Self-assembly of beta hairpin peptides to hydrogels and tuning of material properties by design of turn sequence

ORGN 302

Karthikan Rajagopal1, Bulent Ozbas2, Darrin J. Pochan2, and Joel P Schneider3. (1) Department of Chemistry and Biochemistry, University of Delaware, 022 Lammot Dupont Lab, Newark, DE 19711, (2) Material Science and Engineering, University of Delaware, 201 Dupont Hall, Newark, DE 19716, (3) Chemistry and Biochemistry, University of Delaware, Newark, DE 19716
Molecular self-assembly of de novo designed amphiphilic beta hairpin peptides in aqueous systems is a novel technique in hydrogel biomaterial construction. We have designed five peptides with varying turn sequences to adopt beta hairpin conformation specifically under alkaline conditions. All the peptides fold and self-assemble to form rigid viscoleastic hydrogels. Circular dichroism and infrared spectroscopies show that the kinetics and extent of self-assembly process is strongly dependent on the turn type. Rheology shows that the time dependent evolution of storage modulus is related to the amount of peptide folded and self-assembled. Since the turn region is the only design variant among peptides studied, we propose that turn propensity and possible turn-turn interactions in the self-assembled state play dominant roles in dictating macroscopic material properties. Therefore, rational tuning of material properties is possible through molecular level peptide design. This holds promise for producing robust hydrogels for tissue engineering and drug delivery applications.
 

Molecular Recognition and Materials
8:00 AM-12:00 PM, Tuesday, August 24, 2004 Pennsylvania Convention Center -- 201B, Oral

Division of Organic Chemistry

The 228th ACS National Meeting, in Philadelphia, PA, August 22-26, 2004