Posts tagged ‘DNA’

December 26, 2013

DNA Nanotechnology the Future of Modern Medicine? – The Epoch Times

One of the most significant achievements in the field of biomedical engineering is the creation of DNA nanobots. These molecular robots made of DNA are designed to deliver medicines to specific cells that require healing and to target harmful cells, killing them without harming the healthy ones.

Unlike commonly used drugs and supplements, nanobots have a measure of intelligence and can conveniently move through the body in smart ways.

How are these nanobots produced? Scientists use DNA, breaking up the components and rearranging them into shapes such as barrels to carry medicine. DNA naturally has a tendency to react in certain ways to outside stimuli, and its components assemble according to natural attraction and repulsion. These reactions are manipulated to make the nanobots and to program them.

Nanobots are free-floating structures that move through the bloodstream and remain neutral until they encounter a particular site that requires assistance. With the help of molecular cues programmed into them, they can identify a precise location and perform the necessary actions.

Treatment with nanobots could prove to be especially effective against cancer. With chemotherapy treatment, healthy cells are killed along with the cancerous cells. Nanobots can detect the cancerous cells, however, and only release medicine upon encountering them.

Dr. Ido Bachelet told Israeli publication Globes in May: “It’s a bit like talking about a better gun, which only kills bad people.”

On Discovery News, Lloyd Smith, a chemist at the University of Wisconsin, said: “This is the first time that systems of nano-machines, rather than individual devices, have been used to perform operations, constituting a crucial advance in the evolution of DNA technology.”

People are curious to know what happens to nanobots after the treatment is completed.

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November 25, 2013

New ancestral enzyme identified that facilitates DNA repair

Every day, the human body produces new cells to regenerate tissues and repair those that have suffered injury.

Every day, the human body produces new cells to regenerate tissues and repair those that have suffered injury. Each time this happens, the cells make copies of their DNA that they will pass on to the resulting daughter cells. This process of copying the DNA, also called replication, is very delicate, given that it can generate severe alterations in the DNA that are associated with malignant transformation or ageing.

Researchers from the Spanish National Cancer Research Centre (CNIO), led by Juan Méndez, head of the DNA Replication Group, together with Luis Blanco, from the Severo Ochoa Molecular Biology Centre (CBM-CSIC), have discovered how a new human enzyme, the protein PrimPol, is capable of recognising DNA lesions and facilitate their repair during the DNA copying process, thus avoiding irreversible and lethal damage to the cells and, therefore, to the organism.

The results are published in the online edition of the journal Nature Structural and Molecular Biology. This study represents the continuation of a prior study, published recently by the same researchers in the journal Molecular Cell, in which they described the existence and biochemical properties of the PrimPol enzyme.

The DNA that resides in the nucleus of cells is the carrier of the genes, the instruction manuals that dictate how the cell works. “DNA structure is very stable, except during replication which normally takes approximately eight hours in human cells; during that period it becomes more fragile and can break”, says Méndez. These eight hours are therefore critical for cells: they have to ensure the fidelity of copying DNA, and if errors are found or the DNA is damaged, they have to repair them as efficiently as possible.

Avoiding Collapse

DNA polymerases are the enzymes responsible for synthesising new DNA. “When a DNA polymerase finds an obstacle in the DNA [a chemical alteration introduced by solar ultraviolet radiation, for example], the copy is interrupted and the process stops until the error is repaired. This interruption can cause breaks in the DNA, translocations of fragments from some chromosomes to others, and even cause cell death or malignant transformation”, says Méndez.

The research carried out by CNIO and CSIC demonstrates that the PrimPol enzyme prevents the copying process from being interrupted when there is damage: it recognises lesions and skips over them, and they are repaired when the copy is finished.

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October 21, 2013

Scientists discover DNA body clock

Newly discovered mechanism could help researchers understand ageing process and lead to ways of slowing it down

A US scientist has discovered an internal body clock based on DNA that measures the biological age of our tissues and organs.

The clock shows that while many healthy tissues age at the same rate as the body as a whole, some of them age much faster or slower. The age of diseased organs varied hugely, with some many tens of years “older” than healthy tissue in the same person, according to the clock.

Researchers say that unravelling the mechanisms behind the clock will help them understand the ageing process and hopefully lead to drugs and other interventions that slow it down.

Therapies that counteract natural ageing are attracting huge interest from scientists because they target the single most important risk factor for scores of incurable diseases that strike in old age.

“Ultimately, it would be very exciting to develop therapy interventions to reset the clock and hopefully keep us young,” said Steve Horvath, professor of genetics and biostatistics at the University of California in Los Angeles.

Horvath looked at the DNA of nearly 8,000 samples of 51 different healthy and cancerous cells and tissues. Specifically, he looked at how methylation, a natural process that chemically modifies DNA, varied with age.

Horvath found that the methylation of 353 DNA markers varied consistently with age and could be used as a biological clock. The clock ticked fastest in the years up to around age 20, then slowed down to a steadier rate. Whether the DNA changes cause ageing or are caused by ageing is an unknown that scientists are now keen to work out.

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From Pharmaceutical Industry digital vision