Types of vertebral fractures could influence the selection of clinical bone mineral measures to predict biomechanical properties.

Areal and volumetric BMD (aBMD and vBMD) measured by DXA and quantitative CT (QCT), respectively, are usually employed to predict vertebral fracture risks. In this study, we induced compression and wedge vertebral fractures to test if the types of fracture could influence the selection of bone mineral measures to predict biomechanical properties of vertebral bodies. DXA and QCT were employed to scan twenty-four male cadaveric vertebral bodies of humans for bone mineral content (BMC) and aBMD measures, and vBMD measures, respectively. We computed vBMD measures from three kinds of volumes of interest: intact structures (vertebral body, cortical compartment, and trabecular core), axially middle sections (1.250-1.875 cm height) of the intact structures, and clinically used elliptical regions of trabecular bone. We loaded vertebral bodies to failure for properties of strength (Pu), failure displacement (δu), and stiffness (K). Thirteen vertebral bodies sustained compression fractures and the remaining sustained wedge fractures. Linear and power regression models were used to test bone mineral predictions for Pu, δu, and K. We also did equality tests of correlation coefficients. Our results showed aBMD, BMC, and vBMD of the middle section of trabecular bone had the strongest correlations with Pu (R2 = 0.6420, p < 0.001), δu (R2 = 0.4619, p < 0.001), and K (R2 = 0.5992, p < 0.001) in power regression models, respectively when compression and wedge fractures were mixed. Considering compression fractures only, vBMD of the intact vertebral body displayed the strongest correlations with both Pu (R2 = 0.6529, p < 0.001) and K (R2 = 0.6354, p < 0.001) while BMC showed the strongest correlation with δu (R2 = 0.4376, p < 0.001) in linear regression models. When only wedge fractures were analyzed, vBMD of the elliptical regions of trabecular bone exhibited the strongest correlations with both Pu (R2 = 0.5845, p < 0.001) and K (R2 = 0.6420, p < 0.001) in power regression models, however, no bone mineral measure could significantly correlate with δu. These results may suggest the type of fracture could influence the determination of bone mineral measures to predict biomechanical properties of vertebral bodies.

Adsorption-Desorption Control of Fibronectin in Real Time at the Liquid/Polymer Interface on a Quartz Crystal Microbalance by Thermoresponsivity.

The cell manipulation technique using thermoresponsive polymers is currently attracting much attention for applications in the medical field. To achieve arbitrary and accurate cell control, it is necessary to intensely research fibronectin behavior. A smart surface, which has thermoresponsive wettability and which can adsorb or desorb fibronectin repeatedly without the presence of cells, was fabricated by an electrospinning method. The fabricated coating changed its structure as the temperature was changed, and this transformation could substitute for the pulling force generated by the cytoskeletal contraction of cells. Moreover, a coated quartz crystal microbalance was able to detect the fibronectin behavior as frequency shifts, which could be used in the estimation of the mass shift with the aid of suitable equations. This coating and measurement system can contribute greatly not only to the development in the medical field centered on biomaterial manipulation technologies, but also to the improvement of medical instruments.

Bionic Fish-Scale Surface Structures Fabricated via Air/Water Interface for Flexible and Ultrasensitive Pressure Sensors.

In recent years, wearable and flexible sensors have attracted considerable research interest and effort owing to their broad application prospects in wearable devices, robotics, health monitoring, and so on. High-sensitivity and low-cost pressure sensors are the primary requirement in practical application. Herein, a convenient and low-cost process to fabricate a bionic fish-scale structure poly(dimethylsiloxane) (PDMS) film via air/water interfacial formation technique is presented. High-sensitivity flexible pressure sensors can be constructed by assembling conductive films of graphene nanosheets into a microstructured film. Thanks to the unique fish-scale structures of PDMS films, the prepared pressure sensor shows excellent performance with high sensitivity (-70.86% kPa-1). In addition, our pressure sensors can detect weak signals, such as wrist pulses, respiration, and voice vibrations. Moreover, the whole process of pressure sensor preparation is cost-effective, eco-friendly, and controllable. The results indicate that the prepared pressure sensor has a profitable and efficient advantage in future applications for monitoring human physiological signals and sensing subtle touch, which may broaden its potential applications in wearable devices.

A Lubricant-Sandwiched Coating with Long-Term Stable Anticorrosion Performance.

Lubricant-infused surface(s) (LIS) bioinspired by the Nepenthes pitcher plant are receiving enormous attention owing to their excellent hydrophobicity as well as their self-healing ability. Thus, they have been applied as anticorrosion coatings. However, the loss of lubricant mediated by vapor or other liquids deteriorates their functions. Herein, we introduce a lubricant-inserted (sandwiched) microporous triple-layered surface (LIMITS) that prevents the sudden loss of lubricant. The sandwiched lubricant gradually self-secretes toward the surface, resulting in long-term stability even under water. The LIMITS prevented the corrosion of the Fe plate for at least 45 days, which is much superior to a conventional LIS coating. This work opens an avenue for the application of slippery coating materials that are stable under water and will also promote the development of anticorrosion coating in various industries.