†Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, 35131, Padova, Italy.
‡School of Pharmacy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
Biomacromolecules. 2015 Jul 13;16(7):1924-37. doi: 10.1021/acs.biomac.5b00286. Epub 2015 Jun 2.
New pH-responsive polymersomes for active anticancer oligonucleotide delivery were prepared from triblock copolymers. The delivery systems were formed by two terminal hydrophilic blocks, PEG and polyglycerolmethacrylate (poly-GMA), and a central weakly basic block, polyimidazole-hexyl methacrylate (poly-ImHeMA), which can complex with oligonucleotides and control vesicle formation/disassembly via pH variations. Targeted polymersomes were prepared by mixing folate-derivatized and underivatized copolymers. At pH 5, ds-DNA was found to complex with the pH-responsive copolymers at a N/P molar ratio above ∼2:1, which assisted the encapsulation of ds-DNA in the polymersomes, while low association was observed at pH 7.4. Cytotoxicity studies performed on folate receptor overexpressing KB and B16-F10 cells and low folate receptor expressing MCF-7 cells showed high tolerance of the polymersomes at up to 3 mg/mL concentration. Studies performed with red blood cells showed that at pH 5.0 the polymersomes have endosomolytic properties. Cytofluorimetric studies showed a 5.5-fold higher uptake of ds-DNA loaded folate-functional polymersomes in KB cells compared to nontargeted polymersomes. In addition, ds-DNA was found to be localized both in the nucleus and in the cytosol. The incubation of luciferase transfected B16-F10 cells with targeted polymersomes loaded with luciferase and Hsp90 expression silencing siRNAs yielded 31 and 23% knockdown in target protein expression, respectively.
新型 pH 响应聚合物囊泡用于主动抗癌寡核苷酸递药，由三嵌段共聚物制备。递药系统由两个末端亲水嵌段（PEG 和聚甘油甲基丙烯酸酯（poly-GMA））和一个中心弱碱性嵌段（聚咪唑-己基甲基丙烯酸酯（poly-ImHeMA））组成，可与寡核苷酸复合，并通过 pH 变化控制囊泡形成/解体。通过混合叶酸衍生化和未衍生化的共聚物制备靶向聚合物囊泡。在 pH 5 时，ds-DNA 与 pH 响应共聚物在 N/P 摩尔比高于约 2:1 时被发现复合，这有助于 ds-DNA 封装在聚合物囊泡中，而在 pH 7.4 时观察到低缔合。在高表达叶酸受体的 KB 和 B16-F10 细胞和低表达叶酸受体的 MCF-7 细胞上进行的细胞毒性研究表明，聚合物囊泡在高达 3mg/mL 浓度下具有高耐受性。用红细胞进行的研究表明，在 pH 5.0 时聚合物囊泡具有内溶酶体性质。细胞荧光研究表明，与非靶向聚合物囊泡相比，负载 ds-DNA 的叶酸功能化聚合物囊泡在 KB 细胞中的摄取增加了 5.5 倍。此外，ds-DNA 被发现定位于细胞核和细胞质中。用负载荧光素酶和 HSP90 表达沉默 siRNA 的转染的荧光素酶 B16-F10 细胞孵育靶向聚合物囊泡，分别导致靶蛋白表达降低 31%和 23%。
