Wang Ben, Liu Peng, Liu Zhaoming, Pan Haihua, Xu Xurong, Tang Ruikang
Center for Biomaterials and Biopathways, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310027, China; Institute for Translational Medicine and The Second Affiliated Hospital of Zhejiang University, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
Biotechnol Bioeng. 2014 Feb;111(2):386-95. doi: 10.1002/bit.25016. Epub 2013 Aug 22.
Many unicellular organisms take their outer proteinaceous and lipidic membranes or carbonhydrate-rich cell walls as a template for biomineralization to synthesize a thin mineral layer as a functional covering. In nature most cells cannot be mineralized spontaneously in the normal states. Inspired by nature, we develop cytocompatible methods for cells encapsulated inside a mineral shell, called "cellular shellization." Using Layer-by-Layer (LbL) assembly, the precipitation of calcium minerals can be induced on the yeast cell surfaces. The effects of different synthetic polyelectrolytes on the calcifications of yeast, such as interfacial energy, zeta-potential, introduction time, and the affinity of mineral phase on the yeast cell surface have been studied by using constant composition method (CC) systemically and quantitatively. The results demonstrate that the effective adsorption of polyelectrolytes with carboxyl or sulfonate-rich groups on the yeast can enhance mineralization abilities of yeast cells readily, and the factor of interfacial energy plays a key role in the superficial mineralization of the cells. Furthermore, the influences of ion concentrations, as well as titration rates on the formation of inorganic shell, have also been examined. It is found that the biomimetic shell formation on the cell can also be achieved by using an appropriate selection of titration conditions rather than the pretreatment of LbL. Thus, the control of cellular biomineralization can become more feasible. In this study, we show that adjusting the interfacial energy is the key to cellular mineralization and suggest that these biomineralization treatments of single-cell may be applied as a potential and universal approach for cell-based sensing and therapy.
许多单细胞生物以其外部的蛋白质和脂质膜或富含碳水化合物的细胞壁为生物矿化模板，合成一层薄的矿物质层作为功能覆盖物。在自然界中，大多数细胞在正常状态下不能自发矿化。受自然启发，我们开发了一种细胞相容的方法，用于在包裹于矿物质壳内的细胞上进行“细胞成壳”。利用层层组装法，可以在酵母细胞表面诱导钙矿物质沉淀。通过恒组成法（CC）系统且定量地研究了不同合成聚电解质对酵母钙化的影响，如界面能、zeta电位、引入时间以及矿物质相在酵母细胞表面的亲和力。结果表明，富含羧基或磺酸根基团的聚电解质在酵母上的有效吸附能够轻易增强酵母细胞的矿化能力，且界面能因素在细胞表面矿化中起关键作用。此外，还研究了离子浓度以及滴定速率对无机壳形成的影响。发现通过适当选择滴定条件而非层层预处理也能在细胞上实现仿生壳的形成。因此，细胞生物矿化的控制变得更加可行。在本研究中，我们表明调节界面能是细胞矿化的关键，并提出这些单细胞的生物矿化处理可能作为一种潜在的通用方法应用于基于细胞的传感和治疗。
