Poly(γ-glutamic acid) (γ-PGA) is one of the few bacterial polymers in nature; as such, it possesses the added value of a “green birth” (fermentation) and “green death” (biodegradability), which is ideal for sustainable macromolecular platforms. Efficient functionalization strategies are required in order to transform the native bacterial biopolymer into a material with tailored properties for bulk scale or biomedical applications. We report on a novel approach to the facile functionalization of bacterial γ-PGA, realized with several levels of control: (a) the modulation of the molecular weight through sonication, and the solubilization in organic solvents through counterion exchange with suitable quaternary ammonium salts, (b) the introduction of reactive functionalities through reactions in homogeneous conditions in organic solvents, to afford homo- or copolymers; (c) a second tier functionalization using copper(I)-catalyzed alkyne–azide cycloaddition (CuAAC) click chemistry.

中文翻译：

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“可点击的”细菌聚（γ-谷氨酸）

聚（γ-谷氨酸）（γ-PGA）是自然界中为数不多的细菌聚合物之一；因此，它具有“绿色出生”（发酵）和“绿色死亡”（可生物降解）的附加值，是可持续高分子平台的理想选择。为了将天然细菌生物聚合物转变为具有适合大规模生产或生物医学应用的定制性能的材料，需要有效的功能化策略。我们报告了一种新颖的方法来实现细菌γ-PGA的简便功能化，并实现了多种控制水平：（a）通过声处理调节分子量，以及通过与合适的季铵盐进行抗衡离子交换在有机溶剂中溶解， （b）通过在有机溶剂中均相条件下的反应引入反应性官能团，提供均聚物或共聚物；（c）使用铜的第二层功能化（I）催化炔-叠氮化物环加成（CuAAC）单击化学。