Speed Centrifugation Research Articles

Effect of Centrifugation Speed and Time on the Blood Chemistry Values of Healthy Individuals

Blood chemistry testing requires centrifugation as one of the crucial pre-analytical phases. Usual differences in the speed and time of centrifugation influence specimens to varying extents among laboratories. This prompted the researchers to ascertain the effects of varying centrifugation speeds and times on healthy individuals' blood chemistry values and reduce the centrifugation time attested by the World Health Organization (WHO). Blood specimens were collected from four healthy adults, centrifuged, and then analyzed using the VITROS 5600 Automated Machine. The dry chemistry principle was applied. Three sets of speed and time were applied (1) 3,500 RPM for 15 minutes (WHO recommended), (2) 3,750 RPM for 10 minutes, and (3) 4,000 RPM for 5 minutes. The parameters include Fasting Blood Sugar (FBS), Total Cholesterol (Total CHOLE), Creatinine (Crea), Sodium (Na), and Potassium (K). The results of the serum chemistry values have no significant difference between different speeds and times against the standard set by WHO and were found to be acceptable, normal, and close in range with each other. Therefore, these can be substituted for the WHO-recommended speed and time. The researchers forward the following recommendations: (1) tests should be conducted to respondents with comorbidities and to younger and older individuals; (2) conduct the tests in triplicates and consider using other methods and more participants should be considered; and; (3) consider lesser time in centrifugation.

EVALUATION OF PLATELET RICH PLASMA (PRP) PREPARATION PROCEDURE

The success of PRP therapy in repairing tissue damage is influenced by the PRP preparation procedure. Currently, there’s no standardization of PRP preparation procedures, and various techniques are used, such as the use of anticoagulants and different centrifugation speeds. This study aimed to evaluating the PRP preparation procedures based on the centrifugations steps (single and double centrifugation) and the use of anticoagulants variation (sodium citrate, EDTA and ACD-A). This study was an experimental study and used blood samples from respondents. The selected respondents must meet inclusion and exclusion criteria. The treatment groups in this study were the single centrifugation group and the double centrifugation group. Each group will be divided into 3 subgroups with different anticoagulant usage (sodium citrate, EDTA and ACD-A). Statistical analysis results showed a significant difference in the mean platelet count in the sodium citrate , EDTA, ACD-A groups with single and double centrifugation steps. Evaluation of platelet preparation procedures in this study, a higher platelet count was obtained, specifically in the sodium citrate group (494 x 103 cells/µL), EDTA group (829.4 x 103 cells/µL), and ACD-A group (607.1 x 103 cells/µL), compared to single centrifugation in the sodium citrate group (354.8 x 103 cells/µL), EDTA group (408.1 x 103 cells/µL), and ACD-A group (390.6 x 103 cells/µL). The highest platelet count in PRP was achieved with the preparation procedure using EDTA as the anticoagulant with double centrifugation. Further research is necessary to evaluate PRP preparation procedures regarding the concentration of growth factors present in PRP.

Comparison of structural, mechanical, and histochemical characteristics of L-PRF and T-PRF membranes using different centrifugation protocols – An ex-vivo observational study

ObjectivesMany investigators are looking into the possibility of using platelet-rich. hemoderivatives as a source of the protein structures and cytokines necessary for. periodontal healing of wounds. The objective of the study was to evaluate and. compare the structural, mechanical, and histochemical characteristics of L-PRF and TPRF. membranes prepared by using three different centrifugation protocols. MethodsThirty participants around the ages of 20 and 35 who were in good overall. health had their antecubital veins pricked for ten milliliters of the blood. Venous blood. was centrifuged immediately after collection in silica-coated glass tubes and titaniumcoated. tubes utilizing the APRF machine. The mechanical properties of PRF. membranes (n = 30) for L-PRF and T-PRF each protocol) were assessed using a. desktop universal testing machine. ResultsThe forces around 700 g (3200 rpm, 15 min) yielded a PRF membrane with. desirable mechano-degradation characteristics for its clinical application. Histochemical examination revealed mixed inflammatory infiltrate with predominantly. platelets followed by lymphocytes, neutrophils& monocytes in T-PRF. Whereas, in. LPRF thin strands of mixed inflammatory infiltrate predominantly neutrophils &. monocytes are seen in the connective tissue stroma. ConclusionThis study demonstrated that centrifugation speed, force, and time. influenced the structural, and mechanical properties of PRF membranes prepared with. various protocols. This is the first study to reveal the marked impact of glass and. titanium-reinforced centrifugation tubes on the final production of PRF. It was further. found that a significant difference was observed between L-PRF and T-PRF at. 3200 rpm and 2700 rpm protocols.

