Real-time and in Situ Drug Release Monitoring from Nanoporous Implants under Dynamic Flow Conditions by Reflectometric Interference Spectroscopy

2013 ◽  
Vol 5 (12) ◽  
pp. 5436-5442 ◽  
Author(s):  
Tushar Kumeria ◽  
Karan Gulati ◽  
Abel Santos ◽  
Dusan Losic
Keyword(s):  
Drug Release ◽  
Real Time ◽  
Flow Conditions ◽  
Dynamic Flow ◽  
Reflectometric Interference Spectroscopy

scholarly journals A microfluidic platform for in situ investigation of biofilm formation and its treatment under controlled conditions

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Hervé Straub ◽  
Leo Eberl ◽  
Manfred Zinn ◽  
René M. Rossi ◽  
Katharina Maniura-Weber ◽  
...  
Keyword(s):  
Single Cell ◽  
Real Time ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Rich Medium ◽  
Flow Conditions ◽  
Microfluidic Platform ◽  
Adhesion Rate

Abstract Background Studying bacterial adhesion and early biofilm development is crucial for understanding the physiology of sessile bacteria and forms the basis for the development of novel antimicrobial biomaterials. Microfluidics technologies can be applied in such studies since they permit dynamic real-time analysis and a more precise control of relevant parameters compared to traditional static and flow chamber assays. In this work, we aimed to establish a microfluidic platform that permits real-time observation of bacterial adhesion and biofilm formation under precisely controlled homogeneous laminar flow conditions. Results Using Escherichia coli as the model bacterial strain, a microfluidic platform was developed to overcome several limitations of conventional microfluidics such as the lack of spatial control over bacterial colonization and allow label-free observation of bacterial proliferation at single-cell resolution. This platform was applied to demonstrate the influence of culture media on bacterial colonization and the consequent eradication of sessile bacteria by antibiotic. As expected, the nutrient-poor medium (modified M9 minimal medium) was found to promote bacterial adhesion and to enable a higher adhesion rate compared to the nutrient-rich medium (tryptic soy broth rich medium ). However, in rich medium the adhered cells colonized the glass surface faster than those in poor medium under otherwise identical conditions. For the first time, this effect was demonstrated to be caused by a higher retention of newly generated bacteria in the rich medium, rather than faster growth especially during the initial adhesion phase. These results also indicate that higher adhesion rate does not necessarily lead to faster biofilm formation. Antibiotic treatment of sessile bacteria with colistin was further monitored by fluorescence microscopy at single-cell resolution, allowing in situ analysis of killing efficacy of antimicrobials. Conclusion The platform established here represents a powerful and versatile tool for studying environmental effects such as medium composition on bacterial adhesion and biofilm formation. Our microfluidic setup shows great potential for the in vitro assessment of new antimicrobials and antifouling agents under flow conditions.

scholarly journals Biofilm dynamics: linking in situ biofilm biomass and metabolic activity measurements in real-time under continuous flow conditions

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Kyle B. Klopper ◽  
Riaan N. de Witt ◽  
Elanna Bester ◽  
Leon M. T. Dicks ◽  
Gideon M. Wolfaardt
Keyword(s):  
Real Time ◽  
Metabolic Activity ◽  
Continuous Flow ◽  
Control Strategies ◽  
Mass Function ◽  
Flow Conditions ◽  
Carbon Dioxide Evolution ◽  
Activity Measurements ◽  
The Internet Of Things

Abstract The tools used to study biofilms generally involve either destructive, end-point analyses or periodic measurements. The advent of the internet of things (IoT) era allows circumvention of these limitations. Here we introduce and detail the development of the BioSpec; a modular, nondestructive, real-time monitoring system, which accurately and reliably track changes in biofilm biomass over time. The performance of the system was validated using a commercial spectrophotometer and produced comparable results for variations in planktonic and sessile biomass. BioSpec was combined with the previously developed carbon dioxide evolution measurement system (CEMS) to allow simultaneous measurement of biofilm biomass and metabolic activity and revealed a differential response of these interrelated parameters to changing environmental conditions. The application of this system can facilitate a greater understanding of biofilm mass–function relationships and aid in the development of biofilm control strategies.

Ratiometric and Time-Resolved Fluorimetry from Quantum Dots Featuring Drug Carriers for Real-Time Monitoring of Drug Release in Situ

2014 ◽  
Vol 86 (11) ◽  
pp. 5211-5214 ◽  
Author(s):  
Rijun Gui ◽  
Ajun Wan ◽  
Yalei Zhang ◽  
Huili Li ◽  
Tingting Zhao
Keyword(s):  
Quantum Dots ◽  
Drug Release ◽  
Real Time ◽  
Drug Carriers ◽  
Real Time Monitoring ◽  
Time Resolved

A Dual-FRET-Based Versatile Prodrug for Real-Time Drug Release Monitoring and In Situ Therapeutic Efficacy Evaluation

2015 ◽  
Vol 25 (47) ◽  
pp. 7317-7326 ◽  
Author(s):  
Shi-Ying Li ◽  
Li-Han Liu ◽  
Lei Rong ◽  
Wen-Xiu Qiu ◽  
Hui-Zhen Jia ◽  
...  
Keyword(s):  
Drug Release ◽  
Real Time ◽  
Therapeutic Efficacy ◽  
Efficacy Evaluation

Non-Destructive Molecular FTIR Spectromicroscopy for Real Time Assessment of Redox Metallodrugs

2021 ◽  
Author(s):  
Lucyano J. A. Macedo ◽  
Fernando Postalli Postalli Rodrigues ◽  
Ayaz Hassan ◽  
Leandro Maximo ◽  
Fabio Zobi ◽  
...  
Keyword(s):  
Drug Release ◽  
Real Time ◽  
Redox Chemistry ◽  
Biological Chemistry ◽  
Recent Emergence ◽  
Non Destructive ◽  
Time Assessment

Recent emergence of FTIR spectromicroscopy (micro-FTIR) as a dynamic spectroscopy for imaging to the study of biological chemistry has opened new possibilities for investigating in situ drug release, redox chemistry...

