Featured Research

from universities, journals, and other organizations

Stimuli-responsive drug delivery system prevents transplant rejection

Date:
August 13, 2014
Source:
Brigham and Women's Hospital
Summary:
A way to deliver immunosupressant drugs locally and when prompted, with the use of a biomaterial that self-assembles into a hydrogel (jello-like) material, has been developed by an international team of scientists. The novel system is able to deliver targeted, controlled release of medication where and when it is needed.

In a depiction of a hand transplant, researchers illustrate how injecting a hydrogel-drug combo beneath the skin results in a controlled release of immunosuppressant drug to prevent rejection of the transplanted limb.
Credit: Praveen Kumar Vemula, Ph.D.

Following a tissue graft transplant -- such as that of the face, hand, arm or leg -- it is standard for doctors to immediately give transplant recipients immunosuppressant drugs to prevent their body's immune system from rejecting and attacking the new body part. However, there are toxicities associated with delivering these drugs systemically, as well as side effects since suppressing the immune system can make a patient vulnerable to infection.

A global collaboration including researchers from Brigham and Women's Hospital (BWH); Institute for Stem Cell Biology and Regenerative Medicine in Bangalore, India; and University Hospital of Bern, Switzerland, have developed a way to deliver immunosupressant drugs locally and when prompted, with the use of a biomaterial that self-assembles into a hydrogel (jello-like) material. The novel system is able to deliver targeted, controlled release of medication where and when it is needed.

The study is published online August 13, 2014 in Science Translational Medicine.

"This new approach to delivering immunosuppressant therapy suggests that local delivery of the drug to the grafted tissue has benefits in reducing toxicity, as well as markedly improving therapeutic outcomes, and may lead to a paradigm shift in clinical immunosuppressive therapy in transplant surgery," said Jeff Karp, PhD, Division of Biomedical Engineering, BWH Department of Medicine, co-corresponding study author.

Added Robert Rieben, PhD, associate professor of Transplantation Immunology, Department of Clinical Research, University of Bern, co-corresponding study author: "Continuous release of the drugs irrespective of disease severity is a hallmark of existing drug delivery vehicles and could be a thing of the past. Inflammation-directed drug release offers 'judicious use of locally injected drug' that extends the release for months while eliminating systemic toxicity. "

The researchers developed a hydrogel loaded with the immunosuppressant drug tacrolimus. The hydrogel-drug combo is injected under the skin after transplant surgery. The hydrogel remains inactive until it detects an inflammation/immune response from the transplant site, at which point it delivers the immunosuppressant drug for months locally within the transplanted graft.

In pre-clinical studies conducted by the researchers, a one-time, local injection of the hydrogel-drug combo prevented graft rejection for more than 100 days compared to 35.5 days for recipients receiving only tacrolimus and 11 days for recipients without treatment or only receiving hydrogel.

The innovation may also be applied in medical situations outside of transplant surgery.

"This safe, controlled release platform approach functions for over three months from a single injection, and that has broad implications," said Karp. "Nearly every disease has an inflammatory component. Thus we believe the materials we have developed could be used for localized treatment of multiple inflammatory diseases."

Added Praveen Kumar Vemula, PhD, co-corresponding study author: "This approach should also improve patient compliance, as it obviates the need for daily medications. Also, we plan to expand this prototype for the treatment of numerous diseases such as psoriasis, arthritis and cancer." Vemula, now affiliated with the Institute for Stem Cell Biology and Regenerative Medicine in Bangalore, India, developed the hydrogel with Karp while a postdoc in the Karp laboratory.


Story Source:

The above story is based on materials provided by Brigham and Women's Hospital. The original article was written by Marjorie Montemayor-Quellenberg. Note: Materials may be edited for content and length.


Journal Reference:

  1. T. Gajanayake, R. Olariu, F. M. Leclere, A. Dhayani, Z. Yang, A. K. Bongoni, Y. Banz, M. A. Constantinescu, J. M. Karp, P. K. Vemula, R. Rieben, E. Vogelin. A single localized dose of enzyme-responsive hydrogel improves long-term survival of a vascularized composite allograft. Science Translational Medicine, 2014; 6 (249): 249ra110 DOI: 10.1126/scitranslmed.3008778

Cite This Page:

Brigham and Women's Hospital. "Stimuli-responsive drug delivery system prevents transplant rejection." ScienceDaily. ScienceDaily, 13 August 2014. <www.sciencedaily.com/releases/2014/08/140813174420.htm>.
Brigham and Women's Hospital. (2014, August 13). Stimuli-responsive drug delivery system prevents transplant rejection. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2014/08/140813174420.htm
Brigham and Women's Hospital. "Stimuli-responsive drug delivery system prevents transplant rejection." ScienceDaily. www.sciencedaily.com/releases/2014/08/140813174420.htm (accessed September 30, 2014).

Share This



More Health & Medicine News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How 'Yes Means Yes' Defines Sexual Assault

How 'Yes Means Yes' Defines Sexual Assault

Newsy (Sep. 29, 2014) Aimed at reducing sexual assaults on college campuses, California has adopted a new law changing the standard of consent for sexual activity. Video provided by Newsy
Powered by NewsLook.com
Scientists May Have Found An Early Sign Of Pancreatic Cancer

Scientists May Have Found An Early Sign Of Pancreatic Cancer

Newsy (Sep. 29, 2014) Researchers looked at 1,500 blood samples and determined people who developed pancreatic cancer had more branched chain amino acids. Video provided by Newsy
Powered by NewsLook.com
Colo. Doctors See Cluster of Enterovirus Cases

Colo. Doctors See Cluster of Enterovirus Cases

AP (Sep. 29, 2014) Doctors at the Children's Hospital of Colorado say they have treated over 4,000 children with serious respiratory illnesses since August. Nine of the patients have shown distinct neurological symptoms, including limb weakness. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Dr.'s Unsure of Cause of Fast-Spreading Virus

Dr.'s Unsure of Cause of Fast-Spreading Virus

AP (Sep. 29, 2014) Doctors at the Children's Hospital of Colorado say they have treated over 4,000 children with serious respiratory illnesses since August. Nine of the patients have shown distinct neurological symptoms, including limb weakness. (Sept. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins