负载阿霉素的黄芩苷纳米粒的制备及其体外性能评价

目的 制备负载阿霉素的黄芩苷纳米粒（DOX/SA-SS-BAI NPs）,并评价其体外性能。方法 构建以胱胺为连接臂的海藻酸钠–黄芩苷聚合物,并负载阿霉素,得到DOX/SA-SS-BAI NPs。对DOX/SA-SS-BAI NPs的理化性质进行表征;采用HepG2细胞进行MTT实验验证其细胞毒性。结果 DOX/SA-SS-BAI NPs粒径为（158.2±2.8）nm,PDI为（0.241±0.008）,Zeta电位为（-24.1±0.3）m V,包封率为（64.34±0.25）%,载药量为（16.22±0.06）%。体外释放显示载药纳米粒具有良好的还原响应性;MTT实验证明DOX/SA-SS-BAINPs对HepG2细胞具有良好的抑制作用;细胞摄取实验表明DOX/SA-SS-BAI NPs在HepG2细胞内较快地释放阿霉素。结论 制备的DOX/SA-SS-BAI NPs具有较好的理化性质和体外抗癌作用。     

三甲基化壳聚糖卵清蛋白纳米粒的制备

目的：以N-三甲基壳聚糖盐酸盐（N—trimethyl chitosan chloride，TMC）为材料制备新型纳米粒（nanoparticles，NPs），包裹卵清蛋白（ovalbumin，OVA），以提高卵清蛋白的包封率。方法：利用TMC与三聚磷酸钠（tripolyphosphatesodium，TPP）之间的离子胶凝作用制备纳米粒；用纳米粒度及表面电位分析仪测定纳米粒的粒径及zeta电位；探讨OVA溶液的pH值及浓度，TMC溶液的浓度，TPP溶液的浓度等因素对OVA包封率的影响；用十二烷基硫酸钠一聚丙烯酰胺明胶电泳（Soldium Dodeoyl Sulfate—Polyacrylamide，SDS-PAGE）检验OVA在纳米粒制备及体外释放过程中有无降解。结果：本研究制备的TMC／OVA纳米粒为紧密球形，分布均匀，粒径约为135．4nm，zeta电位约为＋20mV；OVA的pH值及制备工艺是影响包封率的主要因素；SDS-PAGE电泳证实在纳米粒的制备及释放过程中OVA没有降解。结论：用离子胶凝法制备载蛋白多肽类疫苗的纳米粒，操作简便，采用合适的制备方法，调整处方可将包封率提高到90％以。     

共载阿霉素和siRNA的还原敏感型前药纳米粒的制备及体外评价

目的：构建共载阿霉素（DOX）和siRNA的还原敏感型前药纳米粒（PSCSD NPs）,并对其理化性质、细胞摄取和体外细胞毒性进行考察。方法：采用核磁共振氢谱（1H NMR）和傅里叶红外光谱（FT-IR）对羧甲基壳聚糖-二硫键-DOX(CMCSS-DOX)进行结构表征;超声法制备PSCSD NPs,考察其粒径、载药量、包封率、血清稳定性、溶血率和体外释药特性等;采用荧光显微镜和流式细胞术考察4T1细胞对PSCSD NPs的摄取;通过MTT实验测定PSCSD NPs的体外细胞毒性。结果：1H NMR和FT-IR结果表明CMC-SS-DOX成功合成;PSCSD NPs的粒径为（155.1±4.0） nm(PDI=0.144±0.028),Zeta电位为（–29.9±1.0） mV,载药量为（8.25±0.47）%,包封率为（78.41±4.52）%;透射电镜观察PSCSD NPs为球形,且具有良好的血液相容性和血清稳定性。PSCSD NPs具有还原响应释药特性,可在肿瘤部位快速释药。细胞摄取和MTT实验结果表明PSCSD NPs可以有效共载DOX和siRNA进入肿瘤细胞内以发挥抗肿瘤作用。...     

