Rheological Characterization of in Situ Cross-Linkable Hyaluronan Hydrogels

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• 作者：Kaustabh Ghosh ; Xiao Zheng Shu ; Robert Mou ; Jack Lombardi ; Glenn D. Prestwich ; Miriam H. Rafailovich ; and Richard A. F. Clark
• 刊名：Biomacromolecules
• 出版年：2005
• 出版时间：September 2005
• 年：2005
• 卷：6
• 期：5
• 页码：2857 - 2865
• 全文大小：151K
• 年卷期：v.6,no.5(September 2005)
• ISSN：1526-4602

文摘

This report investigates the rheological properties of cross-linked, thiol-functionalized HA (HA-DTPH)hydrogels prepared by varying the concentration and molecular weight (MW) of the cross-linker, poly(ethylene glycol) diacrylate (PEGDA). Hydrogels were subsequently cured for either short-term (hours) orlong-term (days) and subjected to oscillatory shear rheometry (OSR). OSR allows the evaluation andcomparison of the shear storage moduli (G'), an index of the total number of effective cross-links formedin the hydrogels. While the oscillatory time sweep monitored the evolution of G' during in situ gelation, thestress and frequency sweeps measured the G' of preformed and subsequently cured hydrogels. From stresssweeps, we found that, for the hydrogels, G' scaled linearly with PEGDA concentration and was independentof its MW. Upon comparison with the classical Flory's theory of elasticity, stress sweep tests on short-termcured hydrogels revealed the simultaneous, but gradual, formation of spontaneous disulfide cross-links inthe hydrogels. Results from time and frequency sweeps suggested that the formation of a stable, three-dimensional network depended strictly on PEGDA concentration. Results from the equilibrium swelling ofhydrogels concurred with those obtained from oscillatory stress sweeps. Such a detailed rheologicalcharacterization of our HA-DTPH-PEGDA hydrogels will aid in the design of biomaterials targeted forbiomedical or pharmaceutical purposes, especially in applications involving functional tissue engineering.