Bio-Medical Materials and Engineering - Volume 33, issue 6

Authors: He, Fan | Wang, Xinyu | Hua, Lu | Guo, Tingting

Article Type: Research Article

Abstract: BACKGROUND: Microcirculation plays a key role in regulating blood flow but is not considered in previous research of hemodynamics. OBJECTIVE:  A curved artery model is established to study its hemodynamic characteristics based on microcirculation boundary. METHODS: The hemodynamic model of a curved artery is constructed and simulated by computational fluid dynamics. The curved artery model is simulated by fluid-structure interaction. At the same time, a porous medium is used to simulate microcirculation as the outlet boundary. RESULTS: The distribution characteristics of the blood flow velocity, the pressure and the wall shear stress in different …sections at different time of the cardiac cycle are obtained. The results show that the velocities in curved arteries decrease and the pressures gradually increase. The blood flow velocity waveform and value are affected and they are sensitive to the microcirculation boundary. However, the pressure value is only affected by the microcirculation function. CONCLUSIONS:  This work is useful for researchers to deeply understand the hemodynamic characteristics of curved arteries. There is important clinical significance to analyze the pathogenesis of cardiovascular disease considering microcirculation function and its coupling effect. Show more

Keywords: Curved artery, hemodynamics, numerical simulation, microcirculation, computational fluid dynamics

DOI: 10.3233/BME-211275

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 437-451, 2022

Authors: Kim, Sunmin | Yonemitsu, Ikuo | Takemura, Hiroshi | Shimoda, Kunio | Suga, Kazuhiro | Soga, Kohei | Ono, Takashi | Uo, Motohiro

Article Type: Research Article

Abstract: BACKGROUND: Most orthodontic cases consist of varying degrees of crowding. To manage crowded dentitions, nickel-titanium archwires with various ligation methods are often used. OBJECTIVE: We aimed to investigate the effect of different ligation methods with respect to force and moment and suggest the efficient ligation method for treating rotation and displacement simultaneously. METHODS: We built a model that simulated the three anterior teeth of the maxilla. The teeth on the two ends were fixed, and the middle tooth was set in several different positions by manipulating the amount of displacement in bucco-lingual direction and rotation angle. …The measurements were taken with three different ligation methods of self-ligation (SL), elastomeric o-ring ligation on both side wings (EB), and on one side wings (EO). RESULTS: The magnitude of linguo-buccal force exceeded the standard optimal force in each condition examined and was significantly larger in EB than in other ligation methods. Moreover, the magnitude of moment generation with SL was suitable in the 0.0 mm linguo-version, whereas it was suitable with EO in the linguo-version ranging 1.0–3.0 mm. CONCLUSIONS: The ligation method significantly affected the force and moment. SL and EO are recommended in dentitions with light and deep lingual displacements, respectively. Show more

Keywords: Six-axis sensor, orthodontics, force system, moment, orthodontic simulator

DOI: 10.3233/BME-211288

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 453-463, 2022

Authors: Cui, Jingbin | Yi, Yali | Zhang, Jinming | Chai, Liping | Jin, Herong

Article Type: Research Article

Abstract: BACKGROUND: With the increasing aging of population, the incidence rate of diseases such as fracture and osteoporosis has been increasing. The demand for implant in Department of orthopedics has increased. The elastic modulus of the existing solid metal implant is much higher than that of human bone tissue, and it is easy to produce stress shielding effect after operation, which causes complications such as loosening of prosthesis and low fusion efficiency. OBJECTIVE: In order to solve the mismatch of elastic modulus between solid metal orthopedic implants and human bone tissue, metal structures with excellent mechanical properties were prepared. …METHODS: The porous structure was designed by spatial dot matrix method, and the metal porous structure was prepared based on selective laser melting 3D printing technology. The residual stress in the preparation process was eliminated by vacuum annealing heat treatment, and the static compression experiment was carried out to study the effects of different pore shape and porosity parameters on the compressive yield strength and elastic modulus of porous structure. The performance changes of porous structure before and after heat treatment were compared, and the porous structure meeting the performance requirements of human bone tissue was selected. RESULTS: The porous structure prepared by selective laser melting technology met the requirements of human bone tissue. The elastic modulus was as low as 0.74 GPa and the compressive yield strength is 201.91 MPa; After annealing heat treatment, the compressive yield strength of porous structure decreased, the maximum change was 3.69%, the elastic modulus increased, and the maximum change was 8.69%. CONCLUSIONS: For the porous structure with the same pore shape, the lower the porosity, the better the mechanical properties of the porous structure. For the same porosity, the comprehensive mechanical properties of dodecahedral porous structure were the best and octahedral porous structure was the worst; the porous structure after annealing heat treatment was more conducive to meet the performance requirements of human bone tissue. Show more

