Department of Thoracic Surgery, the Second Affiliated Hospital of Soochow University, Suzhou 215004, P.R. China.
Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, P.R. China.
Biomater Sci. 2020 Jan 1;8(1):290-301. doi: 10.1039/c9bm01452g. Epub 2019 Nov 7.
The performance of non-viral gene delivery vehicles, especially cationic polymers, is often challenged by the multiple cellular barriers that pose inconsistent requirements for material properties. A most pronounced inconsistency is exemplified by the molecular weight (MW)-related transfection efficiency and cytotoxicity. In this study, we report the development of photo-degradable, branched poly(β-amino ester)s (BPAE-NB) to realize efficient and photo-controlled DNA and siRNA delivery. BPAE-NB possessing built-in light-responsive 2-nitrobenzene moieties in the polymer backbone was synthesized via the A2 (amine) + B3 (triacrylate) + C2 (diacrylate) polycondensation reaction from 4-amino-1-butanol (A2), trimethylolpropane triacrylate (B3), and (2-nitro-1,3-phenylene)bis(methylene) diacrylate (NPBMDA, C2). The highly branched BPAE-NB with the multivalent arrangement of cationic groups provides stronger nucleic acid binding capacity than its linear analogue LPAE-NB, and thus features stronger trans-membrane gene delivery capabilities and higher transfection efficiencies. Upon UV light irradiation, the backbone of BPAE-NB can quickly degrade into low-MW fragments as a consequence of the cleavage of the light-responsive 2-nitrobenzene, thus promoting intracellular gene release and diminishing the toxicity of materials at the post-transfection state. As such, in multiple mammalian cells, BPAE-NB exhibited remarkably higher DNA/siRNA transfection efficiency yet lower cytotoxicity than its non-responsive analogue BPAE-CC upon light irradiation, notably outperforming commercial reagents PEI 25k and Lipofectamine 2000. This study therefore provides an effective topology- and photo-controlled approach to precisely manipulate the transfection efficiency and toxicity of polycationic gene vectors, and may also provide promising additions to the existing non-viral gene delivery vectors.
非病毒基因传递载体的性能，特别是阳离子聚合物，经常受到多种细胞屏障的挑战，这些屏障对材料性能提出了不一致的要求。最明显的不一致之处体现在分子量（MW）相关的转染效率和细胞毒性上。在本研究中，我们报告了光降解的支化聚（β-氨基酯）（BPAE-NB）的开发，以实现有效的光控 DNA 和 siRNA 传递。BPAE-NB 聚合物主链中内置了光响应的 2-硝基苯基团，通过 A2（胺）+B3（三丙烯酸酯）+C2（二丙烯酸酯）缩聚反应，由 4-氨基-1-丁醇（A2）、三羟甲基丙烷三丙烯酸酯（B3）和（2-硝基-1,3-亚苯基）双（亚甲基）二丙烯酸酯（NPBMDA，C2）合成。具有多价阳离子基团排列的高度支化的 BPAE-NB 比其线性类似物 LPAE-NB 具有更强的核酸结合能力，因此具有更强的跨膜基因传递能力和更高的转染效率。在紫外光照射下，BPAE-NB 的主链由于光响应的 2-硝基苯的断裂，可以迅速降解为低分子量片段，从而促进细胞内基因释放，并在转染后降低材料的毒性。因此，在多种哺乳动物细胞中，与非响应类似物 BPAE-CC 相比，BPAE-NB 在光照下表现出显著更高的 DNA/siRNA 转染效率和更低的细胞毒性，显著优于商业试剂 PEI 25k 和 Lipofectamine 2000。因此，本研究为精确控制聚阳离子基因载体的转染效率和毒性提供了一种有效的拓扑和光控方法，也可能为现有的非病毒基因传递载体提供有希望的补充。
