载血卟啉单甲醚纳米高分子微球的制备及显像实验

Preparation and Imaging Studies of Poly-lactic Acid-glycolic Acid Polymeric Nanoparticles Coated Hematoporphyrin Monomethyl Ether

目的制备出一种载血卟啉单甲醚(HMME)的聚乳酸-羟基乙酸(PLGA)多功能造影剂(MB_(PLGA-HMME),MB:Microbubble),检测MB_(PLGA-HMME)的基本性质以及HMME包裹在PLGA微球上后,性质改变情况,探讨其集显像与治疗一体化的可行性。资料与方法采用双乳化法制备MB_(PLGA-HMME),对其结构、形态、载药率等性质进行检测,采用体外成像比较HMME药物与MB_(PLGA-HMME)超声/光声成像改变情况以及进行初步体内光声成像。结果 MB_(PLGA-HMME)溶于双蒸水后呈淡红色悬液,显微镜下观察MB_(PLGA-HMME)呈球形,形态规则,大小均匀无聚集、粘连现象,能发出红色荧光,HMME均匀分布在微球上,光学显微镜和透射电镜均可见MB_(PLGA-HMME)为壳核结构,外有一层明显的黑色的壳膜,HMME主要分布于PLGA微球壳上。体外光声成像显示,MB_(PLGA-HMME)溶液浓度为408μmol/L、816μmol/L、1632μmol/L的平均光声信号强度分别为0.2009±0.0636、0.3789±0.0431、0.5380±0.0997;同样浓度梯度下,HMME溶液的平均光声信号值分别为0.0738±0.0133、0.1137±0.0065、0.2170±0.0270,组间和组内两两比较,差异有统计学意义,但药物性质基本未改变。MB_(PLGA-HMME)经静脉注入荷瘤鼠体内后,可进行体内光声显像。结论本研究成功制备载血卟啉单甲醚药物的MB_(PLGA-HMME),HMME药物水溶性得到改善,其基本的吸光性质得以保持,可进行体内外超声/光声成像。

Purpose To prepare the poly-lactic acid- glycolic acid（PLGA） polymeric nanoparticles coated hematoporphyrin monomethyl ether（HMME） as a multifunction contrast agent（MBPLGA-HMME, micro-bubble）, and detectits physical and pharmacological properties, as well as its application and feasibility of imaging. Materials and Methods MBPLGA-HMME was prepared by using multi-emulsion method. Its structure, morphology and concentration of HMME loaded on PLGA microcapsules were assessed. In vitro ultrasound/photoacoustic imaging of HMME and MBPLGA-HMME microspheres were compared and in vivo preliminary photo acoustic imaging of MBPLGA-HMME microspheres was performed. Results MBPLGA-HMME was showed as light red suspension after resolving in distilled water; observed as regular and uniformed spherical putamen structure with obvious black shell membrane without aggregation and adhesion, as well as emitting red fluorescence.HMME mainly distributed on the PLGA microspheres. Photoacoustic imaging in vitro showed that the average photoacoustce signal intensity of MBPLGA-HMME were 0.2009±0.0636, 0.3789±0.0431, 0.5380±0.0997 under different concentrations（408 μmol/L, 816 μmol/L, 1632 μmol/L）, respectively, while the average photoacoustce signal intensity of HMME were 0.0738±0.0133, 0.1137±0.0065, 0.2170±0.0270 under the same concentration gradient. There was significant difference of signal intensity between two groups in the same concentration and within one group in different concentrations, while the basic pharmacology properties didn＇t change. Photoacoustic imaging of intravenous injected MBPLGA-HMME can be performed in mice with tumor. Conclusion PLGA microspheres coated with HMME was successfully prepared with improved water-soluble and light absorption properties, which can be used in ultrasound/photoacoustic imaging.