Department of Polymer Engineering, University of Akron, Akron OH 44325, USA.
Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
Soft Matter. 2024 Oct 2;20(38):7623-7633. doi: 10.1039/d4sm00765d.
Coacervates represent models for membrane-free protocells and thus provide a simple route to synthetic cellular-like systems that provide selective encapsulation of solutes. Here, we demonstrate a simple and versatile post-coacervation crosslink method using the thiol-ene click reaction in aqueous media to prepare covalently crosslinked coacervates. The crosslinking of the coacervate enables stability at extreme pH where the uncrosslinked coacervate fully disassembles. The crosslinking also enhances the hydrophobicity within the coacervate environment to increase the encapsulation efficiency of bovine serum albumin (BSA), as compared to the uncrosslinked coacervate. Additionally, the crosslinked coacervate increases the stabilization of BSA at low pH. These crosslinked coacervates can act as carriers for enzymes. The enzymatic activity of alkaline phosphatase (ALP) is enhanced within the crosslinked coacervate compared to the ALP in aqueous solution. The post-coacervation crosslink approach allows the utilization of coacervates for encapsulation of biologicals under conditions where the coacervate would generally disassemble. We demonstrate that these crosslinked coacervates enable the protection of encapsulated protein against denaturation at extreme pH and enhance the enzymatic activity with encapsulation. This click approach to stabilization of coacervates should be broadly applicable to other systems for a variety of biologics and environmentally sensitive molecules.
凝聚体代表了无膜原细胞的模型，因此提供了一种简单的途径来合成类似细胞的系统，从而对溶质进行选择性包封。在这里，我们展示了一种简单而通用的凝聚体后交联方法，即在水相介质中使用硫醇-烯点击反应来制备共价交联的凝聚体。交联使凝聚体在极端 pH 值下稳定，而未交联的凝聚体则完全解体。交联还增强了凝聚体环境中的疏水性，从而提高了牛血清白蛋白 (BSA) 的包封效率，与未交联的凝聚体相比。此外，交联的凝聚体增加了 BSA 在低 pH 值下的稳定性。这些交联的凝聚体可以作为酶的载体。与水溶液中的 ALP 相比，交联凝聚体中的碱性磷酸酶 (ALP) 的酶活性得到增强。后凝聚体交联方法允许在凝聚体通常会解体的条件下，将凝聚体用于封装生物制品。我们证明，这些交联的凝聚体能够保护包封的蛋白质免受极端 pH 值下的变性，并通过包封增强酶活性。这种点击方法稳定凝聚体应该广泛适用于其他各种生物和对环境敏感的分子的系统。
