【文题】Preparation and antibacterial activity of chitosan nanoparticles
【杂志】Carbohydrate Research ，Volume 339, Issue 16 , 15 November 2004, Pages 2693-2700
【作者】Lifeng Qi, , Zirong Xu, Xia Jiang, Caihong Hu and Xiangfei Zou
【单位】Zhenjiang University, Animal Science College, Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310029, China
【文摘】Chitosan nanoparticles, such as those prepared in this study, may exhibit potential antibacterial activity as their unique character. The purpose of this study was to evaluate the in vitro antibacterial activity of chitosan nanoparticles and copper-loaded nanoparticles against various microorganisms. Chitosan nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. Copper ions were adsorbed onto the chitosan nanoparticles mainly by ion-exchange resins and surface chelation to form copper-loaded nanoparticles. The physicochemical properties of the nanoparticles were determined by size and zeta potential analysis, atomic force microscopy (AFM), FTIR analysis, and XRD pattern. The antibacterial activity of chitosan nanoparticles and copper-loaded nanoparticles against E. coli, S. choleraesuis, S. typhimurium, and S. aureus was evaluated by calculation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results show that chitosan nanoparticles and copper-loaded nanoparticles could inhibit the growth of various bacteria tested. Their MIC values were less than 0.25 μg/mL, and the MBC values of nanoparticles reached 1 μg/mL. AFM revealed that the exposure of S. choleraesuis to the chitosan nanoparticles led to the disruption of cell membranes and the leakage of cytoplasm.
【翻译】此文中所研究制备的壳聚糖纳米粒往往具有独特的潜在抗菌活性。我们研究的目的是评价壳聚糖纳米粒在体外的抗菌活性，及载铜纳米粒对各种微生物的作用。壳聚糖纳米粒用壳聚糖和三聚磷酸钠以离子交联法制成。通过离子交换树脂和表面螯合作用将铜离子吸附入壳聚糖纳米粒制成载铜纳米粒。测定其粒径和Zeta电位，并运用原子力显微镜、傅立叶变换红外光谱仪、X射线衍射仪来测定其各种物理化学性质。运用最小抑菌浓度（MIC）和最小杀菌浓度（MBC）来评价壳聚糖纳米粒和载铜纳米粒对E. coli, S. choleraesuis, S. typhimurium, and S. aureus的抗菌活性。结果显示壳聚糖纳米粒和载铜纳米粒均可抑制各种受试细菌的生长，其MIC值小于0.25 μg/mL，MBC值达到1 μg/mL。原子力显微镜显示当S. choleraesuis暴露于壳聚糖纳米粒时，会导致细胞膜的破坏和细胞质的渗漏。
【文题】Preparation and adsorption properties of monodisperse chitosan-bound Fe3O4 magnetic nanoparticles for removal of Cu(II) ions
【杂志】Journal of Colloid and Interface Science, In Press, Corrected Proof, Available online 17 November 2004,
【作者】 Yang-Chuang Chang and Dong-Hwang Chen
【单位】Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 701, Republic of China
【文摘】Monodisperse chitosan-bound Fe3O4 nanoparticles were developed as a novel magnetic nano-adsorbent for the removal of heavy metal ions. Chitosan was first carboxymethylated and then covalently bound on the surface of Fe3O4 nanoparticles via carbodiimide activation. Transmission electron microscopy micrographs showed that the chitosan-bound Fe3O4 nanoparticles were monodisperse and had a mean diameter of 13.5 nm. X-ray diffraction patterns indicated that the magnetic nanoparticles were pure Fe3O4 with a spinel structure, and the binding of chitosan did not result in a phase change. The binding of chitosan was also demonstrated by the measurement of zeta potential, and the weight percentage of chitosan bound to Fe3O4 nanoparticles was estimated to be about 4.92 wt%. The chitosan-bound Fe3O4 nanoparticles were shown to be quite efficient for the removal of Cu(II) ions at pH>2. In particular, the adsorption rate was so fast that the equilibrium was achieved within 1 min due to the absence of internal diffusion resistance. The adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 21.5 mg g−1 and a Langmuir adsorption equilibrium constant of 0.0165 L mg−1. The pH and temperature effects revealed that the adsorption capacity increased significantly with increasing pH at pH 2–5, and the adsorption process was exothermic in nature with an enthalpy change of −6.14 kJ mol−1 at 300–330 K.
