载纳豆激酶的三甲基壳聚糖纳米粒的制备及体外释放度研究

Preparation of Nattokinase-loaded Trimethyl Chitosan Nanoparticles and Study on Its Release Rate in vitro

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Q_(12 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。

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.