两亲性三嵌段共聚物PHB-PEG-PHB的合成及其纳米粒子的制备与表征

基于聚(β-丁内酯)(PHB)和聚乙二醇(PEG)的两亲性三嵌段共聚物聚(β-丁内酯)-聚乙二醇-聚(β-丁内酯)(PHB-PEG-PHB)可在聚乙二醇钾盐大分子引发剂的作用下、以四氢呋喃为溶剂,通过β-丁内酯(BL)的阴离子开环聚合进行制备,调节BL与聚乙二醇钾盐的配比,可制备分子量不同的共聚物.产物可通过1H-NMR、13C-NMR、FTIR、DSC、GPC等测试进行表征,DSC结果表明无定形的PHB阻碍了PEG的结晶,且随着PHB链段长度的增加,阻碍作用更加明显.PHB-PEG-PHB可在水中通过沉淀/溶剂蒸发技术进行自组装形成具有核壳结构的纳米粒子,并通过SEM、DLS手段对其表征,发现粒子尺寸在纳米级,形态为球形或方形.聚合物的初始浓度对纳米粒子的形态和尺寸有明显影响,随着聚合物初始浓度的降低,纳米粒子的尺寸降低.     

聚乙二醇甲醚-聚(D,L-乳酸)嵌段共聚物纳米胶束的制备

聚乙二醇甲醚-聚(D;L-乳酸)嵌段共聚物纳米胶束的制备;聚乙二醇单甲醚;两亲性二嵌段共聚物;纳米沉淀技术     

适配子修饰靶向PLGA纳米基因载体的构建

化学合成了功能性三嵌段复合物乳酸乙醇酸共聚物-聚乙二醇-适配子(PLGA-PEG-Apt)。使用双乳化挥发法制备包裹DNA片段的PLGA-PEG-Apt新型纳米基因药物载体,表征检测显示:制备的纳米基因载体粒径为(225.2±8.1)nm,Zeta电位约(-35.5±-3.3)mV。扫描电子显微镜下纳米颗粒形态呈圆形,表面光滑,粒径分布较均匀。纳米粒子对TFO的包封率为(25.4±3.1)%(n=3),载药量为(1.34±0.16)μg/mg。体外释放实验研究结果显示持续释放过程达23 d,且PLGA-PEG-Apt纳米粒子呈突释之后的持续缓释过程。细胞水平实验结果显示,A10适配子修饰的纳米基因载体能更多进入靶向的前列腺癌细胞株,进而发挥其抗前列腺癌增殖的作用。该研究成功制备了靶向PLGA纳米基因载体,结果满意。     

聚对二氧环己酮/聚乙二醇多嵌段共聚物的合成与表征

首先合成双端羟基的聚对二氧环己酮预聚物(PPDO)和双端羧基的聚乙二醇预聚物(PEG),然后以丁二酸酐/二环己基碳二亚胺(DCC)将PPDO与PEG偶联共聚,得到PPDO/PEG多嵌段共聚物.通过1H-NMR和GPC表征了聚合物的结构和分子量.采用差示扫描量热法(DSC)和热重分析(TGA)研究了共聚物的结晶性能和热稳定性.用透析法制备了共聚物纳米粒子,并用动态光散射(DLS)表征了共聚物纳米粒子的粒径及分散度,结果表明,随着共聚物亲水链段PEG含量的增加,其纳米粒子更易形成,粒子粒径随共聚物分子量增大而增大.     

影响聚乙二醇-g-壳聚糖载药体系的一些因素北大核心CSCD

聚乙二醇-g-壳聚糖可以作为抗肿瘤药物、基因、多肽等多种生物大分子的载体,是一种优良的药物载体。聚乙二醇接枝壳聚糖可以改善壳聚糖的水溶性,保护聚乙二醇-g-壳聚糖纳米不被网状内皮系统(RES系统)识别和清除,促进纳米粒子在体内的长循环,将药物更有效地靶向目标组织。目前,聚乙二醇-g-壳聚糖作为药物载体在生物医药领域发挥着重要作用,本文就聚乙二醇-g-壳聚糖的特点,以及在机体的靶向性、缓释等提高药物疗效的关键因素做一论述。     

