Development of NAMI-A-loaded PLGA-mPEG Nanoparticles:Physicochemical Characterization, in vitro Drug Release and in vivo Antitumor Efficacy

NAMI-A[imidazolium trans-tetrachloro(dimethylsulfoxide)imidazoleruthenium(Ⅲ)] shows extraordinary activities against metastatic tumors. However, the hydrolysis of NAMI-A to produce dimethyl sulfoxide(DMSO) could reduce anti-metastatic activity. To enhance the circulation time and the anti-metastatic effect of NAMI-A, NAMI-A-loaded nanoparticles were prepared by the double emulsion method and characterized by scanning electron microscopy for surface morphology, laser light scattering for size and zeta potential for surface charges. Controlled release of NAMI-A was observed in a sustained manner. Compared with free NAMI-A, NAMI-A-loaded nanoparticles exhibited superior antitumor effect by delaying tumor growth in T739 mice. PLGA-mPEG nanoparticles are promising for further studies as drug delivery carriers.

Development of composite PLGA microspheres containing exenatide-encapsulated lecithin nanoparticles for sustained drug release

This study aimed to prepare poly(D, L-lactic-co-glycolic acid) microspheres(PLGA-Ms)by a modified solid-in-oil-in-water(S/O/W) multi-emulsion technique in order to achieve sustained release with reduced initial burst and maintain efficient drug concentration for a prolonged period of time. Composite PLGA microspheres containing exenatideencapsulated lecithin nanoparticles(Ex-NPs-PLGA-Ms) were obtained by initial fabrication of exenatide-loaded lecithin nanoparticles(Ex-NPs) via the alcohol injection method,followed by encapsulation of Ex-NPs into PLGA microspheres. Compared to Ms prepared by the conventional water-in-oil-in-water(W/O/W) technique(Ex-PLGA-Ms), Ex-NPs-PLGAMs showed a more uniform particle size distribution, reduced initial burst release, and sustained release for over 60 d in vitro. Cytotoxicity studies showed that Ms prepared by both techniques had superior biocompatibility without causing any detectable cytotoxicity.In pharmacokinetic studies, the effective drug concentration was maintained for over 30 d following a single subcutaneous injection of two types of Ms formulation in rats, potentially prolonging the therapeutic action of Ex. In addition, administration of Ex-NPs-PLGA-Ms resulted in a more smooth plasma concentration-time profile with a higher area under the curve(AUC) compared to that of Ex-PLGA-Ms. Overall, Ex-NPs-PLGA-Ms prepared by the novel S/O/W method could be a promising sustained drug release system with reduced initial burst release and prolonged therapeutic efficacy.

PEGylated PLGA Nanoparticles as Tumor Ecrosis Factor-α Receptor Blocking Peptide Carriers:Preparation,Characterization and Release in vitro

To assess the merits of PEGylated poly （lactic-co-glycolic acid） （PEG-PLGA） nanoparticles as drug carriers for tumor necrosis factor-α receptor blocking peptide （TNFR-BP）, PEG-PLGA copolymer, which could be used to prepare the stealth nanoparticles, was synthesized with methoxypolyethyleneglycol, DL-lactide and glycolide. The structure of PEG-PLGA was confirmed with ^1H-NMR and FT-IR spectroscopy, and the molecular weight （MW） was determined by gel permeation chromatography. Fluorescent FITC-TNFR- BP was chosen as model protein and encapsulated within PEG-PLGA nanoparticles using the double emulsion method. Atomic force microscopy and photon correlation spectroscopy were employed to characterize the stealth nanoparticles fabricated for morphology, size with polydispersity index and zeta potential. Encapsulation efficiency （EE） and the release of FITC-TNFR-BP in nanopartieles in vitro were measured by the fluorescence measurement. The stealth nanoparticles were found to have the mean diameter less than 270 nm and zeta potential less than -20 mV. In all nanoparticle formulations, more than 45% of EE were obtained. FITC-TNFR-BP release from the PEG-PLGA nanoparticles exhibited a biphasic pattern, initial burst release and consequently sustained release. The experimental results show that PEG-PLGA nanoparticles possess the potential to develop as drug carriers for controlled release applications of TNFR-BP.