聚乙烯亚胺-聚甲基丙烯酸甲酯阳离子纳米粒介导基因转移的研究

目的研究聚乙烯亚胺-聚甲基丙烯酸甲酯(PEI-PMMA)纳米粒作为基因载体的性能，探讨阳离子纳米粒介导基因转移机制。方法用自由基聚合法制备PEI-PMMA阳离子纳米粒，扫描电镜观察粒子形态，zeta粒度仪测定粒径﹑表面电荷，凝胶电泳阻滞分析载基因能力和激光共焦扫描显微镜观察纳米粒介导的细胞内基因转移情况。结果PEI-PMMA纳米粒呈单分散球形，平均粒径为172 nm，zeta电位为+50.3 mV。当pGL3质粒与纳米粒以N/P为5∶1和20∶1形成复合物后纳米粒平均粒径分别为133和139 nm；zeta电位分别为+21.4和+33.7 mV。pGL3可完全与纳米粒形成复合物。PEI-PMMA纳米粒可携带pGL3质粒进入HeLa细胞，并突破吞噬小泡释放质粒于细胞质，最终质粒聚集于细胞核内进行表达。结论PEI-PMMA纳米粒通过内吞作用介导基因转移入靶细胞，可作为基因转移的非病毒型载体。     

艾塞那肽聚乳酸-羟基乙酸共聚物纳米粒的制备及其分析方法研究

目的 以聚乳酸-羟基乙酸共聚物（PLGA）为载体,用乳化复乳法制备包载艾塞那肽（EX）的PLGA纳米粒（EX-PLGA NPs）,并对其分析方法进行研究。方法 2018年10月至2019年8月,采用Box-Behnken Design(BBD)响应面分析法对纳米粒制备的处方工艺进行优化,动态光散射技术检测EX-PLGA NPs粒径和Zeta电位;通过高效液相色谱法（HPLC）测定EX-PLGA NPs中艾塞那肽含量并进行方法学验证。结果 制备的EX-PLGA NPs粒径为（157.2±3.1）nm,Zeta电位为（-19.5±2.6）mV;载药量和包封率分别为（4.41±0.28）%和（73.43±0.59）%,透射电镜图显示纳米粒外观圆整,分布均匀;EX-PLGA NPs体外稳定性良好,透析袋法释放结果显示其具有缓释效果。结论 制备的EX-PLGA NPs粒径分布均一,包封率和载药量高,稳定性好,艾塞那肽含量分析方法科学有效,为艾塞那肽抗糖尿病口服缓释制剂的分析和开发提供了实验基础。     

α-常春藤皂苷丙烯酸树脂L100-55纳米粒的制备及体外评价

目的：采用肠溶材料丙烯酸树脂L100-55作为载体材料,制备α-常春藤皂苷丙烯酸树脂纳米粒（ SPD-L100-55-NPs）并进行体外评价。方法采用改良乳化溶剂扩散法制备SPD-L100-55-NPs,以粒径、包封率（ EE）和多分散指数（ P. I.）为综合指标,通过单因素实验和正交设计实验优化纳米粒的处方工艺,以红外光谱（ FT-IR）、X射线衍射（ XRD）、差示扫描量热分析（ DSC）等对制备的纳米粒进行评价,并考察其体外释放特性。结果制得的SPD-L100-55-NPs纳米粒外观圆整、分布均匀,平均粒径为（63.5±3.6）nm,包封率为98.91%±0.18%,P. I.为0.198±0.014。药物在纳米粒中被载体材料有效包裹,体外释放具有缓释特性和PH依赖性。结论所制得的纳米粒圆整均匀、包封率高,在体外具有良好的缓释特性和PH敏感性。     

壳聚糖纳米粒用作基因递送载体的初步研究

目的初步研究基因壳聚糖纳米粒的性质和转染活性。方法用复凝聚法制备纳米粒;用透射电镜观察形态;用纳米粒度分析仪测定粒径、多分散度和zeta电位;用荧光分光光度法测定基因包封率;用凝胶阻滞分析和荧光扫描测定基因在纳米粒中的位置;用体外基因转染实验定性评价纳米粒的转染活性。结果纳米粒形态多呈球形,平均粒径为218.9 nm,多分散度为0.276,zeta电位为+21.2 mV;基因包封率为99.6%;凝胶阻滞分析和荧光扫描表明基因几乎全部被包裹在纳米粒内部,表面吸附很少;体外基因转染实验表明基因壳聚糖纳米粒能够转染人胚胎肾细胞(HEK293)和肝癌细胞(HepG2),基因能够在这两种细胞中表达。结论壳聚糖纳米粒能将基因递送到细胞内并且基因能够表达,因此可以用作基因药物载体。     

