Visualization and Quantification of Gold Nanorods Distribution in Prostatic Tumors Using MicroCT Imaging

One uncertainty in use of gold nanorods for laser photothermal therapy is the non-uniform spreading of gold nanorods in tissue after either systemic delivery or intratumoral injections. High concentration of gold nanorods in certain areas influences the resulted optical absorption of the laser and thermal damage to tumors. This also provides challenges in designing optimal heating protocols via modeling thermal transport in laser photothermal therapy. For successful cancer treatment, the tissue should be heated with minimum thermal dosage to induce tumor cell damage, while minimizing overheating in the surrounding healthy tissues. Thus, one of the main challenges for reliable cancer therapy is to precisely control loading and distribution of gold nanorods in the tumour tissue. The critical mass transport processes are the distribution of gold nanorods after injection to the tumor and the redistribution of gold nanorods during laser treatment. Since tumors are opaque, nanostructure distribution in tissue is often studied either by theoretical modeling approaches1, or via dye enhanced imaging on superficial layers of tumors.2 It is important to find a technique which can directly visualize and analyze three-dimensional nanostructure distribution of tumors. Three-dimensional reconstructions of tumors with the ability to trace gold nanorod spreading have the potential for precise theoretical simulation of temperature fields. Previous studies showed that computer tomography (CT) scan is a promising technique to be utilized to characterize the distribution of intratumorally injected magnetic nanoparticles in tumors 3.

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Three-dimensional dynamics of temperature fields in phantoms and biotissue under IR laser photothermal therapy using gold nanoparticles and ICG dye

10.1117/12.848554 ◽

2010 ◽

Author(s):

Georgy G. Akchurin ◽

Akchurin G. Garif ◽

Irina L. Maksimova ◽

Alexander A. Skaptsov ◽

Georgy S. Terentyuk ◽

...

Keyword(s):

Gold Nanoparticles ◽

Photothermal Therapy ◽

Three Dimensional ◽

Temperature Fields ◽

Ir Laser ◽

Laser Photothermal Therapy

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Computational Simulation of Temperature Elevations in Tumors Using Monte Carlo Method and Comparison to Experimental Measurements in Laser Photothermal Therapy

Journal of Biomechanical Engineering ◽

10.1115/1.4025388 ◽

2013 ◽

Vol 135 (12) ◽

Cited By ~ 16

Author(s):

Navid Manuchehrabadi ◽

Yonghui Chen ◽

Alexander LeBrun ◽

Ronghui Ma ◽

Liang Zhu

Keyword(s):

Monte Carlo ◽

Optical Properties ◽

Gold Nanorods ◽

Photothermal Therapy ◽

Energy Deposition ◽

Thermal Damage ◽

Laser Energy ◽

Simulated Temperature ◽

Laser Energy Absorption ◽

Laser Photothermal Therapy

Accurate simulation of temperature distribution in tumors induced by gold nanorods during laser photothermal therapy relies on precise measurements of thermal, optical, and physiological properties of the tumor with or without nanorods present. In this study, a computational Monte Carlo simulation algorithm is developed to simulate photon propagation in a spherical tumor to calculate laser energy absorption in the tumor and examine the effects of the absorption (μa) and scattering (μs) coefficients of tumors on the generated heating pattern in the tumor. The laser-generated energy deposition distribution is then incorporated into a 3D finite-element model of prostatic tumors embedded in a mouse body to simulate temperature elevations during laser photothermal therapy using gold nanorods. The simulated temperature elevations are compared with measured temperatures in PC3 prostatic tumors in our previous in vivo experimental studies to extract the optical properties of PC3 tumors containing different concentrations of gold nanorods. It has been shown that the total laser energy deposited in the tumor is dominated by μa, while both μa and μs shift the distribution of the energy deposition in the tumor. Three sets of μa and μs are extracted, representing the corresponding optical properties of PC3 tumors containing different concentrations of nanorods to laser irradiance at 808 nm wavelength. With the injection of 0.1 cc of a 250 optical density (OD) nanorod solution, the total laser energy absorption rate is increased by 30% from the case of injecting 0.1 cc of a 50 OD nanorod solution, and by 125% from the control case without nanorod injection. Based on the simulated temperature elevations in the tumor, it is likely that after heating for 15 min, permanent thermal damage occurs in the tumor injected with the 250 OD nanorod solution, while thermal damage to the control tumor and the one injected with the 50 OD nanorod solution may be incomplete.

