The Petroleum and Petrochemical College, Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University , Soi Chulalongkorn 12, Pathumwan, Bangkok 10330, Thailand.
Department of Chemical and Materials Engineering, Donadeo Innovation Centre for Engineering , 116 Street and 85 Avenue, Edmonton, AB T6G 2G6, Canada.
Biomacromolecules. 2018 Jan 8;19(1):209-221. doi: 10.1021/acs.biomac.7b01475. Epub 2017 Dec 20.
Cationic glycopolymers have shown to be excellent candidates for the fabrication of gene delivery devices due to their ability to electrostatically interact with negatively charged nucleic acids and the carbohydrate residues ensure enhanced stability and low toxicity of the polyplexes. The ability to engineer the polymers for optimized compositions, molecular weights, and architectures is critical in the design of effective gene delivery vehicles. Therefore, in this study, the aqueous reversible addition-fragmentation chain transfer polymerization (RAFT) was used to synthesize well-defined cationic glycopolymers with various cationic segments. For the preparation of cationic parts, N-[3-(dimethylamino)propyl]methacrylamide hydrochloride (DMAPMA·HCl), water-soluble methacrylamide monomer containing tertiary amine, was polymerized to produce DMAPMA·HCl homopolymer, which was then used as macroCTA in the block copolymerization with two other methacrylamide monomers containing different pendant groups, namely, 2-aminoethyl methacrylamide hydrochloride (AEMA) (with primary amine) and N-(3-aminopropyl) morpholine methacrylamide (MPMA) (with morpholine ring). In addition, statistical copolymers of DMAPMA.HCl with either AEMA or MPMA were also synthesized. All resulting cationic polymers were utilized as macroCTA for the RAFT copolymerization with 2-lactobionamidoethyl methacrylamide (LAEMA), which consists of the pendent galactose residues to achieve DMAPMA·HCl-based glycopolymers. From the in vitro cytotoxicity study, the cationic glycopolymers showed better cell viabilities than the corresponding cationic homopolymers. Furthermore, complexation of the cationic polymers with siRNA, cellular uptake of the resulting polyplexes, and gene knockdown efficiencies were evaluated. All cationic polymers/glycopolymers demonstrated good complexation ability with siRNA at low weight ratios. Among these cationic polymer-siRNA polyplexes, the polyplexes prepared from the two glycopolymers, P(DMAPMA-b-LAEMA) and P[(DMAPMA-b-MPMA)-b-LAEMA], showed outstanding results in the cellular uptake, high EGFR knockdown, and low post-transfection toxicity, suggesting the great potential in siRNA delivery of these novel glycopolymers.
阳离子糖聚合物由于能够与带负电荷的核酸静电相互作用，并且碳水化合物残基确保了多聚物的更高稳定性和低毒性，因此已被证明是基因传递装置制造的优秀候选物。能够对聚合物进行工程设计以优化组成、分子量和结构对于有效基因传递载体的设计至关重要。因此，在这项研究中，使用水性可逆加成-断裂链转移聚合（RAFT）合成了具有各种阳离子段的结构明确的阳离子糖聚合物。为了制备阳离子部分，聚合 N-[3-（二甲基氨基）丙基]甲基丙烯酰胺盐酸盐（DMAPMA·HCl），即含有叔胺的水溶性甲基丙烯酰胺单体，以产生 DMAPMA·HCl 均聚物，然后将其用作含有两个不同侧基的两种其他甲基丙烯酰胺单体（即 2-氨基乙基甲基丙烯酰胺盐酸盐（AEMA）（含伯胺）和 N-（3-氨基丙基）吗啉甲基丙烯酰胺（MPMA）（含吗啉环））的嵌段共聚物的大分子 CTA。此外，还合成了 DMAPMA.HCl 与 AEMA 或 MPMA 的统计共聚物。所有得到的阳离子聚合物均用作 RAFT 共聚反应的大分子 CTA，与 2-乳糖酰乙胺甲基丙烯酰胺（LAEMA）共聚反应，LAEMA 含有乳糖残基，以获得基于 DMAPMA·HCl 的糖聚合物。从体外细胞毒性研究来看，阳离子糖聚合物比相应的阳离子均聚物具有更好的细胞活力。此外，还评估了阳离子聚合物与 siRNA 的复合物形成、所得聚合物-核酸复合物的细胞摄取和基因敲低效率。所有阳离子聚合物/糖聚合物在低重量比下均与 siRNA 表现出良好的复合物形成能力。在这些阳离子聚合物-siRNA 聚合物中，两种糖聚合物 P（DMAPMA-b-LAEMA）和 P[(DMAPMA-b-MPMA)-b-LAEMA]制备的聚合物-核酸复合物在细胞摄取、高 EGFR 敲低和低转染后毒性方面表现出优异的结果，表明这些新型糖聚合物在 siRNA 递送上具有巨大的潜力。
