Biomedical Polymers Laboratory, and Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, PR China.
Biomaterials. 2010 Oct;31(29):7575-85. doi: 10.1016/j.biomaterials.2010.06.021.
Biodegradable chimaeric polymersomes based on asymmetric PEG-PCL-PDEA triblock copolymers were prepared and investigated for delivery of exogenous proteins into cells. PEG-PCL-PDEA copolymers with M(n)(PEG) = 5 kg/mol, M(n)(PCL) = 18.2 kg/mol, and short PDEA blocks ranging from 1.1, 2.7 to 4.1 kg/mol (denoted as copolymer 1, 2 and 3, respectively) were obtained by controlled reversible addition-fragmentation chain transfer (RAFT) polymerization. The direct hydration of copolymer thin films in MES buffer (pH 5.3) yielded uniform polymersomes with sizes of 130-175 nm. These polymersomes had close to neutral zeta potentials (-2 approximately +2.7 mV) at pH 7.4. The polymersomal structures were confirmed by confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and catalytic activity experiment on 3,3',3''-phosphinidyne(trisbenzenesulfonic acid)-loaded polymersomes. MTT assays showed that these polymersomes were non-toxic up to a concentration of 0.5mg/mL. These chimaeric polymersomes, in particular polymersome 2, showed remarkably high protein loading efficiencies and loading contents for bovine serum albumin (BSA), cytochrome C (CC), lysozyme (Lys), ovalbumin (OVA) and immunoglobulin G (IgG). The encapsulation of proteins did not significantly alter the polymersome size distributions and zeta potentials. The protein release studies showed that both BSA and CC were released in a controlled manner. Importantly, the released CC fully maintained its activity. Notably, CLSM studies showed that FITC-CC loaded polymersomes efficiently delivered and released proteins into the cytoplasm of RAW 264.7 cells. Moreover, these chimaeric polymersomes were able to simultaneously load and transport proteins and doxorubicin into the cytoplasm as well as the cell nucleus. We are convinced that these biodegradable chimaeric polymersomes have great potentials in protein therapy.
基于非对称 PEG-PCL-PDEA 三嵌段共聚物的可生物降解杂化聚合物囊泡被制备并研究了其将外源性蛋白质递送到细胞内的作用。通过受控可逆加成-断裂链转移（RAFT）聚合得到具有 M(n)(PEG) = 5 kg/mol、M(n)(PCL) = 18.2 kg/mol 和短 PDEA 嵌段（分别表示为共聚物 1、2 和 3）的 M(n)(PDEA)范围从 1.1、2.7 到 4.1 kg/mol 的 PEG-PCL-PDEA 共聚物。在 MES 缓冲液（pH 5.3）中直接水合共聚物薄膜得到了尺寸为 130-175nm 的均匀聚合物囊泡。这些聚合物囊泡在 pH 7.4 时具有接近中性的 Zeta 电位（-2 到+2.7 mV）。聚合物囊泡结构通过共焦激光扫描显微镜（CLSM）、透射电子显微镜（TEM）和载有 3,3',3''-膦酰基（三苯磺酸）的聚合物囊泡的催化活性实验进行了确认。MTT 测定表明，这些聚合物囊泡在高达 0.5mg/mL 的浓度下是无毒的。这些杂化聚合物囊泡，特别是聚合物囊泡 2，对牛血清白蛋白（BSA）、细胞色素 C（CC）、溶菌酶（Lys）、卵清蛋白（OVA）和免疫球蛋白 G（IgG）具有显著的高蛋白质载药效率和载药含量。蛋白质的包封并没有显著改变聚合物囊泡的大小分布和 Zeta 电位。蛋白质释放研究表明，BSA 和 CC 均以控制方式释放。重要的是，释放的 CC 完全保持其活性。值得注意的是，CLSM 研究表明，负载 FITC-CC 的聚合物囊泡能够有效地将蛋白质递送到 RAW 264.7 细胞的细胞质中并将其释放。此外，这些杂化聚合物囊泡能够同时将蛋白质和阿霉素递送到细胞质和细胞核中。我们相信，这些可生物降解的杂化聚合物囊泡在蛋白质治疗方面具有巨大的潜力。
