Interdisciplinay nanoscience center (iNANO), Aarhus University , 8000 Aarhus, Denmark.
ACS Appl Mater Interfaces. 2014 Aug 13;6(15):12771-9. doi: 10.1021/am502743z. Epub 2014 Jul 9.
The design of compartmentalized carriers as artificial cells is envisioned to be an efficient tool with potential applications in the biomedical field. The advent of this area has witnessed the assembly of functional, bioinspired systems attempting to tackle challenges in cell mimicry by encapsulating multiple compartments and performing controlled encapsulated enzymatic catalysis. Although capsosomes, which consist of liposomes embedded within a polymeric carrier capsule, are among the most advanced systems, they are still amazingly simple in their functionality and cumbersome in their assembly. We report on capsosomes by embedding liposomes within a poly(dopamine) (PDA) carrier shell created in a solution-based single-step procedure. We demonstrate for the first time the potential of PDA-based capsosomes to act as artificial cell mimics by performing a two-enzyme coupled reaction in parallel with a single-enzyme conversion by encapsulating three different enzymes into separated liposomal compartments. In the former case, the enzyme uricase converts uric acid into hydrogen peroxide, CO2 and allantoin, followed by the reaction of hydrogen peroxide with the reagent Amplex Ultra Red in the presence of the enzyme horseradish peroxidase to generate the fluorescent product resorufin. The parallel enzymatic catalysis employs the enzyme ascorbate oxidase to convert ascorbic acid into 2-L-dehydroascorbic acid.
作为人工细胞的隔室化载体的设计被认为是一种有效的工具，具有在生物医学领域应用的潜力。该领域的出现见证了功能、仿生系统的组装，这些系统试图通过封装多个隔室并进行受控的封装酶催化来解决细胞模拟的挑战。尽管由嵌入聚合物载体胶囊内的脂质体组成的 capsosomes 是最先进的系统之一，但它们在功能上仍然非常简单，在组装上仍然很繁琐。我们通过在基于溶液的一步法中在聚多巴胺（PDA）载体壳内嵌入脂质体来报告 capsosomes。我们首次证明了基于 PDA 的 capsosomes 作为人工细胞模拟物的潜力，方法是通过将三种不同的酶封装在分离的脂质体隔室中，同时进行双酶偶联反应和单酶转化来进行。在前一种情况下，酶尿酸酶将尿酸转化为过氧化氢、二氧化碳和尿囊素，然后在辣根过氧化物酶存在下，用过氧化氢与试剂 Amplex Ultra Red 反应生成荧光产物 Resorufin。平行酶催化采用酶抗坏血酸氧化酶将抗坏血酸转化为 2-L-脱氢抗坏血酸。
