Chemotherapy remains a powerful tool to eliminate malignant cells. However, the efficacy of chemotherapy is compromised by the frequent emergence of intrinsic and acquired multidrug resistance (MDR). These chemoresistance modalities are based on a multiplicity of molecular mechanisms of drug resistance, including : 1) Impaired drug uptake into cancer cells; 2) Increased expression of ATP-binding cassette efflux transporters; 3) Loss of function of pro-apoptotic factors; 4) Enhanced DNA repair capacity; 5) Qualitative or quantitative alterations of specific cellular targets; 6) Alterations that allow cancer cells to tolerate adverse or stressful conditions; 7) Increased biotransformation or metabolism of anticancer drugs to less active or completely inactive metabolites; and 8) Intracellular and intercellular drug sequestration in well-defined organelles away from the cellular target. Hence, one of the major aims of cancer research is to develop novel strategies to overcome cancer drug resistance. Over the last decades, nanomedicine, which focuses on targeted delivery of therapeutic drugs into tumor tissues using nano-sized formulations, has emerged as a promising tool for cancer treatment. Therefore, nanomedicine has been introduced as a reliable approach to improve treatment efficacy and minimize detrimental adverse effects as well as overcome cancer drug resistance. With rationally designed strategies including passively targeted delivery, actively targeted delivery, delivery of multidrug combinations, as well as multimodal combination therapy, nanomedicine paves the way towards efficacious cancer treatment and hold great promise in overcoming cancer drug resistance. Herein, we review the recent progress of nanomaterials used in medicine, including liposomal nanoparticles, polymeric nanoparticles, inorganic nanoparticles and hybrid nanoparticles, to surmount cancer multidrug resistance. Finally, the future perspectives of the application of nanomedicine to reverse cancer drug resistance will be addressed.

化疗仍然是消除恶性细胞的有力工具。然而，化学疗法的疗效因内在和获得性多药耐药性 (MDR) 的频繁出现而受到影响。这些化学抗性方式基于多种耐药性分子机制，包括： 1) 癌细胞对药物的吸收受损；2) ATP结合盒外排转运蛋白的表达增加；3）促凋亡因子功能丧失；4）增强DNA修复能力；5) 特定细胞靶标的定性或定量改变；6) 允许癌细胞耐受不利或压力条件的改变；7) 增加抗癌药物向活性较低或完全无活性的代谢物的生物转化或代谢；8) 远离细胞靶点的明确细胞器中的细胞内和细胞间药物隔离。因此，癌症研究的主要目标之一是开发克服癌症耐药性的新策略。在过去的几十年中，专注于使用纳米级制剂将治疗药物靶向递送到肿瘤组织中的纳米医学已成为一种很有前途的癌症治疗工具。因此，纳米药物已被引入作为一种可靠的方法来提高治疗效果，最大限度地减少有害的副作用以及克服癌症耐药性。合理设计被动靶向给药、主动靶向给药、多药联合给药、多模式联合治疗等策略，纳米医学为有效的癌症治疗铺平了道路，并在克服癌症耐药性方面大有希望。在此，我们回顾了用于医学的纳米材料的最新进展，包括脂质体纳米粒子、聚合物纳米粒子、无机纳米粒子和混合纳米粒子，以克服癌症的多药耐药性。最后，将讨论应用纳米药物逆转癌症耐药性的未来前景。