中文摘要：

目的：制备载纳豆激酶（NK）的三甲基壳聚糖（TMC）纳米粒（TMC-NK-NPs）,并研究其体外释放度。方法：合成季胺化度分别为15%、20%、25%的TMC（即TMC15、TMC20、TMC25）,将其与NK自组装形成TMC-NK-NPs。测定TMC-NK-NPs的粒径、多分散系数（PDI）、Zeta电位,筛选TMC;观察并测定最优处方制备的TMC-NK-NPs的形态、包封率、载药量、4℃避光下30 d的稳定性、24 h内的体外累积释放度（Q）及NK活性。结果：采用TMC20所制TMC-NK-NPs的粒径较小[（161.0±4.8）nm],PDI最小（0.204）,Zeta电位为（19.2±1.5）m V,呈球形或类球形;包封率为（45.4±1.51）%,载药量为（14.2±0.25）%;30 d内相对稳定;峰值Q12 h为92.3%;NK活性在1 h时就达到最大（76.6%）,但随着时间延长,活性降低。结论：成功制得形态圆整、包封率与载药量较高,且具有较好缓释作用的TMC-NK-NPs。

英文摘要：

OBJECTIVE： To prepare nattokinase （NK）-loaded tfimethyl chitosan （TMC） nanoparticles （TMC-NK-NPs）, and to study its release rate in vitro. METHODS： TMC with different degree of quatemization （15%, 20%, 25%） were synthetized, i.e. TMC15, TMC20, TMC25; those were combined with NK to form TMC-NK-NPs by self-assembly. The particle size, polydispersity index （PDI） and Zeta potential were determined and TCM was screened; the morphology, entrapment efficiency （EE） , drug-loading amount, 30 d stability at 4 ℃ and dark place, 24 h accumulative release rate in vitro （Q） and NK activity of TMC-NK-NPs by optimal formulation were observed and determined. RESULTS： Using TMC20, TMC-NK-NPs were smaller in particle size [（161.0± 4.8） nm], the lowest in PDI （0.204） ; the Zate potential was （19.2 ± 1.5） mV, spherical or spherical-like, EE was （45.4 ± 1.51）%, drug-loading amount was （14.2 ± 0.25）%, stable within 30 d, the peak Q12h was 92.3%. The maximum released activity of NK was 76.6% at 1 h, but then gradually decreased with time. CONCLUSIONS： TMC-NK-NPs are prepared successfully, round and complete with high EE and drug-loading amount, good sustained-release property.