Tuning the enzymatic degradation and disassembly rates of polymeric amphiphiles and their assemblies is crucial for designing enzyme-responsive nanocarriers for controlled drug delivery applications. The common methods to control the enzymatic degradation of amphiphilic polymers are to tune the molecular weights and ratios of the hydrophilic and hydrophobic blocks. In addition to these approaches, the architecture of the hydrophilic block can also serve as a tool to tune enzymatic degradation and disassembly. To gain a deeper understanding of the effect of the molecular architecture of the hydrophilic block, we prepared two types of well-defined PEG-dendron amphiphiles bearing linear or V-shaped PEG chains as the hydrophilic blocks. The high molecular precision of these amphiphiles, which emerges from the utilization of dendrons as the hydrophobic blocks, allowed us to study the self-assembly and enzymatic degradation and disassembly of the two types of amphiphiles with high resolution. Interestingly, the micelles of the V-shaped amphiphiles were significantly smaller and disassembled faster than those of the amphiphiles based on linear PEG. However, the complete enzymatic cleavage of the hydrophobic end groups was significantly slower for the V-shaped amphiphiles. Our results show that the V-shaped architecture can stabilize the unimer state and, hence, plays a double role in the enzymatic degradation and the induced disassembly and how it can be utilized to control the release of encapsulated or bound molecular cargo.

中文翻译：

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壳形成嵌段从线性到V形的结构变化加快了胶束的分解，但减慢了两亲物的完全酶促降解。

调节聚合物两亲物及其组装体的酶促降解和分解速度对于设计用于可控药物递送应用的酶反应性纳米载体至关重要。控制两亲性聚合物酶促降解的常用方法是调节亲水性和疏水性嵌段的分子量和比例。除了这些方法之外，亲水性嵌段的结构还可以用作调节酶促降解和分解的工具。为了更深入地了解亲水性嵌段分子结构的影响，我们制备了两种定义明确的带有线性或V型PEG链的PEG-树枝状两亲物作为亲水性嵌段。这些两亲分子具有很高的分子精度，它是通过利用树枝状分子作为疏水性嵌段而出现的，它使我们能够以高分辨率研究两种类型的两亲物的自组装和酶促降解与分解。有趣的是，与基于线性PEG的两亲物相比，V形两亲物的胶束明显更小且分解速度更快。但是，对于V形两亲物，疏水端基的完全酶切明显较慢。我们的结果表明，V形结构可以稳定单体状态，因此在酶促降解和诱导的拆解中起着双重作用，以及如何利用它来控制封装或结合的分子货物的释放。使我们能够以高分辨率研究两种类型两亲物的自组装和酶促降解与分解。有趣的是，与基于线性PEG的两亲物相比，V形两亲物的胶束明显更小且分解更快。但是，对于V形两亲物，疏水端基的完全酶切明显较慢。我们的结果表明，V形结构可以稳定单体状态，因此在酶促降解和诱导的拆解中起着双重作用，以及如何利用它来控制封装或结合的分子货物的释放。使我们能够以高分辨率研究两种类型两亲物的自组装和酶促降解与分解。有趣的是，与基于线性PEG的两亲物相比，V形两亲物的胶束明显更小且分解速度更快。但是，对于V形两亲物，疏水端基的完全酶切明显较慢。我们的结果表明，V形结构可以稳定单体状态，因此在酶促降解和诱导的拆解中起着双重作用，以及如何利用它来控制封装或结合的分子货物的释放。与基于线性PEG的两亲物相比，V形两亲物的胶束明显更小且分解更快。但是，对于V形两亲物，疏水端基的完全酶切明显较慢。我们的结果表明，V形结构可以稳定单体状态，因此在酶促降解和诱导的拆解中起着双重作用，以及如何利用它来控制封装或结合的分子货物的释放。与基于线性PEG的两亲物相比，V形两亲物的胶束明显更小且分解更快。但是，对于V形两亲物，疏水端基的完全酶切明显较慢。我们的结果表明，V形体系结构可以稳定单体状态，因此在酶促降解和诱导的拆解中起着双重作用，以及如何利用它来控制封装或结合的分子货物的释放。