The purpose of this paper is to encapsulate neurotoxin-I（NT-I）,a kind of analgesic peptide,into polylactic acid（PLA） nanoparticles（NPs） and to evaluate their transport into the brain after intranasal administrat...The purpose of this paper is to encapsulate neurotoxin-I（NT-I）,a kind of analgesic peptide,into polylactic acid（PLA） nanoparticles（NPs） and to evaluate their transport into the brain after intranasal administration（in） by use of microdialysis sampling technique developed in our laboratory recently.NT-I-NPs(NT-Iradiolabeled with sodium 125I-Iodide) were prepared by a double emulsification solvent evaporation method,and were characterized in terms of surface morphology,particle size distribution,zeta potential and entrapment efficiency.Then,NT-I-NPs were administered intranasally or intravenously to rats and the radioactivities in periaqueductal gray（PAG） were monitored up to 240 min utilizing the microdialysis sampling technique.Nanoparticles prepared were spherical with homogenous size distribution.Their mean particle size and zeta potential measured were（65.3±10.8） nm and（-28.6±2.3） mV,respectively.The entrapment efficiency of NT-Iencapsulated into nanoparticles was（35.5±2.8）%.The brain transport results showed that the time to peak level(Tmax) of NT-I-NPs（in） was（（65±）10） min approximately,apparently shorter compared with NT-I-NPs [iv,（95±10） min] or NT-I [iv,（145±10） min].The concentration to peak level (Cmax) and the area under the curves from zero to 4 h(AUC0-4 h) of each group followed this order: NT-I-NPs（in）>NT-I-NPs（iv） >NT-I（iv）.With nanoparticles as carriers and administered intranasally could be a potential way for centrally active peptides to improve their brain transport.Microdialysis is quite a good technique for the study of drug delivery to the brain.展开更多
目的:考察125I-(a-cobratoxin,Nt)透鼻黏膜吸收的情况及冰片的促进作用。方法:以大鼠、家兔、狗和羊为研究对象,以放射性活性(每分钟计数,count per minute,cpm)为指标,采用离体渗透鼻黏膜实验、在体渗透鼻黏膜重循环实验等方法,研究125...目的:考察125I-(a-cobratoxin,Nt)透鼻黏膜吸收的情况及冰片的促进作用。方法:以大鼠、家兔、狗和羊为研究对象,以放射性活性(每分钟计数,count per minute,cpm)为指标,采用离体渗透鼻黏膜实验、在体渗透鼻黏膜重循环实验等方法,研究125I-Nt对不同动物透鼻黏膜吸收的情况及冰片的促进作用。结果:研究发现,Nt很难透过鼻黏膜吸收,但在冰片作用下吸收显著增加。结论:冰片对Nt透鼻黏膜吸收有显著促进作用。展开更多
文摘The purpose of this paper is to encapsulate neurotoxin-I（NT-I）,a kind of analgesic peptide,into polylactic acid（PLA） nanoparticles（NPs） and to evaluate their transport into the brain after intranasal administration（in） by use of microdialysis sampling technique developed in our laboratory recently.NT-I-NPs(NT-Iradiolabeled with sodium 125I-Iodide) were prepared by a double emulsification solvent evaporation method,and were characterized in terms of surface morphology,particle size distribution,zeta potential and entrapment efficiency.Then,NT-I-NPs were administered intranasally or intravenously to rats and the radioactivities in periaqueductal gray（PAG） were monitored up to 240 min utilizing the microdialysis sampling technique.Nanoparticles prepared were spherical with homogenous size distribution.Their mean particle size and zeta potential measured were（65.3±10.8） nm and（-28.6±2.3） mV,respectively.The entrapment efficiency of NT-Iencapsulated into nanoparticles was（35.5±2.8）%.The brain transport results showed that the time to peak level(Tmax) of NT-I-NPs（in） was（（65±）10） min approximately,apparently shorter compared with NT-I-NPs [iv,（95±10） min] or NT-I [iv,（145±10） min].The concentration to peak level (Cmax) and the area under the curves from zero to 4 h(AUC0-4 h) of each group followed this order: NT-I-NPs（in）>NT-I-NPs（iv） >NT-I（iv）.With nanoparticles as carriers and administered intranasally could be a potential way for centrally active peptides to improve their brain transport.Microdialysis is quite a good technique for the study of drug delivery to the brain.
文摘目的:考察125I-(a-cobratoxin,Nt)透鼻黏膜吸收的情况及冰片的促进作用。方法:以大鼠、家兔、狗和羊为研究对象,以放射性活性(每分钟计数,count per minute,cpm)为指标,采用离体渗透鼻黏膜实验、在体渗透鼻黏膜重循环实验等方法,研究125I-Nt对不同动物透鼻黏膜吸收的情况及冰片的促进作用。结果:研究发现,Nt很难透过鼻黏膜吸收,但在冰片作用下吸收显著增加。结论:冰片对Nt透鼻黏膜吸收有显著促进作用。
