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Sol and gel states in peptide hydrogels visualized by Gd(III)‐enhanced magnetic resonance imaging
Author(s) -
Weerasekare Mahika,
Taraban Marc B.,
Shi Xianfeng,
Jeong EunKee,
Trewhella Jill,
Yu Yihua Bruce
Publication year - 2011
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.21612
Subject(s) - chemistry , chelation , self healing hydrogels , peptide , magnetic resonance imaging , nuclear magnetic resonance , covalent bond , gadolinium , relaxation (psychology) , biophysics , crystallography , polymer chemistry , inorganic chemistry , biochemistry , organic chemistry , biology , medicine , social psychology , psychology , physics , radiology
The hydrogels assembled from a pair of self‐repulsive but mutually attractive decapeptides are visualized by magnetic resonance imaging (MRI). It is found that in the absence of Gd(III)‐chelate, gelation has little effect on MRI signal intensity. In the presence of Gd(III)‐chelate, gelation leads to significant changes in water relaxation and MR signal intensity. The sol to gel transition is best visualized by T 2 ‐weighted imaging using large echo time with the sol producing a bright spot and the gel producing a dark spot. MRI studies point to high local Gd(III)‐chelate concentration. Small‐angle X‐ray scattering study indicates that this local enrichment of Gd(III)‐chelate has two contributing processes: first, the aggregation of peptides into fibers; second, within peptide fibers, Gd(III)‐chelate further aggregate into clusters. This work demonstrates that the status of peptide‐based hydrogels can be visualized by MRI with the aid of covalently linked Gd(III)‐chelates. This result has implications for monitoring peptide scaffolds in vivo. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 734–743, 2011.