Effect of Cellular and Microenvironmental Multidrug Resistance on Tumor-Targeted Drug Delivery in Triple-Negative Breast cancer

A Targeted and Responsive Nanoprodrug Delivery System for Synergistic Glioma Chemotherapy

Doxorubicin (DOX) is widely used as a chemotherapeutic agent for both hematologic and solid tumors and is a reasonable candidate for glioma treatment. However, its effectiveness is hindered by significant toxicity and drug resistance. Moreover, the presence of the blood-brain barrier (BBB) brings a crucial challenge to glioma therapy. In response, a GSH-responsive and actively targeted nanoprodrug delivery system (cRGD/PSDOX-Cur@NPs) are developed. In this system, a disulfide bond-bridged DOX prodrug (PEG-SS-DOX) is designed to release specifically in the high glutathione (GSH) tumor environment, markedly reducing the cardiotoxicity associated with DOX. To further address DOX resistance, curcumin, serving as a P-glycoprotein (P-gp) inhibitor, effectively increased cellular DOX concentration. Consequently, cRGD/PSDOX-Cur@NPs exhibited synergistic anti-tumor effects in vitro. Furthermore, in vivo experiments validated the superior BBB penetration and brain-targeting abilities of cRGD/PSDOX-Cur@NPs, showcasing the remarkable potential for treating both subcutaneous and orthotopic gliomas. This research underscores that this nanoprodrug delivery system presents a novel approach to inhibiting glioma while addressing resistance and systemic toxicity.

Brucea javanica derived exosome-like nanovesicles deliver miRNAs for cancer therapy

Triple-negative breast cancer (TNBC) is characterized by complex heterogeneity, high recurrence and metastasis rates, and short overall survival, owing to the lack of endocrine and targeted receptors, which necessitates chemotherapy as the major treatment regimen. Exosome-like nanovesicles derived from medicinal plants have shown great potential as novel biotherapeutics for cancer therapy by delivering their incorporated nucleic acids, especially microRNAs (miRNAs), to mammalian cells. In this study, we isolated exosome-like nanovesicles derived from B. javanica (BF-Exos) and investigated their influence and underlying molecular mechanisms in TNBC. We found that BF-Exos delivered 10 functional miRNAs to 4T1 cells, significantly retarding the growth and metastasis of 4T1 cells by regulating the PI3K/Akt/mTOR signaling pathway and promoting ROS/caspase-mediated apoptosis. Moreover, BF-Exos were shown to inhibit the secretion of vascular endothelial growth factor, contributing to anti-angiogenesis in the tumor microenvironment. In vivo, BF-Exos inhibited tumor growth, metastasis, and angiogenesis in breast tumor mouse models, while maintaining high biosafety. Overall, BF-Exos are considered promising nanoplatforms for the delivery of medicinal plant-derived nucleic acids, with great potential to be developed into novel biotherapeutics for the treatment of TNBC.

Three-pronged attacks by hybrid nanoassemblies involving a natural product, carbon dots, and Cu2+ for synergistic HCC therapy

Tumor microenvironment (TME) stimuli-responsive nanoassemblies are emerging as promising drug delivery systems (DDSs), which acquire controlled release by structural transformation under exogenous stimulation. However, the design of smart stimuli-responsive nanoplatforms integrated with nanomaterials to achieve complete tumor ablation remains challenging. Therefore, it is of utmost importance to develop TME-based stimuli-responsive DDSs to enhance drug-targeted delivery and release at tumor sites. Herein, we proposed an appealing strategy to construct fluorescence-mediated TME stimulus-responsive nanoplatforms for synergistic cancer therapy by assembling photosensitizers (PSs) carbon dots (CDs), chemotherapeutic agent ursolic acid (UA), and copper ions (Cu2+). First, UA nanoparticles (UA NPs) were prepared by self-assembly of UA, then UA NPs were assembled with CDs via hydrogen bonding force to obtain UC NPs. After combining with Cu2+, the resulting particles (named UCCu2+ NPs) exhibited quenched fluorescence and photosensitization due to the aggregation of UC NPs. Upon entering the tumor tissue, the photodynamic therapy (PDT) and the fluorescence function of UCCu2+ were recovered in response to TME stimulation. The introduction of Cu2+ triggered the charge reversal of UCCu2+ NPs, thereby promoting lysosomal escape. Furthermore, Cu2+ resulted in additional chemodynamic therapy (CDT) capacity by reacting with hydrogen peroxide (H2O2) as well as by consuming glutathione (GSH) in cancer cells through a redox reaction, hence magnifying intracellular oxidative stress and enhancing the therapeutic efficacy due to reactive oxygen species (ROS) therapy. In summary, UCCu2+ NPs provided an unprecedented novel approach for improving the therapeutic efficacy through the three-pronged (chemotherapy, phototherapy, and heat-reinforced CDT) attacks to achieve synergistic therapy.

Overcoming drug resistance with a docetaxel and disulfiram loaded pH-sensitive nanoparticle

Previous studies have demonstrated that breast cancer cells deploy a myriad array of strategies to thwart the activity of anticancer drugs like docetaxel (DTX), including acquired drug resistance due to overexpression of drug-efflux pumps like P-glycoprotein (P-gp) and innate drug resistance by cancer stem cells (CSCs). As disulfiram (DSF) can inhibit both P-gp and CSCs, we hypothesized that co-treatment of DTX and DSF could sensitize the drug-resistant breast cancer cells. To deliver a fixed dose ratio of DTX and DSF targeted to the tumor, a tumor extracellular pH-responsive nanoparticle (NP) was developed using a histidine-conjugated star-shaped PLGA with TPGS surface decoration ([DD]NpH-T). By releasing the encapsulated drugs in the tumor microenvironment, pH-sensitive NPs can overcome the tumor stroma-based resistance against nanomedicines. In in-vitro studies, [DD]NpH-T exhibited increased drug release at pH 6.8, improved penetration in a 3D tumor spheroid, reduced serum protein adsorption, and enhanced cytotoxic efficacy against both innate and acquired DTX-resistant breast cancer cells. In in-vivo studies, a significant increase in plasma AUC and tumor drug delivery was observed with [DD]NpH-T, which resulted in an enhanced in-vivo anti-tumor efficacy against a mouse orthotopic breast cancer, with a significantly increased intratumoral ROS and apoptosis, while decreasing P-gp expression and prevention of lung metastasis. Altogether, the current study demonstrated that the DTX and DSF combination could effectively target multiple drug-resistance pathways in-vitro, and the in-vivo delivery of this drug combination using TPGS-decorated pH-sensitive NPs could increase tumor accumulation, resulting in improved anti-tumor efficacy.