Nanomed. J. 6(3):207-213, Summer 2019 RESEARCH PAPER Application of near-infrared light intensity to determine normal and cancerous breast vessel contrast by gold nanoparticles Parinaz Mehnati 1 , Bahman Alipour 2* , Roya Salehi 3 1 Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran 2 Medical Radiation Sciences Research Team, Tabriz University of Medical Sciences, Tabriz, Iran 3 Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran * Corresponding Author Email: bahmanalipour69@gmail.com Note. Tis manuscript was submitted on December 10, 2018; approved on April 5, 2019 How to cite this article Mehnati P, Alipour B, Salehi R. Application of near-infrared light intensity to determine normal and cancerous breast vessel contrast by gold nanoparticles. Nanomed J. 2019; 6(3):207-213.DOI: 10.22038/nmj.2019.06.00007 ABSTRACT Objective(s): A novel technique for the early diagnosis of breast cancer involves the use of nanoparticles (NPs). Te present study aimed to use gold NPs to assess the variations in light source transfer intensity. Materials and Methods: Blood samples with hemoglobin (Hb) concentrations of ×1, ×2, and ×4 were used to simulate normal and cancerous conditions in the breast. Spherical gold NPs (SGNPs) and gold nanorods (GNRs) with various Hb concentrations were injected into the breast phantom, and the intensity of the light transmitted on the wavelength of 635 nanometers was measured. Transmission electron microscopy (TEM) images revealed that SGNPs and GNRs were prepared with a uniform particle shape. Results: When the SGNPs were blended with the Hb concentrations of ×1, ×2, and ×4, the intensity of the passing light from the vessel was estimated to be 3.62, 2.40, and 1.64 mw, respectively. When GNRs were blended with the Hb concentrations of ×1, ×2, and ×4, the intensity changed to lower values 3.42, 2.13, and 1.98 mw, respectively. Conclusion: According to the results, SGNPs and GNRs in normal and cancerous breast induced various passing intensities of Hb concentrations. In addition, the vascular contrast induced by GNRs was higher compared to SGNPs. Keywords: Breast cancer, Hemoglobin, Rod-shaped gold nanoparticles Spherical gold nanoparticles, Simulation INTRODUCTION Breast cancer is a widespread cancer in women, which is only second to skin cancer. It could be developed in both men and women although the incidence is rather unusual in men. Breast cancer is associated with a high mortality rate among women each year [1]. Evidently, the early diagnosis and treatment of breast cancer could reduce the mortality rate by 95% in patents [2]. Various methods are available for the diagnosis of breast tumors, such as magnetc resonance imaging (MRI), ultrasound (US), computed tomography (CT), conventonal mammography, and optcal mammography, each of which has its own limitatons. CT and mammography involve the use of ionizing radiaton and have limited resoluton [3, 4]. Moreover, the sensitvity of some of these systems is a functon of age. For instance, mammography has reached its highest sensitvity in the women aged 50 years and is not recommended for those aged less than 40 years [5]. Use of light in optcal mammography, especially if the source is near-infrared (NIR), has non-ionizing propertes, low costs, and the ability to show the variatons in the hemoglobin (Hb) concentraton. Therefore, it could be inferred that using methods with high accuracy and reliability for the early detecton of breast cancer remains a signifcant challenge in medicine. Tumor tssues could absorb nutrients and oxygen through transpiraton up to the distance of 70-150 micrometers [6]. Tumor growth necessitates the tumor to develop a new vascular network. Consequently, tumor detecton in the vascularizaton stage should be as early as possible in order to be able to control the tumor growth and even to treat it [7]. It has been well established that tumor tssues have elevated Hb content compared to normal