Science and Technology
publicado em 23/10/2013 às 09h48:00
   Dê o seu voto:

Hydrogel implant enables light-based communication with cells inside the body

Called a light-guiding hydrogel, the implant is constructed from a polymer-based scaffolding capable of supporting living cells

 
font size
A-
A+

As researchers develop novel therapies based on inducing specific cells to do specific things, getting the right message to the right group of cells at the right time remains a major challenge. The use of light to communicate with cells has been restricted by its limited ability to pass through tissues. Now researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital have developed a way to deliver a light signal to specific tissues deep within the body. They describe their accomplishment in the current issue of Nature Photonics.

"Scientists only began investigating light-activated therapy a few years ago, but it is generating huge interest," says Wellman investigator Seok Hyun (Andy) Yun, PhD, senior author of the study. "One of the best known example is use of optogenetics activation or deactivation of brain cells by illumination with different colors of light to treat brain disorders. But how to deliver light deep within the brain or other tissues has been a common problem. The implant we have developed may help solve this problem."

Called a light-guiding hydrogel, the implant is constructed from a polymer-based scaffolding capable of supporting living cells and contains cells genetically engineered either to carry out a specific activity in response to light or to emit light in response to a particular metabolic signal. An optical fiber connects the implant to either an external light source or a light detector.

The investigators first determined the properties of the hydrogel scaffolding including transparency, flexibility and stability that would be most appropriate for delivering or detecting a light signal. After determining how many cells could be implanted into the hydrogel without significantly reducing its ability to transmit a light signal, they developed and tested in mice two different systems, both involving implantation of a 4-centimeter hydrogel beneath the animal's skin.

The first system's implants contained cells genetically engineered to express light-emitting green fluorescent protein (GFP) upon contact with a toxin. After confirming in vitro the hydrogels' response to nanoparticles containing the toxic metal cadmium, the researchers implanted the hydrogels beneath the skin of three groups of mice. One group was then injected with the cadmium nanoparticles, the second received nanoparticles encased in a polymer shell that shielded cells from the toxin, and the third received a control saline injection. The implants only produced a GFP-signal in response to the unshielded nanoparticles, indicating their ability to sense a change in this instance the presence of a toxin in the cellular environment.

To investigate a possible therapeutic application for the system, the investigators used a hydrogel implant containing cells that respond to blue light by producing glucagon-like peptide-1 (GLP-1), a protein playing an essential role in glucose metabolism. After the implants were placed under the skin of mice with diabetes, the blue light signal was delivered for 12 hours. A day and a half later 48 hours after the implant the animals that received the light signal had double the level of GLP-1 in their blood, along with significantly better results in a glucose tolerance test, than did implanted mice not treated with light.

"This work combines several existing technologies well known in their respective fields such as drug delivery, genetic engineering, biomaterial science, and photonics to build a new implant system that enables the delivery of photomedicine deep in the body," says Yun, an associate professor of Dermatology at Harvard Medical School and director of the Harvard Bio-Optics Lab. "This is the first time anyone has shown the ability to talk optically by means of light with cells deep within the body, both to sense the presence of a toxin and to deliver a cell-based therapy."

Source:
  • Share this pageShare this page
  • Share this pageCorrect
  • ShareShare
  • AlertAlert
Reduced link: 
  • You are recommending this story: Hydrogel implant enables light-based communication with cells inside the body
  • Fill in the following form to send your recommendation to your friend:

  • You are suggesting a correction for this story: Hydrogel implant enables light-based communication with cells inside the body


Receba notícias do iSaúde no seu e-mail de acordo com os assuntos de seu interesse.
Seu nome:
Seu email:
Desejo receber um alerta com estes assuntos:
Hydrogel implant    communication with cells    Light-activated    Seok Hyun Yun    Massachusetts General Hospital   
Comments:
Comment
Leave your comment
Close
(Required fields are marked with an *)

(Your email address will never be published or shared.)

Enter the letters and numbers below and click in the button "send"

  • Twitter iSaúde
advertising
Informe Saúde printed version

Recommend the portal
Close [X]
  • You are recommending this story: http://www.isaude.net
  • Fill in the following form to send your recommendation to your friend:

RSS news from the portal  iSaúde.net
Get the newsletter of the portal  iSaúde.net
Recommend the portal iSaúde.net
News from  iSaúde.net in your blog or website.
Get news on the subject of your interest.
© 2000-2011 www.isaude.net Todos os direitos reservados.