Optimizing Platelet and Leucocyte-Rich Plasma as Biomaterials for Ophthalmic Applications: Impact of Centrifugation Speed

Optimizing Platelet and Leucocyte-Rich Plasma as Biomaterials for Ophthalmic Applications: Impact of Centrifugation Speed

Lower centrifugation speed and time are positively associated with platelet concentration in a canine autologous conditioned plasma system.

To evaluate the effect of variable centrifugation protocols on the cellular composition of the final product of a canine autologous conditioned plasma double-syringe system. 30 client-owned healthy adult medium- to large-breed (17- to 45-kg) dogs. 35 mL of anticoagulated whole blood from each subject was aliquoted into 3 samples: a baseline and 2 double syringes. The syringes were processed for platelet-rich plasma (PRP). Each double syringe was randomly assigned to 1 of 5 groups, which varied in centrifugation settings between 580 and 1,304 X g and 5 and 10 minutes. CBC analysis was performed on each of the samples to determine cellular composition. A mixed-effect linear model was fit to the data. 60 PRP samples and 30 whole blood samples were analyzed. Manufacturer settings generated a platelet fold change > 1 but did not increase concentration to the extent expected. When comparing speed alone, increased centrifugation force was associated with lower platelet fold change. When comparing time alone, increased centrifugation time was also associated with lower platelet fold change and lower leukocyte concentration. Autologous conditioned plasma double syringes require a low volume of initial whole blood, making them preferable for canine PRP in clinical settings. This study aimed to evaluate the effect of the centrifugation protocol on the final product cellular composition in dogs and add to the available data on protocols to maximize platelet yield in PRP. Due to inherent individual variability, this study emphasized the importance of evaluating biological samples prior to administration to predict and improve patient outcomes.

A study of screen-printed electrodes modified with MoSe2 and AuNPs-MoSe2 nanosheets for dopamine sensing

Molybdenum selenide nanosheets (MoSe2-NS) were synthesized by liquid-phase exfoliation (LPE) technique and successive liquid cascade centrifugation (LCC) at two different centrifugation rates (1.5 and 5 krpm). By this technique's combination, we were able to prepare MoSe2 nanosheets with different geometric characteristics (i.e., average number of layers <N> and average lateral length <L>). Increasing the centrifugation speed from 1.5 krpm to 5 krpm leads to a decrease in number of layers (down to nL = 2 – 4, with the presence of sparse monolayer flakes) and average lateral size of NS from 280 nm to 180 nm, as confirmed combining optical and morphological analysis. Modified screen-printed carbon electrodes (SPCE) with the as prepared MoSe2-NS were fabricated and applied for the determination of dopamine (DA) as an electroactive model analyte in the concentration ranging from 0.5 to 80 µM. DA is an important neurotransmitter for human beings and its deficiency can bring out various health diseases like Parkinson's and brain disorders, thus the development of simple DA sensors is highly demanding. Results demonstrated the better performances of the modified MoSe2 (5 krpm)/SPCE sensor compared to bare SPCE and the MoSe2 (1.5 krpm)/SPCE. With the objective to improve the electroanalytical performances toward dopamine, AuNPs-MoSe2-NS hybrid composite was also prepared, mixing AuNPs obtained by a green-reduction method with the MoSe2-NS. The developed AuNPs-MoSe2 (5 krpm)/SPCE sensor resulted the most promising with further improved sensitivity as compared to MoSe2/SPCE.

Modeling and Analysis of Metal Liquid Film Flow Characteristics during Centrifugal Spray Forming

