Zheng Hao, Tang Cui, Yin Chunhua
State Key Laboratory of Genetic Engineering Department of Pharmaceutical Sciences, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Pharm Res. 2015 Jun;32(6):2038-50. doi: 10.1007/s11095-014-1597-7. Epub 2014 Dec 23.
Present study aimed at exploring advantages/disadvantages of amino acid modified trimethylated chitosan in conquering multiple gene delivery obstacles and thus providing comprehensive understandings for improved transfection efficiency.
Arginine, cysteine, and histidine modified trimethyl chitosan were synthesized and employed to self-assemble with plasmid DNA (pDNA) to form nanocomplexes, namely TRNC, TCNC, and THNC, respectively. They were assessed by structural stability, cellular uptake, endosomal escape, release behavior, nuclear localization, and in vitro and in vivo transfection efficiencies. Besides, sodium tripolyphosphate (TPP) was added into TRNC to compromise certain disadvantageous attributes for pDNA delivery.
Optimal endosomal escape ability failed to bring in satisfactory transfection efficiency of THNC due to drawbacks in structural stability, cellular uptake, pDNA liberation, and nuclear distribution. TCNC evoked the most potent gene expression owing to multiple advantages including sufficient stability, preferable uptake, efficient pDNA release, and high nucleic accumulation. Undesirable stability and insufficient pDNA release adversely affected TRNC-mediated gene transfer. However, incorporation of TPP could improve such disadvantages and consequently resulted in enhanced transfection efficiencies.
Coordination of multiple contributing effects to conquer all delivery obstacles was necessitated for improved transfection efficiency, which would provide insights into rational design of gene delivery vehicles.
本研究旨在探讨氨基酸修饰的三甲基化壳聚糖在克服多种基因递送障碍方面的优缺点，从而为提高转染效率提供全面的认识。
合成精氨酸、半胱氨酸和组氨酸修饰的三甲基壳聚糖，并分别与质粒DNA（pDNA）自组装形成纳米复合物，即TRNC、TCNC和THNC。通过结构稳定性、细胞摄取、内体逃逸、释放行为、核定位以及体外和体内转染效率对它们进行评估。此外，将三聚磷酸钠（TPP）添加到TRNC中以弥补pDNA递送的某些不利特性。
由于结构稳定性、细胞摄取、pDNA释放和核分布方面的缺陷，最佳的内体逃逸能力未能带来令人满意的THNC转染效率。TCNC由于具有多种优势，包括足够的稳定性、较好的摄取、有效的pDNA释放和高核酸积累，从而引发了最有效的基因表达。不理想的稳定性和不足的pDNA释放对TRNC介导的基因转移产生了不利影响。然而，加入TPP可以改善这些缺点，从而提高转染效率。
为了提高转染效率，需要协调多种促进作用以克服所有递送障碍，这将为基因递送载体的合理设计提供思路。
