Efficient Removal of Platelets from Peripheral Blood Progenitor Cell Products Using a Novel Micro-Chip Based Acoustophoretic Platform

Excessive collection of platelets is an unwanted side effect in current centrifugation-based peripheral blood progenitor cell (PBPC) apheresis. We investigated a novel microchip-based acoustophoresis technique, utilizing ultrasonic standing wave forces for the removal of platelets from PBPC products. By applying an acoustic standing wave field onto a continuously flowing cell suspension in a micro channel, cells can be separated from the surrounding media depending on their physical properties

Computer-aided recording of automatic endoscope washing and disinfection processes as an integral part of medical documentation for quality assurance purposes

<p>Abstract</p> <p>Background</p> <p>The reprocessing of medical endoscopes is carried out using automatic cleaning and disinfection machines. The documentation and archiving of records of properly conducted reprocessing procedures is the last and increasingly important part of the reprocessing cycle for flexible endoscopes.</p> <p>Methods</p> <p>This report describes a new computer program designed to monitor and document the automatic reprocessing of flexible endoscopes and accessories in fully automatic washer-disinfectors; it does not contain nor compensate the manual cleaning step. The program implements national standards for the monitoring of hygiene in flexible endoscopes and the guidelines for the reprocessing of medical products. No FDA approval has been obtained up to now. The advantages of this newly developed computer program are firstly that it simplifies the documentation procedures of medical endoscopes and that it could be used universally with any washer-disinfector and that it is independent of the various interfaces and software products provided by the individual suppliers of washer-disinfectors.</p> <p>Results</p> <p>The computer program presented here has been tested on a total of four washer-disinfectors in more than 6000 medical examinations within 9 months.</p> <p>Conclusions</p> <p>We present for the first time an electronic documentation system for automated washer-disinfectors for medical devices e.g. flexible endoscopes which can be used on any washer-disinfectors that documents the procedures involved in the automatic cleaning process and can be easily connected to most hospital documentation systems.</p

High performance multiplex acoustophoresis for WBC subpopulation isolation

Recently, acoustophoresis has been used to fractionate white blood cells (WBC) into subpopulations, Grenvall et al. [1]. However, at a sample throughput of 8-10 μl/min the separation has limited bioanalytical application. In order to substantially increase throughput, we have redesigned and developed a new separation system that enables unmatched WBC separation performance at a volume throughput of 200μl/min and a cell concentration of 106 cells/ml

Label-free acoustophoretic enrichment of mononuclear cells from blood

We are reporting an efficient, label-free and continuous separation of mononuclear cells (MNC), from blood using microchip acoustophoresis. In standard PBS buffer, MNCs and red blood cells (RBC) display overlapping acoustophoretic mobilities which compromise separation of these cell types from each other. In this paper we capitalize on the fact that MNC and RBC display different acoustophysical properties. By optimizing the buffer conditions and thereby changing the acoustic contrast factor, and hence the acoustophoretic mobility of the cells, a 2800-fold enrichment of MNCs vs. RBCs with MNC recoveries up to 88% was accomplished

Label-free separation of leukocyte subpopulations using high throughput multiplex acoustophoresis

Multiplex separation of mixed cell samples is required in a variety of clinical and research applications. Herein, we present an acoustic microchip with multiple outlets and integrated pre-alignment channel to enable high performance and label-free separation of three different cell or particle fractions simultaneously at high sample throughput. By implementing a new cooling system for rigorous temperature control and minimal acoustic energy losses, we were able to operate the system isothermally and sort suspensions of 3, 5 and 7 μm beads with high efficiencies (>95.4%) and purities (>96.3%) at flow rates up to 500 μL min -1 corresponding to a throughput of ∼2.5 × 10 6 beads per min. Also, human viable white blood cells were successfully fractionated into lymphocytes, monocytes and granulocytes with high purities of 96.5 ± 1.6%, 71.8 ± 10.1% and 98.8 ± 0.5%, respectively, as well as high efficiencies (96.8 ± 3.3%, 66.7 ± 3.2% and 99.0 ± 0.7%) at flow rates up to 100 μL min -1 (∼100000 cells per min). By increasing the flow rate up to 300 μL min -1 (∼300000 cells per min) both lymphocytes and granulocytes were still recovered with high purities (92.8 ± 1.9%, 98.2 ± 1.0%), whereas the monocyte purity decreased to 20.9 ± 10.3%. The proposed isothermal multiplex acoustophoresis platform offers efficient fractionation of complex samples in a label-free and continuous manner at thus far unreached high sample throughput rates

