Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Self-assembling proteins could help repair human tissue

29.03.2004


Protein hydrogels can be genetically engineered to promote the growth of specific cells



Johns Hopkins University researchers have created a new class of artificial proteins that can assemble themselves into a gel and encourage the growth of selected cell types. This biomaterial, which can be tailored to send different biological signals to cells, is expected to help scientists who are developing new ways to repair injured or diseased body parts.

"We’re trying to give an important new tool to tissue engineers to help them do their work more quickly and efficiently," said James L. Harden, whose lab team developed the new biomaterial. "We’re the first to produce a self-assembling protein gel that can present several different biological signals to stimulate the growth of cells."


Harden, an assistant professor in the Department of Chemical and Biomolecular Engineering, reported on his work March 28 in Anaheim, Calif., at the 227th national meeting of the American Chemical Society. His department is within the Whiting School of Engineering at Johns Hopkins.

Tissue engineers use hydrogels, which are macromolecular networks immersed in an aqueous environment, to provide a framework or scaffold upon which to grow cells. These scientists hope to advance their techniques to the point where they can treat medical ailments by growing replacement cartilage, bones, organs and other tissue in the lab or within a human body.

The Harden lab’s new hydrogel is made by mixing specially designed modular proteins in a buffered water solution. Each protein consists of a flexible central coil, containing a bioactive sequence and flanked by helical associating modules on each end. These end-modules come in three distinct types, which are designed to attract each other and form three-member bundles. This bundling leads to the formation of a regular network structure of proteins with three-member junctions linked together by the flexible coil modules. In this way, the new biomaterial assembles itself spontaneously when the protein elements are added to the solution.

The assembly process involves three different "sticky" ends. But between any two ends, Harden can insert one or more bioactive sequences, drawing from a large collection of known sequences. Once the gel has formed, each central bioactive module is capable of presenting a specific biological signal to the tissue engineer’s target cells. Certain signals are needed to encourage the adhesion, proliferation and differentiation of cells in order to form particular types of tissue.

Harden’s goal is to provide a large combinatorial "library" of these genetically engineered proteins. A tissue engineer could then draw from this collection to create a hydrogel for a particular purpose. "We want to let the end-user mix and match the modules to produce different types of hydrogels for selected cell and tissue engineering projects," he said.

Harden believes this technique may speed up progress in the tissue engineering field. For one thing, tissue engineers would not have to do complex chemistry work to prepare a hydrogel for each specific application; his hydrogels form spontaneously upon mixing with water. Also, unlike hydrogels that are made from synthetic polymers, the Harden team’s hydrogels are made of amino acids, the native building blocks of all proteins within the body. Finally, more than one protein signaling segment can be included in the Harden team’s hydrogel mix, allowing a tissue engineer to send multiple signals to the target cells, thereby supporting the simultaneous growth of several types of cells within one tissue.

"Our philosophy is to take a minimalist approach," Harden said. "Our hydrogels are designed to send only the growth signals that are needed for a particular application."

Harden’s colleagues in the hydrogel research are Lixin Mi, who earned his doctorate at Johns Hopkins and now is a postdoctoral researcher at the National Institutes of Health; and Stephen Fischer, a current doctoral student in the Department of Chemical and Biomolecular Engineering.


The Harden team’s research was supported by a grant from NASA through the Program on Human Exploration and Development of Space. Stephen Fischer is also supported by a NASA Graduate Student Researchers Program fellowship.

Science illustrations and color photos of the researchers available; Contact Phil Sneiderman

Related Links:
James Harden’s Web Page: http://www.wse.jhu.edu/chbe/faculty/harden/g
Department of Chemical and Biomolecular Engineering: http://

Phil Sneiderman | EurekAlert!
Further information:
http://www.jhu.edu/
http://www.wse.jhu.edu/chbe/faculty/harden/g/?id=5
http://www.jhu.edu/chbe/

More articles from Life Sciences:

nachricht Insect Antibiotic Provides New Way to Eliminate Bacteria
15.11.2018 | Universität Zürich

nachricht New findings help to better calculate the oceans’ contribution to climate regulation
15.11.2018 | Jacobs University Bremen gGmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

New findings help to better calculate the oceans’ contribution to climate regulation

15.11.2018 | Life Sciences

Automated adhesive film placement and stringer integration for aircraft manufacture

15.11.2018 | Materials Sciences

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>