Dynamic Colloidal Photonic Crystal Hydrogels with Self-Recovery and Injectability

Simulation of self-recovery and diversity of natural photonic crystal(PC)structures remain great challenges for artificial PC materials.Motivated by the dynamic characteristics of PC nanostructures,here,we present a new strategy for the design of hydrogel-based artificial PC materials with reversible interactions in the periodic nanostructures.The dynamic PC hydrogels,derived from self-assembled microgel colloidal crystals,were tactfully constructed by reversible crosslinking of adjacent microgels in the ordered structure via phenylboronate covalent chemistry.As proof of concept,three types of dynamic colloidal PC hydrogels with different structural colors were prepared.All the hydrogels showed perfect self-healing ability against physical damage.Moreover,dynamic crosslinking within the microgel crystals enabled shear-thinning injection of the PC hydrogels through a syringe(indicating injectability or printability),followed by rapid recovery of the structural colors.In short,in addition to the great significance in biomimicry of self-healing function of natural PC materials,our work provides a facile strategy for the construction of diversified artificial PC materials for different applications such as chem-/biosensing,counterfeit prevention,optical display,and energy conversion.

Thermo-responsive imprinted hydrogel with switchable sialic acid recognition for selective cancer cell isolation from blood

In this work,a sialic acid(SA)-imprinted thermo-responsive hydrogel layer was prepared for selective capture and release of cancer cells.The SA-imprinting process was performed at 37℃ using thermo-responsive functional monomer,thus generating switchable SA-recognition sites with potent SA binding at 37℃and weak binding at a lower temperature(e.g.,25℃).Since SA is often overexpressed at the glycan terminals of cell membrane proteins or lipids,the SA-imprinted hydrogel layer could be used for selective cancer cell recognition.Our results confirmed that the hydrogel layer could efficiently capture cancer cells from not only the culture medium but also the real blood samples.In addition,the captured cells could be non-invasively released by lowing the temperature.Considering the non-invasive processing mode,considerable capture efficiency,good cell selectivity,as well as the more stable and durable SA-imprinted sites compared to natural antibodies or receptors,this thermo-responsive hydrogel layer could be used as a promising and general platform for cell-based cancer diagnosis.

Efficient nanozyme engineering for antibacterial therapy

Antimicrobial resistance(AMR)poses a huge threat to human health.It is urgent to explore efficient ways to suppress the spread of AMR.Antibacterial nanozymes have become one of the powerful weapons to combat AMR due to their enzyme-like catalytic activity with a broad-spectrum antibacterial performance.However,the inherent low catalytic activity of nanozymes limits their expansion into antibacterial applications.In this regard,a variety of advanced chemical design strategies have been developed to improve the antimicrobial activity of nanozymes.In this review,we have summarized the recent progress of advanced strategies to engineer efficient nanozymes for fighting against AMR,which can be mainly classified as catalytic activity improvement,external stimuli,bacterial affinity enhancement,and multifunctional platform construction according to the basic principles of engineering efficient nanocatalysts and the mechanism of nanozyme catalysis.Moreover,the deep insights into the effects of these enhancing strategies on the nanozyme structures and properties are highlighted.Finally,current challenges and future perspectives of antibacterial nanozymes are discussed for their future clinical potential.