光热型纳米金-共聚物超声造影剂的制备和体内外显像

目的 制备外包纳米金壳内载全氟丙烷(C₃F₈)的聚乳酸羟基乙酸(PLGA)光热型超声造影剂,观察其在体内外的超声显像效果及体外的光热效能。方法 通过改进的乳化溶剂挥发法制备PLGA纳米粒子,包载C₃F₈气体后,再用种子生长法在PLGA表面形成纳米金壳,制备C₃F₈@PLGA@Au纳米粒子；检测其一般特性,并用近红外激光和超声成像仪评估其体外光热效能及体内外成像效果。结果 成功制备C₃F₈@PLGA@Au纳米粒子,该粒子的平均直径为268.2±80.5 nm,分散性好,无明显细胞毒性；在808 nm激光辐照下,粒子有很好的溶液光热效果；体内外超声成像实验中均有增强显像。结论 成功制备了光热型纳米超声造影剂,其有良好的体外光热性能和体内外超声显像效果,为乳腺癌疾病诊治提供了新思路。

A photothermal ultrasound contrast agent: preparation, in vitro and in vivo investigation of gold nanoshelled poly(lactide-co-glycolic acid) nanoparticles

ABSTRACT Objective To develop a photothermal ultrasound contrast agent with C3F8 filled-gold nanoshelled poly(lactide-co-glycolic acid) nanoparticles (C3F8@PLGA@Au NPs) and to investigate its photothermal effect and contrast enhanced ultrasound imaging capability. Methods The nanoscale agent was fabricated through filling C3F8 into PLGA, followed by the formation of gold nanoshell on the surface. The physicochemical properties of C3F8@PLGA@Au NPs were characterized by electronic microscopies and dynamic laser scattering. And its photothermal effect was assessed via monitoring temperature increase under the laser irradiation in vitro. The ultrasonic diagnostic instrument was used to evaluate the ultrasound contrast behavior of C3F8@PLGA@Au NPs. Results The C3F8@PLGA@Au NPs were observed with spherical morphology, good dispersion, and uniform size with average size of 268.2±80.5 nm. The MTT assay indicated the good biocompatibility of our NPs. And the imaging results in vitro and in vivo demonstrated that C3F8@PLGA@Au NPs provided excellent contrast enhancement for ultrasound imaging. Moreover, the NPs also served as efficient photoabsorbers for NIR photothermal therapy. Conclusion The photothermal ultrasound contrast agent has been designed and fabricated. The preliminary studies demonstrate that C3F8@PLGA@Au NPs have excellent photothermal effect in vitro and ultrasound imaging capability in vitro and in vivo.