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arXiv · 1808.03670

The mechanism of secondary structural changes in Keratinocyte Growth Factor during uptake and release from a hydroxyethyl(methacrylate) hydrogel revealed by 2D Correlation Spectroscopy

Shohini Sen-Britain·Wesley Hicks·Robert Hard·Joseph A. Gardella Jr
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Abstract

Incomplete release profiles of protein delivery systems can be caused by unfolding and denaturation of proteins due to protein-biomaterial interactions. This paper investigates the mechanisms causing incomplete release of the wound healing protein, Keratinocyte Growth Factor (KGF), from a hydroxyethyl(methacrylate) (HEMA) hydrogel by FTIR-ATR spectroscopy and 2D correlation spectroscopy. This work characterizes KGF secondary structure reflected in the amide I region of the FTIR-ATR spectrum, and differences between active and heat denatured KGF. These results have been used to investigate the sequence of time-dependent changes in KGF at the surface of the HEMA hydrogel during uptake and release by 2D correlation spectroscopy. KGF stays active throughout the uptake process, and the KGF loop structures interact with HEMA moieties, potentially mimicking receptor-ligand interactions. KGF denatures during release via changes in the loops and unfolding of the extended strands. Our results suggest that a high affinity interaction between the HEMA hydrogel and KGF is beneficial for efficient loading of KGF into the hydrogel, but is too strong and prevents complete KGF release due to unfolding and denaturation of KGF. This work informs future material design that will target different secondary structural elements of KGF in order to preserve its native conformation and allow for complete release.

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Shohini Sen-Britain, Wesley Hicks, Robert Hard, Joseph A. Gardella Jr. 2018-08-10. The mechanism of secondary structural changes in Keratinocyte Growth Factor during uptake and release from a hydroxyethyl(methacrylate) hydrogel revealed by 2D Correlation Spectroscopy. https://arxiv.org/abs/1808.03670

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