Extensional flow-based microfluidic device: deformability assessment of red blood cells in contact with tumor cells

Vera Faustino,Rui Lima,Diana Pinho,Tomoko Yaginuma,Ricardo C. Calhelha,Isabel C.F.R. Ferreira 한국바이오칩학회 2014 BioChip Journal Vol.8 No.1

Red blood cell (RBC) deformability has become one of the important factors to assess blood and cardiovascular diseases. The interest on blood studies have promoted a development of various microfluidic devices that treat and analyse blood cells. Recet years, besides the RBC deformability assessment, these devices are often applied to cancer cell detection and isolation from the whole blood. The devices for cancer cell isolation rely mainly on size and deformability of the cells. However, the examination of deformability of the RBCs mixed with cancer cells is lacking. This study aims at determining the deformation index (DI) of the RBCs in contact with cancer cells using a hyperbolic microchannel which generates a strong extensional flow. The DIs of human healthy RBCs and human RBCs in contact with a tumor cell line (HCT-15, colon carcinoma) were compared by analyzing the flowing RBCs images captured by a high speed camera. The results reveal that the RBCs that were in contact with HCT-15 cells have lower deformability than the normal RBCs.

A microfluidic device for partial cell separation and deformability assessment

Diana Pinho,Tomoko Yaginuma,Rui Lima 한국바이오칩학회 2013 BioChip Journal Vol.7 No.4

Blood flow in microcirculation shows several interesting phenomena that can be used to develop microfluidic devices for blood separation and analysis in continuous flow. In this study we present a novel continuous microfluidic device for partial extraction of red blood cells (RBCs) and subsequent measurement of RBC deformability. For this purpose, we use polydimethylsiloxane (PDMS) microchannels having different constrictions (25%, 50% and 75%) to investigate their effect on the cell-free layer (CFL)thickness and separation efficiency. By using a combination of image analysis techniques we are able to automatically measure the CFL width before and after an artificial constriction. The results suggest that the CFL width increases with enhancement of the constriction and contributes to partial cell separation. The subsequent measurements of RBCs deformation index reveal that the degree of deformation depends on the constriction geometries and hematocrit after the cell separation module. The proposed microfluidic device can be easily transformed into a simple, inexpensive and convenient clinical tool able to perform both RBC separation and deformability analysis in one single device. This would eliminate the need for external sample handling and thus reducing associated labor costs and potential human errors.

Linseed Oil Attenuates Liver Inflammation, Fatty Acid Accumulation, and Lipid Distribution in Periportal and Perivenous Hepatocytes Induced by a High-Carbohydrate Diet in Mice

Guilherme Godoy,Marina Masetto Antunes,Ingrid de Lima Fernandes,Luciana Pelissari Manin,Caroline Zappielo,Laureane Nunes Masi,Juliana Vanessa Colombo Martins Perles,Jesuı´ Vergı´lio Visentainer,Rui Cu 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.12

We evaluated whether linseed oil (LO) modulates the effects of a high-carbohydrate diet (HCD) on liver inflammation, fatty acid (FA) accumulation, and lipid distribution in periportal and perivenous hepatocytes. The control group (control high-carbohydrate diet [HCD-C]) received an HCD with lard and soybean oil as the lipid source. The L10 and L100 groups received the HCD with 10% and 100% of LO as the lipid source, respectively. The animals were killed by decapitation before (day 0) and after receiving the diets. Liver FA composition, inflammation, and fibrogenesis gene expression were evaluated. Also, the percentage of lipid-occupied area in periportal end perivenous hepatocytes were measured. The L100 group exhibited a higher (P < .05) liver amount of omega-3 polyunsaturated FA (n-3 PUFA) and lower (P < .05) amounts of saturated FA (SFA), monounsaturated FA (MUFA), and omega-6 polyunsaturated FA (n-6 PUFA) compared with L10 or HCD-C mice. On day 56, interleukin 10 and type IV collagen gene expression were significantly upregulated and downregulated, respectively in L100. Also, the L100 group showed lower (P < .05) FA accumulation (i.e., total FA, SFA, MUFA, and n-6 PUFA). Also, L10 and L100 presented lower (P < .05) percentage of high lipid-containing portion in periportal and perivenous hepatocytes. We concluded that LO attenuation of liver inflammation promoted by an HCD is associated with increased liver n-3 PUFA levels, so modulating FA composition, deposition, and distribution in periportal and perivenous hepatocytes.