还原响应型靶向自载药纳米粒的制备及其体外评价

目的 制备靶向性的自载药纳米粒(HA-ss-Bai NPs),并考察其作为药物载体递送姜黄素(curcumin,Cur)的可行性。方法 制备二硫键连接的透明质酸(hyaluronic acid,HA)-黄芩苷(baicalin,Bai)聚合物,利用核磁共振氢谱(hydrogen nuclear magnetic resonance spectroscopy,¹H-NMR)、红外光谱(infrared spectroscopy,IR)确证聚合物的结构;采用超声法制备自组装纳米粒,并对其粒径、Zeta电位进行表征;采用芘荧光探针法测定纳米粒的临界聚集浓度(critical aggregation concentration,CAC);测定载Cur纳米粒包封率和载药量;MTT试验考察载药纳米粒的体外抗肿瘤活性。结果 制备HA-ss-Bai NPs,最小粒径为(124.3±6.5) nm,CAC值为(0.023 8±0.003 5) mg·mL^–1。测得Cur/HA-ss-Bai NPs的粒径为(172.5±3.2) nm,载药量为(17.08±0.25)%,包封率为(51.23±3.97)%。体外释放表明药物在还原条件下可快速释放,MTT试验表明Cur/HA-ss-Bai NPs对HepG2肝癌细胞生长具有显著的抑制作用。结论 制备的Cur/HA-ss-Bai NPs粒径均匀、载药量较高,具有良好的还原响应性和抗肿瘤活性,同时提高了Bai与Cur的体外抗肿瘤效果。     

双重响应靶向双药协同递送纳米系统的制备及体外评价

目的:制备双重响应靶向性双载药纳米粒(DOX/CMCS-ss-MTX NPs),并进行体外抗肿瘤考察。方法:甲氨蝶呤(MTX)通过二硫键接枝到羧甲基壳聚糖(CMCS)上,核磁共振氢谱(¹H-NMR)、红外光谱(IR)确证结构。离子交联法制备纳米粒,对粒径、Zeta电位进行表征;测定载阿霉素(DOX)和甲氨蝶呤(MTX)的DOX/CMCS-ss-MTX NPs包封率和载药量;MTT实验考察DOX/CMCS-ss-MTX NPs体外抗肿瘤活性。结果:DOX/CMCS-ss-MTX NPs粒径为(148.3±2.5)nm,阿霉素载药量为(17.10±0.28)%,包封率为(71.32±3.54)%;甲氨蝶呤载药量为(19.35±0.33)%,包封率为(86.9±2.35)%。实验证明其具有pH和还原响应,肿瘤微环境下可快速释放。MTT实验表明DOX/CMCS-ss-MTX NPs对正常肝细胞没有明显影响,对肝癌细胞有明显抑制作用。结论:DOX/CMCS-ss-MTX NPs粒径均一、载药量较高,具有良好的pH响应性和还原响应性,共同递送甲氨蝶呤和阿霉素,具有协同抗肿瘤效...     

姜黄素超分子纳米粒的制备工艺研究及表征

目的：制备一种姜黄素超分子纳米粒（Man-CURNPs）,并对其进行制备工艺考察及形态表征。方法：基于羟丙基β环糊精（HPβCD）超分子体系,采用纳米沉淀法制备Man-CUR NPs。通过检测粒径、包封率和载药量等指标确定其最佳制备工艺和处方,并对最终纳米粒的粒径、Zeta电位以及形态学表征进行检测。结果：Man-CUR NPs制备的最佳处方工艺为CUR 6 mg,聚合物（HPβCD-S-PBAE）30 mg,配体D-甘露糖聚合物4 mg,油水比为1:5,搅拌转速为400 r/min。通过纳米沉淀法得到纳米分散体系,进一步通过透析法得到Man-CUR NPs。Man-CUR NPs粒径为146.56±2.07nm, Zeta电位为+12.65±0.19 mV,透射电镜观察到纳米粒呈均一球形结构,并且具有良好的稳定性。结论：采用本研究获得的最佳处方工艺制备得到的Man-CUR NPs粒径较小、分布均一,为进一步实验奠定了基础。     

