Computer Methods and Programs in Biomedicine 172 (2019) 79–85 Contents lists available at ScienceDirect Computer Methods and Programs in Biomedicine journal homepage: www.elsevier.com/locate/cmpb Development of a new theoretical model for blood-CNTs effective thermal conductivity pertaining to hyperthermia therapy of glioblastoma multiform L. Benos a , L.A. Spyrou a , I.E. Sarris b,∗ a Biomechanics Group, Institute for Bio-Economy and Agri-Technology, Centre for Research and Technology Hellas (CERTH), 38333 Volos, Greece b Department of Mechanical Engineering, University of West Attica, 12210 Athens, Greece a r t i c l e i n f o Article history: Received 7 January 2019 Accepted 12 February 2019 Keywords: Hyperthermia Glioblastoma Thermal conductivity Blood cells CNTs a b s t r a c t Background and objective: The present study deals with the hyperthermia therapy, which is the type of treatment in which tissues are exposed to high temperatures in order to destroy cancer cells with minimal injury to healthy tissues. In particular, it focuses on glioblastoma multiform, which is the most aggressive cancer that begins within the brain. Conventional treatments display limitations that can be overcome by using nanoparticles for targeted heating. Out of the proposed nanoparticles, this investiga- tion focuses on a new field that utilizes carbon nanotubes (CNTs) which are able to selectively heat the cancer cells since they can convert near infrared light into heat. In the absence of any experiment or the- oretical model for the estimation of an effective thermal conductivity of blood and CNTs, a first principle model is developed in this study which takes into account the blood micro-structure. Besides, a number of factors are included, namely the shape and the size of the nanoparticles, the interfacial layer formed around them and their volume fraction. Methods: Firstly, assuming that the blood consists of blood cells and plasma, the thermal conductivity of the former is estimated. Then, the effective thermal conductivity of plasma/CNTs is calculated for various parameters. Finally, the resulting “bio-nanofluid” consisting of plasma/CNTs and blood cells is formed. Results: It is ascertained that thin and elongated CNTs with relatively large nanolayer thickness as well as large concentrations of CNTs contribute to the increase of the thermal conductivity and, thus, in the enhancement of the heat transfer. Conclusions: Investigating of how design parameters pertaining to CNTs, such as their size and shape, affect the effective thermal conductivity of blood-CNTs, possible regulating ways are suggested regarding the hyperthermic treatment. Finally, the present simple estimation of the effective thermal conductivity can be used as an effective property of the nanofluid when it comes to numerical investigations regarding heat transfer occurring during hyperthermia or other potential clinical uses (for example targeted heat of living tissues). © 2019 Elsevier B.V. All rights reserved. 1. Introduction Given the global burden of cancer worldwide, which is esti- mated to be 9.6 million cancer deaths in 2018 [1], the need for novel methods for cancer treatment has been increased more than ever. Out of the several kinds of cancer, glioblastoma multiforme (GBM) is considered to be the most malignant cancer with median survival being less than 15 months [2]. The treatment of GBM is extremely difficult owing to the limited capacity of the brain to ∗ Corresponding author. E-mail address: sarris@uniwa.gr (I.E. Sarris). repair itself and GBM nature of being both invasive and resistant to therapies [3]. The conventional treatments include surgery as well as chemotherapy and radiation, which use drugs and high doses of ra- diation, respectively, to kill cancer cells and shrink tumors. Surgery tries to improve the quality of patient‘s life and prolong its sur- vival while the objectives contain the confirmation of the diag- nosis or the elevation of symptoms. Radiotherapy, which is the most common treatment, is based on electrons and free radicals via ionizing radiation to destroy DNA [4]. Finally, chemotherapy uses mainly temozolomide as a drug, which displays cytotoxic ef- fects via methylation of specific DNA sites, with bevacizumab being an adjuvant therapy pertaining to GBM via acting as angiogenesis https://doi.org/10.1016/j.cmpb.2019.02.008 0169-2607/© 2019 Elsevier B.V. All rights reserved.