| 1. |
- Adler, Belinda, et al.
(författare)
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Porous silicon immunoaffinity microarrays
- 2018. - 2
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Ingår i: Handbook of Porous Silicon : Second Edition - Second Edition. - Cham : Springer International Publishing. - 9783319713793 - 9783319713816 ; 2-2, s. 1355-1367
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Bokkapitel (refereegranskat)abstract
- Porous silicon with immobilized recognition biomolecules is an attractive platform for many microfluidic chip-based bioanalytical applications. We review the progress in the field since its earliest developments in the 1990s. An improved assay for early detection of prostate cancer has reached clinical evaluation, but there are also exciting developments in both aptamer-based biosensing and mass spectrometry-based biosensing.
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| 2. |
- Antfolk, Maria, et al.
(författare)
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Acoustofluidic, label-free separation and simultaneous concentration of rare tumor cells from white blood cells
- 2015
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 87:18, s. 9322-9328
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Tidskriftsartikel (refereegranskat)abstract
- Enrichment of rare cells from peripheral blood has emerged as a means to enable noninvasive diagnostics and development of personalized drugs, commonly associated with a prerequisite to concentrate the enriched rare cell population prior to molecular analysis or culture. However, common concentration by centrifugation has important limitations when processing low cell numbers. Here, we report on an integrated acoustophoresis-based rare cell enrichment system combined with integrated concentration. Polystyrene 7 μm microparticles could be separated from 5 μm particles with a recovery of 99.3 ± 0.3% at a contamination of 0.1 ± 0.03%, with an overall 25.7 ± 1.7-fold concentration of the recovered 7 μm particles. At a flow rate of 100 μL/min, breast cancer cells (MCF7) spiked into red blood cell-lysed human blood were separated with an efficiency of 91.8 ± 1.0% with a contamination of 0.6 ± 0.1% from white blood cells with a 23.8 ± 1.3-fold concentration of cancer cells. The recovery of prostate cancer cells (DU145) spiked into whole blood was 84.1 ± 2.1% with 0.2 ± 0.04% contamination of white blood cells with a 9.6 ± 0.4-fold concentration of cancer cells. This simultaneous on-chip separation and concentration shows feasibility of future acoustofluidic systems for rapid label-free enrichment and molecular characterization of circulating tumor cells using peripheral venous blood in clinical practice.
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| 3. |
- Broman, Axel, et al.
(författare)
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Multinodal high throughput acoustic trapping of exosomes from urine samples
- 2019
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Ingår i: 23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2019. - 9781733419000 ; , s. 2-3
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Konferensbidrag (refereegranskat)abstract
- We report a new design of an acoustophoretic trapping device with greatly increased capacity and throughput, compared to current commercial systems. Acoustic trapping enables nanoparticle and exosome enrichment without the need for ultracentrifugation. The commercial acoustic trapping technology, AcouTrap (AcouSort AB), typically operates at flow rates < 50 μl/min which limits processing of larger samples. Using a larger capillary that supports an acoustic multi-node resonance, capacity and throughput was increased a factor 40 compared to AcouTrap. It was possible to capture and enrich exosomes from urine samples at 30 times higher flow rate than previously reported.
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| 4. |
- Bryl-Górecka, Paulina, et al.
(författare)
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Effect of exercise on the plasma vesicular proteome : A methodological study comparing acoustic trapping and centrifugation
- 2018
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0197 .- 1473-0189. ; 18:20, s. 3101-3111
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) are a heterogeneous group of actively released vesicles originating from a wide range of cell types. Characterization of these EVs and their proteomes in the human plasma provides a novel approach in clinical diagnostics, as they reflect physiological and pathological states. However, EV isolation is technically challenging with the current methods having several disadvantages, requiring large sample volumes, and resulting in loss of sample and EV integrity. Here, we use an alternative, non-contact method based on a microscale acoustic standing wave technology. Improved coupling of the acoustic resonator increased the EV recovery from 30% in earlier reports to 80%, also displaying long term stability between experiment days. We report a pilot study, with 20 subjects who underwent physical exercise. Plasma samples were obtained before and 1 h after the workout. Acoustic trapping was compared to a standard high-speed centrifugation protocol, and the method was validated by flow cytometry (FCM). To monitor the device stability, the pooled frozen plasma from volunteers was used as an internal control. A key finding from the FCM analysis was a decrease in CD62E+ (E-selectin) EVs 1 h after exercise that was consistent for both methods. Furthermore, we report the first data that analyse differential EV protein expression before and after physical exercise. Olink-based proteomic analysis showed 54 significantly changed proteins in the EV fraction in response to physical exercise, whereas the EV-free plasma proteome only displayed four differentially regulated proteins, thus underlining an important role of these vesicles in cellular communication, and their potential as plasma derived biomarkers. We conclude that acoustic trapping offers a fast and efficient method comparable with high-speed centrifugation protocols. Further, it has the advantage of using smaller sample volumes (12.5 μL) and rapid contact-free separation with higher yield, and can thus pave the way for future clinical EV-based diagnostics.