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Theoretical Simulation of Temperature Elevations in Tumors Using Monte Carlo Method and Comparison to Experimental Measurements During Laser Photothermal Therapy

Volume 1A: Abdominal Aortic Aneurysms; Active and Reactive Soft Matter; Atherosclerosis; BioFluid Mechanics; Education; Biotransport Phenomena; Bone, Joint and Spine Mechanics; Brain Injury; Cardiac Mechanics; Cardiovascular Devices, Fluids and Imaging; Cartilage and Disc Mechanics; Cell and Tissue Engineering; Cerebral Aneurysms; Computational Biofluid Dynamics; Device Design, Human Dynamics, and Rehabilitation; Drug Delivery and Disease Treatment; Engineered Cellular Environments ◽

10.1115/sbc2013-14330 ◽

2013 ◽

Author(s):

Navid Manuchehrabadi ◽

Yonghui Chen ◽

Alexander LeBrun ◽

Ronghui Ma ◽

Liang Zhu

Keyword(s):

Monte Carlo ◽

Monte Carlo Method ◽

Gold Nanorods ◽

Photothermal Therapy ◽

Treatment Protocol ◽

Gold Nanorod ◽

Theoretical Simulation ◽

The Past ◽

Geometric Ratio ◽

Laser Photothermal Therapy

Nanotechnology using gold nanoshells or nanorods is a newly developed hyperthermia approach and has been tested in the past several years in cancer treatment.1–2 Gold nanorods have a diameter of ∼10 nm and an aspect ratio of approximately four. By varying the geometric ratio, the nanostructures can be tuned to have strong absorption and scattering to a specific laser wavelength. Designing an optimal treatment protocol of laser photothermal therapy requires understanding of gold nanorod deposition inside the tumor after injection, its resulted specific absorption rate (SAR) distribution, and the ultimate temperature field in the tumor during the treatment. Recent microCT studies by our group have suggested that the gold nanorod solution injected into PC3 prostatic tumors results in an almost uniform distribution of the gold nanorods in the tumors.3 The Monte Carlo method has been used in the past to determine the heating pattern (SAR) of laser-tissue thermal interaction.4 However, the accuracy of the theoretical simulation of the temperature fields in tumors relies on precise measurements of the optical properties of the tumors with nanorods presence.

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Treatment efficacy of laser photothermal therapy using gold nanorods

International Journal of Biomedical Engineering and Technology ◽

10.1504/ijbet.2013.056508 ◽

2013 ◽

Vol 12 (2) ◽

pp. 157 ◽

Cited By ~ 9

Author(s):

Navid Manuchehrabadi ◽

Raheleh Toughiri ◽

Charles Bieberich ◽

Hong Cai ◽

Anilchandra Attaluri ◽

...

Keyword(s):

Gold Nanorods ◽

Treatment Efficacy ◽

Photothermal Therapy ◽

Laser Photothermal Therapy

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Treatment Efficacy of Laser Photothermal Therapy Using Gold Nanorods: Tumor Shrinkage Study

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80625 ◽

2012 ◽

Cited By ~ 1

Author(s):

N. Manuchehrabadi ◽

R. Toughiri ◽

H. Cai ◽

L. Zhu ◽

A. Attaluri ◽

...

Keyword(s):

Gold Nanorods ◽

Photothermal Therapy ◽

Laser Energy ◽

Experimental Studies ◽

Laser Wavelength ◽

Measured Temperature ◽

Laser Irradiance ◽

Tumor Shrinkage ◽

Wide Range ◽

Laser Photothermal Therapy

Gold nanorods can be tuned to a specific laser wavelength and serve as strong laser energy absorbers. Due to the powerful optical absorption, the laser energy is concentrated in an area congregating by nanorods, and then the energy absorbed can be transferred to the surrounding tumor tissue by heat conduction.1–4 Previous studies have shown a wide range of heating parameters with or without temperature measurements. Our previous experiment4 has demonstrated that using only 0.1 cc gold nanorod solution can lead to tumor temperature higher than 50°C when the laser irradiance is only 2 W/cm2. Based on the measured temperature elevation and heating duration, thermal damage to the tumor is highly likely. However, some researchers raised the question whether temperature sensors used in those experimental studies are truly reflecting the temperatures in the tumors. The objective of this study is to measure quantitatively tumor shrinkage after laser irradiation to evaluate efficacy of laser photothermal therapy.

