Division of Surgical Oncology, Department of Surgery, College of Medicine, Gainesville, FL, USA.
Int J Nanomedicine. 2012;7:351-7. doi: 10.2147/IJN.S26468. Epub 2012 Jan 20.
Photothermal therapy is an emerging cancer treatment paradigm which involves highly localized heating and killing of tumor cells, due to the presence of nanomaterials that can strongly absorb near-infrared (NIR) light. In addition to having deep penetration depths in tissue, NIR light is innocuous to normal cells. Little is known currently about the fate of nanomaterials post photothermal ablation and the implications thereof. The purpose of this investigation was to define the intratumoral fate of nanoparticles (NPs) after photothermal therapy in vivo and characterize the use of novel multidye theranostic NPs (MDT-NPs) for fractionated photothermal antitumor therapy.
The photothermal and fluorescent properties of MDT-NPs were first characterized. To investigate the fate of nanomaterials following photothermal ablation in vivo, novel MDT-NPs and a murine mammary tumor model were used. Intratumoral injection of MDT-NPs and real-time fluorescence imaging before and after fractionated photothermal therapy was performed to study the intratumoral fate of MDT-NPs. Gross tumor and histological changes were made comparing MDT-NP treated and control tumor-bearing mice.
The dual dye-loaded mesoporous NPs (ie, MDT-NPs; circa 100 nm) retained both their NIR absorbing and NIR fluorescent capabilities after photoactivation. In vivo MDT-NPs remained localized in the intratumoral position after photothermal ablation. With fractionated photothermal therapy, there was significant treatment effect observed macroscopically (P = 0.026) in experimental tumor-bearing mice compared to control treated tumor-bearing mice.
Fractionated photothermal therapy for cancer represents a new therapeutic paradigm enabled by the application of novel functional nanomaterials. MDT-NPs may advance clinical treatment of cancer by enabling fractionated real-time image guided photothermal therapy.
光热疗法是一种新兴的癌症治疗方法，它涉及到由于纳米材料的存在而导致的肿瘤细胞的高度局部加热和杀伤，这些纳米材料可以强烈吸收近红外（NIR）光。除了在组织中有较深的穿透深度外，NIR 光对正常细胞是无害的。目前对于光热消融后纳米材料的命运及其影响知之甚少。本研究的目的是确定体内光热治疗后纳米颗粒（NPs）在肿瘤内的命运，并表征新型多染料治疗性 NPs（MDT-NPs）在分割光热抗肿瘤治疗中的应用。
首先对 MDT-NPs 的光热和荧光特性进行了表征。为了研究体内光热消融后纳米材料的命运，使用了新型 MDT-NPs 和一种鼠乳腺肿瘤模型。在分割光热治疗前后，通过肿瘤内注射 MDT-NPs 并进行实时荧光成像，研究 MDT-NPs 在肿瘤内的命运。对 MDT-NP 治疗和对照肿瘤荷瘤小鼠的大体肿瘤和组织学变化进行了比较。
负载双染料的介孔 NPs（即 MDT-NPs；约 100nm）在光激活后保留了其近红外吸收和近红外荧光能力。体内 MDT-NPs 在光热消融后仍保留在肿瘤内位置。与对照治疗的肿瘤荷瘤小鼠相比，分割光热治疗的实验性肿瘤荷瘤小鼠在宏观上观察到显著的治疗效果（P=0.026）。
新型功能纳米材料的应用为癌症的分割光热治疗代表了一种新的治疗范例。MDT-NPs 通过实现分割实时图像引导光热治疗，可能推进癌症的临床治疗。
