Periodic charge matching driven immobilization of gentamicin in nanoclays for stable and long-term antibacterial coating

2021 ◽  
Author(s):  
Tetsuo Yamaguchi ◽  
Su-Joung Ko ◽  
Jin-Song Jung ◽  
Hyoung-Jun Kim ◽  
Jae-Min Oh

Gentamicin was stabilized in a bentonite clay via periodic charge–charge interaction and was successfully incorporated into a polymer film for long-term sustained antibacterial coating.

BioTechniques ◽  
2020 ◽  
Vol 69 (3) ◽  
pp. 171-177
Author(s):  
Nobuyuki Tanaka ◽  
Ryoji Sekine ◽  
Shun-ichi Funano ◽  
Asako Sato ◽  
Núria Taberner Carretero ◽  
...  

This study demonstrates the rapid fabrication and utility of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer film for cell patterning. The film was obtained on a cell culture surface by microcasting MPC polymer ethanol solution into a degassed polydimethylsiloxane mold with a desired pattern. After removal of the mold, 293AD cells were cultured on the surface of the polymer film with the patterned microstructures. Patterned cell adhesion restricted by the film was successfully maintained during at least a 168-h cultivation. The microcast MPC polymer film can be prepared rapidly and used for efficient long-term cell confinement.


2000 ◽  
Vol 663 ◽  
Author(s):  
Allan Hedin ◽  
Ulrik Kautsky ◽  
Lena Morén ◽  
Jan-Olof Selroos ◽  
Patrik Sellin ◽  
...  

ABSTRACTIn preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Company, SKB has carried out the long- term safety assessment SR 97, requested by the Swedish Government. The repository is of the KBS-3 type, where the fuel is placed in isolating copper canisters with a high-strength cast iron insert. The canisters are surrounded by bentonite clay in individual deposition holes at a depth of 500 m in granitic bedrock. Geological data are taken from three sites in Sweden to shed light on different conditions in Swedish granitic bedrock.The future evolution of the repository system is analyzed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings, including climate, persist. The four other scenarios show the evolution if the repository contains a few initially defective canisters, in the event of climate change, in the event of earthquakes, and in the event of future inadvertent human intrusion.The principal conclusion of the assessment is that the prospects of building a safe deep repository for spent nuclear fuel in Swedish granitic bedrock are very good. The results of the assessment also serve as a basis for formulating requirements and preferences regarding the bedrock in site investigations, for designing a program for site investigations, for formulating functional requirements on the repository's barriers, and for prioritization of research.


2017 ◽  
Vol 8 (29) ◽  
pp. 4264-4279 ◽  
Author(s):  
Yaping Gou ◽  
Xiao Yang ◽  
Libang He ◽  
Xinyuan Xu ◽  
Yanpeng Liu ◽  
...  

SSP-PAMAM-NH2 inspired by the salivary statherin protein can tightly adsorb on the HA surface to achieve long-term antibacterial activity.


2020 ◽  
Vol 205 ◽  
pp. 01003
Author(s):  
Lyesse Laloui ◽  
Alessio Ferrari ◽  
Jose A. Bosch

Deep disposal of high-level radioactive waste is the preferred solution worldwide for the long-term disposal of nuclear waste. This concept involves a series of geological and engineered barriers that provide isolation of the waste from the biosphere. Most designs involve bentonite clays as seals in different forms. During the operation of the repository, the bentonite will be subjected to a series of complex thermo-hydro-mechanical phenomena that will interact with each other. Predicting the long-term safety of geological repositories thus involve a rigorous analysis of these multi-physical processes. This paper presents a review of recent numerical approaches and analyses that have aimed to improve the understanding of processes that will take place in clay barriers over the lifetime of nuclear waste repositories. The understanding of bentonite behavior from laboratory experiments under relevant conditions is analyzed. Constitutive models that attempt to predict such behavior are presented, focusing on the stress-strain model ACMEG-TS. These models are implemented in the finite element code Lagamine which allows for the study of real scale tests. Two application cases are presented: the performance of a clay barrier according to the Swiss design, and a model of the FEEBX in situ experiment, which was modelled after a real repository under natural conditions. Overall, the relevant processes are well captured quantitatively by the models, allowing for the establishment of sound basis for future prediction and long-term design of the final underground repositories.


