Solution-based fabrication of mechanically transformative materials for implantable applications

An Integrative Bioorthogonal Nanoengineering Strategy for Dynamically Constructing Heterogenous Tumor Spheroids

Although tumor models have revolutionized perspectives on cancer aetiology and treatment, current cell culture methods remain challenges in constructing organotypic tumor with in vivo-like complexity, especially native characteristics, leading to unpredictable results for in vivo responses. Herein, the bioorthogonal nanoengineering strategy (BONE) for building photothermal dynamic tumor spheroids is developed. In this process, biosynthetic machinery incorporated bioorthogonal azide reporters into cell surface glycoconjugates, followed by reacting with multivalent click ligand (ClickRod) that is composed of hyaluronic acid-functionalized gold nanorod carrying dibenzocyclooctyne moieties, resulting in rapid construction of tumor spheroids. BONE can effectively assemble different cancer cells and immune cells together to construct heterogenous tumor spheroids is identified. Particularly, ClickRod exhibited favorable photothermal activity, which precisely promoted cell activity and shaped physiological microenvironment, leading to formation of dynamic features of original tumor, such as heterogeneous cell population and pluripotency, different maturation levels, and physiological gradients. Importantly, BONE not only offered a promising platform for investigating tumorigenesis and therapeutic response, but also improved establishment of subcutaneous xenograft model under mild photo-stimulation, thereby significantly advancing cancer research. Therefore, the first bioorthogonal nanoengineering strategy for developing dynamic tumor models, which have the potential for bridging gaps between in vitro and in vivo research is presented.

A facile and scalable patterning approach for ultrastretchable liquid metal features

Liquid metals represent an attractive class of compliant conductors featuring metallic conductivity and inherent deformability. The widespread implementation of liquid metal conductors in stretchable electronics is currently hindered by the lack of a facile patterning approach. In this study, we introduce a facile and scalable patterning approach to create liquid metal features on an elastomer substrate. A screen-printed Ag nanoflake pattern is employed as a template for the subsequent selective coating of a liquid metal layer. The as-prepared liquid metal conductors show a bulk-level conductivity of ∼2.7 × 10⁴ S cm^-1, an ultrahigh stretchability of up to 700% tensile strain, and excellent electromechanical durability. The practical suitability is demonstrated by the successful fabrication of an ultradeformable ribbon cable and a smart sensing glove. The efficient and economical access to ultrastretchable liquid metal features may open up a broad range of emerging applications in soft electronic devices and systems.