| 1. |
- Iseri, Emre, 1990-, et al.
(författare)
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A Digital Dipstick for Multiplexed Bacteria Detection
- 2021
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Ingår i: The 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS 2021), 10-14 October 2021, Palm Springs, USA, and hybrid online. ; , s. 805-806
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Konferensbidrag (refereegranskat)abstract
- In this study, we demonstrate a digital bacterial detection assay in a dipstick format that can identify and quantitate Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis, i.e., three of the most common (>90%) bacteria causing urinary tract infections (UTIs). The operation involves nothing more than dipping the stick in urine for a few seconds and let the stick incubate for 10-12 h before read-out. Each of the 180 miniaturised culture wells in the stick contain chromogenic agar and change colour if they contain a CFU. The colour of the wells identifies the presence of a specific type of bacteria; the number of coloured wells indicates the concentration. This format allows detection and quantification at a potentially low cost and without the need for complicated external equipment or technical skills.
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| 2. |
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| 3. |
- Iseri, Emre, et al.
(författare)
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Detection of E.coli in a digital assay
- 2018
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Ingår i: 2018 IEEE Micro Electro Mechanical Systems (MEMS). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538647820 ; , s. 301-303
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Konferensbidrag (refereegranskat)abstract
- In this paper, we demonstrate the dipstick-based digitisation and detection of bacterial sample of concentration down to 103 CFU/ml. The significance of this work is that we are able to detect concentrations of bacteria relevant for urinary tract infection (UTI) with minimal handling time and without the need for complicated external equipment.
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| 4. |
- Iseri, Emre, et al.
(författare)
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Digital dipstick: miniaturized bacteria detection and digital quantification for the point-of-care
- 2020
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0197 .- 1473-0189. ; 20:23, s. 4349-4356
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Tidskriftsartikel (refereegranskat)abstract
- Established digital bioassay formats, digital PCR and digital ELISA, show extreme limits of detection, absolute quantification and high multiplexing capabilities. However, they often require complex instrumentation, and extensive off-chip sample preparation. In this study, we present a dipstick-format digital biosensor (digital dipstick) that detects bacteria directly from the sample liquid with a minimal number of steps: dip, culture, and count. We demonstrate the quantitative detection of Escherichia coli (E. coli) in urine in the clinically relevant range of 102 –105 CFU ml−1 for urinary tract infections. Our format shows 89% sensitivity to detect E. coli in clinical urine samples (n = 28) when it is compared to plate culturing (gold standard). The significance and uniqueness of this diagnostic test format is that it allows a non-trained operator to detect urinary tract infections in the clinically relevant range in the home setting.
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| 5. |
- Iseri, Emre
(författare)
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Microfluidic Compartmentalization for Smart Materials, Medical Diagnostics and Cell Therapy
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The organisation of fluids in small compartments is ubiquitous in nature, such as in the cellular composition of all life. This work explores several engineering avenues where microscale fluid compartmentalization can bring novel material properties or novel functionality in life sciences or medicine. Here, we introduce four unique compartmentalization methods: 1) 3D fluid self-organisation in microscaffolds (FLUID3EAMS), 2) 2D microcapillary arrays on a dipstick (Digital Dipstick), 3) a sliding microfluidic platform with cross-flow (Slip-X-Chip), and 4) compartmentalization by cutting of soft solid matter (Solidify & Cut). These methods were used in a wide range of applications. Within the area of smart materials, we applied FLUID3EAMS to synthesize materials with temperature-tuneable permeability and surface energy and to establish, in a well-controlled fashion, tissue-like materials in the form of 3D droplet interface bilayer networks. Solidify & Cut was used to form soft composites with a new type of magnetic behaviour, rotation-induced ferromagnetism, that allows easy reprogramming of the magnetization of magnetopolymers. Within the area of medical diagnostics, we applied Digital Dipstick to perform rapid digital bacterial culture in a dipstick format and obtained clinically relevant diagnostic results on samples from patients with a urinary tract infection. Furthermore, Slip-X-Chip enables particle concentration and washing as new functions in sliding microfluidic platforms, which significantly expands their potential application area. Finally, within the area of cell therapy, we explored the microencapsulation of high concentrations of therapeutic cells and presented a novel technique to fabricate core-shell microcapsules by exploiting the superior material properties of spider silk membranes.
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| 6. |
- Iseri, Emre, PhD, et al.
(författare)
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Performance of an innovative culture-based digital dipstick for detection of bacteriuria
- 2023
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Ingår i: Microbiology Spectrum. - : American Society for Microbiology. - 2165-0497.
