乙氧基羟乙基纤维素（Hydroxyethyl cellulose，HEC）以其生物相容性和水溶性而广受关注，是一种具有潜在药物应用价值的多糖。本研究合成了聚乙烯亚胺2k（PEI2k）结合的乙氧基羟乙基纤维素（HECP2k），用于多柔比星/Bcl-2 siRNA联合传递系统。HECP2k是通过PEI2k与高碘酸盐氧化的HEC还原胺化合成的。使用1H NMR、13C NMR、基元胺定量、FT-IR和GPC对聚合物的合成进行了表征。通过琼脂糖凝胶电泳和Zeta-sizer测量发现，HECP2k将pDNA压缩成带正电荷和纳米尺寸的复合物（100-300 nm，~30 mV）。HECP2k的细胞毒性低，即使在血清条件下，HECP2k 10X的转染效率也比PEI25k高，显示其因乙氧基侧链而具有的高血清稳定性。流式细胞术和共聚焦激光显微镜观察都验证了HECP2k 10X的高效细胞摄取和内体逃逸。HECP2k 10X也可以载荷Dox和Bcl-2 siRNA，形成纳米粒子（HECP2k 10X@Dox/siRNA）。通过中位效应分析和安替霉素V染色分析，发现HECP2k 10X@Dox/siRNA复合物通过诱导细胞凋亡，具有协同增强的抗癌效果。因此，结论是HECP2k作为一种有前途的多柔比星/Bcl-2 siRNA联合传递载体具有巨大潜力。

Hydroxyethyl cellulose (HEC), widely known for its biocompatibility and water solubility, is a polysaccharide with potential for pharmaceutical applications. Here, we synthesized polyethylenimine2k (PEI2k)-conjugated hydroxyethyl cellulose (HECP2k) for doxorubicin/Bcl-2 siRNA co-delivery systems. HECP2ks were synthesized by reductive amination of PEI2k with periodate-oxidized HEC. The synthesis of the polymers was characterized using 1H NMR, 13C NMR, primary amine quantification, FT-IR, and GPC. Via agarose gel electrophoresis and Zeta-sizer measurement, it was found that HECP2ks condensed pDNA to positively charged and nano-sized complexes (100-300 nm, ~30 mV). The cytotoxicity of HECP2ks was low and HECP2k 10X exhibited higher transfection efficiency than PEI25k even in serum condition, showing its high serum stability from ethylene oxide side chains. Flow cytometry analysis and confocal laser microscopy observation verified the superior cellular uptake and efficient endosome escape of HECP2k 10X. HECP2k 10X also could load Dox and Bcl-2 siRNA, forming nano-particles (HECP2k 10X@Dox/siRNA). By median effect analysis and annexin V staining analysis, it was found that HECP2k 10X@Dox/siRNA complexes could cause synergistically enhanced anti-cancer effects to cancer cells via induction of apoptosis. Consequently, it was concluded that HECP2k possesses great potential as a promising Dox/Bcl-2 siRNA co-delivery carrier.