Scientists at Kyoto University in Japan have developed a gene delivery system, involving gold nanorods and a near infrared laser, which can transport a gene into cells and activate it.
Changing gene expression is a powerful way to affect cell behavior, and scientists hope to use this approach to treat a variety of diseases. Researchers have developed a range of nanoparticle systems to deliver genes into cells. However, regulating when the gene is activated using an external signal, like light, adds a sophisticated level of control.
Gold nanorods coated with lipids efficiently penetrate cells. The gene is turned on by heat generated by the gold nanorods when they are exposed to near infrared light. Credit: Kyoto University iCeMS
In a study published in the journal Scientific Reports, the researchers coated gold nanorods with lipids to allow them to easily penetrate through the cell membrane. The nanorods carry a gene vector containing a ‘heat shock protein’ that can be activated by heat. When the nanorods enter a cell, lighting them up with a near infrared laser causes the nanorods to heat up, activating the gene, while having no ill effects on surrounding cells.
Initially, the team validated that the system could work using mammalian cells and a gene that codes for a green fluorescent protein. The scientists could easily see that the system had worked by looking at the cells using a fluorescence microscope, and in cells where the gene was active there was a bright green fluorescence.
The researchers then used the system to deliver a gene into cancer cells encoding for a protein called TRAIL. When the TRAIL gene was expressed, the cancer cells released the TRAIL protein, killing surrounding cancer cells.
The system could potentially be used for molecular cancer therapies.