N-羧甲基壳聚糖微泡超声造影剂的制备与性能评价

目的制备N-羧甲基壳聚糖微泡超声造影剂,观察其基本特征及对动物肝脏超声显影效果。方法采用(油/水)/油复合乳液-溶剂蒸发法制备微泡超声造影剂,通过光学显微镜和扫描电镜观察微泡的大小、形态及粒径分布,通过股动脉注射0·5ml该超声造影剂到动物体内,观察动物肝脏超声显影效果。结果N-羧甲基壳聚糖微泡为空心球形结构,分散均匀,形状规则,粒径在2~3μm,壁厚为250~300nm。该造影剂对动物肝脏超声显影效果明显增强。结论N-羧甲基壳聚糖微泡可作为一种性能较好的超声造影剂。

Preparation and evaluation of microbubble ultrasound contrast agent with N-carboxymethyl chitosan

OBJECTIVE: To prepare microbubble, made of N-carboxymethyl chitosan, as ultrasound contrast agent and evaluate its characteristics and acoustic effects in vivo. METHODS: Oil-Water-Oil multiple emulsion/solvent evaporation method was used to prepare the microbubble contrast agent. Both optical micrography and scanning electron micrography were performed to determine the bubble size and morphology. The acoustic effect of the N-carboxymethyl chitosan echo contrast agent was evaluated in vivo in rabbit. Liver echo images were recorded with ultrasound machine before and after intravenous bolus injecting 0.5 ml of the agent. RESULTS: The novel N-carboxymethyl chitosan echo contrast agent was formulated as lyophilized product, with a mean diameter of 2-3 microm and a shell thickness of 250-300 nm. Its size is relatively uniform. The imaging effect was remarkably enhanced with the ultrasonic contrast agent when applied in rabbit livers. CONCLUSION: It is feasible to prepare excellent microbubble ultrasound contrast agent with N-carboxymethyl chitosan as membrane components.