纳米尺度超声显影微囊的制备及性能表征简

采用双乳液-溶剂挥发法制备了内部包封氟碳液体的聚乳酸-甲氧基聚乙二醇两嵌段共聚物(MePEG-b-PLA)基超声显影纳米微囊;用2种不同嵌段比的MePEG-b-PLA共聚物研究共聚物组成与纳米囊性能的关系;选用聚乙烯醇(PVA)、羧甲基葡聚糖(CMG)和壳聚糖(CS) 3种乳化剂对纳米囊表面进行亲水性修饰. 对所制备纳米囊的粒径、Zeta电位、形貌和水溶液稳定性进行了表征. 结果表明,利用质量分数为1%的PVA和质量分数为1%的CMG组成的复配乳化剂和m(MePEG)：m(PLA)= 1：3的聚合物制得的纳米囊的平均粒径为432.9 nm,水溶液稳定性优良. 利用超声仪对纳米囊体外超声显影性能进行研究,结果表明,所得聚乳酸-甲氧基聚乙二醇纳米囊具有更好的中心成像区域灰度值和更持久的体外超声显影效果. 结合3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)比色法研究证实该纳米囊具有低细胞毒性. 在超声影像学领域具有良好的应用前景.     

纳米尺度超声显影微囊的制备及性能表征

采用双乳液-溶剂挥发法制备了内部包封氟碳液体的聚乳酸-甲氧基聚乙二醇两嵌段共聚物(MePEG-b-PLA)基超声显影纳米微囊; 用2种不同嵌段比的MePEG-b-PLA共聚物研究共聚物组成与纳米囊性能的关系; 选用聚乙烯醇(PVA)、 羧甲基葡聚糖(CMG)和壳聚糖(CS) 3种乳化剂对纳米囊表面进行亲水性修饰. 对所制备纳米囊的粒径、 Zeta电位、 形貌和水溶液稳定性进行了表征. 结果表明, 利用质量分数为1%的PVA和质量分数为1%的CMG组成的复配乳化剂和m(MePEG)∶m(PLA)= 1∶3的聚合物制得的纳米囊的平均粒径为432.9 nm, 水溶液稳定性优良. 利用超声仪对纳米囊体外超声显影性能进行研究, 结果表明, 所得聚乳酸-甲氧基聚乙二醇纳米囊具有更好的中心成像区域灰度值和更持久的体外超声显影效果. 结合3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)比色法研究证实该纳米囊具有低细胞毒性. 在超声影像学领域具有良好的应用前景.     

多功能NiFeAu纳米粒子的合成与表征

采用一罐纳米乳液法,以聚乙二醇-聚丙二醇-聚乙二醇(PEO-PPO-PEO)三嵌段共聚物为表面活性剂,通过还原前驱体乙酰丙酮镍、乙酰丙酮铁(Ⅱ)和醋酸金,成功制备了NiFeAu纳米粒子.采用透射电镜和X射线衍射仪分析了NiFeAu纳米粒子的形貌和结构;采用傅立叶变换红外光谱仪分析了三嵌段共聚物在NiFeAu纳米颗粒表面的覆盖情况;采用紫外-可见吸收光谱仪和振动样品磁强计测试了纳米粒子的光学和磁学特性.结果表明,三嵌段共聚物成功地结合于NiFeAu纳米颗粒表面;所制备的纳米粒子粒径分布较窄、结晶性能良好,并兼具光学和磁学特性.     

基于聚集诱导发光的纳米粒子用于肝癌细胞靶向成像

利用具有聚集诱导发光特性的荧光染料4,4'-[(1E,1'E)蒽-9,10-二基双(乙烯-2,1-二基)]双(N,N-二甲基苯胺)(NDSA), 通过两亲性聚合物二硬脂酰基磷脂酰乙醇胺-聚乙二醇-N-羟基琥珀酰亚胺(DSPE-PEG-NHS)包覆的方法制备了明亮的橙色荧光纳米粒子, 其最大发射波长为559 nm, 在水溶液中具有2.89%的荧光量子产率. 该纳米粒子具有优异的发光特性和良好的生物相容性. 在该纳米粒子表面修饰肝癌细胞靶向的人类婆罗双树样基因-4(SALL4)抗体后, 荧光纳米粒子NDSA@SALL4可以特异性地靶向肝癌细胞, 还可以在细胞核富集, 呈现出明亮的橙色荧光, 为早期检测肝癌细胞提供了可能.     

