近红外荧光靶向探针用于前列腺神经血管束术中成像

Near-infrared targeted probe designed for intraoperative imaging of prostatic neurovascular bundles

目的:研究近红外荧光靶向探针ICG-NP41在大鼠体内实验中对前列腺周围神经血管束(neurovascular bundles,NVB)的成像效果。方法:构建近红外荧光靶向探针ICG-NP41,建立Sprague-Dawley大鼠(250~400 g)NVB体内成像的动物模型,利用本团队自主研发的近红外二区小动物活体成像系统进行大鼠体内试验,采用ImageJ及Origin对采集的图像进行处理,利用GraphPad Prism对荧光信号数据进行统计分析,定量计算探针用于NVB成像的信背比(signal to background ratio,SBR),探索有效的给药剂量及成像时间,并对成像结构进行石蜡病理切片及HE染色。结果:除对照组大鼠(n=2)外,两组尾静脉注射ICG-NP41的大鼠(n=2)均在给药后2 h、4 h后于NIR-Ⅱ荧光模式下拍摄到右侧NVB中的海绵体神经。给药后2 h和4 h,2 mg/kg组大鼠的海绵体神经在荧光模式下的平均SBR分别为1.651±0.142和1.619±0.110,均高于白光模式(1.111±0.036),但差异无统计学意义(P>0.05);4 mg/kg组大鼠的海绵体神经在荧光模式下的平均SBR分别为1.168±0.066和1.219±0.118,均高于白光模式(1.081±0.040),但差异无统计学意义(P>0.05)。给药后2 h和4 h,2 mg/kg和4 mg/kg组大鼠的海绵体神经在荧光模式下的平均SBR均高于对照组(SBR=1),2 mg/kg组的平均SBR均高于4 mg/kg组,差异均无统计学意义(P>0.05)。通过半高宽法测量神经的平均直径约为(178±15)μm。石蜡切片HE染色可见右侧盆腔大神经节。结论:近红外荧光靶向探针ICG-NP41能够用于大鼠前列腺周围NVB的术中实时成像,为根治性前列腺切除术中实时定位NVB提供了一种可供转化的有效手段。

Objective:To investigate the imaging effect of a near-infrared fluorescent targeted probe ICG-NP41 on the neurovascular bundles(NVB)around the prostate in rats.Methods:A near-infrared fluorescent targeted probe ICG-NP41 was synthesized.An animal model for NVB imaging was established using Sprague-Dawley rats(250-400 g).Experiments were conducted using a custom-built near-infrared windowⅡ(NIR-Ⅱ)small animal in vivo imaging system,and images collected were processed using ImageJ and Origin.The fluorescence signal data were statistically analyzed using GraphPad Prism.The signal-to-background ratio(SBR)for NVB was quantitatively calculated to explore the effective dosage and imaging time points.Finally,paraffin pathology sections and HE staining were performed on the imaging structures.Results:Except for rats in the control group(n=2),right-sided NVB of the rats injected with ICG-NP41(n=2 per group)were all observed in NIR-Ⅱfluorescence mode 2 h and 4 h after administration.At 2 h and 4 h,average SBR of cavernous nerve in 2 mg/kg group in fluorescence mode was 1.651±0.142 and 1.619±0.110,respectively,both higher than that in white light mode(1.111±0.036),with no significant difference(P>0.05);average SBR of 4 mg/kg group in fluorescence mode were 1.168±0.066 and 1.219±0.118,respectively,both higher than that in white light mode(1.081±0.040),with no significant difference(P>0.05).At 2 h and 4 h,the average SBR of 2 mg/kg and 4 mg/kg groups in fluorescence mode were higher than that of the control group(SBR=1),the average SBR of the 2 mg/kg group was higher than that of the 4 mg/kg group,and all the above with no significant difference(P>0.05).The average diameter of the nerve measured by full width at half maxima method was about(178±15)μm.HE staining of paraffin sections showed the right major pelvic ganglion.Conclusion:The near-infrared fluorescent targeted probe ICG-NP41 can be used for real-time imaging of the NVB around the prostate in rats,providing a potential feasible solution for localizing NVB in real time during nerve-sparing radical prostatectomy.