Eivazi Alireza, Medronho Bruno, Lindman Björn, Norgren Magnus
FSCN, Surface and Colloid Engineering, Mid Sweden University, SE-851 70 Sundsvall, Sweden.
MED-Mediterranean Institute for Agriculture, Environment and Development, Universidade do Algarve, Faculdade de Ciências e Tecnologia, Campus de Gambelas, Ed. 8, 8005-139 Faro, Portugal.
Polymers (Basel). 2021 Feb 16;13(4):589. doi: 10.3390/polym13040589.
Polymeric multilayer capsules formed by the Layer-by-Layer (LbL) technique are interesting candidates for the purposes of storage, encapsulation, and release of drugs and biomolecules for pharmaceutical and biomedical applications. In the current study, cellulose-based core-shell particles were developed via the LbL technique alternating two cellulose derivatives, anionic carboxymethylcellulose (CMC), and cationic quaternized hydroxyethylcellulose ethoxylate (QHECE), onto a cationic vesicular template made of didodecyldimethylammonium bromide (DDAB). The obtained capsules were characterized by dynamic light scattering (DLS), ζ potential measurements, and high-resolution scanning electron microscopy (HR-SEM). DLS measurements reveal that the size of the particles can be tuned from a hundred nanometers with a low polydispersity index (deposition of 2 layers) up to micrometer scale (deposition of 6 layers). Upon the deposition of each cellulose derivative, the particle charge is reversed, and pH is observed to considerably affect the process thus demonstrating the electrostatic driving force for LbL deposition. The HR-SEM characterization suggests that the shape of the core-shell particles formed is reminiscent of the spherical vesicle template. The development of biobased nano- and micro-containers by the alternating deposition of oppositely charged cellulose derivatives onto a vesicle template offers several advantages, such as simplicity, reproducibility, biocompatibility, low-cost, mild reaction conditions, and high controllability over particle size and composition of the shell.
通过层层（LbL）技术形成的聚合物多层胶囊是用于药物和生物医学应用中药物及生物分子储存、封装和释放的有趣候选物。在当前研究中，基于纤维素的核壳颗粒通过LbL技术制备，将两种纤维素衍生物，即阴离子羧甲基纤维素（CMC）和阳离子季铵化乙氧基化羟乙基纤维素（QHECE），交替沉积在由十二烷基二甲基溴化铵（DDAB）制成的阳离子囊泡模板上。通过动态光散射（DLS）、ζ电位测量和高分辨率扫描电子显微镜（HR-SEM）对所得胶囊进行了表征。DLS测量表明，颗粒尺寸可从具有低多分散指数的一百纳米（2层沉积）调节至微米级（6层沉积）。在沉积每种纤维素衍生物时，颗粒电荷会反转，并且观察到pH对该过程有显著影响，从而证明了LbL沉积的静电驱动力。HR-SEM表征表明，形成的核壳颗粒形状让人联想到球形囊泡模板。通过将带相反电荷的纤维素衍生物交替沉积在囊泡模板上来开发生物基纳米和微容器具有诸多优点，例如简单、可重复性、生物相容性、低成本、温和的反应条件以及对颗粒尺寸和壳组成的高度可控性。
