微波致热相变介导多尺度氟碳液滴的制备及其增效微波消融疗效

Production of multi-scale fluorocarbon droplets mediated by microwave-induced thermal phase transition and its synergistic efficacy of microwave ablation

目的探讨相变氟碳纳米材料的研究机制并评估其增效微波消融(MWA)疗效的作用。方法制备以聚乳酸-羟基乙酸(PLGA)为外壳,配比全氟化碳(PFC)为核心的相变纳米液滴(PTN),探究一种基于热致相变的相变机制——微波致液滴汽化(MWDV)。通过扫描电子显微镜、动态光散射仪、体外溶血实验及CCK-8实验监测PTN的基本理化性质及生物学特性。构建体外凝胶孔洞模型监测PTN的相变;通过活死荧光实验、流式分析及细胞活性实验评估MWDV介导后相变PTN增效微波消融疗效的作用。结果当全氟戊烷和全氟己烷按3∶2配比构成全氟化碳核心时,PTN的相变温度恰为微波消融的边界温度(60℃)。进一步体外和细胞实验发现,该配比PTN不仅具备较好的稳定性和生物安全性,而且能够在MWDV介导下发生相变,增强二维超声成像和提高微波消融疗效。结论MWDV可以作为氟碳纳米材料的一种相变机制,其为肿瘤消融治疗提供了新的增效策略。

Objective To explore the mechanism of phase-transition fluorocarbon nanomaterials and evaluate its synergistic efficacy on microwave ablation(MWA).Methods A novel phase transition nanodroplet(PTN)was designed with poly(lactic-co-glycolic acid)(PLGA)as the shell and perfluorocarbon(PFC)mixture as the core.Based on that,a phase-transition mechanism of microwave droplet vaporization(MWDV)was explored,which was based on the thermal phased transition.The basic physicochemical properties and biological characteristics of PTN were monitored by scanning electron microscope(SEM),dynamic laser light scattering(DLS),in vitro hemolysis and CCK-8 experiment.Based on the gel-hole model experiment in vitro,the phase transition of PTN were monitored;based on the live/dead cell double staining kit,flow cytometry and cytotoxicity test,the synergistic efficacy of phase-transition PTN on microwave ablation,which was mediated by MWDV was evaluated.Results The phase-transition temperature of PTN was exactly the boundary temperature of microwave ablation(60℃)when the ratio between perfluoropentane(PFP)and perfluorohexane(PFH)in the core of PTN was 3∶2.Furthermore,the smart proportional PTN didn′t only have good stability and biocompatibility,but also could enhance the two-dimensional ultrasonic imaging and increase the efficacy of MWA under the mediation of MWDV.Conclusions MWDV can be treated as a phase-transition mechanism of fluorocarbon nanomaterials,which provides a potential synergistic strategy for the thermal ablation of tumors.