The evaluation of blood compatibility of biomaterials is crucial for ensuring the clinical safety of implantable medical devices. To address the limitations of traditional testing methods in real-time monitoring and electrical property analysis, this study developed a portable electrical impedance tomography (EIT) system. The system uses a 16-electrode design, operates within a frequency range of 1 to 500 kHz, achieves a signal to noise ratio (SNR) of 69.54 dB at 50 kHz, and has a data collection speed of 20 frames per second. Experimental results show that the EIT system developed in this study is highly consistent with a microplate reader ( R ²=0.97) in detecting the hemolytic behavior of industrial-grade titanium (TA3) and titanium alloy-titanium 6 aluminum 4 vanadium (TC4) in anticoagulated bovine blood. Additionally, with the support of a multimodal image fusion Gauss-Newton one-step iterative algorithm, the system can accurately locate and monitor in real-time the dynamic changes in blood permeation and coagulation caused by TC4 in vivo. In conclusion, the EIT system developed in this study provides a new and effective method for evaluating the blood compatibility of biomaterials.
Electric Impedance ; Animals ; Tomography/instrumentation* ; Biocompatible Materials ; Materials Testing/instrumentation* ; Cattle ; Titanium ; Alloys ; Prostheses and Implants

Objective:To assess the effectiveness of a 6-month Ba Duan Jin exercise program in improving the balance of community-dwelling older adults.Methods:A two arms, parallel-group, cluster randomized controlled trial was conducted in 1 028 community residents aged 60-80 years in 40 communities in 5 provinces of China. Participants in the intervention group (20 communities, 523 people) received Ba Duan Jin exercise 5 days/week, 1 hour/day for 6 months, and three times of falls prevention health education, and the control group (20 communities, 505 people) received falls prevention health education same as the intervention group. The Berg balance scale (BBS) score was the leading outcome indicator, and the secondary outcome indicators included the length of time of standing on one foot (with eyes open and closed), standing in a tandem stance (with eyes open and closed), the closed circle test, and the timed up to test.Results:A total of 1 028 participants were included in the final analysis, including 731 women (71.11%) and 297 men (28.89%), and the age was (69.87±5.67) years. After the 3-month intervention, compared with the baseline data, the BBS score of the intervention group was significantly higher than the control group by 3.05 (95% CI: 2.23-3.88) points ( P<0.001). After the 6-month intervention, compared with the baseline data, the BBS score of the intervention group was significantly higher than the control group by 4.70 (95% CI: 4.03-5.37) points ( P<0.001). Ba Duan Jin showed significant improvement ( P<0.05) in all secondary outcomes after 6 months of exercise in the intervention group compared with the control group. Conclusions:This study showed that Ba Duan Jin exercise can improve balance in community-dwelling older adults aged 60-80. The longer the exercise time, the better the improvement.

Objective To prepare decellularized scaffolds from rabbit cartilage at various concentrations and assess their physicochemical properties and compatibility with stem cells to provide an experimental basis for cartilage repair.Methods Bone marrow mesenchymal stem cells(BMSCs)were cultured using the Percoll density gradient separation method,and this was followed by flow cytometric analysis and testing of their osteogenic and chondrogenic differentiation capabilities.Cartilage pieces were excised from rabbit knees and hip joints and subjected to physical crushing,repeated freeze-thaw cycles,and mixed enzymatic digestion for decellularization.To compare and observe the physicochemical properties of the decellularized scaffolds at different concentrations,three groups of scaffolds(labelwd A,B,and C)were designed with concentrations of 100％,50％and 30％,with three replicates each.Third-generation PKH26-labeled BMSCs were seeded onto optimally concentrated scaffolds and cultured for 1 week to observe cell growth.Results Flow cytometry detected BMSC surface antigens with positive expression of CD44 and CD90 and negative expression of CD45.Osteogenic induction stained with alizarin red showed red calcific nodules,and chondrogenic induction stained with alcian blue showed blue cartilaginous nodules.No apparent cell morphology was observed in the three groups of scaffolds stained with hematoxylin-eosin,and toluidine blue.There was a significant difference in DNA concentration between decellularized samples and non-decellularized scaffolds(P＜0.05).The content of glycosaminoglycans was slightly lower than the normal values.Significant differences were observed between the three groups of scaffolds in terms of pore size,water absorption,porosity,tensile strength,and Young's modulus(P＜0.05).After co-cultivation of stem cells with the scaffolds,cell adhesion was found to be good.Conclusions Percoll density gradient separation can obtain high-purity rabbit BMSCs,and the mixed decellularization method is superior.Group B scaffolds were the most suitable for tissue-engineered cartilage repair.BMSCs cultured in vitro grew well on Group B scaffolds.