无稳定剂修饰的汉防己甲素PLGA纳米粒制备及体外评价

目的:制备无稳定剂修饰的汉防己甲素PLGA纳米粒,研究其理化性质及细胞毒和细胞摄取特性。方法:以聚乳酸-羟基醋酸共聚物(PLGA)为载体材料,采用无稳定剂修饰的纳米沉淀法制备汉防己甲素纳米粒;通过单因素试验考察不同制备工艺对纳米粒理化性质的影响;通过载药量、包封率、累积释药量等指标考察其载药特性;采用MTT比色法检测其对人肺腺癌细胞株A549的细胞毒性;采用共聚焦显微镜技术考察其细胞摄取特性。结果:无稳定剂修饰的汉防己甲素PLGA纳米粒平均粒径169.3 nm,与有稳定剂的汉防己甲素PLGA纳米粒相比外观无明显改变。在一定范围内,随着PLGA用量的增加,纳米粒的粒径呈上升趋势;随着投药量的增加,纳米粒的载药量显著增加,包封率下降。在pH7.4的释放介质中,纳米粒释慢释药,96 h累积释药率60.44%。细胞毒试验显示,当培养时间为8 h时,汉防己甲素组的细胞毒性大于汉防己甲素纳米粒组;当培养时间延长至24 h时,汉防己甲素纳米粒组的细胞活性明显低于纯药物组;高剂量的空白纳米粒组始终表现较低的细胞毒性。激光共聚焦电镜断层扫描显示汉防己甲素纳米粒能够较好的被细胞摄取。结论:制备的无稳定剂修饰的汉防己甲素PLGA纳米粒大小均一,包封率高,体外释药表现出较好的缓释效果,易被细胞摄取,对A549细胞的增殖有明显的抑制作用。     

紫杉醇PLGA纳米粒的处方优化与评价

目的 采用生物可降解材料乳酸-羟基乙酸共聚物(PLGA)为载体,比较不同的制备方法和工艺对紫杉醇(PTX)PLGA纳米粒(PTX-PLGA NPs)粒径的影响,筛选出最优制备工艺,并考察所制备纳米粒的体外表征以及对人源胃癌细胞SGC-7901的抗肿瘤效果,为紫杉醇缓释制剂在胃癌中的开发提供一定的实验基础.方法 采用单因...     

N-琥珀酰壳聚糖纳米粒的制备及体外评价

目的制备N-琥珀酰壳聚糖纳米粒并对其进行体外评价。方法采用乳化溶剂挥发法制备N-琥珀酰壳聚糖纳米粒;以包封率、载药量及粒径为指标,采用正交设计法对处方进行优化;考察其理化特征及体外释药行为。结果纳米粒包封率及载药量分别为62.36%和18.98%,平均粒径及zeta电位分别为(206.6±64.7)nm和(-27.2±0.2)mV;1 h药物释放达到45%,随后药物的释药行为是一个缓释过程。结论作者采用乳化溶剂挥发法成功制得N-琥珀酰壳聚糖纳米粒。该方法制得纳米粒包封率较高,制备工艺简单。     

Norcantharidin-associated galactosylated chitosan nanoparticles for hepatocyte-targeted delivery

In this study a new chitosan (CS) derivative, galactosylated chitosan (GC), was synthesized and used to prepare norcantharidin-associated GC nanoparticles (NCTD-GC NPs) by taking advantage of the ionic cross-linkage between the molecules of the anti-hepatocarcinoma medicine NCTD and of the GC as carrier. NCTD-GC NPs were obtained with average particle size of 118.68 ± 3.37 nm, entrapment efficiency of 57.92 ± 0.40%, and drug-loading amount of 10.38 ± 0.06%. Several important factors influencing the entrapment efficiency, drug-loading amount, and particle size of NCTD-GC NPs were studied. The characteristics of sustained and pH-sensitive release of NCTD from NCTD-GC NPs in vitro were studied. In addition, in vitro cellular uptake and cytotoxicity of nanoparticles to hepatoma cell lines SMMC-7721 and HepG2 were also investigated. In vitro, and compared to CS-based NCTD-CS NPs, NCTD-GC NPs demonstrated satisfactory compatibility with hepatoma cells and strong cytotoxicity against hepatocellular carcinoma cells. In vivo antitumor activity of NCTD-GC NPs was evaluated in mice bearing H22 liver tumors. NCTD-GC NPs displayed tumor inhibition effect in mice, better than either the free NCTD or the NCTD-CS NPs. As a hepatocyte-targeting carrier, GC NPs are potentially promising for clinical applications.From the Clinical EditorIn this paper, a galactosylated chitosan (GC), was synthesized and norcantharidin (NCTD)-associated galactosylated chitosan nanoparticles (NCTDGC NPs) were generated by coupling NCTD - an anti-hepatocarcinoma drug - and GC as carrier. Compared to chitosan nanoparticles, NCTD-GC-NPs demonstrated satisfactory compatibility with hepatoma cells and strong cytotoxicity against the cells.     

