Individual molecules have been demonstrated to exhibit promising applications as functional components in the fabrication of computing nanocircuits. Based on their advantage in chemical tailorability, many molecular devices with advanced electronic functions have been developed, which can be further modulated by the introduction of external stimuli. Here, orthogonally modulated molecular transport junctions are achieved via chemically fabricated nanogaps functionalized with dithienylethene units bearing organometallic ruthenium fragments. The addressable and stepwise control of molecular isomerization can be repeatedly and reversibly completed with a judicious use of the orthogonal optical and electrochemical stimuli to reach the controllable switching of conductivity between two distinct states. These photo-/electro-cooperative nanodevices can be applied as resettable electronic logic gates for Boolean computing, such as a two-input OR and a three-input AND-OR. The proof-of-concept of such logic gates demonstrates the possibility to develop multifunctional molecular devices by rational chemical design.

The emergence of drug-resistant microbes has become a threat to global health, and microbial infections severely limit the use of healthcare materials. To achieve efficient antimicrobial therapy, supramolecular hydrogels demonstrate unprecedented advantages in medical applications due to the tunable and reversible nature of their supramolecular interactions and the capability of hydrogels to incorporate various therapeutic agents. Herein, antimicrobial hydrogels are categorized according to their inherent antimicrobial properties or based on their roles in encapsulating antimicrobial materials. Moreover, strategies to further enhance the antimicrobial efficacy of hydrogels are highlighted, such as the incorporation of antifouling agents or the enabling of response towards physiological cues. We envision that supramolecular hydrogels, in combination with modern medical technology and devices, will contribute to the development of efficient and safe systems for antimicrobial therapy.

The reciprocal mechanical interaction of engineered materials with biointerfaces have long been observed and exploited in biomedical applications. It contributes to the rise of biomechano-responsive materials and biomechano-stimulatory materials, constituting the biomechano-interactive interfaces. Here, endogenous and exogenous biomechanical stimuli available for mechanoresponsive interfaces are briefed and their mechanistic responses, including deformation and volume change, mechanomanipulation of physical and chemical bonds, dissociation of assemblies, and coupling with thermoresponsiveness are summarized. The mechanostimulatory materials, however, are capable of delivering mechanical cues, including stiffness, viscoelasticity, geometrical constraints, and mechanical loads, to modulate physiological and pathological behaviors of living tissues through the adaptive cellular mechanotransduction. The biomechano-interactive materials and interfaces are widely implemented in such fields as mechanotriggered therapeutics and diagnosis, adaptive biophysical sensors, biointegrated soft actuators, and mechanorobust tissue engineering, which have offered unprecedented opportunities for precision and personalized medicine. Pending challenges are also addressed to shed a light on future advances with respect to translational implementations.

A platform of mechanotactic hybrids is established by projecting lateral gradients of apparent interfacial stiffness onto the planar surface of a compliant hydrogel layer using an underlying rigid substrate with microstructures inherited from 3D printed molds. Using this platform, the mechanistic coupling of epithelial migration with the stiffness of the extracellular matrix (ECM) is found to be independent of the interfacial compositional and topographical cues.

Bacterial infections remain a leading threat to global health because of the misuse of antibiotics and the rise in drug‐resistant pathogens. Although several strategies such as photothermal therapy and magneto‐thermal therapy can suppress bacterial infections, excessive heat often damages host cells and lengthens the healing time. Here, a localized thermal managing strategy, thermal‐disrupting interface induced mitigation (TRIM), is reported, to minimize intercellular cohesion loss for accurate antibacterial therapy. The TRIM dressing film is composed of alternative microscale arrangement of heat‐responsive hydrogel regions and mechanical support regions, which enables the surface microtopography to have a significant effect on disrupting bacterial colonization upon infrared irradiation. The regulation of the interfacial contact to the attached skin confines the produced heat and minimizes the risk of skin damage during thermoablation. Quantitative mechanobiology studies demonstrate the TRIM dressing film with a critical dimension for surface features plays a critical role in maintaining intercellular cohesion of the epidermis during photothermal therapy. Finally, endowing wound dressing with the TRIM effect via in vivo studies in S. aureus infected mice demonstrates a promising strategy for mitigating the side effects of photothermal therapy against a wide spectrum of bacterial infections, promoting future biointerface design for antibacterial therapy.

No abstract

Graphene has attracted tremendous interest in the fi elds of materials science and biomedicine due to its extraordinary physiochemical properties, such as mechanical strength, large surface area, biocompatibility and chemically stability. [1][2][3][4][5][6] Signifi cant progress has been made in the use of graphene for bio-related applications, including biosensing through graphene-quenched fl uorescence, graphene-assisted cell imaging, and graphene-based nanocarrier for drug delivery and cancer therapy. [ 7,8 ] However, the development of graphene-based biomaterials/devices for applications, such as biological detection and tissue engineering, is still in its infancy, requiring the rational design and assembly of graphene or its derivatives to achieve novel functions. [ 9,10 ] Further integration of the widely available graphene sheets as two-dimensional (2D) nanoscale building blocks, into three-dimensional (3D) macroscopic assemblies and ultimately into a functional system is essential to extend its biomedical applications. [ 9,[11][12][13] Recently, we reported that the graphene-based free standing honeycomb fi lms synthesized via the "on water spreading" method exhibited superior broad spectrum antibacterial activity, which provided a low-cost facile strategy for the creation of such graphene assemblies and may serve as a useful architecture for promising biomedical applications. [ 14 ] Circulating tumor cells (CTCs) are cells that have shed into the vasculate from a primary tumor and circulate in the blood vessel, [ 15,16 ] and facilitate the spread of carcinomas. [ 17,18 ] The detection and isolation of CTCs have recently become a topic of interest in cancer research. [ 19,20 ] To date, several technologies, such as magnetic separation by capture-agent coated magnetic beads, [ 21 ] mechanical separation to isolate CTCs by size difference, [22][23][24] and microfl uidics-based cell capture through enhancing cell-substrate contact frequency, [25][26][27][28][29][30][31] have been developed for specifi c recognition and capture of targeted CTCs. Recently, a silicon nanowire substrate coated with antibody targeting epithelial cell adhesion molecules (i.e., EpCAM), has been successfully utilized to isolate EpCAM-positive CTCs with high capture effi ciency. [ 10,32 ] The mechanism of this relies on the enhanced local topographic interactions between the substrate and nanoscale components of the cellular surface (i.e., microvilli and fi lopodia). [32][33][34][35][36] Such systems allow for considerable increase in the contact frequency between substrate and target cells, thus enhancing the fi ltration and CTCcapture effi ciency, [37][38][39][40][41] and enabling a variety of increasingly sensitive and reproducible techniques for CTC detection and therapy. [ 30,32,42,43 ] Herein, we report a 3D hierarchical nanostructured graphene platform that uniquely combines microporosity with immunoaffi nity-driven cancer cell-capture nanostructure by integrating 1) ZnO nanorod array grown on 3D free-standing graphene foam, a...

Programmable polymer substrates, which mimic the variable extracellular matrices in living systems, are used to regulate multicellular morphology, via orthogonally modulating the matrix topography and elasticity. The multicellular morphology is dependent on the competition between cell-matrix adhesion and cell-cell adhesion. Decreasing the cell-matrix adhesion provokes cytoskeleton reorganization, inhibits lamellipodial crawling, and thus enhances the leakiness of multicellular morphology.