Keywords: Porous structure, 3D printing, pore shape, porosity, mechanical properties

DOI: 10.3233/BME-211377

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 465-476, 2022

Authors: Liu, Sile | Shang, Dongmei | Wang, Hailong | Wu, Jing

Article Type: Research Article

Abstract: BACKGROUND: 5-Hydroxymethylfurfural (5-HMF) is a high value-added platform compound which can be obtained by dehydration of hexose under acidic conditions. OBJECTIVE: In this paper, a novel impregnation strategy for the molecular sieves (ZSM-5) as carrier and phosphotungstic acid (TPA) as active ingredient is proposed, the influence of the fructose dehydration process were studied and eco-friendliness, low-cost 5-hydroxymethylfurfural (5-HMF) was successfully obtained. METHOD: The structure surface area, pore size, acidity and microstructure of solid acid catalysts were investigated by XRD, BET, NH3 -TPD and SEM. The influences of reaction temperature, reaction time, catalyst dosage on the yield …of 5-hydroxymethylfurfural (5-HFM) were investigated. RESULTS: The results showed that TPA/ZSM-5 (mass ratio 20:10) has good dispersion and catalytic activity, fructose dosage 5 g, reaction temperature 140 °C, reaction time 2 h, catalyst dosage 0.5 g, and the yield of 5-hydroxymethylfurfural was 80.75% and after five times use the yield of 5-HMF remained above 75%. CONCLUSION: The novel solid acid TPA/ZSM-5 catalyst exhibited good catalytic activity and stability for the fructose dehydration to produce 5-HMF. Show more

Keywords: Phosphotungstic acid, catalyst, fructose, 5-Hydroxymethylfurfural

DOI: 10.3233/BME-211385

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 477-489, 2022

Authors: Ayala-Ham, Alfredo | Aguilar-Medina, Maribel | León-Félix, Josefina | Romero-Quintana, José Geovanni | Bermúdez, Mercedes | López-Gutierrez, Jorge | Jiménez-Gastélum, German | Avendaño-Félix, Mariana | Lizárraga-Verdugo, Erik | Castillo-Ureta, Hipólito | López-Camarillo, César | Ramos-Payan, Rosalio

Article Type: Research Article

Abstract: BACKGROUND: Nowadays, biomaterials used as a scaffold must be easy to deliver in the bone defect area. Extracellular matrix (ECM) hydrogels are highly hydrated polymers that can fill irregular shapes and act as bioactive materials. OBJECTIVE: This work aims to show the effects of ECM hydrogels derived from bovine bone (bECMh) on proliferation, cytotoxicity and expression of pro-inflammatory cytokines in three cells types involved in tissue regeneration, as well as biocompatibility in vivo . METHODS: In vitro , we used an extract of bECMh to test it on macrophages, fibroblasts, and adipose-derived mesenchymal stem cells (AD-MCSs). …Cell proliferation was measured using the MTT assay, cytotoxicity was measured by quantifying lactate dehydrogenase release and the Live/Dead Cell Imaging assays. Concentrations of IL-6, IL-10, IL-12p70, MCP-1 and TNF-α were quantified in the supernatants using a microsphere-based cytometric bead array. For in vivo analysis, Wistar rats were inoculated into the dorsal sub-dermis with bECMh, taking as reference the midline of the back. The specimens were sacrificed at 24 h for histological study. RESULTS: In vitro, this hydrogel behaves as a dynamic biomaterial that increases fibroblast proliferation, induces the production of pro-inflammatory cytokines in macrophages, among which MCP-1 and TNF-α stand out. In vivo , bECMh allows the colonization of host fibroblast-like and polymorphonuclear cells, without tissue damage or inflammation. CONCLUSIONS: The results indicate that bECMh is a biocompatible material that could be used as a scaffold, alone or in conjunction with cells or functional biomolecules, enhancing proliferation and allowing the filling of bone defects to its further regeneration. Show more