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| 5. |
- Core, Giulia, et al.
(författare)
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Method for selecting optimal operation frequencies in bulk acoustophoretic devices
- 2018
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Ingår i: 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018. - 9781510897571 ; 1, s. 282-284
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Konferensbidrag (refereegranskat)abstract
- We report a new method to select the optimal actuation frequencies in bulk acoustophoresis devices, by means of differential impedance spectrum analysis measured via the actuating piezoelectric transducer (piezo). The impedance spectra is rich of large spurious resonance peaks originating from bulk resonances not related to the channel resonance, Fig. 1a, why direct measurement of the piezo impedance spectra is not a viable strategy. We present here for the first time that the resonance modes of the acoustophoresis channel can be clearly identified by sequentially measuring the impedance spectra of the acoustophoresis manifold when the channel is filled with two different fluids and calculate the normalised differential impedance spectra.
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| 6. |
- Cushing, Kevin W., et al.
(författare)
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Ultrasound Characterization of Microbead and Cell Suspensions by Speed of Sound Measurements of Neutrally Buoyant Samples
- 2017
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 89:17, s. 8917-8923
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Tidskriftsartikel (refereegranskat)abstract
- We present an experimental method including error analysis for the measurement of the density and compressibility of cells and microbeads; these being the two central material properties in ultrasound-based acoustophoretic applications such as particle separation, trapping, and up-concentration. The density of the microparticles is determined by using a neutrally buoyant selection process that involves centrifuging of microparticles suspended in different density solutions, CsCl for microbeads and Percoll for cells. The speed of sound at 3 MHz in the neutrally buoyant suspensions is measured as a function of the microparticle volume fraction, and from this the compressibility of the microparticles is inferred. Finally, from the obtained compressibility and density, the acoustic scattering coefficients and contrast factor of the microparticles are determined, and in a sensitivity analysis, the impact of the measurement errors on the computed acoustic properties is reported. The determination of these parameters and their uncertainties allow for accurate predictions of the acoustophoretic response of the microparticles. The method is validated by determining the density (0.1-1% relative uncertainty) and compressibility (1-3% relative uncertainty) of previously well-characterized polymer microbeads and subsequently applied to determine the density (0.1-1% relative uncertainty), compressibility (1% relative uncertainty), scattering coefficients, and acoustic contrast factors for nonfixed and fixed cells, such as red blood cells, white blood cells, DU-145 prostate cancer cells, MCF-7 breast cancer cells, and LU-HNSCC-25 head and neck squamous carcinoma cells in phosphate buffered saline. The results show agreement with published data obtained by other methods.
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| 7. |
- Garofalo, Fabio, et al.
(författare)
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Statistic estimation of cell compressibility based on acoustophoretic separation data
- 2020
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Ingår i: Microfluidics and Nanofluidics. - : Springer Science and Business Media LLC. - 1613-4982 .- 1613-4990. ; 24:8
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Tidskriftsartikel (refereegranskat)abstract
- We present a new experimental method that measures the compressibility of phenotype-specific cell populations. This is done by performing statistical analysis of the cell counts from the outlets of an acoustophoresis chip as a function of the increasing actuator voltage (i.e. acoustic energy density) during acoustophoretic separation. The theoretical separation performance curve, henceforth, Side-Stream Recovery (SSR), vs the piezo-actuator voltage (V) is derived by moment analysis of a one-dimensional model of acoustophoresis separation, accounting for distributions of the cell or microparticle properties and the system parameters (hydrodynamics, radiation force, drag enhancement, and acoustic streaming). The acoustophoretic device is calibrated with polymer microbeads of known properties by fitting the experimental SSR with the theoretical SSR , in which the acoustic energy density is considered proportional to the squared voltage, i.e. Eac=αV2. The fitting parameter α for the calibration procedure is the device effectivity, reflecting the efficiency in performing acoustophoretic microparticle displacement. Once calibrated, the compressibility of unknown cells is estimated by fitting experimental SSR cell data points with the theoretical SSR curve. In this procedure, the microparticle compressibility is the fitting parameter. The method is applied to estimate the compressibility of a variety of cell populations showing its utility in terms of rapid analysis and need for minute sample amounts.
