Salloum Maher, Ma Ronghui, Zhu Liang
Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA.
Int J Hyperthermia. 2008 Nov;24(7):589-601. doi: 10.1080/02656730802203377.
In magnetic nanoparticle hyperthermia in cancer treatment, the local blood perfusion rate and the amount of nanofluid delivered to the target region are important factors determining the temperature distribution in tissue. In this study, we evaluate the effects of these factors on the heating pattern and temperature elevations in the muscle tissue of rat hind limbs induced by intramuscular injections of magnetic nanoparticles during in vivo experiments. Temperature distribution in the vicinity of the injection site is measured inside the rat limb after the nanoparticle hyperthermia. The measured temperature elevations at the injection site are 3.5 degrees +/- 1.8 degrees C and 6.02 degrees +/- 0.8 degrees C above the measured body temperature, when the injection amount is 0.1 cc and 0.2 cc, respectively. The full width of half maximum (FWHM) of the temperature elevation, an index of heat transfer in the radial direction from the injection site is found to be approximately 31 mm for both injection amounts. The temperature measurements, together with the measured blood perfusion rate, ambient air temperature, and limb geometry, are used as inputs into an inverse heat transfer analysis for evaluation of the specific absorption rate (SAR) by the nanoparticles. It has been shown that the nanoparticles are more concentrated in the vicinity of the injection site when the injection amount is bigger. The current in vivo experimental studies have demonstrated the feasibility of elevating the tissue temperature above 43 degrees C under the experimental protocol and equipment used in this study.
在癌症治疗的磁性纳米颗粒热疗中，局部血液灌注率和输送到靶区的纳米流体数量是决定组织中温度分布的重要因素。在本研究中，我们在体内实验期间评估了这些因素对大鼠后肢肌肉组织中由肌内注射磁性纳米颗粒诱导的加热模式和温度升高的影响。在纳米颗粒热疗后，在大鼠肢体内部测量注射部位附近的温度分布。当注射量分别为0.1 cc和0.2 cc时，在注射部位测得的温度升高分别比测得的体温高3.5摄氏度±1.8摄氏度和6.02摄氏度±0.8摄氏度。温度升高的半高宽（FWHM），即从注射部位沿径向传热的指标，对于两种注射量均约为31毫米。温度测量结果与测得的血液灌注率、环境空气温度和肢体几何形状一起用作反向传热分析的输入，以评估纳米颗粒的比吸收率（SAR）。结果表明，当注射量较大时，纳米颗粒在注射部位附近更集中。当前的体内实验研究已经证明，在本研究中使用的实验方案和设备下，将组织温度升高到43摄氏度以上是可行的。