Enzyme-responsive fluorescent camptothecin prodrug/polysaccharide supramolecular assembly for targeted cellular imaging and in situ controlled drug release

2020 ◽  
Vol 56 (7) ◽  
pp. 1042-1045 ◽  
Author(s):  
Yu-Hui Zhang ◽  
Ying-Ming Zhang ◽  
Xianliang Sheng ◽  
Jie Wang ◽  
Yu Liu
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Real Time ◽  
Supramolecular Assembly ◽  
Controlled Drug Release ◽  
Cellular Imaging ◽  
Targeted Imaging ◽  
Real Time Tracking ◽  
Low Cytotoxicity

An enzyme-responsive polysaccharide assembly was constructed, which possesses low cytotoxicity, targeted imaging and controlled drug release, while providing a concurrent means for the real-time tracking of drug delivery.

scholarly journals Nanostructured P3HT as a Promising Sensing Element for Real-Time, Dynamic Detection of Gaseous Acetone

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1296 ◽  
Author(s):  
Cristina Bertoni ◽  
Pasquale Naclerio ◽  
Emanuele Viviani ◽  
Simone Dal Zilio ◽  
Sergio Carrato ◽  
...  
Keyword(s):  
Real Time ◽  
Short Pulse ◽  
Flow Conditions ◽  
Dynamic Flow ◽  
Sensing Element ◽  
Acetone Concentration ◽  
Electronic Noses ◽  
Time Dynamic ◽  
Decay Times ◽  
Response To Water

The dynamic response of gas sensors based on poly(3-hexylthiophene) (P3HT) nanofibers(NFs) to gaseous acetone was assessed using a setup based on flow-injection analysis, aimed atemulating actual breath exhalation. The setup was validated by using a commercially available sensor.The P3HT NFs sensors tested in dynamic flow conditions showed satisfactory reproducibility down toabout 3.5 ppm acetone concentration, a linear response over a clinically relevant concentration range(3.5-35 ppm), excellent baseline recovery and reversibility upon repeated exposures to the analyte,short pulse rise and fall times (less than 1 s and about 2 s, respectively) and low power consumption(few nW), with no relevant response to water. Comparable responses' decay times under eithernitrogen or dry air suggest that the mechanisms at work is mainly attributable to specific analytesemiconductingpolymer interactions. These results open the way to the use of P3HT NFs-basedsensing elements for the realization of portable, real-time electronic noses for on-the-fly exhaledbreath analysis.

scholarly journals A Microfluidic Platform for in Situ Investigation of Biofilm Formation and Its Treatment Under Controlled Conditions

2020 ◽  
Author(s):  
Hervé Straub ◽  
Leo Eberl ◽  
Manfred Zinn ◽  
René M Rossi ◽  
Katharina Maniura-Weber ◽  
...  
Keyword(s):  
Single Cell ◽  
Real Time ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Rich Medium ◽  
Flow Conditions ◽  
Microfluidic Platform ◽  
Adhesion Rate

Abstract Background Studying bacterial adhesion and early biofilm development is crucial for understanding the physiology of sessile bacteria and forms the basis for the development of novel antimicrobial biomaterials. Microfluidics technologies can be applied in such studies since they permit dynamic real-time analysis and a more precise control of relevant parameters compared to traditional static and flow chamber assays. In this work, we aimed to establish a microfluidic platform that permits real-time observation of bacterial adhesion and biofilm formation under precisely controlled homogeneous laminar flow conditions. Results Using Escherichia coli as the model bacterial strain, a microfluidic platform was developed to overcome several limitations of conventional microfluidics such as the lack of spatial control over bacterial colonization and allow label-free observation of bacterial proliferation at single-cell resolution. This platform was applied to demonstrate the influence of culture media on bacterial colonization and the consequent eradication of sessile bacteria by antibiotic. As expected, the nutrient-poor medium was found to promote bacterial adhesion and to enable a higher adhesion rate compared to the nutrient-rich medium. However, in rich medium the adhered cells colonized the glass surface faster than those in poor medium under otherwise identical conditions. For the first time, this effect was demonstrated to be caused by a higher retention of newly generated bacteria in the rich medium, rather than faster growth especially during the initial adhesion phase. These results also indicate that higher adhesion rate does not necessarily lead to faster biofilm formation. Antibiotic treatment of sessile bacteria with colistin was further monitored by fluorescence microscopy at single-cell resolution, allowing in situ analysis of killing efficacy of antimicrobials.Conclusion The platform established here represents a powerful and versatile tool for studying environmental effects such as medium composition on bacterial adhesion and biofilm formation. Our microfluidic setup shows great potential for the in vitro assessment of new antimicrobials and antifouling agents under flow conditions.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

Flat Flexible Thin Milli-electrode Array for Real-time in situ Water Quality Monitoring in Distribution Systems

2017 ◽  
Vol 2017 (4) ◽  
pp. 5598-5617
Author(s):  
Zhiheng Xu ◽  
Wangchi Zhou ◽  
Qiuchen Dong ◽  
Yan Li ◽  
Dingyi Cai ◽  
...  
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Distribution Systems ◽  
Electrode Array ◽  
Water Quality Monitoring ◽  
Quality Monitoring
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