【翻译】结合了单分散性壳聚糖的四氧化三铁纳米粒作为一种全新的磁吸附剂，可用于除去重金属离子。壳聚糖首先被羧甲基化，然后在碳二亚胺的催化作用下共价结合至四氧化三铁纳米粒的表面。透射电子显微镜照片显示，壳聚糖－四氧化三铁纳米粒具有良好的单分散性，平均粒径为13.5 nm。X射线衍射结果表明磁性纳米粒为针状晶体结构的纯四氧化三铁，与壳聚糖的结合并不导致其相变。通过测定zeta电位也可证实壳聚糖已与纳米粒连接上，其偶联比约为4.92wt%。在PH大于2的条件下，壳聚糖－四氧化三铁纳米粒能有效地除去二价铜离子。由于没有内扩散阻力，吸附速率非常快，以致于1分钟内就可达到平衡。其吸附数据符合Langmuir方程，最在吸附能力为21.5 mg g−1 ，Langmuir吸附平衡常数为0.0165 L mg−1。在PH2-5的范围内，随PH的增加，吸附能力显著增加。吸附过程为放热过程，在300K－330K时焓值改变为−6.14 kJ mol−1。 2 1 2 下一页 尾页
【杂志】Carbohydrate Research ，Volume 339, Issue 16 , 15 November 2004, Pages 2693-2700
【作者】Lifeng Qi, , Zirong Xu, Xia Jiang, Caihong Hu and Xiangfei Zou
【单位】Zhenjiang University, Animal Science College, Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310029, China
【文摘】Chitosan nanoparticles, such as those prepared in this study, may exhibit potential antibacterial activity as their unique character. The purpose of this study was to evaluate the in vitro antibacterial activity of chitosan nanoparticles and copper-loaded nanoparticles against various microorganisms. Chitosan nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. Copper ions were adsorbed onto the chitosan nanoparticles mainly by ion-exchange resins and surface chelation to form copper-loaded nanoparticles. The physicochemical properties of the nanoparticles were determined by size and zeta potential analysis, atomic force microscopy (AFM), FTIR analysis, and XRD pattern. The antibacterial activity of chitosan nanoparticles and copper-loaded nanoparticles against E. coli, S. choleraesuis, S. typhimurium, and S. aureus was evaluated by calculation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results show that chitosan nanoparticles and copper-loaded nanoparticles could inhibit the growth of various bacteria tested. Their MIC values were less than 0.25 μg/mL, and the MBC values of nanoparticles reached 1 μg/mL. AFM revealed that the exposure of S. choleraesuis to the chitosan nanoparticles led to the disruption of cell membranes and the leakage of cytoplasm.
【翻译】此文中所研究制备的壳聚糖纳米粒往往具有独特的潜在抗菌活性。我们研究的目的是评价壳聚糖纳米粒在体外的抗菌活性，及载铜纳米粒对各种微生物的作用。壳聚糖纳米粒用壳聚糖和三聚磷酸钠以离子交联法制成。通过离子交换树脂和表面螯合作用将铜离子吸附入壳聚糖纳米粒制成载铜纳米粒。测定其粒径和Zeta电位，并运用原子力显微镜、傅立叶变换红外光谱仪、X射线衍射仪来测定其各种物理化学性质。运用最小抑菌浓度（MIC）和最小杀菌浓度（MBC）来评价壳聚糖纳米粒和载铜纳米粒对E. coli, S. choleraesuis, S. typhimurium, and S. aureus的抗菌活性。结果显示壳聚糖纳米粒和载铜纳米粒均可抑制各种受试细菌的生长，其MIC值小于0.25 μg/mL，MBC值达到1 μg/mL。原子力显微镜显示当S. choleraesuis暴露于壳聚糖纳米粒时，会导致细胞膜的破坏和细胞质的渗漏。
【文题】Preparation and adsorption properties of monodisperse chitosan-bound Fe3O4 magnetic nanoparticles for removal of Cu(II) ions
【杂志】Journal of Colloid and Interface Science, In Press, Corrected Proof, Available online 17 November 2004,
【作者】 Yang-Chuang Chang and Dong-Hwang Chen
【单位】Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 701, Republic of China
【文摘】Monodisperse chitosan-bound Fe3O4 nanoparticles were developed as a novel magnetic nano-adsorbent for the removal of heavy metal ions. Chitosan was first carboxymethylated and then covalently bound on the surface of Fe3O4 nanoparticles via carbodiimide activation. Transmission electron microscopy micrographs showed that the chitosan-bound Fe3O4 nanoparticles were monodisperse and had a mean diameter of 13.5 nm. X-ray diffraction patterns indicated that the magnetic nanoparticles were pure Fe3O4 with a spinel structure, and the binding of chitosan did not result in a phase change. The binding of chitosan was also demonstrated by the measurement of zeta potential, and the weight percentage of chitosan bound to Fe3O4 nanoparticles was estimated to be about 4.92 wt%. The chitosan-bound Fe3O4 nanoparticles were shown to be quite efficient for the removal of Cu(II) ions at pH>2. In particular, the adsorption rate was so fast that the equilibrium was achieved within 1 min due to the absence of internal diffusion resistance. The adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 21.5 mg g−1 and a Langmuir adsorption equilibrium constant of 0.0165 L mg−1. The pH and temperature effects revealed that the adsorption capacity increased significantly with increasing pH at pH 2–5, and the adsorption process was exothermic in nature with an enthalpy change of −6.14 kJ mol−1 at 300–330 K.
【翻译】结合了单分散性壳聚糖的四氧化三铁纳米粒作为一种全新的磁吸附剂，可用于除去重金属离子。壳聚糖首先被羧甲基化，然后在碳二亚胺的催化作用下共价结合至四氧化三铁纳米粒的表面。透射电子显微镜照片显示，壳聚糖－四氧化三铁纳米粒具有良好的单分散性，平均粒径为13.5 nm。X射线衍射结果表明磁性纳米粒为针状晶体结构的纯四氧化三铁，与壳聚糖的结合并不导致其相变。通过测定zeta电位也可证实壳聚糖已与纳米粒连接上，其偶联比约为4.92wt%。在PH大于2的条件下，壳聚糖－四氧化三铁纳米粒能有效地除去二价铜离子。由于没有内扩散阻力，吸附速率非常快，以致于1分钟内就可达到平衡。其吸附数据符合Langmuir方程，最在吸附能力为21.5 mg g−1 ，Langmuir吸附平衡常数为0.0165 L mg−1。在PH2-5的范围内，随PH的增加，吸附能力显著增加。吸附过程为放热过程，在300K－330K时焓值改变为−6.14 kJ mol−1。 2 1 2 下一页 尾页