Preparation and in vitro Studies of Stealth PEGylated PLGA Nanoparticles as Carriers for Arsenic Trioxide

The aim of this study was to prepare arsenic trioxide （ATO）-loaded stealth PEGylated PLGA nanoparticles （PEG-PLGA-NPs） and to assess the merits of PEG-PLGA-NPs as drug carriers for ATO delivery. PEG-PLGA copolymer was synthesized with methoxypolyethyleneglycol （Mw=5000）, D, L-lactide, and glycolide by the ring-opening polymerization method. Amorphous ATO was transformed into cubic crystal form to increase its solu-bility in the organic solvent. ATO-loaded PEG-PLGA-NPs were prepared by the modified spontaneous emulsification solvent diffusion （SESD） method, and the main experimental factors influencing the characteristics of nanopar- ticles were investigated, to optimize the preparation. To confirm the escape of PEG-PLGA-NPs from phagocytosis by phagocytes, PEG-PLGA-NPs labeled rhodamine B uptake by murine peritoneal macrophages （MPM） were analyzed by flow cytometry. The results showed that the physicochemical characteristics of PEG-PLGA-NPs were affected by the type and concentration of the emulsifiers, polymer concentration, and drug concentration. ATO-loaded PEG-PLGA-NPs, with particle size of 120.8nm, zeta potential of-10.73mV, encapsulation efficiency of 73.6%, and drug loading of 1.36%, were prepared under optimal conditions. The images of transmission electron micros-copy （TEM） indicated that the optimized nanoparticles were near spherical and without aggregation or adhesion. The release experiments in vitro showed the ATO release from PEG-PLGA-NPs exhibited consequently sustained release for more than 26d, which was in accordance with Higuchi equation. The uptake of PEG-PLGA-NPs by MPM was found to decrease markedly compared to PLGA-NPs. The experimental results showed that PEG-PLGA-NPs were potential nano drug delivery carriers for ATO.

黄芩苷PLGA纳米粒的制备及其抗肝癌的体外评价

采用乳化溶剂挥发法制备纳米粒,选取PLGA为载体材料,PVA溶液为水相,黄芩苷为主药,以包封率为评价指标,进行单因素考察和响应面优化,筛选出黄芩苷PLGA纳米粒的最佳制备工艺,并考察其体外释放度行为。最后,通过开展细胞试验,对黄芩苷PLGA纳米粒进行体外药效学评价。结果表明,最优工艺及处方制备出的黄芩苷PLGA纳米粒,体外释放具有缓释性,对肝癌细胞具有显著抑制作用。

Box-Behnken响应面法优化羟基红花黄色素A纳米粒处方工艺及体外释放评价

目的优化羟基红花黄色素A(hydroxysafflor yellow A,HSYA)纳米粒制备工艺,并对其进行体外释放评价。方法以乳酸-羟基乙酸共聚物[poly(lactic-co-glycolicacid),PLGA]为载体,利用改良的复乳法制备HSYA纳米粒,通过Plackett-Burman设计实验联用Box-Behnken响应面法优选最佳制备工艺;利用粒径测定仪、TEM扫描电镜仪、傅里叶红外光谱(FT-IR)仪、X-射线粉末衍射(XRD)仪对纳米粒进行表征;并对其进行4℃储藏稳定性、生理介质中稳定性、冻干保护剂及体外释放率考察。结果优选出纳米粒最佳工艺处方为:pH为6.95,投药量为2.8 mg,载体用量为18.2 mg;在此条件下制备出的纳米粒粒径为(176.4±1.29)nm,多分散系数(Polydiseperse Index,PDI)为(0.152±0.014),Zeta电位为(-17.6±0.46)mV,包封率为(78.5±0.49)%,载药量为(7.3±0.07)%,纳米粒形态圆整,分散性好;在4℃储存环境下、不同生理介质中稳定性良好,最佳冻干保护剂为1%葡萄糖;纳米粒48 h体外释放率为85%。结论该优化方法合理可靠,所得纳米粒稳定性良好,具有一定的缓释作用,体外释放符合一级动力学模型。