Liquid films are an important part of liquid metal granulation in the process of centrifugal spray forming. The size of the granulated particles has an important influence on the density, grain size and microstructure uniformity of the deposited blanks. The particle size is closely related to the flow characteristics of liquid films. Therefore, enhancing our understanding of the flow characteristics of liquid films can provide guidance for forming blanks. In this study, force analysis of a liquid film on the surface of a high-speed rotating centrifugal disc used in centrifugal spray-forming technology was carried out using D’Alembert’s principle and Newton’s law of viscosity. Then, combined with the principle of mass conservation, a theoretical model of the smooth flow of the liquid metal film was established. The experimental values obtained by Leshev were compared with our values to verify the correctness and accuracy of the model. Through the model, the influencing factors of the liquid film flow were obtained, such as the centrifugal disc speed, centrifugal disc radius, inlet volume flow rate and kinematic viscosity. Taking A390 aluminum alloy as the research object, the influence of the process parameters on the thickness, velocity and trajectory of the liquid film was revealed theoretically, and the relationship between the process parameters and the trajectory length and liquid film thickness was clarified. Modeling and analysis can not only help us to understand the flow of a liquid film, but also help us to predict the relevant parameters, which is convenient for the accurate and rapid regulation of the process to obtain the desired flow parameters. Therefore, the research content of this paper is of great significance for the preparation of billets with a uniform microstructure and excellent mechanical properties.

Rapid separation and determination of six anthocyanins in food and beverage using surface-active ionic liquid-based supramolecular solvent dispersion liquid–liquid microextraction

A simple and efficient method of surface-active ionic liquid-based supramolecular solvent dispersion liquid–liquid microextraction (SAIL-SUPRAS-DLLME) has been developed for the separation and determination of six anthocyanins in food and beverages. The analysis was completed by ultra-high performance liquid chromatography (UHPLC). In this work, a supramolecular solvent formed by the self-assembly of surface-active ionic liquid [EMim][NTF2] and the Tergitol TMN-6 solution were used as the extraction phase in DLPME. Some parameters, including the type and volume of extraction solvent used in SAIL-SUPRAS, pH of the sample phase, concentration of salt, shaking time, centrifugation speed and time were investigated and optimized. The calibration curves for six anthocyanins were all linear with correlation coefficients greater than 0.9994. The intra-day and inter-day precision (RSD) measurements were below 8.1%, while the limits of detection (LOD) for six anthocyanins ranged from 2.11 to 3.27 pg mL−1 (S/N = 3). The proposed method had series of advantages, such as simple, rapid, environmentally friendly preparation of the supramolecular solvent, higher enrichment, excellent sensitivity and selectivity for six anthocyanins. It can be used for the quick analysis and detection of anthocyanins in food analysis.

Performance study of 1.5 kWe free piston Stirling generator emulating solar power working conditions

In this paper, solar irradiance, ambient wind speed and power load are emulated by regulating the electric heating power, the centrifugal fan speed and the load resistance to emulate the operation condition of the solar dish Stirling power generation (SDS) system. The couple effects on the generated power and thermoelectric efficiency of a free piston Stirling generator (FPSG) prototype are tested experimentally. The heat dissipation characteristics of the outer wall is analyzed. The results show that in certain start-up condition the generated power drops rapidly from 180.8 W to the lowest point of 77.1 W at 36 s, then rise gradually and stabilize at 12 min. The generated power is approximately positively linear with the heating power while the thermoelectric efficiency rises firstly followed by decline, with a peak of 20.3% at 5 kW. The wind speed reduces the generated power, thermoelectric efficiency and radiation loss, but increases the convection loss. The generated power and thermoelectric efficiency decrease with the load resistance, with the maximum values of 1364.6 W and 23.3% respectively.

Design and Experimental Testing of a Centrifugal Wheat Strip Seeding Device

Wheat sowing has the characteristics of wide and short sowing periods, and there are situations in which the suitable sowing period is missed. In order to meet the needs of high-speed sowing, a centrifugal wheat strip seeding device was designed, the principle of which is that rotating parts were mainly composed of centrifugal concave plate and guide strip rotating in the shell to provide the mechanical force and drive the airflow and then realize high-speed seeding. The influence of the rotational speed of the seed discharging plate, the seed feed rate, and the dip angle of the guide strip on the distribution of the flow field and trajectory of seeds in the device was analyzed. The aerodynamic characteristics of seeds and the distribution of the gas-phase flow field inside the seed displacer under airflow were analyzed by CFD–DEM coupled simulation. The effects of three operating parameters on the coefficient of variation of sowing uniformity (CVSU) and the row-to-row seeding amount coefficient of variation (RSCV) were clarified, and the simulation results were verified by bench experiments after secondary optimization. When the centrifugal concave plate rotational speed, seed feed rate, and guide strip angle were 408 rpm, 4938 grains/s, and 69°, the results showed that CVSU and RSCV were 1.12% and 2.39%, respectively, which was in line with the standards for grain strip seeders stipulated. The designed seed discharge device can sow 3.4 ha per hour. This study provides a reference for research of centrifugal airflow-assisted high-speed seeding devices for wheat.

