wnycradiolab:

The Amazing Monkey Orchid

fuckyeahmolecularbiology:

Lego, Eat Your Heart Out

Single-stranded DNA has already proven itself to be a useful addition to the nanotechnologist’s toolbox. Blocks of DNA have been programmed to automatically build themselves into nanoscopic structures; a very long strand can be intricately folded into complex 3D shapes through a process known, appropriately, as DNA origami. Scientists hope that eventually, the DNA programmes could be sophisticated enough to churn out miniscule therapeutic devices that could work inside the body, and even be used to do highly specific tasks, like ferrying drugs to specific sites.

Usually, the long, single-stranded DNA required comes from a virus, which raises the possibility that the body could attack the structures - but not anymore. Peng Yin and colleagues at Harvard University have designed a similar technology that relies entirely on synthetic DNA - no viruses allowed.

“Our structures could be made to be highly biocompatible,” he says.

Instead of folding one long strand of viral DNA, Yin’s team designed short, synthetic DNA strands that can fold into a small tile. (And I mean seriously small - just 7 by 3 nanometres). “Each tile acts like a Lego block,” says Yin. Tiles automatically interlock with neighbouring tiles that carry a complementary DNA sequence. This means that with a bit of forward planning, the team could design a complete set of tiles that lock together to create more than 100 shapes - including any letter of the alphabet.

 Scientists hope that synthetic DNA shapes could dodge the immune system, buying them more time to shuttle drugs to the right tissue. Yin believes they could be the future: The body’s own therapeutic system, designed by our cells and for our cells.

To read the original article, published in Nature, click here.

Image, top: The alphabet generated by Yin and colleagues during their experiment.

Image, bottom: Another set of images generated by Yin and colleagues, showing the infinite variety of shapes the DNA can combine into and detailing the advantages for targeted therapeutics.

Images, centre line: A computer rendering of how the DNA might fold into the tile structure.

(Source: amolecularmatter)

fuckyeahmolecularbiology:

The Incredible Eye

The eye stands as a testament to the effectiveness and magnitude of what can be achieved through natural selection. These extraordinary false-colour SEM images of the human eye were the brainchild of Professor Pietro Motta at the Institute of Human Anatomy of the University La Sapienza in Rome.

Top Left: Surface cells on the iris of the eye. Pigment cells (melanocytes, blue and brown) can be seen here, joined loosely together by connective tissue fibres (white). Smaller macrophage cells dot the surface.

Top Right: Lens of the eye. Lens cells run diagonally (dark green) across this field of view. The transparency of the lens (width 4 millimetres) is due to the absence of nuclei in these cells, and to the crystalline precision of their arrangement.

Centre: The inner surfaces of the iris and adjoining structures in the human eye. At far right (blue) is the edge of the pupil, the hole that allows light into the eye. Coloured mauve is the iris which controls the size of the pupil and therefore how much light will enter. The band of folds down the centre (red) are the ciliary processes.

Bottom left: The surface of the cornea. The matrix- like pattern (seen here) consists of individual flattened transparent cells. This is a stratified squamous epithelium which is 5 cell layers deep. Although full of nerves, there are no blood vessels in the cornea.

Bottom right: The human retina featuring the central fovea, a crater-like depression in the photosensitive layer of the eye. The foveal retina is the area of greatest visual acuity and contains only cone receptor cells. When an eye looks at an object, that part focused on the fovea is the portion most accurately registered by the brain.

All image credit goes to Professor Pietro Motta and Science Photo Library.

(Source: amolecularmatter)