壳寡糖-水杨酸接枝物纳米粒用于释放阿霉素的研究

Chitosan Oligosaccharide/Salicylic Acid Nanoparticles for Doxorubicin Delivery

关键词:  壳寡糖/水杨酸接枝物  碱化阿霉素  纳米粒  体外释放

Key words:  chitosan oligosaccharide /salicylic acid  alkalized doxorubicin  nanoparticles  in vitro

摘要:

目的 考察壳寡糖/水杨酸纳米粒负载碱化阿霉素的可能性，评价制备而得的微粒给药系统理化性质及其体外释放行为。方法 以碳二亚胺为交联偶合剂合成壳寡糖/水杨酸接枝共聚物，三硝基苯磺酸法测定水杨酸接枝率。运用超声分散法制备壳寡糖/水杨酸空白纳米粒，芘荧光法测定纳米粒临界聚集浓度，动态光散射法测定微粒粒径和表面电位，MTT法考察空白纳米粒的细胞毒性。以碱化阿霉素为模型药物，透析法制备壳寡糖/水杨酸载药纳米粒，经透射电镜考察载药纳米粒的形态，对其体外释放行为进行了研究。结果 合成得到的壳寡糖分子量=9000/水杨酸理论投料量=50%的实际接枝率为16.92%，空白纳米粒的临界聚集浓度为867.0 μg/mL，空白纳米粒的粒径和表面Zeta电位分别为434.0 nm和48.6 mV，对人肝癌细胞Hep-G2的半数抑制浓度为1745μg/mL。在碱化阿霉素理论投药量为10%时壳寡糖/水杨酸载药纳米粒的实际载药量为8.52%，包封率为93.15%。;载药纳米粒的粒径和表面电位分别为214.2 nm和33.6 mV。体外释放结果表明药物的释放呈现pH敏感性；并主要以溶蚀的方式从载体内部释放出来。结论 壳寡糖/水杨酸接枝物可以有效包裹碱化阿霉素并成为粒径均一的纳米粒给药系统。载药纳米粒具有pH敏感和缓释作用。壳寡糖/水杨酸接枝物有望成为潜在的难溶性药物的载体材料。

Abstract:

ABSTRACT: OBJECTIVE To investigate the probability of Chitosan oligosaccharide (CSO)/Salicylic acid (SA) nanoparticles to encapsulate alkalized doxorubicin and to evaluate the physicochemical properties and in vitro profile of drug delivery system. METHODS CSO/SA conjugates were synthesized by a reaction between amino-groups of CSO and carboxyl groups of SA using 1-ethyl-3-(3-dimethyla-minopropyl) carbodiimide as a coupling agent. The amino substitution degree (SD%) of CSO/SA was determined by a 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) test as reported before. The CSO/SA blank nanoparticles were prepared by ultrasonic dispersion method. The critical aggregation concentration of nanoparticles was obtained by the fluorescence pyrene study. Dynamic light scattering method was used to determine the size and zeta potential of nanoparticles. MTT assay was used to evaluate the cytotoxicity of nanoparticles. Alkalizated doxorubicin was used as the model drug, drug-loaded CSO/SA nanoparticles were prepared by dialysis method. RESULTS The amino substitution degree of CSOMW=9000/salicylic acidtheory fed amount%=50% was 16.92%, and the critical aggregation concentration of blanked nanoparticles was 867.0 μg/mL. The particle size and zeta potential of blank nanoparticles were 434.0 nm and 48.6 mV separately; the IC50 of the nanoparticles on cell Hep-G2 was 1745μg/mL. The drug content of nanoparticles was 8.52% and the loading efficiency was 93.15% when the amount of drug fed was 10%，the particle size and zeta potential of drug-loaded nanoparticles were 214.2 nm and 33.6 mV separately. In vitro release results illustrated that drug-loading nanoparticles had pH sensitivity，and the drugs were released mostly in the way of erosion. CONCLUSION CSO/SA could encapsulate alkalized doxorubicin to form uniform, sustained drug delivery nanoparticles. The drug-loaded nanoparticles presented pH-dependent property. CSO/SA nanoparticles may be a potential candidate to be a drug carrier material.