罗哌卡因-醋酸地塞米松PLGA微球的制备及体外释药特性研究

目的制备罗哌卡因-醋酸地塞米松聚乳酸羟基乙酸共聚物(PLGA)微球(简称微球)并研究其体外释药特性。方法以PLGA为载体,采用W1/O/W2双重乳化-溶剂挥发法制备微球,研究实验过程中有机相PLGA浓度、外水相/有机相体积比、内水相体积、外水相聚乙烯醇(PVA)浓度几项因素变化对罗哌卡因-醋酸地塞米松PLGA微球粒径、表面形态、载药量、包封率和突释行为的影响。结果有机相PLGA浓度在制备微球的过程中是一个关键性因素。随着PLGA浓度增加,微球粒径增大,载药量、包封率明显提高,突释降低;外水相/有机相体积比增大,微球粒径增大,载药量、包封率明显提高,微球表面更加光滑、微孔减少,突释降低;随着内水相体积增加使得微球表面的微孔明显增多,突释增加,载药量、包封率降低;当外水相PVA浓度由0.5%增加到2%,微球粒径变小,突释效应增加。通过优化条件制备的微球形状为球形,外观光滑圆整,粒径分布均匀,其中>90%分布在20～70μm。罗哌卡因载药量(7.48±0.33)%,包封率(70.97±2.36)%;醋酸地塞米松载药量(1.52±0.16)%,包封率(57.30±1.17)%。结论采用W1/O/W2双重乳化-溶剂挥发法成功制备罗哌卡因加醋酸地塞米松PLGA微球;以优化工艺制备的微球,在体外具有明显的缓释行为,释药曲线呈典型S形三阶段模式。

响应面试验优化猴头菌素-PLGA微球制备工艺及其体外释药性能

目的:以聚乳酸-羟基乙酸共聚物(poly(lactic-co-glycolic acid),PLGA)为载体,采用乳化溶剂挥发法制备猴头菌素缓释微球,并对其体外药物释放行为进行考察。方法:通过单因素试验,以包封率为评价指标,考察影响微球质量的因素,采用响应面试验法进行优化,筛选出最佳工艺条件。结果:最佳工艺为芯壁比(猴头菌素与PLGA质量比)1∶1.64、PLGA质量分数15%、搅拌速率1 200 r/min。最佳条件制备的猴头菌素微球表面光滑圆整,包封率为99.66%,微球体外384 h累计释放率达84.30%。结论:以PLGA为载体材料,采用乳化-溶剂挥发法可以制备包封率较高的猴头菌素微球,体外释药实验也表明该微球具有明显的缓释作用。

槲皮素-PLGA嵌段共聚物纳米粒的制备及释放机制研究

目的:以聚乳酸-羟基乙酸共聚物(PLGA)为材料,制备用于抗肿瘤的槲皮素-聚乳酸-羟基乙酸QC-PLGA纳米粒,并考察QC-PLGA纳米粒的体外释放机制。方法:采用乳化溶剂挥发法制备QC-PLGA纳米粒,使用透射电镜观察纳米粒的形态特征,研究QC-PLGA纳米粒的粒径、载药量、包封率、稳定性和体外释药。结果:QC-PLGA纳米粒在透射电镜观察下的形态特征为类球形实体粒子,平均粒径为(154.2±0.91)nm,载药量为(5.75±0.19)%,包封率为(43.74±1.42)%,36h体外释放84.76%,QC-PLGA冻干粉的体外释放规律基本符合Higuchi方程的释药模型。拟合的释药动力学方程为:Q=7.923 7+0.020 1t1/2(r=0.967 7)。结论:采用乳化溶剂挥发法制备的QC-PLGA纳米粒,具有明显的缓释作用,在抗肿瘤,尤其是治疗肿瘤切除术后残留癌灶方面具有广阔的应用前景。

恩替卡韦-PLGA缓释微球的处方优化及体外释药研究

目的:优化恩替卡韦聚乳酸-羟基乙酸共聚物(PLGA)缓释微球的处方,并考察其体外释药特性。方法:采用乳化-溶剂挥发法制备恩替卡韦-PLGA缓释微球;以微球的包封率、载药量的综合评分为评价指标,设计正交试验优化投药量、药物-PLGA质量比、PLGA质量浓度、油相-水相体积比、聚乙烯醇(PVA)浓度,并进行验证试验;考察所制微球形态、粒径及体外释药情况(Q)。结果:最优处方为恩替卡韦20 mg、恩替卡韦-PLGA质量比1∶10、PLGA质量浓度200 mg/ml、油相-水相体积比1∶10、PVA浓度2%。所制恩替卡韦-PLGA缓释微球的包封率为(86.52±3.25)%,载药量为(18.36±1.37)%,RSD均小于5.0%(n=3);其表面光滑圆整,平均粒径为58.35μm;Q_(10h)、Q_(96h)、Q_(360h)分别为9.6%、42.9%、89.6%,体外释药符合Higuchi模型(r^2=0.965 8)。结论:优化处方所制恩替卡韦-PLGA缓释微球的缓释性能良好。

