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Centrifugal separation is a highly efficient technique for accelerating the sedimentation of blood constituents in a cylindrical container through highspeed spin-up rotation. Few studies have reported on the separation of different blood constituents from homogeneous mixture of whole blood. In this study, the process through which blood constituent sedimentation occurs in a spin-up rotating cylindrical container is numerically investigated. Whole blood is considered a homogeneous mixture of red blood cells (RBC) and plasma, which are both considered incompressible viscous liquids. The Euler multi-fluid VOF (volume of fluid) model is introduced to simulate the separation of RBCs and plasma. The effects of the rotation speed and the geometric construction of the cylindrical container on the sedimentation and stratification of different blood constituents are studied. A stable interface between the RBC layer and plasma layer forms earlier in a high position. With an increase in the rotation speed, the interface between the RBCs and plasma layers forms more quickly. In the cylindrical container with a helical groove on the outer wall, a stable vortex occurs near the groove, which forces red blood cells to move toward the lower location of the groove, resulting in a conical distribution of the RBC layer and a larger volume fraction of plasma near the exit at the top. This allows for sufficient precipitation of the plasma, improving the separation efficiency. [ABSTRACT FROM AUTHOR]

Centrifugal separation is a highly efficient technique for accelerating the sedimentation of blood constituents in a cylindrical container through high-speed spin-up rotation. Few studies have reported on the separation of different blood constituents from homogeneous mixture of whole blood. In this study, the process through which blood constituent sedimentation occurs in a spin-up rotating cylindrical container is numerically investigated. Whole blood is considered a homogeneous mixture of red blood cells (RBC) and plasma, which are both considered incompressible viscous liquids. The Euler multi-fluid VOF (volume of fluid) model is introduced to simulate the separation of RBCs and plasma. The effects of the rotation speed and the geometric construction of the cylindrical container on the sedimentation and stratification of different blood constituents are studied. A stable interface between the RBC layer and plasma layer forms earlier in a high position. With an increase in the rotation speed, the interface between the RBCs and plasma layers forms more quickly. In the cylindrical container with a helical groove on the outer wall, a stable vortex occurs near the groove, which forces red blood cells to move toward the lower location of the groove, resulting in a conical distribution of the RBC layer and a larger volume fraction of plasma near the exit at the top. This allows for sufficient precipitation of the plasma, improving the separation efficiency.

Microplastics have emerged as ubiquitous contaminants, attracting increasing global attention. Recent evidence confirms the presence of microplastics in human blood, suggesting their potential to interact with cells and induce adverse physiological reactions in various organs as blood circulates. To quantify the distribution of microplastics and assess their potential effects on human health, the effective separation of microplastics from blood is crucial. However, current methods for separating microplastics from blood are limited in effectiveness and simplicity. This study proposes a microfluidic device that utilizes traveling surface acoustic waves to separate microplastics from blood. While traveling surface acoustic waves have been employed to separate various particles, a systematic study on the separation of microplastics from blood samples has not been previously reported. Specifically, the theoretical values of the acoustic radiation factor for various types of microplastics and blood cells were investigated. The significant differences in resonant frequencies indicated the feasibility of separating microplastics of different sizes and types from blood cells. Experimental validation was performed using a polydimethylsiloxane microfluidic device on a piezoelectric lithium niobate substrate. The device successfully separated 5- and 10-micrometer polystyrene microplastics from blood samples. The effects of power and flow rate on separation efficiency were also systematically investigated. This study provides a novel approach for the effective separation of microplastics from blood, contributing to the assessment of their distribution and potential health impacts.

Microplastics have emerged as ubiquitous contaminants, attracting increasing global attention. Recent evidence confirms the presence of microplastics in human blood, suggesting their potential to interact with cells and induce adverse physiological reactions in various organs as blood circulates. To quantify the distribution of microplastics and assess their potential effects on human health, the effective separation of microplastics from blood is crucial. However, current methods for separating microplastics from blood are limited in effectiveness and simplicity. This study proposes a microfluidic device that utilizes traveling surface acoustic waves to separate microplastics from blood. While traveling surface acoustic waves have been employed to separate various particles, a systematic study on the separation of microplastics from blood samples has not been previously reported. Specifically, the theoretical values of the acoustic radiation factor for various types of microplastics and blood cells were investigated. The significant differences in resonant frequencies indicated the feasibility of separating microplastics of different sizes and types from blood cells. Experimental validation was performed using a polydimethylsiloxane microfluidic device on a piezoelectric lithium niobate substrate. The device successfully separated 5- and 10-micrometer polystyrene microplastics from blood samples. The effects of power and flow rate on separation efficiency were also systematically investigated. This study provides a novel approach for the effective separation of microplastics from blood, contributing to the assessment of their distribution and potential health impacts. [ABSTRACT FROM AUTHOR]

