Natural enzymes play an important role in maintaining normal life activities, but suffer in their inherent instability, harsh reaction conditions and high purification costs, which limit their wide applications in vitro. Compared to natural enzymes, nanozymes with high stability, low cost, and ease of structural regulation and modification attract the great interests and are widely applied to biomedicine, environmental control, industrial production and other fields due to their enzyme-like activities and selectivity. As an essential element and one of the active central metals of natural enzymes in the human body, copper-based (Cu-based) nanozymes have received extensive attentions and researches. This review focused on the classification of Cu-based nanozymes, such as Cu nanozymes, Cu oxide nanozymes, Cu telluride nanozymes, Cu single-atom nanozymes, and Cu-based metal organic framework nanozymes. Then this review described the enzyme-like activities and catalytic mechanisms of Cu-based nanozymes, and also summarized the applications of Cu-based nanozymes, including biosensing, wound healing, acute kidney injury, and tumors. The challenges and future development direction of Cu-based nanozymes were proposed.

Hypochlorous acid (HClO) is one of the reactive oxygen species (ROS), taking crucial parts in many physiological and pathological processes. However, excessive HClO causes tissue injuries, atherosclerosis, neurodegeneration diseases, and even cancers. Therefore, real-time detection of HClO in cancer cells is of importance for exploring the effect of HClO in tumor progression or immunotherapy. Quite different from present organic molecular probes, a novel inorganic-based hydrophilic fluorescent nanoprobe was developed by simply integrating fluorescein isothiocyanate (FITC) into hollow mesoporous Prussian Blue nanoparticles (HMPB) in this work. Owing to inner filter effect, fluorescence of FITC within HMPB quenches to some extent, which can be restored via the Fe²⁺-ClO^- redox reaction. A typical fluorescence increase of FITC at emission peak of 520 nm can be clearly observed in the presence of HClO in vitro, which exhibits a good linear relationship in the range of 5×10^-6-50×10^-6 mol/L in HClO detection and its detection limit is calculated to be 2.01×10^-6 mol/L. Furthermore, the cellular experiment demonstrates the specific detection capability of HClO in cancer cells with high sensitivity by the obtained nanoprobe.

The robust development of clinical medicine and biomaterials boosts diagnostic imaging, effective treatment, and precise theranostics in various diseases. The emerging interdiscipline of materials and medicine, termed as materdicine, aims to surmount the critical obstacles and challenges faced by traditional medicine, such as systemic toxicity, poor bioavailability, inferior site-targeting specificity, and unsatisfied diagnostic/therapeutic efficacy. Herein, the state-of-the-art advances regarding the applications of diverse medmaterials for disease diagnosis, therapy, and theranostics are systematically summarized in this review, especially focusing on the nanoscale medmaterials. We firstly emphasize and discuss biomedical imaging (e.g., optical imaging, magnetic resonance imaging, ultrasound imaging, computed tomography imaging) and therapeutic strategies (e.g., photothermal therapy, dynamic therapy, immunotherapy, synergistic therapy) in the field of cancer treatment. Furthermore, we highlight the important progress of medmaterials in the diagnosis and treatment of other kinds of diseases including orthopedic diseases, respiratory system, and brain diseases. Especially, the elaborated medmaterials for other representative biomedical applications, such as biosensing and antibacteria, are illustrated in detail. Finally, we discuss the current challenges and future opportunities for the practical application of these unique medmaterials in materdicine for accelerating their early realization of clinical translations, promoting the progresses of clinical medicine and benefiting the patients.

As a common malignant bone tumor, osteosarcoma is usually treated by surgical resection. However, the bone defects caused by surgery are difficult to heal, and the possibility of osteosarcoma recurrence can also be increased by the residual tumor cells. Therefore, a Nd-doped mesoporous borosilicate bioactive glass-ceramic bone cement was developed for repair of bone defects and synergistic therapy of osteosarcoma. Firstly, as photothermal agent and drug carrier, Nd-doped mesoporous borosilicate bioactive glass-ceramic (MBGC-xNd) microspheres were prepared through Sol-Gel method and solid-state reaction. Then MBGC-xNd microspheres were mixed with sodium alginate (SA) solution to prepare injectable bone cement (MBGC-xNd/SA). The results showed that Nd³⁺ endows microspheres with controllable photothermal properties, and microspheres loaded with doxorubicin (DOX) showed sustained drug release behavior. In addition, the drug release from drug-loaded bone cement was significantly accelerated with the increase of temperature, indicating that the heat generated by photothermal therapy had the possibility of promoting the release of DOX. In vitro cell experiment results showed that MBGC-xNd/SA had good osteogenic activity. Simultaneously, photothermal-chemical combination therapy had a more significant killing effect on MG-63 osteosarcoma cells, indicating a synergistic effect. Therefore, MBGC-xNd/SA, as a novel multifunctional bone repair material, exhibits a potential application in the postoperative treatment of osteosarcoma.