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| 8. |
- Jagadeesan, Kishore, et al.
(författare)
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Filter Plate–Based Screening of MIP SPE Materials for Capture of the Biomarker Pro-Gastrin-Releasing Peptide
- 2017
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Ingår i: SLAS Discovery. - : Sage Publications. - 2472-5560 .- 2472-5552. ; 22:10, s. 1253-1261
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Tidskriftsartikel (refereegranskat)abstract
- Affinity-based solid-phase extraction (SPE) is an attractive low-cost sample preparation strategy for biomarker analysis. Molecularly imprinted polymers (MIPs) as affinity sorbents offer unique opportunities for affinity SPE, due to their low manufacturing cost and high robustness. A limitation is the prediction of their affinity; therefore, screening of analyte recovery and specificity within a large range of SPE conditions is important in order to ensure high-sensitivity detection and assay reproducibility. Here, a µ-SPE method for screening of the MIP-SPE materials using a commercial 384-well filter plate is presented. The method allows for rapid and automated screening using 10?30 µL of packed SPE sorbent per well and sample volumes in the range of 10?70 µL. This enables screening of many different SPE sorbents while simultaneously identifying optimal SPE conditions. In addition, the 384-well format also facilitates detection with a multitude of analytical platforms. Performance of the µ-MIP-SP
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| 9. |
- Jakobsson, Ola, et al.
(författare)
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Acoustic actuated fluorescence activated sorting of microparticles.
- 2014
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0189. ; 14:11, s. 1943-1950
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a fluorescence activated sorter realized in a continuous flow microfluidic chip. Sorting is achieved by deflecting a focused particle stream with short acoustic bursts (2.5 ms), in a fluorescence activated configuration. The system utilizes two-dimensional acoustic pre-focusing, using a single actuation frequency, to position all particles in the same fluid velocity regime at flow rates up to 1.7 mL min(-1). Particles were sorted based on their fluorescence intensities at throughputs up to 150 particles s(-1). The highest purity reached was 80% when sorting at an average rate of 50 particles s(-1). The average recovery of a sort was 93.2 ± 2.6%. The presented system enables fluorescence activated cell sorting in a continuous flow microfluidic format that allows aseptic integration of downstream microfluidic functionalities, opening for medical and clinical applications.
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| 10. |
- Kim, Soo Hyeon, et al.
(författare)
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Highly efficient single cell arraying by integrating acoustophoretic cell pre-concentration and deialctrophoretic cell trapping
- 2015
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Ingår i: Lab on a Chip. - 1473-0189. ; 15:22, s. 4356-4363
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Tidskriftsartikel (refereegranskat)abstract
- To array rare cells at the single-cell level, the volumetric throughput may become a bottleneck in the cell trapping and the subsequent single-cell analysis, since the target cells per definition commonly exist in a large sample volume after purification from the original sample. Here, we present a novel approach for high throughput single cell arraying by integrating two original microfluidic devices: an acoustofluidic chip and an electroactive microwell array. The velocity of the cells is geared down in the acoustofluidic chip while maintaining a high volume flow rate at the inlet of the microsystem, and the cells are subsequently trapped one by one into the microwell array using dielectrophoresis. The integrated system exhibited a 10 times improved sample throughput compared to trapping with the electroactive microwell array chip alone, while maintaining a highly efficient cell recovery above 90%. The results indicate that the serial integration of the acoustophoretic pre-concentration with the dielectrophoretic cell trapping drastically improves the performance of the electroactive microwell array for highly efficient single cell analysis. This simple and effective system for high throughput single cell arraying with further possible integration of additional functions, including cell sorting and downstream analysis after cell trapping, has potential for development to a highly integrated and automated platform for single-cell analysis of rare cells.
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