Pesquisar este blog


terça-feira, 14 de agosto de 2012

Nanozyme destroys virus in human cells and in mice

One of the most promising applications of near-term nanomedicine is in the targeted control of gene expression. Nanoparticles show great promise here because they can be large and complex enough to mimic cellular processes of gene regulation for medical applications. By combining a protein enzyme and a DNA molecule on gold nanoparticles to mimic the gene regulatory mechanism called RNA interference, a “nanozyme” was able to destroy hepatitis C virus in human liver cells and in the livers of mice. A hat tip to Next Big Future for pointing to this University of Florida news release “UF researchers develop ‘nanorobot’ that can be programmed to target different diseases“:

University of Florida researchers have moved a step closer to treating diseases on a cellular level by creating a tiny particle that can be programmed to shut down the genetic production line that cranks out disease-related proteins.

In laboratory tests, these newly created ldquo;nanorobotsrdquo; all but eradicated hepatitis C virus infection. The programmable nature of the particle makes it potentially useful against diseases such as cancer and other viral infections.

The research effort, led by Y. Charles Cao, a UF associate professor of chemistry, and Dr. Chen Liu, a professor of pathology and endowed chair in gastrointestinal and liver research in the UF College of Medicine, is described online this week in the Proceedings of the National Academy of Sciences [abstract].

This is a novel technology that may have broad application because it can target essentially any gene we want,” Liu said. “This opens the door to new fields so we can test many other things. We’re excited about it.”

During the past five decades, nanoparticles — particles so small that tens of thousands of them can fit on the head of a pin — have emerged as a viable foundation for new ways to diagnose, monitor and treat disease. Nanoparticle-based technologies are already in use in medical settings, such as in genetic testing and for pinpointing genetic markers of disease. And several related therapies are at varying stages of clinical trial.

The Holy Grail of nanotherapy is an agent so exquisitely selective that it enters only diseased cells, targets only the specified disease process within those cells and leaves healthy cells unharmed. …

The particle they created can be tailored to match the genetic material of the desired target of attack, and to sneak into cells unnoticed by the body’s innate defense mechanisms.

Recognition of genetic material from potentially harmful sources is the basis of important treatments for a number of diseases, including cancer, that are linked to the production of detrimental proteins. It also has potential for use in detecting and destroying viruses used as bioweapons.

The new virus-destroyer, called a nanozyme, has a backbone of tiny gold particles and a surface with two main biological components. The first biological portion is a type of protein called an enzyme that can destroy the genetic recipe-carrier, called mRNA, for making the disease-related protein in question. The other component is a large molecule called a DNA oligonucleotide that recognizes the genetic material of the target to be destroyed and instructs its neighbor, the enzyme, to carry out the deed. By itself, the enzyme does not selectively attack hepatitis C, but the combo does the trick.

Near-term nanomedicine research is becoming incrementally more impressive as the toolkit for making and arming nanoparticles grows. Problem that have appeared with early generations of nanoparticles, like nonspecific induction of innate immunity, are being addressed with more sophisticated nanoparticle constructions. There is growing reason for optimism as these more complex nanoparticles gradually advance toward clinical trials.
—James Lewis, PhD

Fonte: Foresight Institute