Cellular Flocculation Driven by Concentrated Polymer Brush-Modified Cellulose Nanofibers with Different Surface Charges
Cellular Flocculation Driven by Concentrated Polymer Brush-Modified Cellulose Nanofibers with Different Surface Charges
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DOI：
10.1021/acs.biomac.2c00294
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发表时间：
2022-07-19
影响因子：
6.2
通讯作者：
Matsumura，Kazuaki
中科院分区：
文献类型：
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作者：
Yoshikawa，Chiaki;Sakakibara，Keita;Matsumura，Kazuaki
本研究考察了浓聚刷（CPB）接枝纤维素纳米纤维（CNFs）表面电荷对HepG2细胞絮凝的影响。将聚（对苯乙烯磺酸钠盐）（PSSNa）、聚（丙烯酸）（PAA）、聚（2-（二甲氨基）甲基丙烯酸乙酯）（PDMAEMA）和聚（[（2-甲基丙烯氧基）乙基]三甲基氯化铵）（PMTAC）四种聚电解质通过表面引发原子转移自由基聚合接枝到CNF表面，形成CNF - cpbs。HepG2细胞的絮团大小取决于cnf - cpb的表面电荷，其中阴离子CNF-PSSNa比CNF-PAA形成更大的絮团；由于静电斥力的作用，具有较低ζ电位的CNF-CPBs产生较小的絮团尺寸。相反，细胞毒性阳离子CNF-PDMAEMA和CNF-PMTAC限制了絮团大小的增长。因此，在三维（3D）细胞培养系统中，适当的静电相互作用对于絮团形成和改善细胞功能是必不可少的。有趣的是，在开发一种新的三维细胞培养系统的同时，我们揭示了胶体絮凝理论是这种独特现象背后的驱动机制。
This study examined the effect of the surface charge of concentrated polymer brush (CPB)-grafted cellulose nanofibers (CNFs) on HepG2 cell flocculation. Four polyelectrolytes, poly(p-styrenesulfonic acid sodium salt) (PSSNa), poly(acrylic acid) (PAA), poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), and poly([(2-methacryloyloxy)ethyl]trimethylammonium chloride) (PMTAC), were grafted onto the CNF surface via surface-initiated atom transfer radical polymerization to form CNF–CPBs. The floc size of HepG2 cells depended on the surface charge of CNF–CPBs, where the anionic CNF–PSSNa formed larger flocs than CNF–PAA; due to the electrostatic repulsive forces, CNF–CPBs with a lower ζ-potential yielded smaller floc sizes. Contrastingly, the cytotoxic cationic CNF–PDMAEMA and CNF–PMTAC limited the floc size growth. Thus, appropriate electrostatic interactions are essential for floc formation and improved cell function in three-dimensional (3D) cell culture systems. Interestingly, while developing a novel 3D cell culture system, we reveal that colloidal flocculation theory is the driving mechanism behind this unique phenomenon.