The separation of bio-suspensions, such as blood, is of great interest for many biomedical applications, such as the extraction of leucocytes from whole blood, the laboratory analysis of specific cells or a mixed cell suspensions from bioreactors or the preparation of cellular products for cellbased therapy. In particular, mechanical separation processes have been established for the rapid separation of biosuspensions. The principle of mechanical separation is based on the specific density of the particles or the particle size. Thus, the corresponding processes are based on centrifugation and/or filtration. The standard process to prepare blood products from whole blood donations contains several steps. First the blood is separated into different phases by centrifugation and then further separated by filters containing specific filtration layers. The shortcomings of this process is the low yield due to bio-particles remaining in the filter and the high costs for equipment due to the use of multiple devices for centrifugation and filtration. Here we present the proof of principle of an adaptive, size-selective filter that addresses the above mentioned shortcomings. The filter is designed to combine the filtration and centrifugation process within one step. Therefore a novel filtration device was designed that can be used within a standard centrifugation tube. During centrifugation, the centrifugal force changes the filtration coefficient of the filter. This can be used to separate different sized of bio-particles at different centrifugation speeds. Moreover, the cells that were hold back in the filter can be removed afterwards by increasing the centrifugation speed. In this way, the filter is created to gradually release cells of a specific size yielding in a high purity of different cell fractions.

In this paper, we report a point-of-care (POCT) testing strip based on a porous membrane structure for whole blood separation and colorimetric analysis without external supporting equipment. Conventional blood tests rely on large instruments for blood pretreatment and separation to improve measurement accuracy. Cellulose acetate (CA) membranes with different pore diameters and structures were prepared via a non-solvent method for the separation of whole blood. Among them, CA@PEG-2000 membranes with nano-pores on the surface and micro-pores in the interior facilitated the capture of blood cells on the surface, as well as the free diffusion of plasma through the porous interior structure. The fluid flow of blood in the asymmetric porous structure can be theoretically estimated using the Lucas-Washburn equation. Compared with the conventional paper strips and other porous membranes, the CA@PEG-2000 membrane with an immobilized sensing layer exhibited efficient blood separation, a short response time (less than 2 min), an ultralow dosage volume (5 μL), and high sensitivity. The fabricated blood separation membranes can be further used for the detection of various biomarkers in whole blood, providing additional options for rapid quantitative POCT tests. [ABSTRACT FROM AUTHOR]

In recent years, viscoelastic particle manipulation within microfluidic systems has received much attention due to the ease with which micron-sized objects may be maneuvered and isolated on the basis of size. While several factors, including both fluid and particle properties, regulate the precise locations and trajectories of micron-sized species flowing along a microchannel, the role of channel cross-section shape is critical, since it directly influences the fluid velocity profile and thus the direction and magnitude of hydrodynamic forces. It is therefore surprising that this parameter has not been comprehensively investigated for cell-based separations, especially since most viscoelastic microfluidic systems are only able to efficiently sperate cells over limited size ranges. To address this shortcoming, we present a viscoelastic microfluidic system integrating a triangular cross-section microchannel, for efficient and tunable size-based separations of micron-sized species. We find that particle focusing patterns can be controlled by simple variation of volumetric flow rates, which allows for the efficient separation of particles and cells of variable size. To showcase the efficacy of the approach, we present a size-based separation of various blood components, including white blood cells, platelets, and rare cells. By quantifying the number of particles collected at the outlets, we achieve recovery efficiencies of over 98%. • Viscoelastic particle manipulation is used to separate micron-sized particles. • A triangular cross-section microfluidic channel design is used for particle separation. • Passive separation of different blood components at low blood dilutions. • Size-selective separation of blood components via tunable viscoelastic focusing. [ABSTRACT FROM AUTHOR]

In this article, we introduce the importance of blood processing for human consumption while also presenting the methodology of porcine blood membrane separation to plasma and red blood cell fractions, as well as the membrane purification after porcine blood separation. Basic analytical measurements were carried out to investigate the blood product attributes, which relate to technological and nutritional quality depending on the separation parameters. Next, we present how the relevant hydrodynamical parameters were calculated during the experiments. Membrane separation was realized by crossflow microfiltration with pore size of 0.8 μm or 1.2 μm, retentate flow rate of 200 l·h-1 or 300 l·h-1 and with transmembrane pressure of 1 x 105 Pa, 2 x 105 Pa or 3 x 105 Pa. The experimental design was analysed, the parameters of the objective function and effect sizes were estimated and the global minimum of the objective function was successfully identified. The results of this optimization can be applied in practice. The membrane separation parameters were then optimized according to a model based on the observed data. An optimum was detected within the examined factor levels and experimental conditions at the lowest transmembrane pressure and at the highest membrane pore size. [ABSTRACT FROM AUTHOR]

