Objective To evaluate the transfection efficiency and cytotoxicity of polyamine cationic liposomes (PCL), and to screen for a cationic liposome with high potency and low toxicity. Methods Four kinds of PCLs, namely PCL-A, PCL-B, PCL-C and PCL-D, were prepared with polyamine cationic lipid TC-Chol or DC-Chol and the neutral phospholipid DOPE in different molar ratios (1∶1 or 3∶1). The morphology of the liposome was observed by transmission electron microscope. Plasmid PIRES2-EGFP, which contained an enhanced green fluorescencent-protein (EGFP) reporter gene, was transfected into Hela cells or Hep2 cells with PCL-A, PCL-B, PCL-C and PCL-D, respectively. Expression of EGFP was examined by fluorescence microscopy and the cytotoxicity of the transfected cells was determined with MTT assay. Results The shape of PCL-A, PCL-B, PCL-C and PCL-D was round or oval, most of the PCLs were about 50-200nm in diameter. The transfection efficiency of the four kinds of PCLs was about 19.8%-42.1%. Among them, PCL-C prepared with TC-Chol and DOPE at a molar ratio of 3∶1 showed a higher transfection efficiency (39.5%-42.1%) and lower cytotoxicity (cellular survival rate was 86.57%?3.23%-84.43%?4.18%). Conclusions The polyamine cationic liposome prepared with polyamine cationic lipids TC-Chol or DC-Chol and the neutral phospholipid DOPE at a certain molar ratio mediated the transfection of the plasmid PIRES2-EGFP into mammalian cells. PCL-C exhibited higher transfection efficiency and lower cytotoxicity, and it might be a promising agent for gene transfection and gene therapy.

Objective To evaluate the effects of the modified opration of benign tumor in parotid gland on the prevention of Frey syndrome.Methods the Parotid benign tumor resection in 28 cases were selected,according to the different treatment methods were divided into observation group of 12 cases,16 cases of the control group.The modified surgical patients in the observation group,two flap method,preservation,preservation of parotid masseter fascia in the branches of the great auricular nerve and parotid region resection,the control group was treated by routine tumors of the parotid gland and parotid superficial lobectomy or resection.Patients were followed up for 6 months to 1 years,underwent minor test,the incidence of Frey syndrome in 2 cases were recorded,postoperative incidence of Frey syndrome were compared.Results The incidence of Frey syndrome in the observation group was significantly reduced compared with the control group.The difference was statistically significant (χ2 =7.479,P <0.05 ). Conclusion The effects of modified opetation combined with secondry disc method in benign tumor of parotid gland on the prevention of Frey syndrome has obvious advantages comparing with the control.