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MicroCT Imaging and In Vivo Temperature Elevations in Implanted Prostatic Tumors in Laser Photothermal Therapy Using Gold Nanorods

Journal of Nanotechnology in Engineering and Medicine ◽

10.1115/1.4007161 ◽

2012 ◽

Vol 3 (2) ◽

Cited By ~ 4

Author(s):

N. Manuchehrabadi ◽

A. Attaluri ◽

H. Cai ◽

R. Edziah ◽

E. Lalanne ◽

...

Keyword(s):

Gold Nanorods ◽

Photothermal Therapy ◽

Imaging System ◽

Laser Energy ◽

Gold Nanorod ◽

Laser Irradiance ◽

Theoretical Simulation ◽

Microct Imaging ◽

Laser Photothermal Therapy

In this study, in vivo animal experiments are performed on implanted xenograph prostatic tumors in nude mice to investigate enhanced laser energy absorption in the tumors by an intratumoral injection of gold nanorod solutions. In vivo temperature mapping of the tumors during laser photothermal therapy has shown the feasibility of elevating tumor temperatures higher than 50 °C using only 0.1 ml nanorod solution and a low laser irradiance of 1.6 W/cm2 incident on the tumor surface. The temperature profile suggests that normal tumor tissue still absorbs some amount of the laser energy without nanorod presence; however, the injected nanorods ensure that almost all the laser energy is absorbed and confined to the targeted tumors. The inverse relationship between the temperature elevations and the tumor size implies a relatively uniform spreading of the nanorods to the entire tumor, which is also shown by microcomputed tomography (microCT) imaging analyses. The feasibility of detecting 250 OD gold nanorod solution injected to the tumors is demonstrated via a high resolution microCT imaging system. Compared to other nanostructures, the gold nanorods used in this study do not accumulate surrounding the injection site. The relatively uniform deposition of the nanorods in the tumors observed by the microCT scans can be helpful in future study in simplifying theoretical simulation of temperature elevations in tumors during laser photothermal therapy.

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THE MATHEMATICAL MODELLING OF THE THREE-DIMENSIONAL NONSTATIONARY NONLINEAR TEMPERATURE FIELDS OF GAS-TURBINE ENGINE BLADES

Proceeding of International Heat Transfer Conference 10 ◽

10.1615/ihtc10.2540 ◽

1994 ◽

Author(s):

V. M. Epifanov ◽

V. Stankiewitcz

Keyword(s):

Mathematical Modelling ◽

Gas Turbine ◽

Three Dimensional ◽

Gas Turbine Engine ◽

Temperature Fields ◽

Turbine Engine ◽

Nonlinear Temperature

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MEASUREMENT OF THREE-DIMENSIONAL TEMPERATURE FIELDS BY HETERODYNE HOLOGRAPHIC INTERFEROMETRY

International Journal of Energetic Materials and Chemical Propulsion ◽

10.1615/intjenergeticmaterialschemprop.v3.i1-6.280 ◽

1994 ◽

Vol 3 (1-6) ◽

pp. 271-284

Author(s):

B. Ineichen ◽

R. Muller

Keyword(s):

Holographic Interferometry ◽

Three Dimensional ◽

Temperature Fields

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Mathematical Model Investigation of Far-Field Transport of Ocean-Dumped Sewage Sludge Related to Remote Sensing

Water Science & Technology ◽

10.2166/wst.1982.0007 ◽

1982 ◽

Vol 14 (3) ◽

pp. 33-39

Author(s):

C Y Kuo

Keyword(s):

New York ◽

Sewage Sludge ◽

Laboratory Data ◽

Three Dimensional ◽

Approximate Model ◽

Transport Processes ◽

Far Field ◽

New York Bight ◽

Mean Current

An existing, three-dimensional, Eulerian-Lagrangian finite-difference model was modified and used to examine the far-field transport processes of dumped sewage sludge in the New York Bight. Both in situ and laboratory data were utilized in an attempt to approximate model inputs such as mean current speed, vertical and horizontal diffusion coefficients, particle size distributions, and specific gravities. Concentrations of the sludge near the sea surface predicted from the computer model were compared qualitatively with those remotely sensed.

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