Transferrin-appended PEGylated nanoparticles for temozolomide delivery to brain: in vitro characterisation

Polymer-based nanotechnologies are proposed to be an alternative for drug administration, delivery and targeting to those of conventional formulations. The blood brain barrier is frequently a rate-limiting factor in determining permeation of a drug into brain. In this study, the surface-engineered long-circulating PLGA nanoparticles (NPs) were assessed for brain-specific delivery. Long circulating NPs of PLGA- and PEG-synthesised copolymer were prepared by emulsification solvent evaporation method. Further, the surface of PEGylated NPs was modified by anchoring transferrin (Tf) ligand for receptor-mediated targeting to brain. NPs were characterised for shape and size, zeta potential, entrapment efficiency and in?vitro drug release. In?vitro cytotoxicity studies were performed on human cancer cell lines. Confocal Laser Scanning Microscopy studies show the enhanced uptake of Tf-appended PEGylated NPs and their localisation in the brain tissues. Hence, the specific role of Tf ligand on PEGylated NPs for brain delivery was confirmed.     

Polymeric nanoparticles for siRNA delivery and gene silencing

Gene silencing using small interfering RNA (siRNA) has several potential therapeutic applications. In the present study, we investigated nanoparticles formulated using the biodegradable polymer, poly(d,l-lactide-co-glycolide) (PLGA) for siRNA delivery. A cationic polymer, polyethylenimine (PEI), was incorporated in the PLGA matrix to improve siRNA encapsulation in PLGA nanoparticles. PLGA-PEI nanoparticles were formulated using double emulsion-solvent evaporation technique and characterized for siRNA encapsulation and in vitro release. The effectiveness of siRNA-loaded PLGA-PEI nanoparticles in silencing a model gene, fire-fly luciferase, was investigated in cell culture. Presence of PEI in PLGA nanoparticle matrix increased siRNA encapsulation by about 2-fold and also improved the siRNA release profile. PLGA-PEI nanoparticles carrying luciferase-targeted siRNA enabled effective silencing of the gene in cells stably expressing luciferase as well as in cells that could be induced to overexpress the gene. Quantitative studies indicated that presence of PEI in PLGA nanoparticles resulted in 2-fold higher cellular uptake of nanoparticles while fluorescence microscopy studies showed that PLGA-PEI nanoparticles delivered the encapsulated siRNA in the cellular cytoplasm; both higher uptake and greater cytosolic delivery could have contributed to the gene silencing effectiveness of PLGA-PEI nanoparticles. Serum stability and lack of cytotoxicity further add to the potential of PLGA-PEI nanoparticles in gene silencing-based therapeutic applications.     

Encapsulation of curcumin in alginate-chitosan-pluronic composite nanoparticles for delivery to cancer cells

We report a nanoformulation of curcumin with a tripolymeric composite for delivery to cancer cells. The composite nanoparticles (NPs) were prepared by using three biocompatible polymers—alginate (ALG), chitosan (CS), and pluronic—by ionotropic pre-gelation followed by polycationic cross-linking. Pluronic F127 was used to enhance the solubility of curcumin in the ALG-CS NPs. Atomic force and scanning electron microscopic analysis showed that the particles were nearly spherical in shape with an average size of 100 ± 20 nm. Fourier transform–infrared analysis revealed potential interactions among the constituents in the composite NPs. Encapsulation efficiency (%) of curcumin in composite NPs showed considerable increase over ALG-CS NPs without pluronic. The in vitro drug release profile along with release kinetics and mechanism from the composite NPs were studied under simulated physiological conditions for different incubation periods. A cytotoxicity assay showed that composite NPs at a concentration of 500 μg/mL were nontoxic to HeLa cells. Cellular internalization of curcumin-loaded composite NPs was confirmed from green fluorescence inside the HeLa cells. The half-maximal inhibitory concentrations for free curcumin and encapsulated curcumin were found to be 13.28 and 14.34 μM, respectively.From the Clinical EditorA nanoformulation of curcumin with a tri-component polymeric composite for delivery to cancer cells is reported in this paper. Cellular internalization of curcumin loaded composite nanoparticles was confirmed from green fluorescence inside the HeLa cells.     