2003 ◽  
Vol 807 ◽  
Author(s):  
Nicholas R. Smart ◽  
Andrew P. Rance ◽  
Lars O. Werme

ABSTRACTIn Sweden, spent nuclear fuel will be encapsulated in sealed cylindrical canisters, consisting of a ferrous insert and a copper outer container, for disposal in a geologic repository. Ferrous support structures will also be used in the repository, which will be backfilled with bentonite clay. Once any residual oxygen has been consumed, any ferrous material exposed to anoxic groundwater will undergo anaerobic corrosion, liberating hydrogen, forming a magnetite film, and releasing iron ions into the surrounding matrix. In order to characterise these processes the rate of hydrogen generation of steel in bentonite was measured using a barometric gas cell technique. The initial corrosion rates were found to be higher than measured previously in comparable aqueous solutions, but the long-term corrosion rates were similar. Analysis of the bentonite matrix showed that iron produced by corrosion had penetrated into the bentonite matrix, suggesting that ferrous ion exchange had occurred.


2018 ◽  
Vol 876 ◽  
pp. 97-102 ◽  
Author(s):  
Jakub Hodul ◽  
Jana Hodná ◽  
Rostislav Drochytka

Currently fillers for antibacterial layers in hygienic operations are mainly primary raw materials, whose properties are verified and well-known due to their long-term use. However, the use of proper secondary raw materials appears to be a good option from an environmental and economic point of view. This work assesses the possible adverse effects of specially treated secondary raw materials in relation to antibacterial properties, chemical resistance and Shore hardness of the antibacterial coating on an epoxy base (AC-E) providing no physiological damage. This coating reliably eliminates the widest possible range of bacteria and yeasts, has sustained effectiveness, consistent functionality over time, provides permanent protection and is suitable for use in healthcare facilities and food processing plants. Two kinds of transparent waste glass (NaSX, VLG) and two types of waste foundry sand (FSC, FSB) were tested, and all fillers were treated so that particle size was below 0.063 mm, including the reference filler (Dorsilit sand). On the basis of antibacterial resistance tests, Shore hardness and chemical resistance, it was assessed that the tested fillers may be effectively used for antibacterial coatings while maintaining the properties of the reference coating. Within the rapid testing of chemical resistance, the surface microstructure of the antibacterial coating was also examined after long-term exposure to aggressive organic and inorganic liquid media. When adding 30% and 35% of the selected waste fillers, the hardness and chemical resistance of the cured coating did not change. The treated waste fillers tested had no negative impact on the antibacterial properties of the coating and were judged to be appropriate fillers in place of Dorsilit silica sand or glass flakes.


2021 ◽  
Vol 108 (Supplement_3) ◽  
Author(s):  
J E de la Cruz Conty ◽  
A Budía Alba ◽  
J L Sanz Migueláñez ◽  
J A Galán Llopis ◽  
T Fernández Aparicio ◽  
...  

Abstract INTRODUCTION The aim of this study is to assess the effectiveness of heparin to inhibit the development of early bacteriuria as a coating for biodegradable ureteral stents. MATERIAL AND METHODS The BraidStent®-H biodegradable stent, whose heparin coating is incorporated by dip coating, was chosen for this study. Twenty-four swine were randomly divided into two groups: 12 animals underwent unilateral placement of the BraidStent®-H and 12 were fitted with a standard double-j stent (DJS). Bacteriuria is comparatively analyzed over time by consecutive urine sampling at 0, 1, 3, 6, 12, 24 and 48 hours. In addition, the concentration of heparin released in vitro in artificial urine at 0, 3, 6, 12, 24, 48, 72, 92 and 120 hours is determined via ELISA. RESULTS BraidStent®-H generates a significantly lower bacteriuria rate than a DJS at 6 and 12 hours. Heparin coating shows a significant delaying effect on the onset of bacteriuria, reaching 100% of the animals at 48 hours, compared to the DJS, which takes place at 6 hours. ELISA results reveal the presence of heparin in urine for a total of 72 hours. The coating does not affect the degradation of the device, which is completed at 6 weeks. CONCLUSIONS Heparin evidences an effective inhibition of early bacteriuria, showing its potential as an antibacterial coating for biodegradable ureteral stents. Future studies should focus on the development of long-term heparin coatings for biodegradable materials.


2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.


2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


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