Responsive nanomaterials have emerged as promising candidates for advanced drug delivery systems (DDSs), offering the potential to precisely target disease sites and enhance treatment efficacy. To fulfil their potential, such materials need to be engineered to respond to specific variations in biological conditions. In this work, we present a series of pH/redox dual-responsive hybrid nanoparticles featuring an amphiphilic shell polymer and a pH-responsive core polymer. These nanoparticles incorporate a polyoxometalate (POM), specifically the cobalt(III)-substituted borotungstate ([B^IIIW₁₁O₃₉Co^III]⁶⁻), loaded through coordination chemistry between the encapsulated Co^III ions of the POM and pyridyl functional groups on the core polymer. The resulting hybrid nanoparticles show potential for controlled release with excellent stability at physiological pH, and efficient particle disassembly in response to the combination of pH and redox stimuli. Disassembly is proposed to occur following a two step mechanism. Structural rearrangement of the nanoparticle occurs on acidification followed by destabilization of the coordination bond between the polyanion and the pyridyl functionality in the core polymer following reduction. In this system, the POM acts in a novel role as a redox active structural cross-linker. These hybrid dual-responsive nanoparticles, featuring superior colloidal stability under extracellular conditions and controllable disintegration in response to the dual stimuli of acidic pH and redox conditions, provide a novel platform for the controlled intracellular release of therapeutics.

中文翻译：

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具有 pH/氧化还原双响应性的多金属氧酸盐-聚合物杂化纳米颗粒的简单结构


响应性纳米材料已成为先进药物递送系统 （DDS） 的有前途的候选者，具有精确靶向疾病部位和提高治疗效果的潜力。为了发挥其潜力，需要对此类材料进行设计，以应对生物条件的特定变化。在这项工作中，我们提出了一系列 pH/氧化还原双响应杂化纳米颗粒，具有两亲性外壳聚合物和 pH 响应核心聚合物。这些纳米颗粒掺入了多金属氧酸盐 （POM），特别是钴 （III） 取代的硼钨酸盐 （[B^IIIW₁₁O₃₉Co^III]⁶⁻），通过 POM 的封装 Co^III 离子与核心聚合物上的吡啶官能团之间的配位化学负载。所得的杂化纳米颗粒显示出控释的潜力，在生理 pH 值下具有出色的稳定性，并且可以响应 pH 值和氧化还原刺激的组合而有效地分解颗粒。建议按照两步机制进行拆卸。纳米颗粒的结构重排发生在酸化时，随后还原后核心聚合物中聚阴离子和吡啶官能团之间的配位键不稳定。在该系统中，POM 作为氧化还原活性结构交联剂发挥着新作用。这些杂化双响应纳米颗粒在细胞外条件下具有卓越的胶体稳定性，并且在酸性 pH 和氧化还原条件下的双重刺激下可控崩解，为治疗药物的受控细胞内释放提供了新的平台。