Developing a hydrogel with tumor therapy and skin wound healing is of great significance for eliminating residual tumor cells and promoting skin wound healing after surgical resection of skin cancers. Here, copper- incorporated calcium silicate (Cu-CS) nanorods were prepared by a molten salt method with calcium hydrate silicate as matrix, NaCl and KCl as molten salt, and CuSO₄·5H₂O as Cu source, and then incorporated into sodium alginate (SA) hydrogel to achieve Cu-CS/SA composite hydrogel. The results showed that Cu content of Cu-CS nanorods increased with the increase of the Cu source addition and the treatment temperature, but their catalytic activity for producing hydroxy radical (·OH) from H₂O₂ exhibited the trend of increasing and then decreasing. Nanorods, prepared with 3% copper source (3Cu-CS) at 700 ℃, displayed the best catalytic performance. Cu with +2 valence state could be uniformly distributed on the surface of Cu-CS nanorods, with Cu content as low as 0.61%. Importantly, Cu-CS/SA hydrogel with Cu-CS nanorods less than 20% were biocompatible and could catalyze H₂O₂ to produce cytotoxic ·OH in a simulated tumor microenvironment, exhibiting outstanding chemodynamic effect. Furthermore, Cu-CS/SA hydrogel could promote proliferation and migration of human umbilicle vein endothelial cells and human dermal fibroblast. Therefore, Cu-CS/SA hydrogel is a promising material for applying in tumor therapy and skin wound healing.

With the development of mesoporous materials and biomedicine, hollow periodic mesoporous organosilicas (HPMOs), as a new type of mesoporous silicon material, stands out among many mesoporous materials because of its high specific surface area, high drug loading, good biocompatibility, multifunctional organic-inorganic hybrid framework, low cytotoxicity and biodegradability. Drug delivery systems based on HPMOs have been continuously developed, it provides a new strategy for tumor treatment. This article summarized the synthetic progress of HPMOs in recent years, briefly introduced the types of HPMOs, mainly expounded the hard template method, liquid interface assembly method and interface recombination-transformation method, and summarized its application in tumor therapy. Finally, challenges and future development trends as a drug carrier were prospected, in order to provide reference for the preparation and application of HPMOs in tumor therapy.

Two-dimensional (2D) materials have brought about significant technological advancements in the field of biomaterials. Transition metal carbides and/or nitrides (MXenes) have a planar structure educed from their corresponding parent MAX phase by selective etching of ‘A’ and further delamination. Since the first MXene was reported in 2011, MXenes now comprise a rapidly growing family of 2D materials, having attracted extensive attention from researchers. Owing to their excellent electronic properties, outstanding photothermal conversion performance, high specific surface area, good biocompatibility, and low toxicity, MXenes have shown a good application prospect in tumor theranostics. This paper reviews substantive findings of the original researches focused on the preparation, property and application in tumor theranotics, including recent advances, challenges and future perspectives of MXenes. Firstly, we briefly summarize the preparation methods and property of MXenes, including HF acid method, fluoride salt method, molten salt method, alkali-assisted hydrothermal method, and chemical vapor deposition method, as well as stability, mechanical, optical, and electrical properties. Secondly, we focus on the application of MXenes in photothermal therapy and combined therapy. The usual method is to combine photothermal therapy, photodynamic therapy and chemotherapy to carry out multi-modal combined treatment of tumors. The combined therapy can also be improved by constructing surface nanopores of MXenes and loading chemotherapy drugs in them. Furthermore, enhanced MXenes synergistic therapeutic effect on tumor and reduced toxic side effects on normal tissue can be endued by active targeting technology. In addition, the preparation of multifunctional MXenes composite nanomaterials to obtain radiation treatment and imaging capabilities such as computed tomography scans and magnetic resonance imaging, can establish an integrated platform for MXenes theranostics. Finally, we briefly introduced other applications of MXenes in biomedicine which are beneficial to tumor theranostics, and elaborate the current challenges and future development prospects of MXenes in cancer theranostics.