Sickle cell disease (SCD) is an inherited autosomal recessive hemoglobinopathy. This red cell disorder is a molecular disease caused by a point mutation of the gene encoding β-globin yielding characteristic sickle Hb (HbS; βGlu6Val). HbS makes red cells rigid and fragile. Red cells show a sickle shape by HbS polymerization in deoxygenated state, which severely impairs cellular deformability. Systemic vaso-occlusive crisis (VOC) is the main characteristics observed in patients with SCD, and persistent ischemia-reperfusion injury impairs vascular redox balance leading to platelet activation, leukocyte adhesion, and endothelial dysfunction. Sickle cells with short lifespans are easily hemolyzed, which induces anemia (sickle cell anemia), releases HbS into circulation, and reduces bioavailability of nitric oxide underlying systemic vascular inflammation. Such rheological derangement and vascular aging are heterogeneous among the patients with SCD. Hydroxyurea is a drug approved first and used widely to ameliorate SCD symptoms. Several drugs have emerged recently as promising disease-modifying agents leading to restoration of hemorheology and reduction in hemolysis and painful VOC. This review article focuses on the hemorheology, pathophysiology, and recent advances in the disease-modifying treatments and healthcare of SCD patients to alert that rapid globalization may place Japan out of the exception for SCD-endemic countries.

BACKGROUND: Current investigation of erythrocyte deformability based on elongation index ignores deviation of erythrocyte shape from the theoretical ellipsoid. Our study investigates how the actual shape of a human erythrocyte deviates from the theoretical ellipsoid shape when subjected to a sinusoidally changing shear flow. We hope to lay the groundwork for developing a more precise theoretical basis for measuring erythrocyte deformability via image analysis. OBJECTIVE: The purpose of this study was to quantify the deviation of erythrocyte shape from the theoretical ellipsoid during dynamic deformation. METHODS: Footage of a single erythrocyte subjected to a quasi-Couette flow was analyzed using MATLAB software. The actual and theoretical shape of erythrocyte were compared using binarization and calculation of its two-dimensional area respectively. RESULTS: The deviation of erythrocyte shape from the theoretical ellipsoid was shown by the percentage difference of actual to theoretical erythrocyte area as a function of its elongation index. The relationship between cell shape and elongation index corresponding to shear conditions was shown. CONCLUSIONS: An erythrocyte subjected to a sinusoidally changing shear flow does not always exhibit an ideal ellipsoid shape but undergoes deviations corresponding to shear conditions. Such deviations should be considered when investigating erythrocyte deformability via image analysis.

The tumor microenvironment consists of a physical gradient field that guides tumor invasion. Collagen, a major component of the extracellular matrix (ECM), forms a fibrous network with flexible stiffness. Increased ECM stiffness enhances collective tumor migration, an indicator of metastasis. However, tumor growth can also deform and remodel the collagen matrix into a dense-fiber environment, which may limit tumor migration. Therefore, the mechanisms underlying tumor behavior in response to individual matrix properties must be clarified. In this study, we developed a collagen-coating technique to delineate the effects of fiber density and matrix stiffness on tumor growth. Low and high collagen concentrations represented low- and high- fiber-density substrates, respectively, which were applied to glass or polyacrylamide gels, representing stiff and soft matrices. The stiff matrix supported A549 tumor spheroid expansion, whereas the collagen fiber density slightly counteracted stiffness-guided cancer migration. Specifically, the degree of collagen fiber density decelerated tumor spheroid expansion on the stiff matrix but not on a soft matrix. Our study provides a novel engineering approach for deciphering the effects of both matrix stiffness and fiber density. These results suggest that fiber density exerts its inhibitory effects on stiff matrices.

We investigated the mesoscale aggregation in rennet gels of low-temperature pasteurized milk (LT) and ultra-high temperature (UHT) treated milk in terms of image analysis methods. In the viscoelastic measurements, both milk types showed qualitatively similar gelation behavior and comparable storage modulus at lower pH. However, image analysis revealed that UHT milk formed large aggregation structures of fat globules after gelation, which was not observed in LT milk. Heat treatment causes complex formations between casein micelles and whey proteins, as well as between fat globules and both whey proteins and casein micelles. These interactions alter the fundamental building components of milk gel, resulting in large-scale aggregation of fat globules.

