copper(2+)

Overview

Copper(2+) (Cu²⁺), commonly referred to as the cupric ion, is the divalent cationic form of copper and the predominant oxidation state of copper in biological systems. As an essential trace element, Cu²⁺ serves as a critical cofactor for a wide range of metalloenzymes and proteins involved in mitochondrial respiration, antioxidant defense, iron metabolism, and connective tissue synthesis. Its biological activity is tightly regulated by dedicated copper transporters—including ATPase copper-transporting proteins—and intracellular copper chaperones, ensuring that free ionic copper is maintained at extraordinarily low concentrations to prevent cytotoxicity. Dysregulation of copper homeostasis is implicated in a growing number of pathological states, including neurodegenerative diseases such as Alzheimer's disease, various cancers, and inflammatory conditions.

The redox activity of Cu²⁺, cycling between the cupric (Cu²⁺) and cuprous (Cu⁺) oxidation states, underpins both its physiological utility and its toxicological potential. This redox cycling enables Cu²⁺ to participate in Fenton-like reactions that generate reactive oxygen species (ROS), which can damage cellular macromolecules including proteins, lipids, and nucleic acids. In the context of oncology, this property has been deliberately exploited to induce a recently characterized form of copper-dependent cell death termed cuproptosis, which operates through mechanisms distinct from ferroptosis and apoptosis and is linked to disruption of mitochondrial metabolic function, particularly through targets such as Ferredoxin 1 (FDX1).

Focus of Latest Publications

Recent investigations of copper(2+) have focused predominantly on its therapeutic applications in cancer treatment, antimicrobial activity, and materials chemistry. Researchers have developed copper-based nanoplatforms that exploit copper's unique biological properties to induce selective tumor cell death with minimal systemic toxicity. These applications span diverse chemical architectures, including copper-doped nanoparticles, self-assembled copper nanoassemblies, and copper-coordinated organic frameworks, with particular emphasis on copper's capacity to trigger regulated cell death pathways and enhance conventional cancer therapies through synergistic mechanisms.

cuproptosis—a copper-dependent form of programmed cell death triggered by intracellular copper accumulation—has emerged as a central therapeutic mechanism. Investigators have engineered nanocarriers that deliver Cu²⁺ into tumor cells to initiate cuproptosis via inhibition of iron-sulfur cluster biosynthesis, suppression of Ferredoxin 1, and disruption of tricarboxylic acid cycle enzymes. Multiple studies demonstrate that integrating cuproptosis with complementary modalities—including photodynamic therapy, photothermal therapy, ferroptosis, and immunogenic cell death—produces synergistic antitumor effects. These integrated approaches activate antitumor immune responses through the cGAS-STING pathway and promote dendritic cell maturation. Parallel investigations have developed copper chelators based on Schiff base chemistry to deplete bioavailable copper and exploit the "copper addiction" phenotype of malignant cells, inducing necroptosis and reactive oxygen species-mediated mitochondrial damage. Clinical advancement includes phase 2 evaluation of tiomolibdate choline, an oral copper-binding agent, for Wilson disease treatment.

Beyond malignancy, copper(2+) exhibits substantial antimicrobial and tissue-regenerative properties that address clinical challenges in resistant infections. Copper-based nanoassemblies have demonstrated potent bactericidal efficacy against multidrug-resistant pathogens, particularly methicillin-resistant Staphylococcus aureus, through mechanisms combining membrane disruption and cuproptosis-like bacterial cell death mediated by intracellular copper overload. These materials simultaneously promote wound healing in diabetic and infected wound models through direct antimicrobial action and facilitation of tissue repair. Notably, copper has also been shown to restore the photostability of tigecycline, an important broad-spectrum antibiotic, by modulating its photodegradation pathway under light exposure, suggesting potential utility in topical formulations.

