An international team of cancer researchers has achieved a breakthrough in gene therapy by detonating microscopic tumor-targeted bubbles.
The noninvasive method combines ultrasound with tumor-targeted microbubbles. Once the ultrasound is activated, the microbubbles explode like smart and targeted warheads, creating holes in cancer cells' membranes, enabling gene delivery.
"Microbubbles are microscopic bubbles filled with gas, with a diameter as small as one tenth of a blood vessel," explains Dr. Tali Ilovitsh of the Biomedical Engineering Department at Tel Aviv University.
The technique utilises low-frequency ultrasound (250 kHz) to detonate microscopic tumor-targeted bubbles. In vivo, cell destruction reached 80 percent of tumor cells.
"At certain frequencies and pressures, sound waves cause the microbubbles to act like balloons: They expand and contract periodically. This process increases the transfer of substances from the blood vessels into the surrounding tissue. We discovered that using lower frequencies than those applied previously, microbubbles can significantly expand, until they explode violently. We realised that this discovery could be used as a platform for cancer treatment and started to inject microbubbles into tumors directly," explains Dr. Ilovitsh, who led the research team.
On its own, the gene cannot enter into the cancer cells. However, this gene aimed to enhance the immune system was co-injected together with the microbubbles. Membrane pores were formed in the remaining 20 percent of the cancer cells that survived the initial explosion, allowing the entry of the gene into the cells. This triggered an immune response that destroyed the cancer cell.
"The blood-brain barrier does not allow for medications to penetrate through, but microbubbles can temporarily open the barrier, enabling the arrival of the treatment to the target area without the need for an invasive surgical intervention."
Dr. Ilovitsh developed this breakthrough technology during her post-doctorate research at the lab of Professor Katherine Ferrara at Stanford University. The study has been published in the journal Proceedings of the National Academy of Sciences (PNAS).
Dr. Ilovitsh says that in the future she intends to attempt using this technology as a noninvasive treatment for brain-related diseases such as brain tumors and other neurodegenerative conditions such as Alzheimer's and Parkinson's diseases.