We have used two different kinds of commercial GNRs in order to compare their photothermal transduction efficiency. Both are tuned to the laser source and have their maximum surface plasmon resonance (SPR) at 808 nm (longitudinal band). The first commercial GNRs used are bare GNRs (B-GNRs) MNK inhibitor A12-10-808-100 Nanorodz (Nanopartz, Salt Lake City, UT, USA). B-GNRs are dispersed in deionized water (DI-H2O) with <0.1% ascorbic acid and <0.1% cetyltrimethylammonium bromide (CTAB) surfactant

capping agent. B-GNRs have an axial diameter of 10 nm and a length of 41 nm. The other commercial GNRs used are PEGylated GNRs (PEG-GNRs) PEG-10-808-50 (Nanoseedz, China). PEG-GNRs are functionalized by thiol-terminated methoxypoly(ethylene glycol) (mPEG-PH) and are also dispersed in DI-H2O. The

dimensions of PEG-GNRs are equal to the dimensions of B-GNRs (axial diameter = 10 nm, length = 41 nm). The laser is connected to the system via Selleckchem BI 10773 a multimode optical fiber with a core diameter of 600 μm, a length of 1.5 m, and a power transmission of 90% to 99% (600-μm MM fiber, Changchun New Industries, China). The laser light from AG-881 supplier the fiber irradiates the samples through a collimation lens (78382, Newport Corporation, Irvine, CA, USA), which is in direct contact with a 4-well plate containing the samples, which have a total volume of 500 μl, and is located on a Teflon support. A temperature sensor (F100 Precision Thermometer, Automatic Systems Laboratories, Redhill, UK) is fixed vertically with the aid of a tripod stand and

a burette clamp and remains in contact with the samples during the experiments (Figure 1). Figure 1 Experimental setup: complete view (A), fiber-lens connection details (B), and sample and temperature these sensor details (C). Thermal parameters In order to determine the parameters that characterize and describe the thermal behavior of our hyperthermia device, it is needed to develop a thermal model, which can be raised from the resolution of an equivalent electric circuit (Figure 2). Figure 2 Electrical equivalent circuit used to obtain the thermal parameters of the optical hyperthermia device. In this circuit, P is the delivered power, T(t) is the sample temperature which is time dependent, and C d (W/K) and C t (J/K) are the thermal conductance and the thermal capacitance of our experimental enclosure, respectively. Solving the circuit, we can formulate the equation that describes the power distribution, obtaining that the delivered power (P) is equal to the sum of the stored power in the capacitor (P s) and the dissipated power in the resistor (P d): (1) In this equation, T ref – m is the reference temperature (the subscript m refers to the thermal model), that is to say, the initial temperature of our sample before the laser irradiation that should match the environment temperature.