Processing stallion semen for on‐farm use and cooled transport

SummarySimple dilution of semen is the oldest method to process semen for artificial insemination with either fresh or cooled semen. This was developed prior to the optimisation of centrifugation techniques for semen processing through a combination of trial and error and research. Simple dilution is a faster method to process semen, is easy to use and works in many circumstances. For on‐farm semen use a 1:1 (v/v) semen to extender ratio is used. A variety of other techniques have been developed, such as cushion centrifugation, density gradient centrifugation and sperm filtration. Cushion centrifugation is used to concentrate the sperm and allows higher centrifugation speeds than centrifugation alone. This allows for improved recovery rates of sperm. Density gradient centrifugation has been used to select for morphologically normal sperm but suffers from low recovery rates. Processing sperm with this technique can result in improved motility and improved DNA integrity of sperm. Sperm filtration is another method to concentrate sperm without the use of centrifugation; however, it has lower recovery rates compared to cushion centrifugation. This review will discuss these techniques in the application of processing equine semen for either fresh or cooled‐shipped use.

Application of Response Surface Method for Determination of Optimized Conditions for Quantification of 1,4-Dioxane in Model System of Polyethylene Glycol 200

The release of 1,4-dioxane probably contributes to the deterioration of marine habitats, animal health, and human liver and kidneys. The formulation of 1,4-dioxane in glycols, which has been applied for dehumidifying agents in refineries, may need to be replaced to ensure public health. Further, it is necessary to identify and precisely determine the levels of 1,4-dioxane in glycols for food quality control and environmental safety regulation. The objectives of this study were to validate a liquid–liquid extraction (LLE) method for 1,4-dioxane analysis and to optimize the LLE conditions using a response surface methodology (RSM). With consideration of the food matrix and its applications, polyethylene glycol 200 was used as the model system and analyzed by gas chromatography with flame ionization detection. In the experiments for the optimum extraction temperature and time of 1,4-dioxane in ultrasonic treatment, they were 20 °C and 10 min, respectively. The experimental conditions and results were analyzed by RSM with the Box–Behnken design, and the optimal extraction conditions for the LLE were determined to be coded with three independent variables (sample weight, solvent volume, and centrifugation speed). The amount of 1,4-dioxane increased as the amount of sample increased, whereas the amount of 1,4-dioxane decreased as the amount of solvent increased. This information can help to find the analytical methods for regulating the 1,4-dioxane content and its precise quantification in food products.

Efficacy of Autologous Platelet-Rich Gel Combined with Negative Pressure Drainage in Patients with Diabetic Foot

Autologous platelet-rich gel (APG) has emerged as a novel treatment modality for diabetic foot, demonstrating potential in promoting wound healing and tissue repair. Negative pressure drainage has been shown to effectively remove wound exudates and facilitate wound healing. The objective of this research was to demonstrate the clinical efficacy of APG combined with negative pressure drainage in patients with diabetic foot. Following the preparation of platelet-rich plasma (PRP) gel, the influence of various temperatures and centrifugation speeds on gel properties was analyzed. PRP was assessed, and the slope and effective disaggregation rate of PRP were compared. A total of 30 healthy volunteers without diabetic foot were recruited as the control group and randomly assigned into three groups, with 10 participants in each group. The mean volume and concentration of PRP in the three groups were analyzed. A total of 30 patients with diabetic foot were selected as the observation group to analyze the therapeutic effects of APG combined with negative pressure drainage in patients with diabetic foot. The results showed that the prepared separated gel effectively isolated components in the blood, with a decrease in gel viscosity observed with increased centrifugation speed and temperature. The pH of the separated plasma remained stable. The plasma showed the best effects when immediately placed. At 0 h, 3 h, and 6 h, the PRP concentration in Group 1 was drastically superior to the other two groups (P &lt; 0.05). Regarding the slope of PRP, at 30 °C, the slope remained relatively stable; at 25 °C, the slope exhibited the largest variation. At 5 °C, the slope changed between 25 °C and 30 °C. The effective disaggregation rate was lowest when immediately placed, and it gradually increased with the prolongation of placement time. At 30, 60, 90, and 120 minutes of placement, the difference in effective disaggregation rate between 5 °C and 25 °C or 30 °C was considerable (P &lt; 0.05). The pH of PRP at 0 h, 3 h, and 6 h was weakly acidic, with inconsiderable difference in pH values among the three time periods (P &gt; 0.05). At 0 h, 3 h, and 6 h, the PRP concentration in Group 1 was markedly superior to the other two groups (P &lt; 0.05). In summary, the prepared separated gel effectively isolated PRP and the combination of APG with negative pressure drainage demonstrated remarkable therapeutic efficacy in patients with diabetic foot. The adoption of APG provides a personalized and innovative treatment option for diabetic foot patients, offering the potential to improve treatment outcomes.

