Researchers from UD's College of Engineering and the University of California-Santa Barbara are working together to produce new biomaterials that could lead to important advances in plastics and human health.

In fact, the scientists say, it is possible that the work could someday result in the development of much-needed replacement organs to save the lives of individuals in failing health.

The research, which involves self-assembling synthetic polypeptides inspired by natural proteins, was reported in a recent issue of Nature magazine.

"The paper describes our collaborative, interdisciplinary efforts to produce new, advanced biomaterials," Darrin J. Pochan, assistant professor in the Department of Materials Science and Engineering, says.

Pochan says many scientists worldwide are focusing on the production of new biomaterials, but he notes, "What makes this research unique is the way we are doing it, through designed molecular self-assembly.

"We can design into a molecule all the information it needs, so that when it is thrown into an aqueous solution, it will self-assemble into a material with a desired structure and function."

At the foundation of the new biomaterials are polypeptides, molecular chains of amino acids and "the same chemistry as found in our bodies," Pochan says. "We are using molecular tools inherent in natural biomolecules to design our synthetic polypeptides and the ultimate properties of the assembled material."

Several inherent properties are unique to this new class of self-assembled, peptide-based hydrogels, he says.

As described in the Nature article, the underlying self-assembled polypeptide scaffold has a porous microstructure--a structure not observed in, and difficult to process into, traditional hydrogel materials. The gel scaffold also is porous on the nanoscale, which allows the gel to reassemble easily and quickly after flow or processing.

Furthermore, the gels are stable up to the boiling point of water and, because they are peptide-based, should be "enzymatically degradable and easily made useful for further biofunctionality," according to Pochan.

A technology that can take advantage of these unique hydrogel properties is the engineering of human body tissue. Looking far to the future, Pochan says, it is conceivable that this work could lead to the generation of transplantable organs and tissues, which would not be rejected because they would be created using cells from a patient's own body and thus have the same genetic material.

The microscale porosity and peptidic nature of the gel network are both desired ingredients for interaction with living human cells.

"When a person is young, we could potentially take tissue samples and grow copies of that person's organs for when they are needed," Pochan says. "That's a Holy Grail kind of thing, but it is what motivates further development of our work."

The work also could have applications in other biomedical fields, such as drug delivery and biomineralization, and even have potential applications in more traditional plastics technology.

"One could potentially produce tough plastics with inherent biofunctionality (e.g., antimicrobial properties) with block copolypeptides, simply by choosing the correct amino acids in your polymer," Pochan says.

Working in his research group at UD are graduate students Lisa Pakstis and Bulent Ozbas, who also are co-authors of the paper. UC-Santa Barbara researchers who co-authored the paper are Andrew P. Nowak, Victor Breedveld, David J. Pine and Timothy J. Deming.

The National Science Foundation funds the group's research.

--Neil Thomas, AS '76