Cancer Treatment Centers of America (CTCA) and Nanospectra Biosciences have planned the first clinical trial for lung cancers of a new therapy that uses gold nanoshells, which were invented at Rice University.
Nanospectra’s AuroLase Therapy uses a combination of lasers and nanoparticles to destroy cancer tumors with heat. Because the nanoparticles — balls of silica encased in a thin shell of gold — are absorbed by tumors and not healthy tissue, the technology can destroy tumors with minimal damage to healthy tissues.
Results of the study are published in the June 25, 2004 issue of the journal Cancer Letters.
Invented in the 1990s by Naomi Halas at Rice, nanoshells are about 20 times smaller than a red blood cell. The multilayered nanoshells consist of a silica core covered by a thin gold shell. The size, shape and composition of nanoshells give them unique optical properties. By varying the size of the core and the thickness of the gold shell, researchers can tailor a nanoshell to respond to a specific wavelength of light.
The photothermal cancer treatment uses nanoshells that are tuned to respond to near-infrared light. Located just outside the visible spectrum, near-infrared light passes harmlessly through soft tissue. In the treatment, nanoshells convert this light into heat that destroys nearby tumor cells. The heating is very localized and does not affect healthy tissue adjacent to the tumor.
The animal trial involved 25 mice with tumors ranging in size from 3-5.5 millimeters. The mice were divided into three groups. The first group was given no treatment. The second received saline injections, followed by three minutes exposure to near-infrared laser light. The final group received nanoshell injections and laser treatments.
Nanospectra and CTCA said the clinical trial has been approved by the Food and Drug Administration and the CTCA Institutional Review Board and will involve treatment of primary and metastatic lung tumors. The trial will be conducted by Dr. Mark Lund and colleagues in CTCA’s Interventional Pulmonology Department.
Nanospectra said AuroLase technology is also being tested in ongoing human clinical trials for metastatic head and neck tumors and for prostate cancer.
AuroLase Therapy begins with an injection of nanoshell particles into the patient’s bloodstream. After 12-24 hours — enough time for the particles to accumulate inside the tumor — an infrared laser is used to heat the particles and destroy tumor cells