‘Nano-Cocoons’ Offer Targeted Drug Delivery Against Cancer Cells

Biomedical engineering researchers have developed a drug delivery system consisting of nanoscale “cocoons” made of DNA that target cancer cells and trick the cells into absorbing the cocoon before unleashing anticancer drugs. The paper was published online Oct. 13 in the Journal of the American Chemical Society.

In an acidic environment, the activity of DNase I was activated
 through the acid-triggered shedding of the polymeric shell of
 the NCa,  resulting in the cocoon-like self-degradation of the
 NCl and promoting the release of DOX for enhanced
therapeutic efficacy.
The technique specifically targets cancer cells, and can carry a large drug load and releases the drugs very quickly once inside the cancer cell. In addition, because the researchers used self-assembling DNA techniques, it is relatively easy to manufacture.
Each nano-cocoon is made of a single strand of DNA that self-assembles into what looks like a cocoon, or ball of yarn, that measures 150 nanometers across. The core of the nano-cocoon contains the anticancer drug doxorubicin (DOX) and a protein called DNase. The DNase, an enzyme that would normally cut up the DNA cocoon, is coated in a thin polymer that traps the DNase like a sword in a sheath.
The surface of the nano-cocoon is studded with folic acid ligands. When the nano-cocoon encounters a cancer cell, the ligands bind the nano-cocoon to receptors on the surface of the cell, causing the cell to suck in the nano-cocoon.
Once inside the cancer cell, the cell’s acidic environment destroys the polymer sheath containing the DNase. Freed from its sheath, the DNase rapidly slices through the DNA cocoon, spilling DOX into the cancer cell and killing it.
The researchers are preparing to launch preclinical testing.