PLGA nanoparticle encapsulated paclitaxol for sustained release and its anticancer effect for HeLa cells in vitro

Poly (D,L-lactide-co-glycolide) (PLGA) is a biodegradable and biocompatible polymer material for drug deliver system. The aim of this study is to synthesize drug-loaded

左氧氟沙星/PLGA亚微粒的制备、表征和体外释药考察

目的:制备左氧氟沙星/PLGA亚微粒,并进行相关表征和体外释放行为考察。方法:采用纳米共沉淀法制备左氧氟沙星/PLGA亚微粒,采用激光粒度分析仪以及扫描电镜分别进行亚微粒粒度测定和形貌分析。同时采用紫外-可见分光光度法(UV)测定其载药量与体外药物释放行为。结果:经过激光粒度分析仪测定,所制备的左氧氟沙星/PLGA亚微粒粒径为197～230 nm,Zeta电位为-24 mv。扫描电镜观察亚微粒呈圆形/椭圆形,分布均匀。UV法测定亚微粒的载药量为6.25%～9.38%,包封产率为12.45%～46.59%。体外释放结果显示相比于商品化左氧氟沙星滴眼液,所制备的左氧氟沙星/PLGA亚微粒具有良好的缓释效果。结论:通过纳米共沉淀法成功制备粒径均一,高载药量的左氧氟沙星PLGA亚微粒,同时能实现药物的缓慢释放,减少给药次数的目的。

红细胞膜包载粉防己碱PLGA纳米粒的制备与体外评价

目的制备红细胞膜包载粉防己碱PLGA纳米粒(RPTNs),并进行体外评价。方法采用乳化溶剂挥发法制备粉防己碱PLGA纳米粒(PTNs);单因素考察了PLGA的质量浓度、有机相体积、稳定剂浓度;优化了红细胞膜囊泡(RVs)和RPTNs的制备方法;对纳米粒的粒径、PDI、电位、包封率、形态和稳定性进行了表征;透析法考察了PTNs和RPTNs的体外释放特性;CCK-8法考察了该载药系统的体外细胞毒性。结果最佳制备工艺为:PLGA质量浓度20 g·L-1,稳定剂质量浓度10 g·L-1,油水体积比1∶20,RVs的制备采用超声合并挤压法;制备的PTNs形状圆整,粒径为(147.9±0.25) nm,PDI<0.15,包封率为(84.1±0.41)%,在30 d内保持稳定;RPTNs具有清晰的壳-核双层结构,粒径为(164.1±1.65) nm,PDI<0.2,在15 d内保持稳定;体外释放实验显示PTNs和RPTNs在120 h内对粉防止碱(tetrandrine,TET)均有缓释作用,且RPTNs平均累计释放量减少了5.33%;体外细胞毒性实验表明在正常细胞和肿瘤细胞中,RPTNs的IC50值均高于游离TET组和PTNs组,且对293T细胞的IC50值高于对MCF-7的IC50值。结论采用该制备方法得到的纳米粒包封率高、稳定性好,能显著延缓药物的释放,降低体外细胞毒性,增强对肿瘤细胞的抑制作用。

壳寡糖修饰的盐酸川芎嗪mPEG-PLGA微球的制备及体外释放特性

目的以单甲氧基聚乙二醇-聚乳酸羟基乙酸共聚物(mPEG-PLGA)为载体制备盐酸川芎嗪(TMPH)微球,用壳寡糖(COS)对微球进行修饰,并对其包封前后的体外药物释放行为进行考察。方法采用复乳-溶剂挥发法制备壳寡糖修饰的盐酸川芎嗪缓释微球,通过单因素试验,以包封率为评价指标,考察影响微球质量的因素,采用正交试验进行优化,筛选出最佳的处方,并进行体外释药性能的考察。结果mPEG-PLGA浓度为50g/L,药物浓度为30g/L,内水相/油相比为1∶10,外水相油相比为4∶1,最佳处方制备的盐酸川芎嗪微球表面光滑圆整,包封率在60%以上。经壳寡糖修饰后微球突释效应减少。结论以mPEG-PLGA为载体材料,采用复乳-溶剂挥发法可以制备包封率较高的盐酸川芎嗪微球,壳寡糖修饰有减小突释效应的作用。

