Dynamic biointerfaces with reversible surface bioactivities enable dynamic modulation of cell−material interactions, thus attracting great attention in biomedical science. Herein, we demonstrated a paradigm shift of dynamic biointerfaces from macroscopical substrates to micron-sized particles by reversible engineering of a phenylboronic acid (PBA)-functionalized magnetic microbead with mussel-inspired cancer cell-targeting peptide. Due to reversible catechol−boronate interactions between the peptides and microbeads, the micron-sized dynamic biointerface exhibited sugarresponsive cancer-targeting activity, showing the potential as a microplatform for magnetic and noninvasive isolation of cancer cells through natural biofeedback mechanism (e.g., human glycemic volatility). Our results demonstrated that the dynamic magnetic platform was capable of selective cancer cell capture (∼85%) and sugar-triggered release of them (>93%) in cell culture medium with high efficiency. More importantly, by using this platform, a decent number of target cells (∼23 on average) could be magnetically isolated and identified from artificial CTC blood samples (1 mL) spiked with 100 cancer cells. In view of the biomimetic nature, high capture efficiency, excellent selectivity, and superiority in cell separation and purification processes, the dynamic magnetic microplatform reported here would be a promising and general tool for rare cell detection and separation and cell-based disease diagnosis.

Membrane-disrupting antimicrobial peptides continue to attract increasing attention due to their potential to combat multidrug-resistant bacteria. However, some limitations are found in the success of clinical setting-based antimicrobial peptide agents, for instance, the poor stability of antimicrobial peptides in vivo and their short-term activity. Self-assembled peptide materials can improve the stability of antimicrobial peptides, but the biosafety of peptide-based materials is the main concern, although they are considered to be biocompatible, because some peptide aggregates would possibly induce protein misfolding, which could be related to amyloid-related diseases. Therefore, in this work, we designed two peptides and constructed peptide-based nanofibrils by self-assembly before its utilization. It is found that the fibrils could release the antimicrobial peptide by disassembly for microbial membrane lysis in the presence of bacteria. The designed peptide-based fibrils presented a good and long-term antimicrobial activity with bacterial membrane disruption and the efflux of calcium from bacteria. Furthermore, it could be used to construct hybrid macrofilms displaying low cytotoxicity, low hemolytic activity, and good biocompatibility. The innovative design strategy could be beneficial for the development of smart antimicrobial nanomaterials.

Herein we reported a versatile dynamic biointerface based on pH-responsive peptide self-assembling and disassembling to capture the bacteria to avoid bacteria further infected tissue around, and can release peptides from...

As mimics of the extracellular matrix, surfaces with the capability of capturing and releasing specific cells in a smart and controllable way play an important role in bacterial isolation. In this work, we fabricated a dual-responsive smart biointerface via peptide self-assembly and reversible covalent chemistry biomimetic adhesion behavior for bacterial isolation. Compared with that of the biointerface based on a single reversible covalent bond, the bacterial enrichment efficiency obtained in this work was 2.3 times higher. Furthermore, the release of bacteria from the surface could be achieved by dual responsiveness (sugar and enzyme), which makes the biointerface more adaptable and compatible under different conditions. Finally, the reusability of the biointerface was verified via peptide self-assembly and the regenerated smart biointerface still showed good bacterial capture stability and excellent release efficiency, which was highly anticipated to be more widely applied in biomaterial science and biomedicine in the future.