Copper Phosphide Nanoparticles Used for Combined Photothermal and Photodynamic Tumor Therapy

Cuproptosis: A new mechanism for anti-tumour therapy

As an indispensable trace metal element in the organism, copper acts as a key catalytic cofactor in a wide range of biological processes. Copper homeostasis disorders can be caused by either copper excess or deficiency, and copper homeostasis disorders will affect the normal physiological functions of cells and induce cell death through a variety of mechanisms, such as the emerging cuproptosis model. The imbalance of copper homeostasis will lead to the occurrence of cancer, and copper is a key factor in cell signalling, so copper is involved in the development of cancer by promoting cell proliferation, angiogenesis and metastasis, etc. The therapeutic role of Cuproptosis as a hotspot of research in cancer has also attracted much attention. Therefore, this paper comprehensively searches the literature to review the roles and mechanisms of Cuproptosis in the treatment of malignant tumours, aiming to provide new insights into the role and mechanism of Cuproptosis in anti-malignant tumour therapy and present novel ideas and methods.

Harnessing stimuli-responsive biomaterials for advanced biomedical applications

Cell behavior is intricately intertwined with the in vivo microenvironment and endogenous pathways. The ability to guide cellular behavior toward specific goals can be achieved by external stimuli, notably electricity, light, ultrasound, and magnetism, simultaneously harnessed through biomaterial-mediated responses. These external triggers become focal points within the body due to interactions with biomaterials, facilitating a range of cellular pathways: electrical signal transmission, biochemical cues, drug release, cell loading, and modulation of mechanical stress. Stimulus-responsive biomaterials hold immense potential in biomedical research, establishing themselves as a pivotal focal point in interdisciplinary pursuits. This comprehensive review systematically elucidates prevalent physical stimuli and their corresponding biomaterial response mechanisms. Moreover, it delves deeply into the application of biomaterials within the domain of biomedicine. A balanced assessment of distinct physical stimulation techniques is provided, along with a discussion of their merits and limitations. The review aims to shed light on the future trajectory of physical stimulus-responsive biomaterials in disease treatment and outline their application prospects and potential for future development. This review is poised to spark novel concepts for advancing intelligent, stimulus-responsive biomaterials.

Copper-Based biomaterials for anti-tumor therapy: Recent advances and perspectives

Copper, an essential trace element, is integral to numerous metabolic pathways across biological systems. In recent years, copper-based biomaterials have garnered significant interest due to their superior biocompatibility and multifaceted functionalities, particularly in the treatment of malignancies such as sarcomas and cancers. On the one hand, these copper-based materials serve as efficient carriers for a range of therapeutic agents, including chemotherapeutic drugs, small molecule inhibitors, and antibodies, allowing them for precise delivery and controlled release triggered by specific modifications and stimuli. On the other hand, they can induce cell death through mechanisms such as ferroptosis, cuproptosis, apoptosis, and pyroptosis, or inhibit the proliferation and invasion of cancer cells via their outstanding properties. Furthermore, advanced design approaches enable these materials to support tumor imaging and immune activation. Despite this progress, the full scope of their functional capabilities remains to be fully elucidated. This review provides an overview of the anti-tumor functions, underlying mechanisms, and design strategies of copper-based biomaterials, along with their advantages and limitations. The aim is to provide insights into the design, study, and development of novel multifunctional biomaterials, with the ultimate goal of accelerating the clinical application of copper-based nanomaterials in cancer therapy. STATEMENT OF SIGNIFICANCE: This study explores the groundbreaking potential of copper-based biomaterials in cancer therapy, uniquely combining biocompatibility with diverse therapeutic mechanisms such as targeted drug delivery and inhibition of cancer cells through specific cell death pathways. By enhancing tumor imaging and immune activation, copper-based nanomaterials have opened new avenues for cancer treatment. This review examines these multifunctional biomaterials, highlighting their advantages and current limitations while addressing gaps in existing research. The findings aim to accelerate clinical applications of these materials in the field of oncology, providing valuable insights for the design of next-generation copper-based therapies. Therefore, this work is highly relevant to researchers and practitioners focused on innovative cancer treatments.

Surface Plasmon Modulation in Cu3-xP Nanocrystals

We demonstrate modulation of the surface plasmon resonance in nonstoichiometric copper phosphide nanocrystals using spectroelectrochemical methods. Application of an anodic potential resulted in a blue-shift of the surface plasmon resonance and an incremental increase in its extinction coefficient. Conversely, upon application of a cathodic potential, the surface plasmon band red-shifted and reduced in intensity. These changes were found to be reversible over multiple cycles of anodic and cathodic potential steps. We also discuss how the postsynthetic ligand treatment impacts the surface plasmon peak and the structure of Cu3-xP nanocrystals. For example, the addition of alkylthiols resulted in the chemical decomposition of the nanocrystals. This work demonstrates how the surface plasmon peak in Cu3-xP can be used to probe changes in the structure and carrier density in these nanocrystals.