In Vitro Blood Flow and Cell-Free Layer in Hyperbolic Microchannels: Visualizations and Measurements

Raquel O. Rodrigues,Raquel Lopes,Diana Pinho,Ana I. Pereira,Valdemar Garcia,Stefan Gassmann,Patrícia C. Sousa,Rui Lima 한국바이오칩학회 2016 BioChip Journal Vol.10 No.1

Red blood cells (RBCs) in microchannels has tendency to undergo axial migration due to the parabolic velocity profile, which results in a high shear stress around wall that forces the RBC to move towards the centre induced by the tank treading motion of the RBC membrane. As a result there is a formation of a cell free layer (CFL) with extremely low concentration of cells. Based on this phenomenon, several works have proposed microfluidic designs to separate the suspending physiological fluid from whole in vitro blood. This study aims to characterize the CFL in hyperbolic-shaped microchannels to separate RBCs from plasma. For this purpose, we have investigated the effect of hyperbolic contractions on the CFL by using not only different Hencky strains but also varying the series of contractions. The results show that the hyperbolic contractions with a Hencky strain of 3 and higher, substantially increase the CFL downstream of the contraction region in contrast with the microchannels with a Hencky strain of 2, where the effect is insignificant. Although, the highest CFL thickness occur at microchannels with a Hencky strain of 3.6 and 4.2 the experiments have also shown that cells blockage are more likely to occur at this kind of microchannels. Hence, the most appropriate hyperbolic-shaped microchannels to separate RBCs from plasma is the one with a Hencky strain of 3. Red blood cells (RBCs) in microchannels has tendency to undergo axial migration due to the parabolic velocity profile, which results in a high shear stress around wall that forces the RBC to move towards the centre induced by the tank treading motion of the RBC membrane. As a result there is a formation of a cell free layer (CFL) with extremely low concentration of cells. Based on this phenomenon, several works have proposed microfluidic designs to separate the suspending physiological fluid from whole in vitro blood. This study aims to characterize the CFL in hyperbolic-shaped microchannels to separate RBCs from plasma. For this purpose, we have investigated the effect of hyperbolic contractions on the CFL by using not only different Hencky strains but also varying the series of contractions. The results show that the hyperbolic contractions with a Hencky strain of 3 and higher, substantially increase the CFL downstream of the contraction region in contrast with the microchannels with a Hencky strain of 2, where the effect is insignificant. Although, the highest CFL thickness occur at microchannels with a Hencky strain of 3.6 and 4.2 the experiments have also shown that cells blockage are more likely to occur at this kind of microchannels.Hence, the most appropriate hyperbolic-shaped microchannels to separate RBCs from plasma is the one with a Hencky strain of 3.

Decreased Docosahexaenoic Acid Levels in Serum of HIV Carrier Patients

Guilherme Godoy,Marina Masetto Antunes,Maria Angelica Raffaini Covas Pereira da Silva,Ingrid de Lima Fernandes,Jesuí Vergílio Visentainer,Jeane Eliete Laguila Visentainer,Rui Curi,Roberto Barbosa Bazo 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.6

The study aimed to measure serum fatty acids (FAs) composition in HIV carrier patients and compare it with non-HIV carrier patients. The FAs composition was measured by gas chromatography as follows: four saturated FAs myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), and docosanoic acid (22:0); four monounsaturated FAs 7-hexadecenoic acid (16:1 n-9), palmitoleic acid (16:1 n-7), oleic acid (18:1 n-9), and vaccenic acid (18:1 n-7); and three polyunsaturated FAs linoleic acid (18:2 n-6), dihomo-γ-linolenic acid (20:3 n-6), and docosahexaenoic acid (DHA, 22:6 n-3). We reported herein lower (P < .05) DHA concentration (by 40%) in the serum of HIV carrier patients than in non-HIV carrier patients. This FA has a pivotal role as a precursor of anti-inflammatory molecules with beneficial effects on metabolism, cardiovascular system, and immunological system. Even though most clinical studies reported beneficial effects of DHA supplementation in HIV carrier patients, this issue remains under debate. Further investigations then require to fully clarify the role of DHA in preventing or alleviating the comorbidities associated with HIV infection.