Nanotechnology, the science of manipulating matter on a molecular scale, offers obvious advantages for the medical market. However, the question of nanotoxicology — the study of the toxicity of nanomaterials — may also play a role in the future of this technology. In 2006, the FDA formed the Nanotechnology Task Force to identify and address ways to better evaluate possible adverse health effects associated with FDA-regulated nanotechnology products. There's no question that the toxicity of nanoparticles should be an ongoing area of research, but it's also encouraging to see researchers continue to make progress in utilizing nanotechnology in medicine. Let's take a look at some highlights of recent biomedical advances that are utilizing the power of nanotechnology.
Implant Deters Breast Cancer Cell Growth
Brown University researchers have created an implant that appears to deter breast cancer cell regrowth. The implant is the first to be modified at the nanoscale in a way that causes a reduction in the blood-vessel architecture that breast cancer tumors depend on, while also attracting healthy endothelial cells for breast tissue. Made from a common federally approved polymer, the implant is a “bed-of-nails” surface at the nanoscale that deters cancer cells from dwelling and thriving. Researchers believe that the surface works by being incompatible with the stiffness of malignant breast cells. When they come in contact with the bumpy surface, it's possible that they are unable to fully wrap themselves around the rounded contours, depriving them of the ability to take root and thrive.
Cancer Therapeutics
Nanotechnology offers great potential for cancer diagnosis and therapeutics. Gold nanoparticles have been investigated as a tool for cancer treatment, but thus far, scientists have struggled to achieve efficiency with this method. Researchers at The Methodist Hospital Research Institute recently developed a system to amplify the gold particles' response to infrared light by loading gold nanoparticles into porous silicon, potentially making this method of cancer therapeutics much more efficient. Silicon wafers were designed to preferentially bind to breast cancer cells, rather than other types of cells. The shape and size of the silicon particles are crucial, researchers found. The wafers are about one micrometer in diameter (one-thousandth of a millimeter). By contrast, the typical breast cancer cell is about 10 to 12 times that size. Next, the team plans to set its sights on bigger targets. Pre-clinical studies have been planned to study the technology's impact on whole tumors, rather than just cancerous cells.
DNA Origami for Nanorobots
Researchers at Harvard University's Wyss Institute for Biologically Inspired Engineering are creating a robotic device, made from DNA, that could treat various diseases — not with drugs, but by programming the body's own immune system to fight those diseases.
The researchers used the DNA origami method to create a nanosized robot in the form of an open barrel whose two halves are connected by a hinge. The DNA barrel, which acts as a container, is held shut by special DNA latches that can recognize and seek out combinations of cell-surface proteins, including disease markers. When the latches find their targets, they reconfigure, causing the two halves of the barrel to swing open and expose its contents, or payload. The container can hold various types of payloads, including specific molecules with encoded instructions that can interact with specific cell surface signaling receptors.
This programmable nanotherapeutic approach was modeled on the body's own immune system. The programmable power of the DNA nanorobot's modular components could someday be used to customize and develop new types of targeted therapies.
Medical Diagnostics
Researchers at Oregon State University are utilizing the power of carbon nanotubes to increase the speed of biological sensors. This work could someday allow a doctor to routinely perform lab tests in minutes. Their findings have almost tripled the speed of prototype nano-biosensors, and could accomplish the same task as a handheld sensor while cutting the cost of an existing $50 lab test to about $1, researchers said. Key to the technology is the unusual capability of carbon nanotubes, long hollow structures that offer unique mechanical, optical, and electronic properties. In this case, carbon nanotubes are used to detect a protein on the surface of a sensor. The nanotubes change their electrical resistance when a protein lands of them, and the extent of this change can be measured to make an accurate diagnosis. Further work is still required to improve the selective binding of proteins, before it is ready to develop into commercial biosensors.
