【摘要】 利用静电自组装法制备了壳聚糖/siRNA纳米粒,建立了SYBR?Gold核酸染料法测定siRNA复合率(CR),并系统性考察了n(N)/n(P)比,壳聚糖分子量(Mw)、脱乙酰度(DD)及制备环境pH值、缓冲液浓度(Bc)对纳米粒siRNA复合率、粒径及表面电位的影响规律。结果表明,siRNA复合率由n(N)/n(P)0.5时的(18.6±4.0)%快速增大至n(N)/n(P)为2时的(92.9±2.0)%,但随n(N)/n(P)增大复合率不再升高;n(N)/n(P)<2时,难以形成稳定纳米粒,复合物表面电位为负,n(N)/n(P)由5升至150时,纳米粒粒径由(179.3±5.7)nm增大至(235.5±8.3)nm,表面电位由(17.2±1.3)mV升高至(23.6±0.9)mV。另外,n(N)/n(P)150时,CR随DD升高而升高,随Bc升高而降低;纳米粒粒径随Mw增大而增大,随DD及缓冲液浓度(Bc)升高而减小;纳米粒表面电位随DD升高而升高,随pH值及Bc升高而降低。n(N)/n(P)比对纳米粒特性及siRNA复合率影响最为显著,调整n(N)/n(P)、Mw、DD、pH值及离子强度可得到siRNA复合率在90%以上,粒径100~300nm,表面电位15~25mV的纳米粒。更多还原

【Abstract】 With the preparation of Chitosan/siRNA nanoparticles based on electrostatic self-assembly,a nucleic acid dye assay with SYBR  Gold was established to determine the condensation rate(CR)of siRNA in nanoparticles,and then the influence of n(N)/n(P)ratio,Mw,DD,pH and ion strength of chitosan solution on siRNACR,nanoparticle size and zeta-potential was investigated by SYBR  Gold assay,dynamic light scattering and laser doppler electrophoresis respectively.The results showed that CR rose from(18.6±4.0)% to(92.9±2.0)% as n(N)/n(P)increased from 0.5to 2and stayed stable even when n(N)/n(P)reached 150.When n(N)/n(P)was below 2,no stable nanoparticles were detected and the complex was negative charged,while n(N)/n(P)went from 5to 150,the size of nanoparticles increased from(179.3±5.7)nm to(235.5±8.3)nm and zeta-potential rose from(17.2±1.3)mV to(23.6±0.9)mV.At n(N)/n(P)150,CRraised with the increase of DDor with the decrease of Bc,the size of nanoparticles increased with the increase of Mw and decreased with the increase of DD or Bc,the zeta-potential of nanoparticles increased with the increase of pH value or DDbut decreased with the decrease of Bc.It demonstrated that n(N)/n(P)ratio is the most important factor determining the size,zeta-potential and CR,and nanoparticles with the diameter ranging from 100-300 nm and zeta-potential ranging from 15-25 mV can be easily obtained via adjusting above parameters.更多还原