A group of Korean scientists said Sunday that it has developed a nano-sized drug delivery vector that moves along blood vessels and releases drugs around cancer cells.

The team at the Korea Institute of Science and Technology said it created an empty nano particle, put anti-cancer medicine into it, and injected it into a mouse.

Researchers also said they confirmed that the nano particle released the medicine only around cancer cells.

When nano particles containing CPT, an insoluble anti-cancer medine, were injected into a mouse with human breast cancer cells, the team said the particles concentrated around the cancer cells and released anti-cancer medicine for one week.