A laser for nanomedicine

Oct 28, 2005

A modified femtosecond laser can correct poor eyesight and identify malignant melanomas. In addition, it represents an effective tool for laser nanomedicine: It can be used for example to drill nanoholes in cellular membranes and to transfer genes into cells by means of light.

Sixty-four percent of Germans cannot see properly without glasses or contact lenses. One in two short- or long-sighted adults could be treated by a laser operation, and femtosecond lasers are being increasingly used. This type of laser can be focussed through the tissue directly onto the working area, saving time and improving the healing process.

There is a disadvantage, however: residual radiation permeates the eye right through to the retina, and may cause impaired vision. Karsten König and his team at the Fraunhofer Institute for Biomedical Engineering IBMT are working on eliminating these side effects. “We are attempting to remove tissue constituents gently and very precisely using extremely low pulse energies of just a few nanojoules,” explains König. This is made possible by a heavily modified femtosecond laser system with a very high pulse sequence, which can focus its beam with great accuracy using precision optics from Zeiss.

The laser paves the way for entry into nanolaser medicine, a new branch dealing with the diagnosis and therapy of individual cells. Depending on the laser power and optics used, the system can be a “femtoscope” providing insights into living tissue which are a thousand times more precise than the best computer tomographs. It is also a precision tool.

The team of research scientists succeeded in performing the world’s smallest incision into living tissue – with a width of just 70 nanometers. This opens up new possibilities: gene transfer by light, in which foreign genetic material is inserted into living cells using ultra-short laser pulses, without destroying the cells. “In this way we can introduce pharmaceutical agents or genes into individual cells,” emphasises König. He has been awarded the new Technology Prize for his human-centered technology.

The first application – diagnosis and therapy of melanomas – was realized in cooperation with dermatologists at Jena University Hospital. The “femtoscope” renders the cell layers of the skin visible. Diseased cells are diagnosed by comparing samples. In future, doctors could use the same device for treatment: The diseased cell would be radiated with increased laser power and destroyed. After approval of the process, it would no longer be necessary to perform biopsies and time-consuming histological tests. The laser system could also be used outside the medical field, in microchip manufacture. The high-precision lasers are able to produce structures in silicon which are smaller than 100 nanometers.

Source: Fraunhofer-Gesellschaft

Explore further: Project uses crowd computing to improve water filtration

Related Stories

Manipulating cell membranes using nanotubes

Jun 01, 2015

Japanese researchers have developed a targeted method for opening up cell membranes in order to deliver drugs to, or manipulate the genes of, individual cells.

Chameleon proteins make individual cells visible

May 19, 2015

Researchers discovered a new mechanism of how fluorescent proteins can change colour. It enables the microscopic visualization of individual cells in their three-dimensional environment in living organisms.

Exposing breast cancer using nanoscale polymers

May 13, 2015

Photoacoustic imaging is a ground-breaking technique for spotting tumors inside living cells with the help of light-absorbing compounds known as contrast agents. A*STAR researchers have now discovered a way ...

Recommended for you

Project uses crowd computing to improve water filtration

10 hours ago

Nearly 800 million people worldwide don't have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. ...

Engineering the world's smallest nanocrystal

14 hours ago

In the natural world, proteins use the process of biomineralization to incorporate metallic elements into tissues, using it to create diverse materials such as seashells, teeth, and bones. However, the way ...

A stretchy mesh heater for sore muscles

Jul 03, 2015

If you suffer from chronic muscle pain a doctor will likely recommend for you to apply heat to the injury. But how do you effectively wrap that heat around a joint? Korean Scientists at the Center for Nanoparticle ...

Polymer mold makes perfect silicon nanostructures

Jul 03, 2015

Using molds to shape things is as old as humanity. In the Bronze Age, the copper-tin alloy was melted and cast into weapons in ceramic molds. Today, injection and extrusion molding shape hot liquids into ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.