Centriselect – A novel approach for centrifugal cell separation

Abstract 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.

Lactose/tannin-based calcium aluminate coatings for carbon-bonded alumina foam filters: A novel approach in environment-friendly steel melt filtration

In this paper, a new approach in the development of calcium aluminate (CA) coatings for ceramic foam filters for steel melt filtration is presented. This approach is based on applying an environmentally friendly binder system based on lactose and tannin. The use of such a binder was previously demonstrated for the matrix of carbon-bonded alumina filters. In this research, the influence of the total solid content, the binder content, and the centrifugation speed on the coated ceramic foam filters’ final properties was studied. All of the prepared coating slips were analyzed in terms of their rheology. The most promising slips were applied on carbon-bonded alumina filters, which were prepared using a lactose- and tannin-based binder system. For the selected coating slips, three different centrifugation speeds (600, 1000, and 1400 rpm) were used to optimize the coating layer thickness and the overall amount of the coating material applied to the filter. The coated and thermally treated filters were tested in terms of their cold crushing strength. Furthermore, the microstructure of the filters and mainly the coating layer thickness were studied. It was observed that both the centrifugation speed and the total solid content in the coating slip have a major impact on the filter properties. The most promising results were obtained for a coating containing 72.5 wt% of total solids applied at 1000 rpm centrifugation speed. This batch of coated samples showed a cold crushing strength of more than double the value obtained for the uncoated reference, while having a uniform coating layer with the thickness of ∼177 μm.

Centrifugation forced ice-concentrate separation to enhance suspension freezing desalination performance

Suspension freeze desalination is a promising route for treatment of high salinity wastewater, but the poor ice-concentrate separation often generates decrease of desalination efficiency. In this work, it is demonstrated that centrifugation forced dewatering can assist in ice purification and enhance suspension freeze desalination performance. The positive correlation and good linear fitting relationship between ice purity and dewatering rate were identified at various centrifugation speeds, centrifugation time, and ice layer thickness. Changes of ice shape were recorded by low-temperature optical microscope observation system. The free water removal and ice floc destruction induced by centrifugal field have an important contribution to ice purification. Increasing centrifugation speed from 100 r/min to 500 r/min, the corresponding relative centrifugal force increased 27-fold, creating sharp increases in ice purity (rate constant k = 0.1605) and dewatering rate (rate constant D = 0.0563). Due to the strong binding characteristics and small portion of bound water, ice desalination efficiency per unit centrifugal force dropped when centrifugation speed increased from 1000 r/min to 3000 r/min. Besides, the multi-step dewatering and purification mechanism involved in ice centrifugation was depicted. The suspension freeze technology hybrid with centrifugation not only enhances desalination efficiency but also is beneficial to obtain high-purity ice.

Studying the Factors Affecting De-Emulsification of Crude Oil

The paper deals with highly stable emulsions. It is concentrated on de-emulsification of crude oil. In the petroleum industry, de-emulsification is an important and urgent task that is typically required for the treatment of crude oil. This work, suggests method using coupling device integrated centrifuge with chemical to strengthen the de-emulsification efficiency. A number of de-emulsification runs were conducted to determine how centrifuge and chemical components affected the effectiveness of de-emulsifying crude oil and the separation of water, Different types of de-emulsifiers the (ethylene glycol, choline chloride and ethyl cellulose), were used with different concentration of de-emulsifiers, de-emulsification time in centrifuge and centrifugal speed. Also studied at the same time. Studies on the de-emulsification of crude oil were conducted at room temperature. As the concentration of de-emulsifiers was increased, crude oil's de-emulsification efficiency rose , centrifuge time and centrifugal speed ,with de-emulsifier type effect on de- emulsification ,which reached maximum (85.9%,84.4% and 74.07%) at rate 4% of ethylene glycol, choline chloride and ethyl cellulose respectively ,at 60 min and 4000 rpm . This method provides higher water separation from crude oil emulsion and quicker method.

