红光响应眼镜蛇神经毒素PEG-PLGA纳米囊的制备与表征

Preparation and Characterization of Red Light Responsive Cobra Neurotoxin PEG-PLGA Nanocapsule

摘要:

以聚乙二醇-聚乳酸-聚乙醇酸嵌段共聚物为囊材，添加脱镁叶绿酸作为光敏剂，采用复乳法制备了光响应的眼镜蛇神经毒素纳米囊（PEG-PLGA）。采用单因素法优化以包封率、载药量和纳米囊的粒径为指标优化配方，；对以其结构、差示量热扫描分析其热流变性和能，并以累积释药量分析其光控释测定行为。优化的PEG-PLGA、眼镜蛇神经毒素及光敏剂脱镁叶绿酸质用量配比为40:12.5:1，获得的纳米囊包封率为72.3%±3.6%，载药量为15.1%±1.3%，平均粒径为(862±23) nm，电位(-46.5±3.8) mV，呈紧密球形，光敏剂分布在囊壳；在650nm半导体激光光照射30 min，体外释放明显加快。该纳米囊在不光照时具有增强药物稳定和缓释作用，而红光可促进释药，因而可实现光控靶向。

Abstract:

PEG-PLGA was used as the capsule material, and added by photosensitizer pheophorbide to make photo responsive Cobra neurotoxin (CNT) nanocapsule by double emulsion method. The formula was optimized by with encapsulation efficiency, drug loading and particle size as the indexes by single factor tests. Its structure, The thermo rheological properties were analyzed by differential scanning calorimeter, and photo responsiveness were was analyzed by cumulative release. The optimal ratio of PEG-PLGA , CNT and pheophorbide was 40:12.5:1, and the encapsulation efficiency 72.3%±3.6%, drug loading 15.1%±1.3%, average particle size (862±23) nm, and zeta potential (-46.5±3.8) mV were obtained with tight spherical shape and pheophorbide in outer layer of the nanocapsule. Drug release was accelerated under illumination of 650 nm for 30 min with semiconductor laser. This new type of nanocapsule can keep drug stable and sustain release without illumination, but release quickly under red light, thus light controlled targeting can be achieved.