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Abstract Background Traditional chemotherapeutic agents suffer from a lack of selectivity, poor targeting ability, and drug resistance. Developing tumor-specific therapies is crucial for precisely eliminating tumors while circumventing toxicity to normal tissues. Disulfiram (DSF), an FDA-approved drug for treating alcohol dependence, exhibits antitumor effect by forming complexes with copper ions (Cu(DDC)2). Here, we developed a Cu-doped polydopamine-based nanosystem (DSF@CuPDA-PEGM) to achieve in situ generation of toxic Cu(DDC)2. Results In cancer cells with elevated H2O2 contents, CuPDA responsively degrades to release Cu ions and DSF, allowing on-site synthesis of Cu(DDC)2 with potent antitumor activity. DSF@CuPDA-PEGM exhibits excellent therapeutic efficacy against both drug-sensitive and drug-resistant cancer cells while minimizing toxicity to noncancerous cells. Moreover, DSF@CuPDA-PEGM promotes the immune response by inducing cancer cell immunogenic death, thereby augmenting anti-PD-1-based immune checkpoint blockade therapy. Conclusion A tumor-specifically degradable Cu-doped polydopamine-based nanosystem is developed to achieve in situ synthesis of antitumor compounds, providing a promising approach to precisely eliminate tumors and heighten chemo-immunotherapy. Graphical Abstract

The excessive reactive oxygen species (ROS) is a hallmark associated with the initiation and progression of inflammatory bowel disease (IBD), which execrably form a vicious cycle of ROS and inflammation to continually promote disease progression. Here, the gold nanoparticles-embedded ceria nanoparticles (Au/CeO2) with enhanced antioxidant activities are designed to block this cycle reaction for treating IBD by scavenging overproduced ROS. The Au/CeO2 with core-shell and porous structure exhibits significantly higher enzymatic catalytic activities compared with commercial ceria nanoparticles, likely due to the effective exposure of catalytic sites, higher content of Ce (III) and oxygen vacancy, and accelerated reduction from Ce (IV) to Ce (III). Being coated with negatively-charged hyaluronic acid, the Au/CeO2@HA facilitates accumulation in inflamed colon tissues via oral administration, reduces pro-inflammatory cytokines, and effectively alleviates colon injury in colitis mice. Overall, the Au/CeO2@HA with good biocompatibility is a promising nano-therapeutic for treating IBD.

Rapid drug clearance and off-target effects of therapeutic drugs can induce low bioavailability and systemic side effects and gravely restrict the therapeutic effects of inflammatory bowel diseases (IBDs). Here, we propose an amplifying targeting strategy based on orally administered gallium (Ga)-based liquid metal (LM) nano-agents to efficiently eliminate reactive oxygen and nitrogen species (RONS) and modulate the dysregulated microbiome for remission of IBDs. Taking advantage of the favorable adhesive activity and coordination ability of polyphenol structure, epigallocatechin gallate (EGCG) is applied to encapsulate LM to construct the formulations (LM-EGCG). After adhering to the inflamed tissue, EGCG not only eliminates RONS but also captures the dissociated Ga to form EGCG-Ga complexes for enhancive accumulation. The detained composites protect the intestinal barrier and modulate gut microbiota for restoring the disordered enteral microenvironment, thereby relieving IBDs. Unexpectedly, LM-EGCG markedly decreases the Escherichia_Shigella populations while augmenting the abundance of Akkermansia and Bifidobacterium, resulting in favorable therapeutic effects against the dextran sulfate sodiuminduced colitis. [ABSTRACT FROM AUTHOR]