KAIST’s Department of Bio and Brain Engineering Professor Ji-Ho Park and his team successfully developed a new highly-efficacious anti-cancer nanotechnology by delivering anti-cancer drugs uniformly to an entire tumor. Their research results were published in Nano Letters online on March 31, 2015.

To treat inoperable tumors, anti-cancer medicine is commonly used. However, efficient drug delivery to tumor cells is often difficult, treating an entire tumor with drugs even more so.

Using the existing drug delivery systems, including nanotechnology, a drug can be delivered only to tumor cells near blood vessels, leaving cells at the heart of a tumor intact. Since most drugs are injected into the bloodstream, post-medication tumor recurrence is frequent.

Therefore, the team used liposomes that can fuse to a cell membrane and enter the cell. Once inside the liposomes, the drug can travel into the bloodstream and enter tumor cells near blood vessels where they are loaded to exosomes, which are naturally occurring nanoparticles in the body. Since exosomes can travel between cells, the drug can be delivered efficiently into the inner cells of the tumor.

Exosomes, which are secreted by cells that exist in the tumor microenvironment, are known to play an important role in tumor progression and metastasis since they transfer biological materials between cells. The research team started the investigation recognizing the possibility of delivering anti-cancer drugs to the entire tumor using exosomes.

The team injected a light-sensitive anti-cancer drug using their new delivery technique into experimental mice. The researchers applied light to the tumor site to activate the anti-cancer treatment and analyzed a tissue sample. They observed the effects of the anti-cancer drug in all of the tissue around the tumor.

The team’s results establish a ground-breaking foothold in drug delivery technology development that can be tailored to specific diseases. The work paves the way toward more effective drug delivery systems for many chronic diseases, including cancerous tumors that were difficult to treat due to the inability to penetrate deep into the tissue.

The team is currently conducting experiments with other anti-cancer drugs, which are being developed by pharmaceutical companies, using their tumor-penetrating drug delivery nanotechnology to identify its effect on malignant tumors.

Professor Park said, “This research is the first to apply biological nanoparticles, exosomes that are continuously secreted and can transfer materials to neighboring cells, to deliver drugs directly to the heart of tumor.”