羟基喜树碱/GA-PEI-PLGA纳米粒的体外释放特性考察

目的考察载羟基喜树碱(HCPT)的甘草次酸(GA)修饰PEI-PLGA(HCPT/GA-PEI-PLGA)纳米粒的体外释药特性。方法应用乳化-溶剂挥发法制备HCPT/GA-PEI-PLGA纳米粒。采用动态透析法,考察载药纳米粒在0.5%吐温80的磷酸盐缓冲液(p H 7.4)中的释放特性,并与游离药物进行比较;对载药纳米粒的释药模型进行拟合。结果 8 h时,HCPT/GA-PEI-PLGA纳米粒中HCPT的累积释放率约为43%,显著低于游离药物的累积释放率(约80%);48 h时,载药纳米粒中HCPT的累积释放率为82%,而游离HCPT已释放完全(累积释放率达97%)。由此可见,经GA-PEI-PLGA纳米粒包载后,HCPT表现出一定的缓释作用。模型拟合结果表明,HCPT/GA-PEI-PLGA纳米粒的体外释药曲线与Higuchi模型拟合度最好,拟合方程为Q=0.1296t 1/2-0.0069(R2=0.9624)。结论 GA-PEI-PLGA纳米粒可延缓HCPT的释放,药物释放符合Higuchi方程。

载肿瘤坏死因子拮抗肽PEG-PLGA纳米粒与血清蛋白作用研究

目的:研究聚乙二醇(polyethyleneglycol,PEG)链长、含量以及载药对聚乙二醇-聚乳酸羟基乙酸[polyethyleneglycol modified poly(D,L-lactide-co-glycolide),PEG-PLGA]纳米粒吸附血清蛋白的影响,研究负载肿瘤坏死因子-α拮抗肽(tumor necrosis factor alpha blocking peptide,TNF-BP)的PEG-PLGA纳米粒在血清中药物释放行为。方法:采用二喹啉甲酸(bicinchoninic acid,BCA)蛋白定量试剂盒和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)技术检测吸附于纳米粒表面的血清蛋白,采用紫外分光光度法检测载药PEG-PLGA纳米粒在血清中释放TNF-BP。结果:PEG链长以相对分子质量表示为5 000,含量为7.5%时,空载纳米粒吸附血清蛋白为(2.57±0.19)%;负载TNF-BP后纳米粒吸附血清蛋白能力降低。载药纳米粒在血清中存在突释效应,并随着PEG链长的增加,累积释放率增大。PEG含量由2.5%变化至10.0%时,对释药性能影响程度不明显。结论:负载TNF-BP和PEG修饰可降低血清蛋白在纳米粒表面的吸附,载药PEG-PLGA纳米粒在血清中的累积释药率大于PLGA纳米粒。

透明质酸修饰的葛根素PEG-PLGA纳米粒的处方工艺优化及其体外评价

目的以乳酸-羟基乙酸共聚物(PEG-PLGA)为载体,优化纳米沉淀法制备透明质酸修饰的葛根素PEG-PLGA纳米粒(HA/Pue-NPs),并对其体外性质进行初步评价。方法以PEG-PLGA为载体材料,透明质酸为表面修饰剂,采用纳米沉淀法制备了透明质酸修饰的HA/Pue-NPs;应用正交实验设计优化处方,对其体外性质进行表征;并采用体外释药行为评价透明质酸修饰HA/Pue-NPs。结果制备出的载药纳米粒外观呈球形,平均粒径、Zeta电位分别为(88.9±2.2)nm、(-21.9±0.54)mV,载药量及包封率分别为6.75%、78.52%。体外释药试验表明,载药纳米粒释药缓慢,24h的累计释放率为65.8%。结论透明质酸修饰的葛根素PEG-PLGA纳米粒粒径大小均一,体外性质良好且具有一定的缓释特性。