叶酸修饰星型端氨基PEG-PLGA纳米胶束的制备及肿瘤细胞靶向作用

合成了星型多臂端氨基聚乙二醇(PEG)/聚乳酸-羟基乙酸(PLGA)两亲性嵌段共聚物(4s-PLGA-PEG-NH₂), 并通过核磁共振和凝胶渗滤色谱法对其结构进行表征; 采用溶剂挥发法制备阿霉素载药纳米胶束, 利用EDC缩合法与叶酸偶联, 得到叶酸修饰的星型端氨基PEG-PLGA纳米胶束; 采用动态光散射、 紫外光谱及透射电镜等手段对纳米胶束进行了表征; 对载药纳米胶束在HeLa细胞中的摄取及细胞毒性进行了初步评价. 结果表明, 经叶酸修饰的星型多臂端氨基PEG-PLGA载药纳米胶束可有效提高HeLa细胞的摄取率以及对HeLa细胞的杀伤率, 表明其可作为一类新型的靶向抗肿瘤药物递送载体.     

A study of the effect of the synthesis conditions of titanium dioxide on its morphology and cell toxicity properties

In this study, titanium dioxide nanoparticles (NPs) were synthesized using the home microwave method, and the effect of the microwave irradiation time on the structure of NPs was investigated. In addition, the morphological effect of these NPs on the toxicity of HDMSCs cells was investigated. The crystalline structure and morphology of the NPs were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM); the cytotoxicity was determined by the methyl thiazolyl tetrazolium (MTT) assay. X-ray diffraction analysis revealed that all thin films had a polycrystalline nature with an anatase phase of TiO₂. It was also found that the crystallite size increased with increasing microwave radiation time. The FTIR spectrum showed Ti-O-Ti properties by the peak in the range between 527 and 580 cm^?1. Further, the FE-SEM images showed that the grain size increased with increasing irradiation time. The MTT assay results showed that the accumulation of NPs leads to toxicity.     

Ultrasonic green synthesis of silver nanoparticles mediated by Pectin: Characterization and evaluation of the cytotoxicity,antioxidant, and colorectal carcinoma properties

Regarding applicative, facile, green chemical research, a bio-inspired approach is being reported for the synthesis of Ag nanoparticles by pectin as a natural reducing and stabilizing agent without using any toxic and harmful reagent. The biosynthesized Pectin/Ag NPs were characterized by advanced physicochemical techniques like ultraviolet–visible (UV–Vis), Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HR-TEM), Energy Dispersive X-ray spectroscopy (EDX), and X-ray Diffraction (XRD) study. It has been established that pectin-stabilized silver nanoparticles have a spherical shape with a mean diameter from 15 to 20 nm. After that, the biological performance of those biomolecules functionalized Ag NPs was investigated. In the MTT assay, human colorectal carcinoma (HCT-8 [HRT-18], Ramos.2G6.4C10, HT-29, and HCT 116) and normal cell lines (HUVEC) were used to study the cytotoxicity and anticancer potential of human colorectal over the AgNO₃ and Pectin/Ag NPs. The cell viability of Pectin/Ag NPs was very low against human colorectal carcinoma cell lines without any cytotoxicity on the normal (HUVEC) cell line. The best anti-human colorectal carcinoma properties of Pectin/Ag NPs against the above cell lines was in the case of the HCT 116 cell line. The antioxidant properties of the AgNO₃ and Pectin/Ag NPs were calculated against DPPH free radicals. The IC50 of Pectin/Ag NPs was 167 µg/mL. According to the above results, the Pectin/Ag NPs may be administrated to treat human colorectal carcinoma in humans.     

Simple surface functionalization of magnetic nanoparticles with methotrexate-conjugated bovine serum albumin as a biocompatible drug delivery vehicle

Magnetic nanoparticles (MNPs) functionalized with methotrexate (MTX)-conjugated bovine serum albumin (BSA) as a biocompatible drug delivery vehicle were synthesized using a facile method. Characterization of the functionalized MNPs (Fe₃O₄@BSA-MTX NPs) was performed using various techniques including UV–visible spectroscopy, dynamic light scattering, vibrating sample magnetometry and X-ray diffraction. The particle size and zeta potential of Fe₃O₄@BSA-MTX NPs were 105.7 ± 3.81 nm (mean ± SD) and −18.2 mV, respectively. MTX release from Fe₃O₄@BSA-MTX NPs showed an enzyme-dependent release pattern. Hemo-biocompatibility of Fe₃O₄@BSA-MTX NPs was confirmed using hemolysis test. In addition, the cytotoxicity of functionalized MNPs and free MTX against MCF-7 cell line was investigated using MTT assay. The results of experiments revealed that the Fe₃O₄@BSA-MTX NPs as a biocompatible carrier could improve the therapeutic effect of MTX.     

