ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering , The University of Melbourne , Parkville , Victoria 3010 , Australia.
Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering , Shandong University , Jinan , Shandong 250100 , China.
ACS Appl Mater Interfaces. 2019 Aug 14;11(32):28720-28731. doi: 10.1021/acsami.9b10304. Epub 2019 Aug 1.
In the present study, a capsule system that consists of a stealth carrier based on poly(ethylene glycol) (PEG) and functionalized with bispecific antibodies (BsAbs) is introduced to examine the influence of the capsule shape and size on cellular targeting. Hollow spherical and rod-shaped PEG capsules with tunable aspect ratios (ARs) of 1, 7, and 18 were synthesized and subsequently functionalized with BsAbs that exhibit dual specificities to PEG and epidermal growth factor receptor (EGFR). Dosimetry (variation between the concentrations of capsules present and capsules that reach the cell surface) was controlled through "dynamic" incubation (i.e., continuously mixing the incubation medium). The results obtained were compared with those obtained from the "static" incubation experiments. Regardless of the incubation method and the capsule shape and size studied, BsAb-functionalized PEG capsules showed >90% specific cellular association to EGFR-positive human breast cancer cells MDA-MB-468 and negligible association with both control cell lines (EGFR negative Chinese hamster ovary cells CHO-K1 and murine macrophages RAW 264.7) after incubation for 5 h. When dosimetry was controlled and the dose concentration was normalized to the capsule surface area, the size or shape had a minimal influence on the cell association behavior of the capsules. However, different cellular internalization behaviors were observed, and the capsules with ARs 7 and 18 were, respectively, the least and most optimal shape for achieving high cell internalization under both dynamic and static conditions. Dynamic incubation showed a greater impact on the internalization of rod-shaped capsules (∼58-67% change) than on the spherical capsules (∼24-29% change). The BsAb-functionalized PEG capsules reported provide a versatile particle platform for the evaluation and comparison of cellular targeting performance of capsules with different sizes and shapes in vitro.
在本研究中，引入了一种由基于聚乙二醇（PEG）的隐形载体和双特异性抗体（BsAbs）功能化组成的胶囊系统，以研究胶囊形状和大小对细胞靶向的影响。合成了具有可调纵横比（AR）为 1、7 和 18 的空心球形和棒形 PEG 胶囊，随后用对 PEG 和表皮生长因子受体（EGFR）具有双重特异性的 BsAbs 功能化。通过“动态”孵育（即连续混合孵育介质）控制剂量学（存在的胶囊浓度和到达细胞表面的胶囊浓度之间的变化）。将获得的结果与“静态”孵育实验获得的结果进行比较。无论孵育方法以及研究的胶囊形状和大小如何，BsAb 功能化的 PEG 胶囊在孵育 5 小时后均表现出对 EGFR 阳性人乳腺癌细胞 MDA-MB-468 的>90％特异性细胞结合，而与对照细胞系（EGFR 阴性中国仓鼠卵巢细胞 CHO-K1 和鼠巨噬细胞 RAW 264.7）的结合可忽略不计。当剂量学得到控制并且剂量浓度被归一化为胶囊表面积时，大小或形状对胶囊的细胞结合行为几乎没有影响。然而，观察到不同的细胞内化行为，并且在动态和静态条件下，纵横比分别为 7 和 18 的胶囊是实现高细胞内化的最不理想和最佳形状。动态孵育对棒状胶囊的内化（约 58-67％的变化）的影响大于对球形胶囊的内化（约 24-29％的变化）。报道的 BsAb 功能化的 PEG 胶囊提供了一种通用的颗粒平台，用于评估和比较不同尺寸和形状的胶囊在体外的细胞靶向性能。
