负载液态氟烷的聚合物纳米胶束及囊泡的制备及超声显像

摘要

Objective To formed ranoscale ultrasound contrast agents loading PFOB by selfassembly of amphiphilic block copolymer for ultrasonic imaging in vivo and in vitro.Methods The biodegradable copolymer-poly(ethylene glycol)-b-poly (D, L-lactic acid) (PEG-PDLLA) self-assembled to form PFOB-loaded nanomicelle and nanovesicle with different PFOB concentration by solvent volatilization.The configuration and particle-sizing of resulting nanoparticles was determined,and their ultrasonic imaging in vitro and contrast-enhanced ultrasonography on subcutaneous tissue by focal injection in vivo were observed.Results In transmission electron microscope images, these micelles and vesicles appeared uniformly spherical with smooth surface.All the size distributions were narrow and mean diameters were from 404.3 to 475.8 nm using laser particle-sizing analyzer.In vitro and in vivo experiment showed that,the higher PFOB concentration, the more remarkable effect of ultrasound imaging.Especially, nanovesilces'ultrasonography effect was much better than nanomicelles' under same conditions.Conclusions PFOB-loaded nano-micelles and nano-vesicles prepared by solvent volatilization and self-assembly of PEG-PDLLA can obviously enhance ultrasound contrast and nanovesicle behaves better than nano-micelle.%目的 应用人工合成高分子聚合物——聚乙烯二醇与多聚乳酸的两亲性嵌段共聚物制备纳米级超声造影剂（胶束及囊泡）,并评估其体内外的超声显影效果。方法 采用溶剂挥发法通过生物可降解共聚物自组装制备负载不同浓度1-溴代全氟辛烷(PFOB)的纳米胶束与囊泡，并观察其超微结构及粒径分布情况。分别对不同浓度的纳米胶束及囊泡进行体外超声检测及动物皮下注射体内超声显像。结果 透射电子显微镜下观察纳米胶束及囊泡形态规则呈球形，表面光滑;激光测径仪测量其平均粒径集中在404.3～475.8 nm，分布范围窄。体内外超声检测均可显像，且随着液态氟烷浓度的增加，显像效果逐渐增强；负载同一浓度液态氟烷的囊泡超声显像效果优于胶束。结论 采用溶剂挥发法通过生物可降解共聚物自组装可成功制备纳米级超声造影剂——纳米胶束及囊泡，体内外均可进行超声显像，且囊泡显像效果优于胶束。