Researchers have designed nano-sized capsules made from short stretches of DNA that can deliver cargos to a targeted site1. The capsules have small pores on the surface and encapsulated gold nanoparticles. The capsules can ferry life-saving drugs to destined sites without any degradation.
The researchers took oligonucleotides, short nucleic acid polymers with twenty or fewer bases. Through heat treatment, they first produced star like DNA structures having five separate strands. These DNA strands were further mixed and exposed to heat to yield cup-shaped DNA half-icosahedra.
To see whether such DNA nanocapsules can encapsulate any cargo, the researchers merged two half-icosahedra to form an icosahedron (a DNA polyhedron with 20 plane surfaces) in the presence of citrate-capped gold nanoparticles. Sophisticated imaging technique showed that gold nanoparticles were present only in clusters of at least 6 or 8 particles in DNA icosahedron.
"For the first time, we show that these beautiful architectures could also have useful functions," says lead researcher Yamuna Krishnan. As DNA can bind proteins, the DNA nanostructures could be reshaped in a way that protein can bind to the outer surface of the icosahedron, she added. According to her, such DNA shell could also prevent dangerous drugs from leaking out till the capsule reaches its target site.
The authors of this work are from: National Centre for Biological Sciences, TIFR, GKVK, Bangalore; Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore and Indian Institute of Virology, Pune.