Chitosan-Linseed mucilage polyelectrolyte complex nanoparticles of Methotrexate: In vitro cytotoxic efficacy and toxicological studies

The goal of this research was to develop, fabricate and analyze polymeric nanoparticles for the administration of methotrexate (MTX). Linseed mucilage and chitosan nanoparticles (NPs) were prepared using a slightly modified polyelectrolyte complex (PEC) method. The size, shape, and encapsulation effectiveness of the resultant nanoparticles were measured. MTX release profiles at gastrointestinal pH (1.2 and 7.4) and tumor pH (5.5) were examined to determine the targeted potential of NPs as pH-responsive nanocarriers. Zeta analysis showed that nanoparticles prepared by PEC have a size range of 192.1 nm to 246 nm, and PDI was 0.3 of the optimized formulation, which showed homogenous nature of prepared nanoparticles formulation. The findings demonstrated that NPs have a low polydispersity index and a positive zeta potential (PDI). The in-vitro release of the drug indicated a pH-dependent, sustained drug release up to 24 h. Blank LSMCSNPs had almost no in-vivo cytotoxicity for 14 days, while optimum MTX loaded NPs had strong antitumor effects on HepG2 and MCF-7 cells as measured by the MTT assay. Cell apoptosis induction was also checked and MCF-7 cells treated with MTX-LSMCSNPs had a significantly greater rate of apoptosis (21.2 %) than those treated with MTX alone (14.14 %). The findings show that LSMCSNPs could be a potential delivery mechanism for methotrexate to cancer cells in a secure, steady, and ideally controlled manner to improve therapeutic outcomes.     

Synthesis of nickel cobalt-codoped tin oxide nanoparticles from Psidium guajava with anticancer properties

Metal oxide nanoparticles have been found to selectively target the tumor cells while non-toxic to the normal cells. Leukemia is one of the widespread and deadly cancers in adults, as well as the most common cancer in children. Recently, the nanoparticles have evolved as a simple, economic, effective, and ecologically sound strategy among the known nanoparticle synthesis techniques. In the present study, the structural, optical, and antibacterial effects of nickel cobalt-codoped Tin oxide nanoparticles (SnNiCoO2 NPs) formulated by the green process and the anticancer potential of SnNiCoO2 NPs in Molt-4 cells have been studied. The cytotoxic potential of the NPs against Molt-4 cells was estimated by MTT assay. The ROS and MMP levels were measured using fluorescent dyes and the changes in morphology and nuclei were noted using AO/EB staining. CAT, SOD, MDA, and GSH), and Proinflammatory Cytokines (TNF-α and IL1β) were also studied. The activity of caspase-3, ?9, and ?8 levels was examined to analyze the apoptotic mechanism. The XRD patterns of SnNiCoO2 NPs revealed a tetragonal structure. The SnNiCoO2 NPs was revealed a diameter of 126 nm by the DLS study. The morphology and elemental composition were studied using FESEM and EDAX spectra. In the FT-IR study, the O-sn-O stretching band was found to be 615 and 542 cm-1. The antimicrobial potential of the SnNiCoO2 NPs was examined against S. aureus, E. coli, and C. Albicans strains. A tremendous reduction in the viability of MOLT-4 cells at concentration-dependent mode witnessed the cytotoxic potential of the formulated NPs. The augmented ROS accumulation, depletion of MMP status, depleted antioxidants, and increased proinflammatory cytokines (TNF-α and IL1β) were noted on the NPs exposed cells. Furthermore, the increased expressions of caspase-3, ?9, and ?8 was also noted in the NPs treated MOLT-4 cells. Hence, the outcomes suggest that the formulated SnNiCoO2 NPs had remarkably potent antimicrobial and anticancer properties and could potentially prove beneficial in cancer treatment. Induces mitochondrial oxidative stress with nickel–cobalt-codoped tin oxide nanoparticles from Psidium guajava, which is a potential drug candidate for the antibiotic, antifungal, and anticancer activities of plant-based nanoparticles.     

Oak gum mediated green synthesis of silver nanoparticles under ultrasonic conditions: Characterization and evaluation of its antioxidant and anti-lung cancer effects

Herein, we represent the bio-synthesis of silver nanoparticles (Ag NPs) employing Oak gum as the green template, an efficient natural and non-toxic reductant and stabilizer based on its phytochemicals by using ultrasonic irradiation. The characterization of as-synthesized Ag NPs was performed through Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), elemental mapping, UV–Vis and X-ray diffraction (XRD). After the characterization, the synthesized Ag NPs/O. Gum was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using MeOH and BHT as reference molecules. Thereafter, on having a significant IC₅₀ value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of A549, Calu6 and H358 human lung cell lines in-vitro through MTT assay. They had very low cell viability and high anti-human lung cancer activities dose-dependently against the cell lines without any cytotoxicity on the normal cell line (MRC-5). The IC₅₀ of Ag NPs/O. Gum was found 161.25, 289.26 and 235.29 µg/mL against A549, Calu6 and H358 cell lines, respectively. Maybe significant anti-human lung cancer potentials of Ag NPs/O. Gum against common lung cancer cell lines are related to their antioxidant activities. So, these results suggest that synthesized Ag NPs/O. Gum as a chemotherapeutic nanomaterial have a suitable anticancer activity against lung cell lines.     

