Human breast milk is an understudied biological fluid that may be useful for early detection of breast cancer. Methods for enriching and detecting biomarkers in human breast milk, however, are not as well-developed as compared with other biological fluids. In this work, we demonstrate a new enrichment method based on polymeric nanoassemblies that is capable of enhancing the mass spectrometry-based detection of peptides and proteins in human breast milk. In this method, positively charged nanoassemblies are used to selectively deplete abundant proteins in milk based on electrostatic interactions, which simplifies the mixture and enhances detection of positively charged peptides and proteins. Negatively charged nanoassemblies are used in a subsequent enrichment step to further enhance the detection and quantification of trace-level peptides and proteins. Together the depletion and enrichment steps allow model biomarkers to be detected at low nM levels, which are close to instrumental limits of detection. This new method not only demonstrates the ability to detect proteins in human breast milk but also provides an alternative approach for targeted protein detection in complex biological matrices. Graphical abstract.

中文翻译：

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用于富集和检测人母乳中肽和蛋白质的聚合物纳米组件。

人乳是一种未被充分研究的生物流体，可能对乳腺癌的早期检测有用。然而，与其他生物液体相比，用于富集和检测人母乳中生物标志物的方法尚不完善。在这项工作中，我们演示了一种基于聚合物纳米组件的新富集方法，该方法能够增强基于质谱的人类母乳中肽和蛋白质的检测。在这种方法中，带正电的纳米组件用于基于静电相互作用选择性地消耗牛奶中的大量蛋白质，从而简化了混合物并增强了对带正电的肽和蛋白质的检测。带负电的纳米组件用于后续的富集步骤，以进一步增强痕量级肽和蛋白质的检测和定量。消耗和富集步骤一起使模型生物标记物可以在低nM水平下被检测到，这接近仪器的检测极限。这种新方法不仅证明了检测人母乳中蛋白质的能力，而且还为复杂生物基质中靶向蛋白质的检测提供了另一种方法。图形概要。这种新方法不仅证明了检测人母乳中蛋白质的能力，而且还为复杂生物基质中靶向蛋白质的检测提供了另一种方法。图形概要。这种新方法不仅证明了检测人母乳中蛋白质的能力，而且还为复杂生物基质中靶向蛋白质的检测提供了另一种方法。图形概要。