Abstract：
The combination of ferroptosis, cuproptosis, and chemodynamic therapy (CDT) would be a potential strategy for tumor diagnosis and enhanced treatment. However, the therapeutic effect was severely limited by the lack of specific delivery of catalytic ions and the low Fenton reaction efficiency in tumor microenvironment (TME) with excess glutathione, limited acidity and insufficient endogenous hydrogen peroxide. In this work, p-carboxybenzenesulfonamide (BS), a carbonic anhydrase IX (CA IX) inhibitor, was modified on the surface of generation-5 poly(amidoamine) dendrimer to load copper peroxide nanoparticles, which were complexed with iron (Fe)-tannic acid (TF) networks for targeted magnetic resonance (MR) imaging and enhanced ferroptosis/cuproptosis/CDT by regulating TME. The formed CuO2@G5-BS/TF nanocomplexes with an average size of 39.4 nm could be specifically accumulated at tumor site and effectively internalized by metastatic 4T1 cells via the specific interaction between BS and CA IX over-expressed on tumor cells. Meanwhile, the inhibition of CA IX activity could not only decrease the intracellular pH to accelerate Fe3+/Cu2+ release, H2O2 self-supply and Fenton reaction, but also suppress tumor metastasis by alleviating the extracellular acidity in TME. Moreover, the reduction of Fe3+/Cu2+ by intracellular glutathione (GSH) could further amplify ROS generation and enhance CDT efficacy, and the GSH depletion could in turn inhibit GPX-4 mediated antioxidant reaction to induce ferroptosis, resulting in effective therapeutic efficacy. In vivo experimental results demonstrated that CuO2@G5-BS/TF could provide better tumor MR imaging, effectively inhibit the growth and metastasis of 4T1 breast tumors, and be metabolized without significant systemic toxicity. Thus, CuO2@G5-BS/TF nanocomplexes provided a new approach for targeted MR imaging and enhanced ferroptosis/cuproptosis/CDT of triple-negative breast cancer. STATEMENT OF SIGNIFICANCE: Taking the advantage of dendrimer and metal-phenolic system, stable CuO2@G5-BS/TF nanocomplexes with an average size of 39.4 nm were synthesized to efficiently load Fe3+ and CuO2 nanoparticles for TNBC treatment and MR imaging. CuO2@G5-BS/TF nanocomplexes could target tumor cells overexpressing CAIX via the specific binding with BS, and the inhibition of CAIX activity could not only decrease the intracellular pH to accelerate Fe3+/Cu2+ release, H2O2 self-supply and Fenton reaction, but also suppress tumor metastasis by alleviating the extracellular acidity. The reduction of Fe3+/Cu2+ by intracellular GSH could further amplify ·OH generation, and the GSH depletion could in turn inhibit GPX-4 mediated antioxidant reaction to induce ferroptosis, resulting in effective therapeutic efficacy by enhanced ferroptosis/cuproptosis/CDT via tumor microenvironment regulation.
摘要：
铁性死亡的组合，突起，和化学动力学疗法（CDT）将是肿瘤诊断和增强治疗的潜在策略。然而,治疗效果受到缺乏催化离子的特异性递送和肿瘤微环境（TME）中过量谷胱甘肽的低Fenton反应效率的严重限制，有限的酸度和不足的内源性过氧化氢。在这项工作中,对羧基苯磺酰胺（BS），碳酸酐酶IX（CAIX）抑制剂，在5代聚(酰胺基胺)树枝状聚合物的表面上进行改性，以负载过氧化铜纳米颗粒，与铁（Fe）-单宁酸（TF）网络络合，用于靶向磁共振（MR）成像，并通过调节TME增强铁性凋亡/角化/CDT。形成的平均尺寸为39.4nm的CuO2@G5-BS/TF纳米复合物可以特异性地积累在肿瘤部位，并通过在肿瘤细胞上过度表达的BS和CAIX之间的特异性相互作用被转移性4T1细胞有效地内化。同时,抑制CAIX活性不仅可以降低细胞内pH以加速Fe3/Cu2释放，H2O2自供和Fenton反应，还可以通过减轻TME中的细胞外酸度来抑制肿瘤转移。此外，细胞内谷胱甘肽(GSH)对Fe3+/Cu2+的还原可以进一步放大ROS的产生并增强CDT的功效,而GSH耗竭又能抑制GPX-4介导的抗氧化反应诱导铁凋亡，产生有效的治疗效果。体内实验结果表明CuO2@G5-BS/TF能提供更好的肿瘤MR成像,有效抑制4T1乳腺肿瘤的生长和转移，并且被代谢而没有明显的全身毒性。因此，CuO2@G5-BS/TF纳米复合物为三阴性乳腺癌的靶向MR成像和增强铁性凋亡/角化凋亡/CDT提供了新的途径。重要声明：利用树枝状聚合物和金属-酚醛体系，合成了平均尺寸为39.4nm的稳定的CuO2@G5-BS/TF纳米复合物，以有效地负载Fe3和CuO2纳米颗粒，用于TNBC治疗和MR成像。CuO2@G5-BS/TF纳米复合物可以通过与BS的特异性结合靶向过表达CAIX的肿瘤细胞,抑制CAIX活性不仅可以降低细胞内pH，加速Fe3+/Cu2+的释放，H2O2自供和Fenton反应，而且还通过减轻细胞外酸度来抑制肿瘤转移。细胞内GSH对Fe3+/Cu2+的还原可以进一步放大·OH的产生，而GSH耗竭又能抑制GPX-4介导的抗氧化反应诱导铁凋亡，通过肿瘤微环境调节增强铁性凋亡/角化凋亡/CDT，从而产生有效的治疗效果。