Supported silver nanoparticles over alginate-modified magnetic nanoparticles: Synthesis,characterization and treat the human lung carcinoma

This article displays synthesis of Silver nanoparticles (Ag NPs) decorated on sodium alginate covered magnetite (Fe₃O₄/Alg-Ag NPs) nanocomposite. Sodium alginate shell as a natural anionic polysaccharide on Fe₃O₄ microparticles core acted as a stabilizing agent for the reduction of Ag(I) ions into Ag NPs. The structural features of the synthesized nanocomposite were investigated by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopes (FE-SEM), transmission electron microscopes (TEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating-sample magnetometer (VSM) studies and inductively coupled plasma-optical emission spectroscopy (ICP-OES). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used on common lung cancer cell lines i.e., NCI-H1975, NCI-H1563, and NCI-H1299 to survey the cytotoxicity and anti-lung cancer effects of the synthesized nanocomposite. The synthesized nanocomposite had very low cell viability and high anti-lung cancer activities dose-dependently against NCI-H1975, NCI-H1563, and NCI-H1299 cell lines without any cytotoxicity on the normal cell line (Human umbilical vein endothelial cells (HUVECs)). To determine the antioxidant properties of the synthesized nanocomposite, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test was used in the presence of butylated hydroxytoluene as the positive control. The synthesized nanocomposite inhibited half of the DPPH molecules in the concentration of 194 µg/mL. Maybe significant anti-human lung cancer potentials of the synthesized nanocomposite against common human lung cancer cell lines are linked to their antioxidant activities.     

Preparation of bismuth sulfide nanoparticles as targeted biocompatible nano-radiosensitizer and carrier of methotrexate

In this study, Bi₂S₃@BSA–Bio–MTX nanoparticles (NPs) were synthesized for the first time by bovine serum albumin (BSA)-mediated biomineralization (Bi₂S₃@BSA NPs) followed by covalent bonding of biotin (Bio) and methotrexate (MTX) on the surface of the Bi₂S₃@BSA NPs via carbodiimide chemistry. The synthesized NPs were globular and exhibited uniform morphology with a hydrodynamic diameter of 107.6 ± 6.81 nm (mean ± standard deviation) and zeta potential of −20.9 ± 2.18 mV. Drug release from Bi₂S₃@BSA–Bio–MTX NPs indicated an enzyme-dependent release pattern. The in vitro biocompatibility of NPs was confirmed by investigating their cytotoxicity against the HEK-293 cell line and hemolysis assay test, whereas the in vivo biocompatibility of the NPs was evaluated and confirmed by the lethal dose 50 (LD₅₀) test. To evaluate the in vitro anticancer activity of the functionalized NPs and MTX, their cytotoxic effects was assessed against 4T1 cancer cells by 5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with and without X-ray radiation. Results showed that Bi₂S₃@BSA–Bio–MTX NPs have excellent anticancer activity, especially following X-ray radiation.     

Cytotoxic dammarane glycosides from processed ginseng

Steaming ginseng at high temperature increased its cytotoxicity to SK-Hep-1 hepatoma cancer cells. HPLC separation and fractionation followed by MTT assay revealed that ginsenosides Rg3, Rg5, Rk1, Rs5, and Rs4 are the active principles. Their 50% growth inhibition concentration (GI50) values were 41, 11, 13, 37, and 13 microM, respectively. Cisplatin had a GI50 of 84 microM in the same assay conditions.     

Two new epimeric pairs of iridoid from mangrove plant Scyphiphora hydrophyllacea

Two new epimeric pairs of iridoid scyphiphin A_1(1a),A_2(1b) and scyphiphin B_1(2a),B_2(2b) were isolated from Scyphiphora hydrophyllacea Gaertn.F.Their structures were elucidated by spectroscopic methods.The mixture of scyphiphin B_1 and scyphiphin B_2 showed moderate cytotoxicity against human hepatoma SMMC-7721 cell line in vitro by MTT method.