聚己内酯微泡的制备与表征

Preparation and Characterization of Polycaprolactone Microbubbles

微泡包覆气体的核壳结构赋予其独特性能,使其成为超声示踪剂和药物与生物活性气体载体的优质候选,其中微泡能否稳定地包覆核心气体成为关键。本文用溶剂挥发界面沉积法制备了以聚己内酯为外壳主体、核心包覆氮气的微泡,并对微泡进行了结构、形貌、粒径分布、超声成像和稳定性的表征。结果表明聚己内酯微泡制备成功,且具有薄壳空腔的结构,外壳完整,尺寸均一,平均粒径为2.2μm;微泡的超声成像信号强度在微泡浓度范围10~4mL^(-1)～10~6mL^(-1)之间随浓度增加而明显增强;并且微泡在生理环境下能够稳定包覆核心气体至少14 d,具备成为超声示踪剂和药物与生物活性气体载体的潜力。

The core-shell structure of gas-encapsulated microbubbles endues them unique properties and makes them excellent candidates of ultrasound tracer and drug and bioactive gas carrier.However,the key is whether the encapsulated gas can be durably maintained.In the present work,nitrogen gas was encapsulated by polycaprolactone as the polymer shell using a solvent evaporation interfacial deposition technique.The structure,morphology,size distribution,acoustic activity and acoustic duration of the microbubbles were also characterized.The results show that the polycaprolactone microbubbles are successfully prepared with gas core,intact thin shell and uniform size distribution with a mean size of 2.2μm.The video intensity of the microbubbles enhances significantly as their concentration increases from 104mL-1to 106mL-1during the ultrasound imaging.The microbubbles can maintain the encapsulated gas for at least 14 d,which proves their potential and capacity for being excellent ultrasound tracers and drug and bioactive gas carriers.