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 Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>