Stable hydrogen-bonded organic frameworks and their photo-and electro-responses

Hydrogen-bonded organic frameworks(HOFs)are a recent class of porous materials that have garnered considerable research interest owing to their distinctive characteristics.HOFs can be constructed through judicious selection of H-bonding motifs,which are further enforced by other weak intermolecular interactions such asπ–πstacking,van der Waals forces,and framework interpenetration.Taking advantage of these interactions,we can expand the functional field of HOFs by introducing active molecules.Recently,researchers have made substantial advancements in using HOFs for chemical sensing,catalysis,proton conduction,biological applications,and others.The low bonding energy of H-bonds allows for precise control over the concentration of ligands in solvents,forming diverse HOF structures.These varied structures offer significant advantages for producing HOFs with photo-responsive and electro-responsive properties.However,the presence of H-bonds in HOFs results in their inherent lower stability compared to metal-organic frameworks(MOFs)and covalent-organic frameworks(COFs)formed via coordination and covalent bonds,respectively.As a result,the pursuit of stable and innovative HOF materials with novel functional sites remains an ongoing challenge.This review provides an overview of recent research progress in the development of new strategies for stable HOF synthesis and applications of HOFs with stimuli-responsive properties.We first classified all synthetic methods reported to date and discussed the stable HOFs synthesized,as well as their unique properties and applications.In addition,we summarized the applications of HOFs utilizing their synergistic responses to external stimuli,including photo,electrical,pressure,and chemical stimuli.We systematically reviewed stable HOF synthesis and applications,which may lead to a deeper understanding of the structure–activity relationship for these materials and guide future HOF design.

Engineering nanomedicines for immunogenic eradication of cancer cells:Recent trends and synergistic approaches

Resistance to cancer immunotherapy is mainly attributed to poor tumor immunogenicity as well as the immunosuppressive tumor microenvironment(TME)leading to failure of immune response.Numerous therapeutic strategies including chemotherapy,radiotherapy,photodynamic,photothermal,magnetic,chemodynamic,sonodynamic and oncolytic therapy,have been developed to induce immunogenic cell death(ICD)of cancer cells and thereby elicit immunogenicity and boost the antitumor immune response.However,many challenges hamper the clinical application of ICD inducers resulting in modest immunogenic response.Here,we outline the current state of using nanomedicines for boosting ICD of cancer cells.Moreover,synergistic approaches used in combination with ICD inducing nanomedicines for remodeling the TME via targeting immune checkpoints,phagocytosis,macrophage polarization,tumor hypoxia,autophagy and stromal modulation to enhance immunogenicity of dying cancer cells were analyzed.We further highlight the emerging trends of using nanomaterials for triggering amplified ICD-mediated antitumor immune responses.Endoplasmic reticulum localized ICD,focused ultrasound hyperthermia,cell membrane camouflaged nanomedicines,amplified reactive oxygen species(ROS)generation,metallo-immunotherapy,ion modulators and engineered bacteria are among the most innovative approaches.Various challenges,merits and demerits of ICD inducer nanomedicines were also discussed with shedding light on the future role of this technology in improving the outcomes of cancer immunotherapy.

Multi-functional stimuli-responsive biomimetic flower assembled from CLCE and MOF-based pedals

Simulating the structures and behaviors of living organisms are of great significance to develop novel multi-functional intelligent devices. However, the development of biomimetic devices with complex deformable structures and synergistic properties is still on the way. Herein, we propose a simple and effective approach to create the multi-functional stimuli-responsive biomimetic devices with independently pre-programmable colorful visual patterns, complex geometries and morphable modes. The metal organic framework(MOF)-based composite film acts as a rigidity actuation substrate to support and mechanically guide the spatial configuration of the soft chiral nematic liquid crystal elastomer(CLCE) sheet. We can directly program the structural color of the CLCE sheet by adjusting the thickness distribution without tedious chemical modification. By using this coordination strategy, we fabricate an artificial flower, which exhibits a synergistic effect of both shape transformation and color change like paeonia ‘Coral Sunset’at different flowering stages, and can even perform different flowering behaviors by bending, twisting and curling petals. The assembled bionic flower is innovatively demonstrated to respond to local stimuli of humidity, heat or ultraviolet irradiation. Therefore, the spatial assembly of CLCE combined with functional MOF materials has a wide range of potential application in multi-functional integrated artificial systems.