Objectives: Our objectives were to determine the separation characteristics and blood product quality of a gravity‐driven microfiltration blood separation system (HemoClear, The Netherlands). Background: A range of centrifugal blood separation devices, including intraoperative cell salvage devices (cell savers) and apheresis machines, are available to assist in preparing both allogenic and autologous blood products. These devices are expensive to operate and require extensive training. Methods and Materials: Nine whole blood units were collected under standard conditions and analysed for haematological parameters, thromboelastographic properties, platelet morphology and activation, and red blood cell (RBC) deformability and morphology. Three whole blood units were separated by means of the HemoClear device, into a liquid and cellular component. The cellular component was diluted with SAGM and cold stored for 14 days. To simulate cell salvage six whole blood units were diluted with isotonic saline, followed by multiple HemoClear separation rounds. Results: The recovery of both RBCs (100 ± 1.6%) and white blood cells (99 ± 4.5%) after undiluted filtration were very high, while platelet recovery was high (83 ± 3.0%). During the filtration, and cold storage after filtration storage both the non‐deformable RBC fraction and the RBC maximum elongation remained stable. Parameters of thromboelastography indicated that platelets remain functional after filtration and after 7 days of cold storage. In the cell salvage simulation the total protein load in the cellular fraction was reduced by 65 ± 4.1% after one washing round and 84 ± 1.9% after two consecutive washing rounds. Conclusion: The novel blood filter studied effectively separates whole blood into diluted plasma and platelet‐rich RBCs. Moreover, the device effectively washed diluted whole blood, driving over 80% of proteins to the liquid component. [ABSTRACT FROM AUTHOR]

In this paper, we report a point-of-care (POCT) testing strip based on a porous membrane structure for whole blood separation and colorimetric analysis without external supporting equipment. Conventional blood tests rely on large instruments for blood pretreatment and separation to improve measurement accuracy. Cellulose acetate (CA) membranes with different pore diameters and structures were prepared via a non-solvent method for the separation of whole blood. Among them, CA@PEG-2000 membranes with nano-pores on the surface and micro-pores in the interior facilitated the capture of blood cells on the surface, as well as the free diffusion of plasma through the porous interior structure. The fluid flow of blood in the asymmetric porous structure can be theoretically estimated using the Lucas-Washburn equation. Compared with the conventional paper strips and other porous membranes, the CA@PEG-2000 membrane with an immobilized sensing layer exhibited efficient blood separation, a short response time (less than 2 min), an ultralow dosage volume (5 μL), and high sensitivity. The fabricated blood separation membranes can be further used for the detection of various biomarkers in whole blood, providing additional options for rapid quantitative POCT tests.

Excellent detection capability, a simple assay procedure, and easy device acquisition are three key factors to analyze biomarkers for disease diagnosis using a point-of-care device in resource-limited settings or in emergency situations. However, constructing a platform with the simultaneous presence of these factors to sense multiple biomarkers remains a challenge. In the spirit of "frugal science", a simple method is developed by combining a low-cost portable paper centrifuge with surface-enhanced Raman scattering (SERS) immunoassay for sample pretreatment and multiple-cytokine (IL-6, IL-1, and TNF-α) detection. The paper centrifuge can achieve rapid blood separation as a commercial centrifuge and also concentrate sandwich immune composites to generate abundant hot spots, thus enhancing the SERS signal. By analyzing three prospective cytokines (IL-6, IL-1, and TNF-α) closely related to tumors, the combined paper centrifugation–SERS immunoassay method realizes sensitive assays with detection limits down to 0.86, 0.42 and 0.22 pg/mL. Meanwhile, the proposed approach possesses capabilities of specific recognition and accurate quantitative detection for three cytokines in serum. Hence, the constructed multifunctional SERS platform is expected to be applied in the development of decentralized and battery-free diagnostic devices in facility-limited areas and field settings. [Display omitted] • A combined paper centrifugation–SERS immunoassay method is developed. • Paper centrifuge can achieve rapid blood separation as a commercial centrifuge. • Sensitive, quantitative, and specific detection for three cytokines are realized. [ABSTRACT FROM AUTHOR]

