Unveiling the promising anticancer effect of copper-based compounds: a comprehensive review

Copper is a necessary micronutrient for maintaining the well-being of the human body. The biological activity of organic ligands, especially their anticancer activity, is often enhanced when they coordinate with copper(I) and (II) ions. Copper and its compounds are capable of inducing tumor cell death through various mechanisms of action, including activation of apoptosis signaling pathways by reactive oxygen species (ROS), inhibition of angiogenesis, induction of cuproptosis, and paraptosis. Some of the copper complexes are currently being evaluated in clinical trials for their ability to map tumor hypoxia in various cancers, including locally advanced rectal cancer and bulky tumors. Several studies have shown that copper nanoparticles can be used as effective agents in chemodynamic therapy, phototherapy, hyperthermia, and immunotherapy. Despite the promising anticancer activity of copper-based compounds, their use in clinical trials is subject to certain limitations. Elevated copper concentrations may promote tumor growth, angiogenesis, and metastasis by affecting cellular processes.

Recent Advances in Cancer Therapeutic Copper-Based Nanomaterials for Antitumor Therapy

Copper serves as a vital microelement which is widely present in the biosystem, functioning as multi-enzyme active site, including oxidative stress, lipid oxidation and energy metabolism, where oxidation and reduction characteristics are both beneficial and lethal to cells. Since tumor tissue has a higher demand for copper and is more susceptible to copper homeostasis, copper may modulate cancer cell survival through reactive oxygen species (ROS) excessive accumulation, proteasome inhibition and anti-angiogenesis. Therefore, intracellular copper has attracted great interest that multifunctional copper-based nanomaterials can be exploited in cancer diagnostics and antitumor therapy. Therefore, this review explains the potential mechanisms of copper-associated cell death and investigates the effectiveness of multifunctional copper-based biomaterials in the field of antitumor therapy.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Hyaluronic acid functionalized ZnO nanoparticles co-deliver AS and GOD for synergistic cancer starvation and oxidative damage

Artesunate was reported to have inhibition effect on tumors via amplified oxidative stress while the lack of intratumoral ferrous ions supply greatly hinders its efficacy. Herein, the AS/GOD@HAZnO NPs we proposed could be efficiently taken in by the affinity between hyaluronic acid and the CD44 receptors. DLS and TEM results manifested the nano-size (~ 160 nm) and circular shape of AS/GOD@HAZnO NPs. Due to the acid-responsive degradation, AS/GOD@HAZnO NPs realized responsive release (up to 80%) in acid environment while only 20% was released in neutral medium. The cellular and in vivo experiment showed that co-delivery of AS and GOD via HAZnO NPs could effectively induce the overproduction of ROS and cut the glucose supply of tumor cells, and thus result in efficient cell apoptosis and tumor inhibition.

Self-Assembled Fluorosome-Polydopamine Complex for Efficient Tumor Targeting and Commingled Photodynamic/Photothermal Therapy of Triple-Negative Breast Cancer

Photodynamic/photothermal therapy (PDT/PTT) that deploys a near-infrared responsive nanosystem is emerging to be a promising modality in cancer treatment. It is highly desirable to have a multifunctional nanosystem that can be used for efficient tumor targeting and inhibiting metastasis/recurrence of cancer. In the current study, self-assembled chlorophyll-rich fluorosomes derived from Spinacia oleracea were developed. These fluorosomes were co-assembled on a polydopamine core, forming camouflaged nanoparticles (SPoD NPs). The SPoD NPs exhibited a commingled PDT/PTT (i.e., interdependent PTT and PDT) that inhibited both normoxic and hypoxic cancer cell growth. These nanoparticles showed stealth properties with enhanced physiological stability and passive tumor targeting. SPoD NPs also exhibited tumor suppression by synergistic PTT and PDT. It also prevented lung metastasis and splenomegaly in tumor-bearing Balb/c mice. Interestingly, treatment with SPoD NPs also caused the suppression of secondary tumors by eliciting an anti-tumor immune response. In conclusion, a co-assembled multifunctional nanosystem derived from S. oleracea showed enhanced stability and tumor-targeting efficacy, resulting in a commingled PDT/PTT effect.

Nano-herb medicine and PDT induced synergistic immunotherapy for colon cancer treatment

A variety of therapies have been developed and used for the treatment of colon cancer, however, the high mortality rate remains high and more effective strategies are still in urgent needs. In this study, an immunotherapy approach that is composed of innate immune activator Astragaloside III (As) and the photodynamic therapy (PDT) reagent chlorine e6 (Ce6) ((As + Ce6)@MSNs-PEG), was developed for colon cancer treatment. We showed that (As + Ce6)@MSNs-PEG could effectively activate NK cells and inhibit the proliferation of tumor cells in vitro. It could also effectively reach tumor sites, induce infiltration of immune cells into the tumor, and enhance the cytotoxicity of natural killer cells and CD8⁺ T cells in vivo. Without obvious side effects, (As + Ce6)@MSNs-PEG treatment significantly inhibited tumor growth and extended the lifespan of tumor-bearing mice. Further results revealed that treatment of (As + Ce6)@MSNs-PEG led to enhanced IFN secretion by immune cells and increased T-box transcription factor (T-bet), which is highly expressed by T cells. Therefore, (As + Ce6)@MSNs-PEG may serve as an effective and safe platform for combinatory use with nano-herb medicine and PDT to provide a new therapy for colon cancer treatment.

Full-spectrum responsive WO3−x@HA nanotheranostics for NIR-II photoacoustic imaging-guided PTT/PDT/CDT synergistic therapy

A WO_3−x-based nanotheranostic has been successfully fabricated for photoacoustic imaging-guided synergistic tumor targeting therapy in the second near-infrared (NIR-II) biological window.

Semiflexible polymer scaffolds: an overview of conjugation strategies

Semiflexible polymers are excellent scaffolds for the presentation of a wide variety of (bio)molecules. This manuscript reviews advantages and challenges of the most common conjugation strategies for the major classes of semiflexible polymers.

Full-spectrum responsive ZrO2-based phototheranostic agent for NIR-II photoacoustic imaging-guided cancer phototherapy

A second near-infrared window (NIR-II) responsive, cancer targeting ZrO₂-based phototheranostic agent has been fabricated for imaging-guided precise synergetic phototherapy.

Hyaluronic acid hydrophilic surface rehabilitating curcumin nanocrystals for targeted breast cancer treatment with prolonged biodistribution

Due to its high therapeutic efficiency and low systemic toxicity, natural bioactive curcumin has attracted more and more attention as a potential antineoplastic drug.