生物素化全氟碳纳米颗粒荷载药物体外释放和磁共振影像观察

Sustained release of drug loaded within biotinylated perfluorocarbon nanoparticles and use in magnetic resonance imaging

目的制备生物素化全氟碳载药纳米颗粒,分析纳米载药的释放特点及其对磁共振信号强度的影响。方法以全氟碳为纳米核心,通过高压均质方法,分别包被抗内膜增生药物地塞米松磷酸钠或醋酸地塞米松,以及磁共振造影剂钆喷酸葡胺。采用扫描电镜和激光粒度分析仪检测纳米颗粒形态和粒径,高效液相色谱仪测定纳米颗粒载药包封率和体外溶出情况,同时观察磁共振影像及波谱信号强度变化。结果地塞米松磷酸钠和醋酸地塞米松全氟碳纳米粒径分别为(224±s6)和(236±9)nm。荷载亲水性地塞米松磷酸钠药物的包封率为(66.4±1.0)%,并有一定突释现象,首日溶出比率为77.2%;荷载疏水性醋酸地塞米松药物的包封率为(95.3±1.3)%,首日溶出比率为23.6%。全氟碳纳米颗粒荷载2种药物体外溶出时间都超过1wk。全氟碳纳米颗粒携带顺磁性造影剂钆喷酸葡胺,可增加后者的信号强度约16%。结论全氟碳纳米颗粒荷载药物具有较好的缓释性,并能增加磁共振造影剂的信号强度,提高磁共振检测敏感性。

AIM To investigate the in vitro release profile of loading drugs encapsulated within the perfluorocarbon （PFC） nanoparticles （NPs） and its ability of enhancing magnetic resonance imaging （MRI） . METHODS Dexamethasone sodium phosphate （DxP） or dexamethasone acetate （DxA）, and gadopentetate dimeglumine （Gd-DTPA） loaded within biotinylated PFC NPs were constructed by high pressure homogeneous processing method. The morphology and size of NPs were examined by scanning electron microscope （SEM） and laser particle size analyzer. Drug loading and in vitro releasing were assessed by high performance liquid chromatography （HPLC）. MRI was used to observe the imaging and signal intensity of contrast within the NPs. RESULTS The particle size of DxP-NP and DxA-NP were （224 ±s 6） and （236 ± 9） nm, respectively. The encapsulation efficiency （EE） of DxP-NP were （66.4 ±1.0） %, with an obviously bursting phenomenon, the initial releasing rate were 77.2%, while the EE of DxA-NP were （95.3±1.3） %, the initial releasing were 23.6%. Both of the two NPs could release persisted over one week. The NPs loading Gd-DTPA could enhance the signal intensity of Gd-DTPA about 16% detected by MRI. CONCLUSION PFC NPs loaded with hydrophilic drug have relatively high encapsulation efficiency and sustained release pattern. Contrast loaded within NPs could enhance the signal intensity detected by MRI.