409299 Thermoresponsive Properties and Mechanical Response of Highly Concentrated Aqueous Poly(L-proline) Solutions

Thursday, November 12, 2015: 4:45 PM
251C (Salt Palace Convention Center)
Manos Gkikas1, Reginald K. Avery2 and Bradley D. Olsen1, (1)Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, (2)Department of Biological Engineering, MIT, Cambridge, MA

The gelation behavior of the left helical N-substituted homopolypeptide poly(L-proline) (PLP) in water was explored, employing rheological and small-angle scattering studies at different temperatures and concentrations in order to investigate the network structure and its mechanical properties. Stiff gels were obtained at 10 wt. % or higher at 5oC, the first time gelation has been observed for homopolypeptides. It was found that, with temperature, the network transitions in D2O from a homogenous to a two-phase network, with broad scattering features of similar correlation length for all the examined high concentration PLP samples. A thermoresponsive transition was also achieved between 5 and 35oC, with moduli higher than gelatin, collagen and collagen-mimetic peptide gels, and higher/comparable to β-sheets gels. The brittle gels could tolerate strains of 1 % before yielding, and the linear properties were also independent of angular frequency over the range 0.001-100 rad/s, similar to proline-rich proteins, showing that the gel structure is not dynamic. The secondary structure and helical rigidity of PLP has large structural similarities to collagen, but in gels, the two materials show a different trend with temperature

Extended Abstract: File Not Uploaded
See more of this Session: Biomacromolecular Gels
See more of this Group/Topical: Materials Engineering and Sciences Division