Owing to their unique physicochemical properties and comparable size to biomacromolecules, functional nanostructures have served as powerful supports to construct enzyme-nanostructure biocatalysts (nanobiocatalysts). Of particular importance, recent years have witnessed the development of novel nanobiocatalysts with remarkably increased enzyme activities. This review provides a comprehensive description of recent advances in the field of nanobiocatalysts, with systematic elaboration of the underlying mechanisms of activity enhancement, including metal ion activation, electron transfer, morphology effects, mass transfer limitations, and conformation changes. The nanobiocatalysts highlighted here are expected to provide an insight into enzyme–nanostructure interaction, and provide a guideline for future design of high-efficiency nanobiocatalysts in both fundamental research and practical applications.

Magnetic nanomaterials with enhanced enzymatic activities have garnered significant attention from researchers worldwide. Magnetic nanomaterials, including nanozymes and immobilized enzymes, can initiate specific catalytic reactions in the diseased microenvironment for cancer treatment. In this review, we aim to present the significant advancements in synthesizing various types of magnetic nanomaterials with enhanced enzymatic activities and their antitumor therapy applications in the past five years. We first show the representative magnetic nanomaterials and elucidate their fundamental mechanisms related to magnetic properties and electromagnetic effects (such as magneto-thermal, magneto-mechanical, and magneto-electric effects). Secondly, we introduce magnetic nanozymes and magnetic immobilized enzymes and discuss the creative methods allowing the enzymatic activities of nanomaterials to be remotely enhanced by various electromagnetic effects. We also discuss some innovative magnetic nanomaterials that exhibit unique responsiveness to external energies (such as X-rays and ultrasounds) for killing cancer cells. Finally, we address future research suggestions in rationally designing advanced magnetic nanomaterials with remote increased enzymatic activities and discuss challenges and opportunities for efficient cancer therapy.

X-ray-mediated wireless optogenetic neurostimulation (X-optogenetics) at any brain depth is a powerful technology for neuroscience studies and neurological disorder treatment. However, there is still a lack of effective and safe X-optogenetic neural inhibition technology because of the need for a precise spectral match degree between scintillator and inhibitory opsins and sufficient light intensity emitted from X-ray-induced scintillation. Here, we report an efficient X-optogenetic neural inhibition technology that achieves both wireless deep-brain stimulation and rapid behavioral suppression in freely moving mice. First, we developed two novel inorganic scintillators: terbium-doped gadolinium oxysulfide (Gd₂O₂S: Tb) and europium-doped yttrium oxide (Y₂O₃: Eu). The Gd₂O₂S: Tb and Y₂O₃: Eu can absorb X-ray energy and emit green and red visible light, respectively. We demonstrated that the visible light emitted from X-ray-mediated scintillation effectively activated two inhibitory opsins (ArchT and eNpHR 3.0), which facilitated successful inhibition of the GABAergic neural activity in the ventral tegmental area (VTA) of mice. Further, this X-optogenetic neural inhibition technology wirelessly and significantly suppressed itch-induced scratching bouts (about 52%) in awake, freely moving mice. Importantly, owing to the superior radioluminescence performances of scintillators, our X-optogenetic neural inhibition technology only required a low dose of X-ray (2.78 Gy), which is substantially lower than that (7 Gy) reported in a previous study. By enabling wirelessly efficient and safe neural inhibition in the deep brain, this X-optogenetic technology holds promise for advancing neuroscience investigations and therapeutic applications in large living subjects.