槲皮素肠溶PLGA纳米粒各肠段的吸收特性研究

目的研究槲皮素肠溶PLGA纳米粒各肠段的吸收特性。方法采用高压均质法结合复乳-溶剂挥发法等方法制备槲皮素PLGA纳米粒,进行纳米粒形态学分析与粒径考察及包封率的测定,并优化制备工艺;考察药物在人工胃液、人工肠液不同介质中的槲皮素PLGA纳米粒的释放度;分别以Eudragit L100、Eudragit L100-55、Eudragit S10、HP55、HP50等肠溶包衣材料与PLGA以一定比例量制备槲皮素纳米粒,比较粒径、包封率,筛选肠溶材料及制备方法;分别于人工胃液及人工肠液中测定不同槲皮素肠溶PLGA纳米粒释放度,与槲皮素PLGA纳米粒比较;从吸收部位、药物质量浓度、灌流速度三个方面对槲皮素肠溶PLGA纳米粒的各肠段吸收特性进行考察。结果 5种不同肠溶包衣材料与PLGA以一定比例量制备槲皮素纳米粒的包封率、粒径等指标比较差异均无统计学意义(P>0.05),且在PLGA浓度为100 mg/m L和50 mg/m L时析出大颗粒沉淀;在人工肠液中的槲皮素PLGA纳米粒释放度明显高于人工胃液中,差异有统计学意义(P<0.05);在人工肠液中的槲皮素PLGA纳米粒释放度为(84.6±9.8)%,明显高于人工胃液中的(64.7±4.6)%,差异有统计学意义(t=5.81,P<0.05);质量浓度为1μg/m L时,药物吸收速率常数为(6.6±1.6)Ka/h,质量浓度为10μg/ml时,药物吸收速率常数为(3.5±1.5)Ka/h,质量浓度为20.0μg/m L时,药物吸收速率常数为(2.0±0.4)Ka/h,十二指肠、空肠中的药物吸收速率常数为(7.5±2.5)Ka/h,回肠、结肠中的药物吸收速率常数为(2.7±1.4)Ka/h;灌流速度为0.2 m L/min时,药物吸收速率常数为(15.5±3.5)Ka/h;灌流速度为0.8 m L/min时,药物吸收速率常数为(26.5±1.7)Ka/h;药物吸收速率在质量浓度10~20μg/m L范围内出现了自身浓度抑制;在十二指肠、空肠的药物吸收速率常数明显高于回肠、结肠段,且药物吸收速度常数随着灌流速度的增高而逐渐增高,差异均有统计学意义(P<0.05)。结论制备槲皮素-聚乳酸-羟基乙酸(QC-PLGA)纳米粒可显著提高抗肿瘤的缓释作用,在质量肿瘤切除术后残留癌灶方面前景广阔。

葛根素HA/PEG-PLGA纳米粒的制备及质量分析研究

目的对葛根素进行质量分析研究。方法以透明质酸为表面修饰剂、PEG-PLGA为载体材料,用纳米沉淀法制备透明质酸修饰的葛根素PEG-PLGA纳米粒(HA/Pue-NPs),采用高效液相色谱法(HPLC)对其进行载药量的测定,并考察透明质酸修饰的葛根素PEG-PLGA纳米粒的体外释药行为。结果制备出的载药纳米载药量为6.75%,体外释药试验表明,载药纳米粒释药缓慢,24 h的累计释放率为65.8%。结论透明质酸修饰的葛根素PEG-PLGA纳米粒质量性质良好,且体外具有一定的缓释特性。

Preparation and characterization of atrazine-loaded biodegradable PLGA nanospheres

Atrazine is the second mostly used herbicide in USA,but low utilization ratio causes severe environmental problem,so controlled release system is highly needed in order to minimize the negative impact on environment.In this paper,a herbicide delivery system,atrazine-loaded poly(lactic-co-glycolic acid)(PLGA)nanoparticles(NPs)were prepared by forming an oilin-water emulsion using the emulsion-solvent evaporation method.By varying the preparation conditions of PLGA-NPs,such as sonication time,surfactant content,solvent fraction,and polymer content,the particle sizes of the PLGA-NPs were well controlled from 204 to 520 nm.The morphology and size distribution of PLGA-NPs were evaluated using dynamic light scattering(DLS)and scanning electron microscopy(SEM).Both the encapsulation efficiency and release profile of the herbicide from the PLGA-NPs were typically evaluated by using 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine(atrazine,ATZ)as the model.ATZ encapsulation efficiency within the PLGA-NPs was ranged from 31.6 to 50.5%.The release profiles of ATZ-loaded PLGA-NPs exhibited a much slower release rate in comparison with that of pure herbicide.The results demonstrated that the prepared PLGA-NPs had a high encapsulation efficiency and slow release rate,which could be used as a promising herbicide release system in agriculture to diminish the impact on the environment and minimize the potential harm to the farmers.