Biocompatibility Testing of Liquid Metal as an Interconnection Material for Flexible Implant Technology

Galinstan, a liquid metal at room temperature, is a promising material for use in flexible electronics. Since it has been successfully integrated in devices for external use, e.g., as stretchable electronic skin in tactile sensation, the possibility of using galinstan for flexible implant technology comes to mind. Usage of liquid metals in a flexible implant would reduce the risk of broken conductive pathways in the implants and therefore reduce the possibility of implant failure. However, the biocompatibility of the liquid metal under study, i.e., galinstan, has not been proven in state-of-the-art literature. Therefore, in this paper, a material combination of galinstan and silicone rubber is under investigation regarding the success of sterilization methods and to establish biocompatibility testing for an in vivo application. First cell biocompatibility tests (WST-1 assays) and cell toxicity tests (LDH assays) show promising results regarding biocompatibility. This work paves the way towards the successful integration of stretchable devices using liquid metals embedded in a silicone rubber encapsulant for flexible surface electro-cortical grid arrays and other flexible implants.

Development, Evaluation, and Molecular Docking of Oral Dissolving Film of Atenolol

The development of oral dissolving film (ODF) of atenolol is an attempt to enhance convenience and compliance for geriatric patients suffering from hypertension. Film former is the most essential component in ODF that determines the physical characteristic and drug release. In this study, three different types of film former including HPMC E5 4% (w/v), 5% (w/v), CMC-Na 3% (w/v), 4% (w/v), and Na-alginate 2.5% (w/v), 3% (w/v) were optimized in Formula 1 (F1) to Formula 6 (F6), respectively. A solvent casting method was employed to develop ODF of atenolol. The films formed by HPMC E5 produced a smooth and flexible surface, whereas CMC-Na and Na-alginate produced gritty textured films. Satisfactory results were obtained from several physical parameters such as film thickness, folding endurance, swelling index, and disintegration time. The homogeneity, drug content, and dissolution properties of ODF with HPMC exhibited better characteristics than the other formulas. Formula 1 exhibited the highest drug release compared to the other ODFs. The molecular docking results showed that there was a hydrogen bonding between atenolol and film formers which was also supported by the FTIR spectrum. The findings of this study suggest that HPMC E5 is the most favorable film former for ODF of atenolol.

МОДЕЛЮВАННЯ ПРОЦЕСУ ШТАМПУВАННЯ ОПУКЛОГО КУТНИКА ЗГИНАННЯМ-ФОРМУВАННЯМ ПЕРЕДАВАЛЬНИМ СЕРЕДОВИЩЕМ

Computer simulation allows you to monitor the load of material and its behavior in the course of molds, to determine the energy parameters of the process, to reflect the kinematics of the tool movement, the transmitting agent and the workpiece itself. This provides a significant reduction in time and expenses for natural experiments, in general, a significant decrease in the volumes of technological preparation of stamping works. The indicated method is most suitable for improving modern stamping production using transmitting environments. For numerical experiments in the punching region of billets from the sheet, the most acceptable variational method or ICE is the most acceptable. This approach provides minimal discrepancy between the results of natural and numerical experiments. Its is widely used in various programmates Nastran, Ansys, Katy, etc., which allows you to optimize the process of receiving data reduction in time, quickly edit to all sorts of changes on deformation conditions. During the process of shaping the convex corner there are significant changes in geometry related to corrugated formation on the collateral part of the workpiece. For this reason, the approach to the formation of a mesh sampling for the MSE calculations have the features of methods of use in the size of the breakdown elements, in particular for the transmitting medium and the leaf workpiece, the size of the elements small, and for equipping can be selected large, except the flexible surface. The construction of the mathematical model based on the ITS allows not only to determine the necessary parameters of the process, but also to consider the process of shapes in individual stages, to determine the painting of a stress-deformed state, to identify the most dangerous zones of bending-stamping, changing the thickness of the material, and trace the behavior of the material after unloading . All this makes it possible to evaluate the quality of the resulting product according to the specified parameters of the process, as well as the desired results by varying the initial parameters of the model.