中文摘要：

目的研究非病毒基因载体聚酰胺-胺型树枝状大分子（PAMAM）-透明质酸（HA）聚合物的体外细胞毒性。方法采用MTT法和流式细胞术,分别检测合成的多种PAMAM-HA聚合物对HeLa细胞、Bel-7402细胞和Hep G2细胞的细胞毒性及其诱导细胞凋亡的能力。结果 PAMAM-HA聚合物的细胞毒性随浓度（50-800 mg·L^-1）增加、作用时间（24-72 h）延长、PAMAM的代数（G4,G5）增加及HA的相对分子质量（3850和17 200）和接枝密度（5%-25%）降低而增加。与聚合物PAMAM G4-HA3850-5%和PAMAM G5-HA3850-5%孵育24 h,肝癌细胞Bel-7402细胞凋亡率分别为4.5%和9.9%。聚合物与DNA形成的复合物PAMAM G4-HA3850-5%/DNA和PAMAM G5-HA3850-5%/DNA与细胞共孵育24 h后,细胞存活率均在80%以上,较PAMAM G4/DNA和PAMAM G5/DNA毒性降低（P〈0.05）。结论经不同接枝量和接枝密度HA修饰的PAMAM细胞毒性降低,是一种较有前途的非病毒基因载体。

英文摘要：

OBJECTIVE To study the cytotoxicity of polyamide amine dendrimers（PAMAM）-hyaluronic acid（HA）as a non-viral gene delivery vector in vitro. METHODS PAMAM-HA was synthesized by our laboratory. Cytotoxicities of various polymers on He La cells,Bel-7402 cells and Hep G2 cells were evaluated by MTT assay. Apoptotic rates were determined by flow cytometry. RESULTS The cytotoxicity of PAMAM-HA polymer increased with the concentration of polymer（50-800 mg·L^-1）,the time of action（24-72 h）,the number of generations of PAMAM（G4,G5） and decrease in the molecular mass（3850,17 200）and the graft density（5%-25%）of HA. After incubation with PAMAM G4-HA3850-5% or PAMAM G5-HA3850-5% for 24 h,the apoptotic rate of hepatoma cells—Bel-7402 cells was 4.5%and 9.9%,respectively. After incubation with complexes of PAMAM G4-HA3850-5%/DNA or PAMAM G5-HA3850-5%/DNA for 24 h,the viability of He La cells was more than 80%,which was lower than that of PAMAM G4/DNA 和 PAMAM G5/DNA. CONCLUSION Cytotoxicity of PAMAM modified by HA of different grafting density and quantity can be reduced,suggesting the PAMAM is a promising non-viral gene vector.