Study on Flight Dynamics and Heat Transfer Solidification of Metal Droplets during Centrifugal Spray Deposition Forming Process

Centrifugal spray deposition forming technology, which is used in the preparation process of near-net-forming billets, not only reduces the macroscopic segregation and refines the microstructures of billets but also has the characteristics of a rapid solidification structure. The trajectory, velocity, heat transfer and solidification of metal droplets granulated by the centrifugal force during flight will affect the shape, precision and microstructure of the billet. Therefore, it is necessary to study the dynamics and thermal history of droplets in flight. In this study, a single droplet is taken as the object. Considering the resistance of ambient gas, Newton’s second law, classical nucleation theory, Newton’s cooling law and the energy conservation equation were used to establish a dynamic model and heat transfer solidification model of liquid metal droplets during flight. The influence of the centrifugal disc speed on the diameter of granulated droplets was analyzed. The variation law of droplet flight trajectory and velocity was explored. The supercooling degree in metal droplet nucleation was quantified, and the influence of droplet diameter, superheat and other factors on heat transfer and solidification was revealed. The results show that the numerical calculation results are basically consistent with the previous research results. The trajectory of the droplet is parabolic during flight. The initial velocity of the droplet, the environmental gas resistance and the convective heat transfer coefficient are positively correlated with the rotating speed of the centrifugal disc; however, the droplet diameter is negatively correlated with the rotating speed of the centrifugal disc. The super cooling degree at the time of droplet nucleation and the flight time required for solidification are negatively correlated with the droplet diameter. Among them, the droplet diameter has a linear relationship with the solidification start time and a quadratic curve relationship with the solidification end time. The effect of superheat on the heat transfer and solidification of droplets is not obvious. The conclusions obtained can provide a theoretical basis for the determination of the preparation process parameters.

Simulation Methods for MEMS S&A Devices for 2D Fuze Overload Loading.

An experimental testing system for the two-dimensional (2D) fuze overload loading process was designed to address the loading issues of recoil overload and centrifugal overload in fuze safety and arming (S&A) device. By incorporating centrifuge rotation energy storage, impact acceleration simulation, and equivalent centrifugal rotation simulation, a block equipped with a fuze S&A device accelerated instantly upon having impact from a centrifuge-driven impact hammer, simulating recoil overload loading. The impact hammer was retracted instantaneously by adopting an electromagnetic brake, which resulted in the centrifugal rotation of the block around its track, to simulate the centrifugal overload loading. The dynamic equations of the experimental testing system and the equations of impact hammer motions were established, whereby the rotation speed of the centrifuge and the braking force of the electromagnetic brake were calculated and selected. A dynamic model of the collision between the impact hammer and block was established using ANSYS/LS-DYNA software for simulation analysis. The acceleration curves of the recoil overload and centrifugal overload with variations in the centrifuge speed, cushion material, and buffer thickness were obtained, which verified the feasibility of the proposed loading simulation method. Two-dimensional overload loading simulation tests were performed using the developed experimental testing system, and the acceleration curves of the recoil overload and centrifugal overload were measured. The test results indicated that the proposed system can accomplish 2D overload loading simulations for a recoil overload of several 10,000× g and centrifugal overload of several 1000× g.

Optimized conditions for gene transduction into primary immune cells using viral vectors

Chimeric antigen receptor (CAR) T cell therapy has emerged as a promising modality for anti-cancer treatment. Its efficacy is quite remarkable in hematological tumors. Owing to their excellent clinical results, gene- modified cell therapies, including T cells, natural killer (NK) cells, and macrophages, are being actively studied in both academia and industry. However, the protocol to make CAR immune cells is too complicated, so it is still unclear how to efficiently produce the potent CAR immune cells. To manufacture effective CAR immune cells, we need to be aware of not only how to obtain highly infective viral particles, but also how to transduce CAR genes into immune cells. In this paper, we provide detailed information on spinoculation, which is one of the best known protocols to transduce genes into immune cells, in a methodological view. Our data indicate that gene transduction is significantly dependent on speed and duration of centrifugation, concentration and number of viral particles, the concentration of polybrene, and number of infected immune cells. In addition, we investigated on the optimal polyethylene glycol (PEG) solution to concentrate the viral supernatant and the optimized DNA ratios transfected into 293T cells to produce high titer of viral particles. This study provides useful information for practical production of the gene-modified immune cells using viral vectors.