In vitro comparative evaluation of three CLD/siRNA nanoplexes prepared by different processes

In this study, a gemini-like cationic lipid (CLD) was used as the carrier to study the complexation features of CLD/siRNA nanoplexes (CLD/siRNA NPs). Three types of CLD/siRNA nanoplexes (named as AT NPs, HT NPs and MT NPs) were prepared by different processes: AT method (mixing siRNA solution with preformed CLD nanoparticles), HT method (hydrating a CLD thin film with siRNA solution), and MT method (dropping an ethanolic solution of CLD into siRNA solution under sonication). The particle size, zeta potential, morphology, siRNA protection, cytotoxicity, cellular uptake, and targeted mRNA down-regulation were studied. At the optimal N/P ratio of 10, the sizes of the three CLD/siRNA NPs were MT NPs ((222.3±19.1) nm)> HT NPs ((105.7±1.31) nm)>AT NPs ((91.8±1.75) nm). Different nanostructures were formed despite the fact that they were composed of the same components. Furthermore, the TEM images indicated that different morphologies were found in the three NPs, indicating that the nanoplexes were assembled by different mechanisms. Among the three NPs, the cell uptake capacity were as follows: AT NPs>MT NPs>HT NPs, whereas the silencing levels on epidermal growth factor receptor (EGFR) in HeLa cells were MT NPs>AT NPs>HT NPs. Based on the above results, we hypothesized that the different preparation processes resulted in nanostructures with varying biological effects. Therefore, we believe that structural optimization of siRNA nanoplexes is essential in achieving better siRNA encapsulation, protection, and gene silencing efficiency.     

Preparation and characterization of polymeric nanoparticles for siRNA delivery to down-regulate the expressions of exogenous and endogenous target genes

Gene silencing induced by RNA interference using small interfering RNA (siRNA) provides a promising therapeutic approach for cancers. However, the lack of siRNA delivery vector has limited the development of siRNA therapy. The purpose of this study was to use the novel copolymer (mPEG5k-PCL1.2k)1.4-g-PEl10k to prepare siRNA-loaded nanoparticles for siRNA delivery. The results suggested that (mPEG5k-PCL1.2k)1.4-g-PEl10k could load siRNA to form nanoparticles with particle size less than 200 nm in a narrow distribution. Moreover, a certain density of positive charge existed onto the surfaces of nanoparticles. MTT assay results demonstrated that (mPEG5k-PCL1.2k)1.4-g-PEl10k/siRNA nanoparticles showed very low cytotoxicity. The gene silencing efficiency of (mPEG5k-PCL1.2k)1.4-g-PEl10k/siRNA nanoparticles was investigated through luciferase reporter gene assays. The expression of exogenous luciferase gene was significantly downregulated at a range of N/P ratio from 50 to 125, and was maximally inhibited at the N/P ratio of 125 with 54% and 59% reduction in MCF-7 and HepG2 cells, respectively. In the 4T1-luc cell line expressing luciferase stably, the silencing of endogenous luciferase gene also has a similar overall profile with maximal 54% reduction of luciferase expression. These results suggested that (mPEG5k-PCL1.2k)1.4-g-PEI10k/SiRNA nanoparticles could serve as a kind of highly efficient siRNA delivery system for down-regulating the expression of exogenous and endogenous target genes.     

Nebulized anionic guanidinylated O-carboxymethyl chitosan/N-2-hydroxypropyltimehyl ammonium chloride chitosan nanoparticles for siRNA pulmonary delivery: preparation,characterization and in vitro evaluation

This study developed a pH-sensitive anionic system composed of guanidinylated O-carboxymethyl chitosan (GOCMCS) and N-2-hydroxypropyltimehyl ammonium chloride chitosan (N-2-HACC) for efficient siRNA delivery to the lungs following nebulization. About 16.8% of guanidine groups were incorporated into O-carboxymethyl chitosan (OCMCS) with the aid of O-methylisourea. Gel electrophoresis images demonstrated that siRNA was successfully encapsulated in nanoparticles ranging from 150 to 180?nm with zeta potential of about ?17?mV. The nanoparticles containing GOCMCS existed superior transfection performance compared with their amino-based analogs. The evaluation in vitro revealed that nanoparticles were internalized into A549 cells by energy-dependent endocytosis, then achieved endosomal escape by direct transmembrane penetration of guanidine moieties as well as swelling behavior of nanoparticles due to the pH sensitivity of GOCMCS. The mRNA level of survivin gene was down-regulated to 6.9% using GOCMCS/N-2-HACC/siSurvivin NPs. The survivin siRNA mediated by nanoparticles caused 30% of cell growth inhibition and induced 19.45% of cell apoptosis, which was comparable to Lipofectamin2000. After nebulization of siRNA-loaded nanoparticles, the stability of siRNA was maintained and fine particle fractions were detected by two-stage impinger that accounted for more than 60%. These results suggested that GOCMCS/N-2-HACC nanoparticles possessed potential as safe and efficient carrier for siRNA pulmonary delivery.