分枝PEI修饰的PLGA纳米粒转染DNA的研究季明辉冷胡贵方匚顾大勇舄谢伟东3谈书勤'徐华4欧青叶4（1南方医科大学公共卫生与热带医学学院，广东省广州市515000：2深圳出入境检验检疫局疾病预防控制研究室，广东省深圳市518045：3清华大学深圳研究生院，广东省深圳市518045：4南通大学公共卫生学院，江苏省南通市226019）摘要：目的建立基于聚（乳酸■羟基乙酸）纳米粒（PLGA）载DNA的基因转染体系，比较用空白聚（乳酸■羟基乙酸）纳米粒（PLGA-E）吸附质粒DNA和用分枝PEI修饰后的PLGA纳米粒（PLGA.BPEI）吸附质粒DNA优缺点。方法用乳化蒸发法制备纳米粒，对纳米粒进行表征研究，包括包封率、Zeta电位、粒径大小、稳定性，用荧光显微镜观察它们对NIH3T3和HEK293细胞的转染效率，用MTT检测对它们细胞的毒性。结果制备了两种基于PLGA的纳米粒，PLGA-E和PLGA-BPEI粒径大小为200-270nm,zeta电位为0-30mV,在血清和不同的pH值时两者均较稳定，转染效率PLGA-BPEI较PLGA-E高，且释放时间早,但前者较后者对细胞毒性大。结论这两种基于PLGA纳米粒均能有效转染质粒DNA,它们存在不同的优缺点，应根据不同需要进行选择。词：聚(乳酸■羟基乙酸)，纳米粒，基因转染分类号：Q-782文献标识码：A：SurfacemodificationofPLGAnanopswithBranchespolyethyleneimineforDNAtransfectionresearch激Mi〃g-hui以,HUGui-fang'^,GUDa-yong2A,XIEWeid,TANShu-qin1,XUHua4,OUQin-ye4(ISchoolofPublicHealthandTropicalMedicine,SouthernMedicalUniversity,Guangzhou515000,GuangdongProvince,China;2InstituteofDiseaseControlandPrevention,ShenzhenInternationalTravelHealthCareCenterShendienEntry-exitInspectionandQuarantineBureau,Shendien518045.China;3GraduateSchoolatShenzhen.TsinghuaUniversity,Shenzhen5/8000GuangdongProvince,China;4SchoolofPublicHealth,NantongUniversity,Nantong226000,激angsuProvince,China)ABSTRACT：ObjectiveTheaimofthisstudyistobuilduptwoPLGAnanop(NP)-basedgenedeliverysystemsnamely,plasmidDNA(pDNA)enc叩sulatedPLGANPs(PLGA-E)andsurfaceadsorbedpDNAonPLGA-BPEINPs(PLGA-BPEI),withrespecttotheextentofinternalizationandintracellularreleaseofpDNA.MethodsSeveralformulationshavealsobeenevaluatedsystematicallyfbrdeterminationoftheoptimal*国家自然科学基金项目（81072680；30972827）；质检总局项目（2010IK212）；深港创新圈计划（联合资助）项目（ZYB200907090128A）；深圳市科技计划切块项目（HZ0907004）作者简介：季明辉（1983-）,男，研究生，主要研究方向：生物纳米材料和生物芯片△通讯作者：顾大勇，电话：0755-83391344,E-maikwanhood@163。胡贵方，电话020-61648653,hgt@fimmutransiectionefficiency.Thezeta-potential,psizemeasurementsandDNaseIprotectionassayestablishedtheimportanceoftheBPEIchainlengthinregulatingtheeffectiveloadingandcondensationofpDNAwithPLGA-BPEINPsandpDNAprotectionabilityofPLGA-BPETNPs.Thestabilityoftheseformulationswasalsoinvestigatedasafunctionofserumconcentration.Invitrotime-dependentgenetransfectionefficiencieswerestudiedinpresenceaswellasinabsenceofserumfbrNIH3T3andHEK293cells.ThecellviabilitywerealsoinvestigatedusingMTTassay.ResultswebuilduptwoPLGAnanop(NP)-basedgenedeliverysystemsnamely,plasmidDNA(pDNA)encapsulatedPLGANPs(PLGA-E)andsurfaceadsorbedpDNAonPLGA-BPEINPs(PLGA-BPET),thesizeofPLGA-EandPLGA-BPEIarcbetween200to270nm,zetaarcfrom0to30mV,InserumanddifferentpHbotharestable,thetransfectionefTiciencyofPLGA-BPEIarehigherthanPLGA-Eandreleaseearly,butthelormerhavemoretoxictothecell.ConclusionWehavedevelopedtwokindsofPLGA-basedgenedeliverysystemsandinvestigatedtheirtransiectionefficiencies.Thereforeitcanbeassumedthatthiskindofstudyshouldprovideastrongbasisinchoosingappropriatedeliverysystemfbrspecificgeneexpression...