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Tidskriftsartikel (refereegranskat)abstract
- UTI-lizer is a recent digital format for easy-to-use culture-based detection, preliminary identification, and quantification of bacteria in urine at the point of care (PoC). This study aimed to evaluate the diagnostic accuracy of UTI-lizer tests for detection of bacteriuria caused by five common bacterial species: Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Proteus mirabilis, and Staphylococcus saprophyticus. We evaluated the accuracy of UTI-lizer tests by comparing test results of UTI-lizer with those of current standard bacterial culture-based diagnostics in clinical microbiology laboratories in a retrospective and a prospective study. Comparator methods were classical bacterial culture in combination with matrix-assisted laser desorption/ionization-time of flight mass spectrometry mediated bacterial identification. In the retrospective study, we tested 104 urine samples with in-panel microorganisms, plain urethral microbiota, and culture-negative samples. In the prospective study, we used 137 urine samples within 10 hours of their collection at general practitioner clinics. The retrospective study demonstrated 100% sensitivity and specificity in the detection of bacteriuria, and 98.6% sensitivity and 96.8% specificity in identifying primary pathogens with UTI-lizer when compared to clinical standards. S. saprophyticus and E. coli could not be distinguished. The combined nitrite and esterase test predicted the presence of bacteriuria in only 36.5% of cases. The prospective study demonstrated 100% sensitivity and 89.6% specificity in the detection of significant bacteriuria for in-panel microorganisms with a coverage rate of 88.3% (121/137). This study indicates that digital dipsticks are a promising alternative for the detection of the five main pathogens that cause the vast majority of urinary tract infections (UTIs). The results demonstrate that digital dipsticks have the potential to uniquely provide—in primary care or at the point of care—a UTI diagnostic quality on par with that of current gold-standard testing. The ease of testing, rapid test handling time, and time to result as well as simple test equipment make digital dipsticks an attractive solution for decentralized testing for bacteriuria and with that improvement in UTI diagnostics. These results motivate future studies to validate the use of UTI-lizer at the PoC setting.
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| 7. |
- Iseri, Emre, et al.
(författare)
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Slip-X-Chip: A sliding microfluidic platform with cross-flow
- 2022
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Ingår i: 2022 IEEE 35th International Conference on Micro Electro Mechanical Systems Conference (MEMS). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 912-914
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Konferensbidrag (refereegranskat)abstract
- In sliding microfluidic platforms (“SlipChip” [1]), two plates with microfluidic wells slide in close contact to perform multiplexed reactions in a single operation. In- plane “sliding-flow” liquid transport, however, limits the potential assay operations to 1) sample compartmentalization/metering, 2) reagent addition, 3) mixing, and 4) aliquoting. Here, we introduce a three-plate sliding microfluidics platform, “Slip-X-Chip”, that additionally includes out-of-plane “cross-flow” liquid transport. Slip-X-Chip allows two additional assay operations: 5) sample concentration and 6) liquid exchange/washing, while retaining the simplicity of operation (one-step operation; no precise pipetting required; no external equipment). These additional assay operations extend the range and complexity of applications enabled by sliding microfluidics. We here demonstrate 1) splitting bead solutions in compartments with different concentrations and 2) compartmentalizing human cells from solution, followed by a viability assay. We foresee that Slip-X-Chip could be further adapted to, e.g., cell counting, cell staining, or ELISA.
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| 8. |
- Iseri, Emre, et al.
(författare)
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Tuneable Microparticle Filters
- 2019
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Ingår i: 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS). - : IEEE. ; , s. 290-291
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Konferensbidrag (refereegranskat)abstract
- We introduce microparticle filters with temperature tuneable size cut-off and surface energy. At room temperature, the filter cut-off is 164 ±23 μm, and the filter is water-absorbing/oil-repelling (hydrophilic). At 50 °C, the filter cut-off is 695±31 μm, and the filter is oil-absorbing/water-repelling (hydrophobic).
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| 9. |
- Kaya, Kerem, et al.
(författare)
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Programmable Matter with Free and High-Resolution Transfiguration and Locomotion
- 2024
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 34:14
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Tidskriftsartikel (refereegranskat)abstract
- “Hot flow in the coldchanges shape in a dead worldcomes matter to life”Programmable matter that allows free shape transfiguration and locomotionon command promises ubiquitous access to objects or functions of interest.Current approaches for the autonomous reshaping of solid objects (smartmaterials, soft actuators, modular robotics) are limited in spatial resolution andshape. Solid-liquid phase change pumping as a mechanism for the contactlesstransfiguring and locomotion of solid objects is introduced. Thin objects aredeformed into any intended shape with sub-millimeter resolution and the abilityto freely change their topology is demonstrated, including adding or removingholes, splitting and merging. The unique locomotion of objects throughmillimeter-sized constrictions narrower than their body size is demonstrated,followed by restoring the original shape. This approach opens up avenues fordeveloping autonomous programmable matter with free shape transfiguration.
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