Affinity-Bead-Mediated Enrichment of CD8+ Lymphocytes from Peripheral Blood Progenitor Cell Products Using Acoustophoresis

Acoustophoresis is a technique that applies ultrasonic standing wave forces in a microchannel to sort cells depending on their physical properties in relation to the surrounding media. Cell handling and separation for research and clinical applications aims to efficiently separate specific cell populations. Here, we investigated the sorting of CD8 lymphocytes from peripheral blood progenitor cell (PBPC) products by affinity-bead-mediated acoustophoresis. PBPC samples were obtained from healthy donors (n = 4) and patients (n = 18). Mononuclear cells were labeled with anti-CD8-coated magnetic beads and sorted on an acoustophoretic microfluidic device and by standard magnetic cell sorting as a reference method. CD8 lymphocytes were acoustically sorted with a mean purity of 91% ± 8% and a median separation efficiency of 63% (range 15.1%–90.5%) as compared to magnetic sorting (purity 91% ± 14%, recovery 29% (range 5.1%–47.3%)). The viability as well as the proliferation capacity of sorted lymphocytes in the target fraction were unimpaired and, furthermore, hematopoietic progenitor cell assay revealed a preserved clonogenic capacity post-sorting. Bead-mediated acoustophoresis can, therefore, be utilized to efficiently sort less frequent CD8+ lymphocytes from PBPC products in a continuous flow mode while maintaining cell viability and functional capacity of both target and non-target fractions

Rapid and effective enrichment of mononuclear cells from blood using acoustophoresis

Effective separation methods for fractionating blood components are needed for numerous diagnostic and research applications. This paper presents the use of acoustophoresis, an ultrasound based microfluidic separation technology, for label-free, gentle and continuous separation of mononuclear cells (MNCs) from diluted whole blood. Red blood cells (RBCs) and MNCs behave similar in an acoustic standing wave field, compromising acoustic separation of MNC from RBC in standard buffer systems. However, by optimizing the buffer conditions and thereby changing the acoustophoretic mobility of the cells, we were able to enrich MNCs relative to RBCs by a factor of 2,800 with MNC recoveries up to 88%. The acoustophoretic microchip can perform cell separation at a processing rate of more than 1 × 105 cells/s, corresponding to 5 μl/min undiluted whole blood equivalent. Thus, acoustophoresis can be easily integrated with further down-stream applications such as flow cytometry, making it a superior alternative to existing MNC isolation techniques

Efficient Purification of CD4+ Lymphocytes from Peripheral Blood Progenitor Cell Products Using Affinity Bead Acoustophoresis

Processing of peripheral blood progenitor cells (PBPC) for clinical transplantation or research applications aims to effectively isolate or deplete specific cell populations, utilizing primarily magnetic or fluorescence activated sorting methods. Here, we investigated the performance of microfluidic acoustophoresis for the separation of lymphocyte subsets from PBPC, and present a novel method for affinity-bead-mediated acoustic separation of cells which can otherwise not be acoustically discriminated. As the acoustic force on a particle depends on particle size, density and compressibility, targeting of cells by affinity specific beads will generate cell-bead complexes that exhibit distinct acoustic properties relative to nontargeted cells and are, thus, possible to isolate. To demonstrate this, PBPC samples (n = 22) were obtained from patients and healthy donors. Following density gradient centrifugation, cells were labeled with anti-CD4-coated magnetic beads (Dynal) and isolated by acoustophoresis and, for comparison, standard magnetic cell sorting technique in parallel. Targeted CD4+ lymphocytes were acoustically isolated with a mean (±SD) purity of 87 ± 12%, compared with 96 ± 3% for control magnetic sorting. Viability of sorted cells was 95 ± 4% (acoustic) and 97 ± 3% (magnetic), respectively. The mean acoustic separation efficiency of CD4+ lymphocytes to the target fraction was 65 ± 22%, compared with a mean CD4+ lymphocyte recovery of 56 ± 15% for magnetic sorting. Functional testing of targeted CD4+ lymphocytes demonstrated unimpaired mitogen-mediated proliferation capacity and cytokine production. Hematopoietic progenitor cell assays revealed a preserved colony forming ability of nontarget cells post sorting. We conclude that the acoustophoresis platform can be utilized to efficiently isolate bead-labeled CD4+ lymphocytes from PBPC samples in a continuous flow format, with preserved functional capacity of both target and nontarget cells. These results open up for simultaneous affinity-bead-mediated separation of multiple cell populations, something which is not possible with current standard magnetic cell separation technolog