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Chips-based platforms intended for single-cell manipulation are considered powerful tools to analyze intercellular interactions and cellular functions. Although the conventional cell co-culture models could investigate cell communication to some extent, the role of a single cell requires further analysis. In this study, a precise intercellular interaction model was built using a microelectrode array [microelectrode array (MEA)]-based and dielectrophoresis-driven single-cell manipulation chip. The integrated platform enabled precise manipulation of single cells, which were either trapped on or transferred between electrodes. Each electrode was controlled independently to record the corresponding cellular electrophysiology. Multiple parameters were explored to investigate their effects on cell manipulation including the diameter and depth of microwells, the geometry of cells, and the voltage amplitude of the control signal. Under the optimized microenvironment, the chip was further evaluated using 293T and neural cells to investigate the influence of electric field on cells. An examination of the inappropriate use of electric fields on cells revealed the occurrence of oncosis. In the end of the study, electrophysiology of single neurons and network of neurons, both differentiated from human induced pluripotent stem cells (iPSC), was recorded and compared to demonstrate the functionality of the chip. The obtained preliminary results extended the nature growing model to the controllable level, satisfying the expectation of introducing more elaborated intercellular interaction models.

Blood contact materials require strong anti-fouling capabilities to avoid thrombus formation. Recently, TiO2-based photocatalytic antithrombotic treatment has gained focus. Nevertheless, this method is restricted to titanium materials with photocatalytic abilities. This study offers an alternative solution that can be applied to a broader range of materials: piranha solution treatment. Our findings revealed that the free radicals generated by the treatment effectively altered the surface physicochemical properties of various inorganic materials, enhancing their surface hydrophilicity and oxidizing organic contaminants, thus improving their antithrombotic properties. Additionally, the treatment resulted in contrasting effects on the cellular affinity of SS and TiO2. While it significantly reduced the adhesion and proliferation of SMCs on SS surfaces, it significantly enhanced these on TiO2 surfaces. These observations suggested that the impact of the piranha solution treatment on the cellular affinity of biomaterials was closely tied to the intrinsic properties of the materials. Thus, materials suitable for piranha solution treatment could be selected based on the functional requirements of implantable medical devices. In conclusion, the broad applicability of piranha solution surface modification technology in both blood-contact and bone implant materials highlights its promising prospects.

Silver nanoparticles (AgNPs) are widely used because of their excellent antimicrobial properties. However, the poor hemocompatibility limits the application of AgNPs in blood contact materials. General approaches to improve the hemocompatibility of AgNPs-containing surfaces are to construct barrier layers or co-immobilize anticoagulant biomolecules. But such modification strategies are often cumbersome to prepare and have limited applications. Therefore, this study proposes a simple UV-photo-functionalization strategy to improve the hemocompatibility of AgNPs. We loaded AgNPs onto titanium dioxide (TiO2) nanoparticles to form a composite nanoparticles (Ag@TiO2NPs). Then, UV treatment was performed to the Ag@TiO2NPs, utilizing the diffusible photo-induced anticoagulant properties of TiO2 nanoparticles to enhance the hemocompatibility of AgNPs. After being deposited onto the PU surface, the photo-functionalized Ag@TiO2NPs coating showed excellent antibacterial properties against both Gram-positive/Gram-negative bacteria. Besides, In vitro and ex-vivo experiments demonstrated that the photo-functionalized Ag@TiO2NPs coating had desirable hemocompatibility. This modification strategy can provide a new solution idea to improve the hemocompatibility of metal nanoparticles.