Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9110, USA.
J Endourol. 2010 Dec;24(12):1903-8. doi: 10.1089/end.2010.0110. Epub 2010 Sep 21.
The objective of this study was to demonstrate the feasibility of quantum dot (QD)-mediated fluorescence thermometry to monitor thermal dose in an in-vitro thermal ablation zone generated by laser-heated gold nanoshells (LGNS).
Hyperthermic cell death of human prostate cancer cell line (PC-3) was determined after various heating settings and correlated to the thermal conditions using an Arrhenius model prior to LGNS ablation. PC-3 cells with gold nanoshells (GNS) and QDs were exposed to a near-infrared laser and QD excitation light. When the cells were heated by GNS, local temperature was measured using the temperature-dependent fluorescence intensity of QDs. Using the predetermined Arrhenius model, the thermal dose (i.e., cell death of PC-3 cells) by LGNS was estimated with local temperatures measured with QD-mediated thermometry. The estimated thermal dose was confirmed with calcein-acetoxy-methylester viability assay.
For PC-3 cell line, the activation energy and frequency factor of the Arrhenius model were 86.78 kcal/mol and 6.35 × 10(55) Hz, respectively. During LGNS ablation of PC-3 cells, QD-mediated temperature measurement showed that the temperature of the laser spot increased rapidly to ∼58 °C ± 4 °C. The estimated thermal dose showed that cell death reached to ∼90% in 120 seconds. The death cell zone observed after staining corresponded to a peak area of the temperature profile generated after analysis of the QD fluorescence intensity.
This study shows that the QD fluorescence thermometry can accurately monitor the PC-3 cell death by LGNS ablation. This approach holds promises for a better monitoring of thermal ablation procedures in clinical practice.
本研究旨在展示利用量子点（QD）介导的荧光测温法监测激光加热金壳纳米球（LGNS）产生的体外热消融区热剂量的可行性。
在进行 LGNS 消融之前，通过 Arrhenius 模型确定不同加热条件下人类前列腺癌细胞系（PC-3）的过热细胞死亡，并将其与热条件相关联。用近红外激光和 QD 激发光照射载金纳米壳（GNS）和 QD 的 PC-3 细胞。当 GNS 加热细胞时，使用 QD 荧光强度与温度相关的特性来测量局部温度。利用预先确定的 Arrhenius 模型，通过 QD 介导的测温法测量的局部温度来估计 LGNS 的热剂量（即 PC-3 细胞的死亡）。用 calcein-acetoxy-methylester 活力测定法验证估计的热剂量。
对于 PC-3 细胞系，Arrhenius 模型的活化能和频率因子分别为 86.78 kcal/mol 和 6.35×10(55) Hz。在 LGNS 消融 PC-3 细胞期间，QD 介导的温度测量显示激光点的温度迅速升高至约 58°C±4°C。估计的热剂量显示，细胞死亡在 120 秒内达到约 90%。染色后观察到的死亡细胞区与分析 QD 荧光强度后生成的温度曲线的峰值区域相对应。
本研究表明，QD 荧光测温法可准确监测 LGNS 消融导致的 PC-3 细胞死亡。这种方法有望更好地监测临床实践中的热消融程序。
