Nucleic acid-based therapies hold promise for treating previously intractable diseases but require effective delivery vectors to protect the therapeutic agents and ensure efficient transfection. Cationic polymeric vectors are particularly notable for their adaptability, high transfection efficiency, and low cost, but their positive charge often attracts blood proteins, causing aggregation and reduced transfection efficiency. Addressing this, we designed an anionic peptide-grafted dextran (Dex-LipE5H) to serve as a cross-linkable coating to bolster the stability of cationic polymer/nucleic acid complexes. The Dex-LipE5H was synthesized through a Michael addition reaction, combining an anionic peptide (LipE5H) with dextran modified by divinyl sulfone. We demonstrated Dex-lipE5H utility in a novel ternary nucleic acid delivery system, CDex-LipE5H/PEI/nucleic acid. CDex-LipE5H/PEI/nucleic acid demonstrated lower cytotoxicity and superior anti-protein absorption ability compared to PEI/pDNA and Dex-LipE5H/PEI/pDNA. Most notably, the crosslinked CDex-LipE5H/PEI/pDNA demonstrated remarkable transfection performance in HepG2 cells, which poses significant transfection challenges, even in a medium with 20% serum. This system's effective siRNA interference performance was further validated through a PCSK9 gene knockdown assay. This investigation provides novel insights and contributes to the design of cost-effective, next-generation nucleic acid delivery systems with enhanced blood stability and transfection efficiency.

中文翻译：

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通过稳定的阴离子肽-葡聚糖三元系统提高核酸递送。

基于核酸的疗法有望治疗以前的难治性疾病，但需要有效的递送载体来保护治疗剂并确保有效的转染。阳离子聚合载体尤其以其适应性强、转染效率高和成本低而著称，但其正电荷常常吸引血液蛋白，导致聚集并降低转染效率。为了解决这个问题，我们设计了一种阴离子肽接枝葡聚糖（Dex-LipE5H）作为可交联涂层，以增强阳离子聚合物/核酸复合物的稳定性。Dex-LipE5H 通过迈克尔加成反应合成，将阴离子肽 (LipE5H) 与二乙烯基砜修饰的葡聚糖结合。我们展示了 Dex-lipE5H 在新型三元核酸递送系统 CDex-LipE5H/PEI/核酸中的实用性。与PEI/pDNA和Dex-LipE5H/PEI/pDNA相比，CDex-LipE5H/PEI/核酸表现出较低的细胞毒性和优异的抗蛋白吸收能力。最值得注意的是，交联的 CDex-LipE5H/PEI/pDNA 在 HepG2 细胞中表现出卓越的转染性能，即使在含有 20% 血清的培养基中，这也带来了重大的转染挑战。该系统有效的 siRNA 干扰性能通过 PCSK9 基因敲低实验得到进一步验证。这项研究提供了新颖的见解，有助于设计具有成本效益的下一代核酸递送系统，提高血液稳定性和转染效率。