Mechanical ventilation(MV)provides life support for critically ill respiratory patients,but in the meantime can cause fatal ventilator-induced lung injury(VILI),and the latter remains a major challenge in respiratory and critical care medicine,because the pathological mechanism has not been fully elucidated.Recent studies show that on the one hand,in the lung with VILI,there exists airway collapse at multi-sites of an individual airway,which can not be explained by traditional airway collapse models.But on the other hand,under MV conditions,airway smooth muscle cells(ASMC)exhibit abnormal mechanical behaviors,accompanied by regulation of Piezo1 expression and endoplasmic reticulum stress.These phenomenons indicate that the MV-induced abnormal mechanical behavior of ASMC is closely related to multiple airway collapse and VILI.Therefore,by studying the MV-induced changes of ASMC mechanical behaviors and their relationship with airway collapse in lung injury,as well as the related mechanochemical signal coupling process,it is expected to reveal a novel mechanism of MV-associated airway collapse and lung injury from the perspective of cell mechanics.In this review,the recent research progress of airway collapse during MV,the regulation of ASMC mechanical behavior by MV-related high stretch,especially the related mechanochemical signal coupling mechanism is summarized.These advances may provide a novel insight for exploring the roles of ASMC abnormal mechanical behavior in the pathological mechanism of VILI,alternative targets of drug intervention for prevention and treatment of VILI,as well as for optimizing the ventilation mode in clinical practice.

BACKGROUND:The development of tissues and organs in the body is a precise and autonomously regulated process,and the function of biomechanical factors at this macroscale is a basic scientific question worth exploring. OBJECTIVE:To investigate the roles of cell mechanics in morphogenesis of the lobular organoid of 3D Madin-Darby canine kidney(MDCK). METHODS:The formation of MDCK lobular organoid was visualized by fluorescence resonance energy transfer technology,and the influence of different cellular mechanical signals and extracellular matrix environment on lobular organoid formation and corresponding changes in extracellular regulated protein kinases(ERK)activity were examined. RESULTS AND CONCLUSION:(1)Inhibition of ERK signaling pathway can inhibit the growth of MDCK lobular organoid.(2)Inhibition of cell contractile force signals such as ROCK pathway and Myosin Ⅱ activity,reduced ERK activity and lobular organoid size.(3)Selective inhibition of calcium channels in plasma membrane and endoplasmic reticulum led to reduced ERK activity and lobular organoid growth.(4)By inhibiting the mechanically-sensitive receptor Piezo ion channel or integrin signal on the cell membrane,the lobular organoid became smaller or MDCK cells could not generate tissue morphology.(5)Extracellular matrix compositions affected the morphogenesis of lobular organoid.The addition of type I collagen in Matrigel changed the lobular organoid to elongated shape.(6)The results of this study preliminarily show that mechanical signals in the cells and extracellular matrix environment play an important role in culturing MDCK lobular organoid,and provides certain molecular mechanisms.

Objective To investigate the molecular mechanism of palmitoylation modification in regulating the activity of non-receptor tyrosine kinase Fyn. Methods The intracellular Fyn activity was detected by applying fluorescence resonance energy transfer (FRET) technology, and the mechanism was investigated by combining with Fyn palmitoylation deficiency and C-terminal Src kinase ( CSK ) plasmid co-expression. ResultsExperimental data showed that single loss of either of ( C3, C6) palmitoylation sites resulted in higher Fyn activity, and C6 seemed more significant. It is known that CSK membrane translocation occurred after activation. FRET assay confirmed that CSK could down-regulate the activity of Fyn in cells, but could not effectively regulate the activity of Fyn(GSS) with the loss of palmitoylation sites. Conclusions The results in this study support the hypothesis on Fyn regulation by spatial localization, namely, non-palmitoylated Fyn (GSS) is less effective in the inhibitory regulation by CSK on cell membrane, thus promoting constitutive high activity expression

The critically ill coronavirus disease 2019 (Covid-19) patients usually present acute respiratory distress syndrome (ARDS), or even acute respiratory failure, and require mechanical ventilation (MV) to provide support for breathing. However, clinical studies have found an extraordinarily high mortality rate (>50%) for those Covid-19 patients who underwent MV. Considering the mechanical nature of MV, the high mortality rate is highly possible to be associated with mechanical stretch-induced lung injury during MV. Thus, it is imperative to understand the MV-induced pathological alterations in the respiratory system and corresponding mitigation measures in order to improve the therapy of critically ill Covid-19 patients. Ventilator-induced lung injury in therapy of critically ill Covid-19 patients involves several biomechanical factors and mechanisms, including changes in respiratory parameters, inflammatory cytokines storm, ciliary-mucus system, airway smooth muscle cells, lung fibrosis, and stretch-activated cell signaling. It is hoped that these biomechanical issues can be diligently investigated, so as to provide insights for optimizing the therapy for Covid-19 as well as other respiratory diseases.