Cuproptosis, ferroptosis and PANoptosis in tumor immune microenvironment remodeling and immunotherapy: culprits or new hope

Normal life requires cell division to produce new cells, but cell death is necessary to maintain balance. Dysregulation of cell death can lead to the survival and proliferation of abnormal cells, promoting tumor development. Unlike apoptosis, necrosis, and autophagy, the newly recognized forms of regulated cell death (RCD) cuproptosis, ferroptosis, and PANoptosis provide novel therapeutic strategies for tumor treatment. Increasing research indicates that the death of tumor and immune cells mediated by these newly discovered forms of cell death can regulate the tumor microenvironment (TME) and influence the effectiveness of tumor immunotherapy. This review primarily elucidates the molecular mechanisms of cuproptosis, ferroptosis, and PANoptosis and their complex effects on tumor cells and the TME. This review also summarizes the exploration of nanoparticle applications in tumor therapy based on in vivo and in vitro evidence derived from the induction or inhibition of these new RCD pathways.

A metal ions-mediated natural small molecules carrier-free injectable hydrogel achieving laser-mediated photo-Fenton-like anticancer therapy by synergy apoptosis/cuproptosis/anti-inflammation

Tumor microenvironment (TME) plays an important role in the tumorigenesis, proliferation, invasion and metastasis. Thereby developing synergistic anticancer strategies with multiple mechanisms are urgent. Copper is widely used in the treatment of tumor chemodynamic therapy (CDT) due to its excellent laser-mediated photo-Fenton-like reaction. Additionally, copper can induce cell death through cuproptosis, which is a new modality different from the known death mechanisms and has great promise in tumor treatment. Herein, we report a natural small molecules carrier-free injectable hydrogel (NCTD Gel) consisted of Cu²⁺-mediated self-assembled glycyrrhizic acid (GA) and norcantharidin (NCTD), which are mainly governed by coordination and hydrogen bonds. Under 808 nm laser irradiation, NCTD Gel can produce reactive oxygen species (ROS), consume glutathione (GSH) and overcome hypoxia in TME, leading to synergistically regulate TME via apoptosis, cuproptosis and anti-inflammation. In addition, NCTD Gel's CDT display high selectivity and good biocompatibility as it relies on the weak acidity and H₂O₂ overexpression of TME. Notably, NCTD Gel's components are originated from clinical agents and its preparation process is easy, green and economical, without any excipients. This study provides a new carrier-free hydrogel synergistic antitumor strategy, which has a good prospect in industrial production and clinical transformation.

Copper-containing nanoparticles: Mechanism of antimicrobial effect and application in dentistry-a narrative review

Copper has been used as an antimicrobial agent long time ago. Nowadays, copper-containing nanoparticles (NPs) with antimicrobial properties have been widely used in all aspects of our daily life. Copper-containing NPs may also be incorporated or coated on the surface of dental materials to inhibit oral pathogenic microorganisms. This review aims to detail copper-containing NPs' antimicrobial mechanism, cytotoxic effect and their application in dentistry.

Transforming a Sword into a Knife: Persistent Phototoxicity Inhibition and Alternative Therapeutical Activation of Highly-Photosensitive Phytochlorin

The phototoxicity of photosensitizers (PSs) is a double-edged sword with one edge beneficial for destroying tumors while the other is detrimental to normal tissues, and the conventional "OFF-ON" strategy provides temporary inhibition so that phototoxicity would come sooner or later due to the inevitable retention and transformation of PSs in vivo. We herein put forward a strategy to convert "double-edged sword" PSs into "single-edged knife" ones with simultaneously persistent phototoxicity inhibition and alternative multiple therapeutical activation. The Chlorin e6 (Ce6) as the PS model directly assembles with Cu²⁺ ions into nanoscale frameworks (nFs) whose Cu²⁺-coordination includes both carboxyl groups and a porphyrin ring of Ce6 instead of Fe³⁺/Mn²⁺-coordination with only carboxyl groups. Compared to the high phototoxicity of Ce6, the nFs exhibit efficient energy transfer due to the dual-coordination of paramagnetic Cu²⁺ ions and the aggregation, achieving the persistent and high phototoxicity inhibition rate of >92%. Alternatively, the nFs not only activate a high photoacoustic contrast and near-infrared (NIR)-driven photothermal efficacy (3.5-fold that of free Ce6) due to the aggregation-enhanced nonradiative transition but also initiate tumor microenvironment modulation, structure disassembly, and chemodynamic effect by Cu²⁺ ions. Given these merits, the nFs achieve long-term biosecurity, no retina injury under sunlight, and a higher therapeutical output than the photodynamic effect of Ce6. This work presents a possibility of converting numerous highly phototoxic porphyrins into safe and efficient ones.