Scientists at University of California, Santa Barbara have developed a gene silencing technique that uses a combination of gold nanoshells and siRNA (silencing ribonucleic acid) conjugates for delivery. A low energy laser is then used to activate and release the siRNA at the specific site of a tumor where treatment is needed.
The scientists used cancer cells from mice, and grew them in culture. They then introduced gold nanoshells, with a peptide-lipid coating, that encapsulated “silencing ribonucleic acid” (siRNA), which was the drug that was taken up by the cells. Next, they exposed the cells to a non-harmful infrared laser.
“A major technical hurdle is how to combine multiple biochemical components into a compact nanoparticle which may be taken up by cells and exist stably until the release is desired,” said Gary Braun, first author and a graduate student in UCSB’s Department of Chemistry and Biochemistry. “Laser-controlled release is a convenient and powerful tool, allowing precise dosing of particular cells within a group. The use of biologically friendly tissue penetration with near-infrared light is the ideal for extending this capability into larger biological systems such as tissues and animals.”
The authors demonstrated, for the first time, the delivery of a potent siRNA cargo inside mammalian cancer cells, released by exposing the internalized nanoparticles for several seconds to a pulsed near-infrared laser tuned for peak absorption with a specific spatial pattern. The technique can be expanded to deliver numerous drug molecules against diverse biological targets.
Press release: UCSB Researchers Develop Drug Delivery System Using Nanoparticles and Lasers
Abstract in ACS NANO: Laser-Activated Gene Silencing via Gold Nanoshell-siRNA Conjugates