This preliminary study aims to understand the mechanism of haemolysis in the process of blood separation in porous membranes in a confined scope. Two typical membranes (polysulfone and glass fibre membranes) were chosen as the representatives for the two different (vertical and lateral) blood separation directions. The wall shear stress (WSS) applied on the RBCs and the effects of the morphology of the pores in the membranes on the integrity of RBCs, were investigated to find the main reason for inducing the release of intracellular components into the plasma occurring as haemolysis. With the evaluation of WSS in the two membranes, it has been found that the impact of WSS is insufficient as a single factor causing haemolysis. Based on the morphology of the internal structures of the two porous membranes characterised by SEM imaging combined with the quantitative analysis on the number of sharp ends in the membranes, it has been shown that haemolysis is mainly caused by the puncture on the RBCs because of the sharp ends of the fibrous structure in the membranes. The membranes having more sharp ends show a higher level of haemolysis. The haemolysis during blood separation has been characterised using UV–vis spectrophotometry. • Sharp ends of fibres in membranes cause haemolysis during blood plasma separation. • Wall shear stress during blood separation using membrane does not cause haemolysis. • Blood flow models are established to estimate wall shear stress in membrane. [ABSTRACT FROM AUTHOR]

In this paper, a microfluidic chip inspired by fish gills has been designed and fabricated in order to separate blood cells from serum. This microchip is modeled after fish gills which filter particles from fluids. In this way, the blood passes through a reservoir that contains several parallel rows of filter columns, which perform the filtering action. COMSOL Multiphysics software was used to conduct several simulations to optimize the pressure and velocity parameters of blood entering the microchip, and these parameters were used to determine the appropriate dimensions of the microchip. The simulation results indicate that the microchip is able to completely separate the cells from the serum, assuming a blood flow rate of 134 μl/s. With the help of the proposed filter, blood cells are separated from the plasma after 20 s and the aggregation occurs in the outlet reservoirs. In order to fabricate the microchip, the filter component made of polydimethylsiloxane (PDMS) was bonded to the copper substrate. In this paper a new copper to PDMS bonding process is proposed. Copper was chosen as the substrate because it allows the application of voltage to separate particles through the Dielectrophoresis method. The chemical etching method reinforced with noble metals was used to create micro holes on the silicon wafer, which are used to mold PDMS filters with a diameter of several micrometers. The main reservoir with a depth of 20 µm was created by the wet etching method. The reservoir was coated with silane coating and the oxygen plasma was utilized to bond the PDMS filters and the main reservoir. The copper substrate allows the microchip to be used with other electronic devices and circuits on printed circuit boards. Scanning Electron Microscopy (SEM) was used to observe the silane-coated copper surface, the micro holes on the silicon wafer, and the PDMS pillars. The topography and roughness of the copper surface before and after silane coating was evaluated through Atomic Force Microscopy (AFM). Optical Microscopy (OM) was utilized to observe the separation of the cells from the plasma. The results showed acceptable adhesion between copper and PDMS and good results for serum separation from blood cells. [Display omitted] • Design and simulation of Microfluidic Chip inspiring fish gill geometry. • Ag Assisted Chemical Etching of Si for fabrication of mold of PDMS micro pillars. • Proposing Silane intermediate layer to bond PDMS and copper. • Proposing a process for implementation of microfluidic chips with electronics, all in one. [ABSTRACT FROM AUTHOR]

Objective: To investigate the evolution of blood separation results by gel extraction of multiple myeloma (MM) patients, and to evaluate the clinical value of abnormal blood separation results for the evaluation of disease and prognosis., Methods: The clinical data of 5 patients diagnosed newly MM patients with abnormal blood separation of gel collection vessels in our hospital were retrospectively analyzed, and the changes of blood separation results and blood index levels were followed up with the improvement of treatment effect, and the correlation of different blood index levels was analyzed., Results: In 5 patients with newly diagnosed MM, the blood separation result showed floating phenomenon after centrifugation, which divided into three layers and the order from top to bottom is separator gel, serum, and red blood cells(RBC). With partial remission of clinical symptoms, the blood separation results were still abnormal, which were divided into three layers from top to bottom: serum, RBC and separator gel. Finally, with complete remission of the disease, blood separation results returned to normal, from top to bottom: serum, separator gel, RBC. With the blood separation results from abnormal to normal, the blood routine indicators: Hb, Hct levels gradually increased, neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR) gradually decreased; biochemical indexes: TP, GLB, Ig and β 2 -MG levels gradually decreased. Tumor load related indicators: serum IL-6, TNF-α, IL-17 levels gradually decreased, and IL-35 levels gradually increased; and the differences were statistically significant (P<0.05). Pearson correlation analysis showed that serum β 2 -MG was positively correlated with IL-6, TNF-α and IL-17 levels (r=0.710, 0.756, 0.581, P<0.05), and negatively correlated with IL-35 level (r=-0565, P<0.05)., Conclusion: Abnormal blood separation exists in MM patients, and there are significant differences in blood, tumor load and immune balance related indexes in patients with different blood separation results, which provides partial experimental basis for evaluation of disease, efficacy and prognosis with different blood separation results.