This study aimed to evaluate the effect of sanguinarine on biomechanical properties of rat airway smooth muscle cells (rASMCs) including stiffness, traction force and cytoskeletal stress fiber organization. To do so, rASMCs cultured were treated with sanguinarine solution at different concentrations (0.005~5 μmol/L) for 12 h, 24 h, 36 h, and 48 h, respectively. Subsequently, the cells were tested for their viability, stiffness, traction force, migration and microfilament distribution by using methylthiazolyldiphenyl-tetrazolium bromide assay, optical magnetic twisting cytometry, Fourier transform traction microscopy, scratch wound healing method, and immunofluorescence microscopy, respectively. The results showed that at concentration below 0.5 μmol/L sanguinarine had no effect on cell viability, but caused dose and time dependent effect on cell biomechanics. Specifically, rASMCs treated with sanguinarine at 0.05 μmol/L and 0.5 μmol/L for 12 and 24 h exhibited significant reduction in stiffness, traction force and migration speed, together with disorganization of the cytoskeletal stress fibers. Considering the essential role of airway smooth muscle cells (ASMCs) biomechanics in the airway hyperresponsiveness (AHR) of asthma, these findings suggest that sanguinarine may ameliorate AHR via alteration of ASMCs biomechanical properties, thus providing a novel approach for asthma drug development.

Objective: To investigate the prevalence of hypercholesterolemia among Chinese adults in different geographic areas, and to analyze the related factors. Methods: China Chronic and Non-Communicable Disease and Risk Factor Surveillance was conducted in 2013, based on 298 counties/districts in 31 provinces of Chinese mainland. The adults aged 18 years old were randomly selected using multi-stage stratified clustering sampling method. Information on chronic disease and risk factors was collected using face-to-face questionnaire interview and physical measurement. Blood samples were collected by local staffs. Serum total cholesterol (TC) was determined using standard method in a central laboratory. After excluding 565 participants missing key variables and 1 558 participants with abnormal TC values, a total of 174 976 participants were included. Weighted prevalence of hypercholesterolemia was calculated. Hypercholesterolemia related individual or geographic determinants were defined using multilevel logistic regression. Results: The prevalence of hypercholesterolemia in Chinese adults age 18 years old and above was 6.9% (95%CI: 6.4%-7.3%), ranged from 3.0% (95%CI: 2.5%-3.4%) in the northwest of China to 14.2% (95%CI: 12.9%-15.5%) in the south (χ²=183.42, P<0.001). The prevalence of hypercholesterolemia was higher in 6 provinces including Tianjin, Liaoning, Fujian, Guangdong, Guangxi, and Hainan (≥9.0%), but lower in 7 provinces including Shanxi, Shannxi, Gansu, Qinghai, Ningxia, Xinjiang, and Tibet (<3.9%). There was a 1.27 fold variation in hypercholesterolemia prevalence by provincial level, and 72.5% of the geographical variation in hypercholesterolemia prevalence was account for by area-level determinants. With multilevel logistic analysis, the individual risk factors associated with hypercholesterolemia included aging, higher education level or annual household income per capita, regular drinking, too much red meal intake, inactivity, overweight or obesity. For geographic factors, residents living at south China, counties/districts with higher urbanization rates, higher education level or lower standardized death rates were more likely to have hypercholesterolemia (all P<0.05). Conclusion The prevalence of hypercholesterolemia was high in Chinese adults, it was different between regions and related with characteristics of population, individual behaviors and geographical regions.

Objective To test the expression level of IL-37 in peripheral blood mononuclear cells (PBMCs)of patients with primary biliary cirrhosis (PBC)and further explore its clinical significance in the pathological process of PBC.Methods Pe-ripheral blood samples were collected from 42 patients diagnosed as PBC and 38 health individuals examined at the same time during June 2013 to August 2015 in Changhai Hospital.PBMCs were separated by sucrose density gradient centrifugation, qualified Real Time-Polymerase Chain Reaction (qRT-PCR)was used to measure IL-37 mRNA expression level in PBMCs. Enzyme-Linked Immuno Sorbent Assay (ELISA)was to measure the protein level of IL-37,IL-6,IL-17,TNF-α,TGF-β,IL-18 and IL-23 in plasma.Meanwhile,the pathological stages of PBC cases were recorded.Pearson correlation analysis was performed on IL-37 and IL-6,TNF-α,IL-17,TGF-β,IL-18 and IL-23.Spearman rank correlation analysis was on IL-37 and pathological stages of PBC.Results The mRNA and protein level of IL-37 in experimental and controlled group were 2.81 ±0.94 vs 1.09±0.56,356.14±169.36 pg/ml vs 86.68±48.23 pg/ml separately(t=9.811,9.462,P<0.000 1),with sta-tistical differences.The correlation analysis showed that IL-37 was positively related with IL-17,TNF-α,IL-6 and TGF-β(r=0.561 2,0.661 9,0.672 1,0.765 3,P<0.001),and disease stages (Ⅰ~Ⅳ)(rs=0.348 9,P<0.05).Conclusion IL-37 might involve in the pathological process of PBC,and it is significant for disease prediction and diagnosis.