Keywords: Bovine extracellular matrix hydrogel, demineralized bone matrix, biocompatibility, regeneration, biomaterial

DOI: 10.3233/BME-211387

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 491-504, 2022

Authors: Lai, Mun Kit | Otgon, Baasansuren | Ohashi, Toshiro

Article Type: Research Article

Abstract: BACKGROUND: Imaging of cells and cellular organelles has been of great interest among researchers and medical staff because it can provide useful information on cell physiology and pathology. Many researches related to collective cell migration have been established and leader cells seem to be the ones that regulate the migration, however, the identification of leader cells is very time-consuming. OBJECTIVE: This study utilized computer vision with deep learning to segment cell shape and to identify leader cells through filopodia. METHODS: Healthy Madin–Darby Canine Kidney (MDCK) cells cultured in a Polydimethylsiloxane (PDMS) microchannel device allowed collective cell …migration as well as the formation of leader cells. The cells were stained, and cell images were captured to train the computer using UNet++ together with their corresponding masks created using Photoshop for automated cell segmentation. Lastly, cell shape and filopodia were filtered out using Filopodyan and FiloQuant were detected. RESULTS: The segmentation of cell shape and the identification of filopodia were successful and produced accurate results in less than one second per image. CONCLUSIONS: The proposed approach of image analysis would be a great help in the field of cell science, engineering, and diagnosis. Show more

Keywords: Leader cells, cell segmentation, filopodia identification, computer vision, deep learning

DOI: 10.3233/BME-221397

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 505-513, 2022

Authors: Ao, Yunong | Tang, Wenbao | Tan, Hongbo | Li, Jun | Wang, Fuyou | Yang, Liu

Article Type: Research Article

Abstract: BACKGROUND: Cartilage tissue engineering is a promising way to repair cartilage defects. Different materials have been applied in the preparation of cartilage hydrogels, but all with various disadvantages. OBJECTIVE: The aim of this study was to prepare cartilage hydrogel using type II collagen, chondroitin sulfate and hyaluronic acid, to explore their gelation effect and compressive strength, and to analyze the feasibility of their application in cartilage tissue engineering. METHODS: Type II collagen (Col II), hyaluronic acid (HA) and chondroitin sulfate (CS) were mixed in a certain proportion to prepare gel scaffolds; changes in chemical groups were …detected by Fourier transform infrared. After the hydrogel was prepared, its compressive strength was measured. Umbilical cord stem cells were co-cultured with hydrogel scaffolds to observe its cytocompatibility and analyze whether stem cells had cellular activity during co-culture; histological staining was applied to observe the hydrogel loaded with stem cells. RESULTS: Cartilage hydrogels were successfully prepared with good compressive strength, and Fourier transform infrared analysis showed that Schiff base reaction occurred during the preparation process and tight chemical cross-linking was formed. The results of umbilical cord stem cell co-culture showed that the hydrogel had good cytocompatibility and the stem cells had good activity in the hydrogel. CONCLUSIONS: Cartilage hydrogels with stable structures were successfully prepared and had good compressive strength. Hydrogel scaffold could provide a suitable living environment for umbilical cord stem cells, so that they maintain normal cell morphology and activity, and has a good application potential in cartilage tissue engineering. Show more

Keywords: Cartilage, hydrogel, tissue engineering, scaffold

DOI: 10.3233/BME-221404

Citation: Bio-Medical Materials and Engineering, vol. 33, no. 6, pp. 515-523, 2022