Copper(2+) has been extensively characterized in environmental remediation and bioanalytical applications. Multiple investigations have developed high-capacity copper-adsorbing materials—including cellulose-based composite hydrogels, covalent organic framework-enhanced platforms, and functionalized bacterial cellulose aerogels—for removing Cu(II) from heavy-metal-contaminated wastewater while maintaining structural stability and reusability over multiple adsorption-desorption cycles. In bioanalytical contexts, copper has been leveraged as a catalyst in click chemistry reactions for sensitive biomarker detection and incorporated into quantum dot systems for diagnostic imaging applications. Additionally, investigations have characterized copper(2+) roles in trace element homeostasis, including associations with metabolic dysfunction in polycystic ovary syndrome, and explored copper chelation strategies in neurodegeneration, where targeted copper sequestration has shown promise for inhibiting amyloid-beta aggregation and mitigating oxidative stress in Alzheimer's disease models.

Key Publications

• NEWJun Impact of long-term cryopreservation on serum proteome and metallome: Implications for Biobank quality control. (PloS one, 2026, PMID 42348576): "Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify ten metals: vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), rubidium (Rb), strontium (Sr), and cesium (Cs)."
• NEWJul Aromatic/aliphatic residue balance regulates Cu(II)-induced supramolecular gel formation and drug release in histidine-containing tetrapeptides. (Soft matter, 2026, PMID 42300085): "In this study, the effect of the balance between aromatic and aliphatic residues in Cu(II)-responsive tetrapeptides on self-assembly and supramolecular metallogel formation was investigated systematically."
• Jun Efficient fabrication of cellulose-based hydrogels for effective heavy metal ion adsorption from oral medical wastewater. (International journal of biological macromolecules, 2026, PMID 42235769): "The MCC@MF hydrogel exhibited effective adsorption performance for Co2+, Cd2+, Cu2+, and Ni2+ ions, with a maximum adsorption capacity of 136.2 mg g-1 for Co2+."
• May A covalent organic framework-enhanced hydrogel based on carboxylated cellulose nanofibers and water hyacinth carbon for efficient capture of dyes and heavy metal ions. (International journal of biological macromolecules, 2026, PMID 42219096): "Adsorption results revealed that the adsorption of methylene blue (MB), crystal violet (CV), Pb2+, and Cu2+ followed the pseudo-second-order kinetic and Langmuir isotherm models"
• May Copper ions restore antibacterial activity of tigecycline by regulating photodegradation pathway under light exposure‌. (Communications biology, 2026, PMID 42215682): "Cu2+ salts with development potential were confirmed to restore the antibacterial activity of tigecycline under light exposure against all tested bacterial strains (FIC<0.5) except for P. aeruginosa."
• Jun Effect of tiomolibdate choline on copper balance in patients with Wilson disease: An open-label phase 2 trial. (Hepatology communications, 2026, PMID 42155004): "The effect of repeat-dose TMC on Cu balance, serum Cu parameters, and safety was evaluated in an open-label, single-arm phase 2 study in 9 patients with WD."
• May Self-enhanced copper-doped Prussian blue nanoplatform for amplifying enzyme-like activity and photothermal effects. (International journal of pharmaceutics, 2026, PMID 42142675): "The incorporated copper ions play crucial roles in depleting excessive GSH and catalyzing Fenton-like reactions, thereby boosting the peroxidase-like activity of PB."
• May Association of serum levels of zinc and copper with pathophysiological features of polycystic ovary syndrome. (African journal of reproductive health, 2026, PMID 42137979): "This study was designed to assess the relationship between circulating levels of zinc (Zn) and copper (Cu) and the pathophysiological features of PCOS."
• Dec Impact of process impurities on developability assessments of complex antibody formats: the striking role of leachable copper. (mAbs, 2026, PMID 42125798): "...the dominant phosphate species may act as a ligand capable of mobilizing trace catalytic copper from disposable chromatography columns."
• May CaO2-Powered Nanomotors with Enhanced Cellular Uptake and Lysosomal Escape for Cuproptosis and Reactive Oxygen Species-Mediated Synergistic Cancer Therapy. (ACS applied materials & interfaces, 2026, PMID 42126988): "Notably, Cu2+ and H2O2 engage in an amplified Fenton-type reaction, yielding abundant hydroxyl radicals."