The rheological properties of semi-hard cheese (H), made from raw Holstein milk with a fat content below 4%, and cheese (J), made from raw Jersey milk with a fat content of approximately 5%, were compared. Load-deformation curves obtained using the cone indentation method at 30°C under large deformation were analyzed using second-degree polynomials. Cheese J exhibited a firmer texture than cheese H. The temperature dependence of the dynamic elastic modulus in the linear region was measured, and the melt behavior of both cheeses was compared using the temperature dependence of tan δ as a parameter. Before aging, H and J exhibited similar melt behavior. However, after one month of aging, tan δ remained below 1 up to 80°C for H, while for J, tan δ exceeded 1 at higher temperatures than before aging. These differences in rheological properties, which occur as milk fat crystals soften or melt, are believed to result from variations in the protein network structure formed by casein micelles.

A unique plant-based alternative to whipped cream was successfully made only with water, vegetable oil, and starch. Four types of starch-based whipped cream were obtained using typical starches: potato, corn, tapioca, and rice starches. Each starch-based whipped cream formed a stiff peak when piped as a decoration, and had both a fluffy texture and a chewy texture unique to starch. The optical microscopic images show that the air bubbles were surrounded and stabilized by partially gelatinized starch. To evaluate the unique texture, a modified overrun formula was proposed, which considers the excluded volume effect of starch at the gas-liquid interface.

Meat substitutes are still challenging to develop, particularly in mimicking food texture. This is because there was no technology to model meat fibers. Therefore, we developed a laser 3D printer that can mimic meat fibers. It produced an alternative meat sample with fibers oriented in uni-direction. The bonding strength among fibers could be tuned by controlling the overlap region depending on the distance of laser irradiation. This made it possible to control fiber-based “chewiness” from kakuni (braised pork belly) to steak meat. This technology enables diverse meat texture reproduction through structural and laser control.

The physical properties of a food bolus are crucial for safe swallowing and are shaped through mastication and saliva incorporation. While texture and moisture content influence bolus formation, taste components such as salt and sugar also affect mastication by increasing salivary secretion. If these effects can be evaluated objectively, it may enable a novel sensory assessment method. This study aimed to develop a method to assess taste effects on mastication by analyzing facial movements, particularly mandibular motion, using 3D data from a smartphone-based scanner.

Electrospun non-woven fabric was fabricated from the mixtures of konjac glucomannan (KGM) and sodium alginate to introduce the selective adsorption properties of alginate. The adsorption curves of methylene blue, used as a model substance for the absorbents of the fabrics, were determined for the KGM fabrics with different compositions of alginate. The adsorption data at the initial stage showed a typical feature for the diffusion-limited adsorption, depending on the composition of alginate in the fabric and the molar concentration of methylene blue in the immersing solution. The theoretical data analyzed were investigated to characterize the adsorption properties of the electrospun KGM-alginate composite fabrics.

Texture evaluation has still been challenging for the past five decades, particularly for foods with similar textures. Additionally, it is the same situation for foods with different sizes and/or shapes. In this study, we investigated a method to evaluate texture in more detail by compressing food using a teeth-shaped test fixture that mimics mastication and acquiring six times the amount of information compared to conventional methods. The purpose is to investigate the effect of a teeth-shaped fixture on food compression test, and to develop an automated food compression system toward food texture evaluation based on deep learning.

In this study, we designed a bifurcated flow channel with a bifurcation angle of 140° and successfully generated a shear stress gradient (SSG) of 280–4800 Pa/m without vortex formation. In areas with high SSG, the cultured endothelial cells (ECs) remained round and randomly oriented even after 24 h of flow exposure. In addition, increased expression of intercellular adhesion molecule 1, a marker of inflammatory response in ECs, was observed. Overall, our findings revealed that disturbed and directional changes caused by flow and wall SSG induce inflammatory responses in ECs.