Keyword(s):  
Surface Area ◽  
Anatase Phase ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Photocatalytic Decomposition ◽  
Titanium Dioxides ◽  
Decomposition Efficiency ◽  
Templating Synthesis ◽  
Mb Adsorption

Mesoporous titanium dioxides nanoparticles (TiO2 NPs) were synthesized using activated carbon (AC) as templates after the decomposition of AC. All results indicated that TiO2 NPs with the small grain size presented the anatase phase structure. Mesoporous TiO2 NPs showed the high surface area and the surface area decreased with the TiO2 content. The removal of methylene blue (MB) indicated that the photocatalytic decomposition efficiency of mesoporous TiO2 NPs increased up to 92% for three-times doping with the TiO2 content, and then decreased. This should be attributed to the synergistic effect from the MB adsorption of mesoporous-structure and the photocatalysis of TiO2 NPs. Therefore, the higher MB concentration near TiO2 NPs from the mesoporous-structure increased the touch chance and the MB photocatalytic decomposition was promoted greatly.

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