微泡辅助低频超声联合不同表面结构的纳米颗粒治疗前列腺癌原位瘤的增效作用

Synergistic effect of microbubble-assisted low-frequency ultrasound(MAUS)combined with optimizing the nanoparticle structure on the treatment of prostate cancer

目的针对目前有效提高纳米颗粒在肿瘤内富集的研究较少,文中旨在探讨微泡辅助低频超声(MAUS)联合纳米颗粒表面结构的优化对纳米颗粒在前列腺癌原位瘤内富集和抗前列腺癌治疗的增效作用。方法制备表面修饰IR825的二氧化硅包裹内部磁性Fe_(3)O_(4)的特殊核壳结构纳米颗粒,并进行性质评价。通过溶血实验、主要器官的HE染色评价纳米颗粒的体内安全性。将小鼠随机分为6组:MSSN-IR825组(仅尾静脉注射MSSN-IR825)、MSSN-IR825+MAUS组(尾静脉注射MSSN-IR825,同时采用MAUS递送)、MMSN-IR825组(仅尾静脉注射MMSN-IR825)、MMSN-IR825+MAUS组(尾静脉注射MMSN-IR825,同时采用MAUS递送)、MVSN-IR825组(仅尾静脉注射MVSN-IR825)、MVSN-IR825+MAUS组(尾静脉注射MVSN-IR825,同时采用MAUS递送)。每组5只,尾静脉前及给药后20 h监测采集肿瘤光声信号。将小鼠随机分为对照组(单纯尾静脉注射相同体积的等渗盐水)和激光辐照组(尾静脉注射MVSN-IR825,同时采用MAUS递送,注射20 h后开始近红外激光辐照原位肿瘤治疗),通过超声监测激光辐照后荷瘤小鼠的肿瘤大小、肿瘤组织HE染色、Ki67染色及活性氧染色评价抑瘤效果。结果合成了粒径相仿、生物相容性较好的光滑、介孔、仿病毒表面的纳米颗粒。HE染色及溶血性实验表明纳米颗粒具有较好的生物安全性。光声成像显示MVSN-IR825瘤内富集的光声信号明显多于MSSN-IR825和MMSN-IR825;当联合使用MAUS后,瘤内光声信号显著增强。超声监测激光辐照后的原位瘤大小所示,对照组原位瘤10 d后体积显著增加,激光辐照组的原位瘤大小得到明显抑制。与对照组相比,MVSN-IR825+MAUS组DHE染色可见明显活性氧产生的红色荧光。HE染色可见肿瘤细胞部分破坏、Ki67染色表达相对降低。结论联合使用MAUS及仿病毒结构优化可提高纳米颗粒在前列腺原位瘤的摄取,近红外激光辐照后可通过光热及光动力效果抑制PC-3前列腺癌原位瘤。

Objective Currently,there are few studies on effectively enhancing the enrichment of nanoparticles in tumors.To explore combination of optimizing the nanoparticle structure and using microbubble-assisted low-frequency ultrasound(MAUS)for enhanced intratumor accumulation of nanoparticles and improved treatment of prostate cancer.Methods Special core-shell structure nanoparticles with inner magnetic Fe_(3)O_(4) coated with silica modified IR825 were prepared and their properties were evaluated.The in-vivo safety of nanoparticles was evaluated by hemolysis test and HE staining of major organs.The mice were randomly divided into 6 groups with 5 mice in each:MSSN IR825(intravenous injection of MSSN IR825),MSSN IR825+MAUS group(intravenous injection of MSSN IR825,and MAUS delivery),MMSN IR825 group(intravenous injection of MMSN IR825),MMSN IR825+MAUS group(intravenous injection of MMSN IR825,and MAUS delivery),MVSN IR825 group(intravenous injection of MVSN IR825),MVSN IR825+MAUS group(intravenous injection of MVSN IR825,and MAUS delivery).Tumor photoacoustic signals were monitored and collected before intravenous injection and 20h after.The mice were randomly divided into control group(only injected with the same volume of isotonic saline)and laser irradiation group(injected with MVSN-IR825 and MAUS ddivery treatment of cancer in-situ with laser irradiation after 20h injection).The tumor size,HE staining,Ki67 staining and reactive oxygen species staining of tumor bearing mice irradiated by near infrared laser were monitored by ultrasound to evaluate the tumor suppressive effect.Results In this study,smooth,mesoporous,virus-like nanoparticles with similar size and good biocompatibility were synthesized.HE staining and hemolytic test showed that the nanoparticles had good biosafety.Photoacoustic imaging showed that the accumulation of photoacoustic signal in MVSN IR825 was significantly higher than that in MSSN IR825 and MMSN IR825.When combined with MAUS,the intratumor photoacoustic signal was significantly enhanced.Ultrasound monitoring of the size of in-situ tumors after laser irradiation showed that the volume of in-situ tumors in the control group increased significantly after 10 days,while the size of in-situ tumors in the laser irradiation group was significantly inhibited.Compared with the control group,DHE staining of MVSN IR825+MAUS group showed obvious red fluorescence generated by reactive oxygen species.HE staining showed partial destruction of tumor cells and relatively decreased expression of Ki67 staining.Conclusion Combined use of MAUS and virus-like structure optimization can improve the uptake of nanoparticles in-situ tumor of prostate,and near-infrared laser irradiation can inhibit in-situ tumor of PC3 prostate cancer by photothermal and photodynamic effect.