Preparation and Characterization of a Hydrogel from Low-Molecular Weight Hyaluronic Acid

✍ Scribed by Xuejun, X.; Netti, P. A.; Ambrosio, L.; Nicolais, L.; Sannino, A.

• Book ID: 126905770
• Publisher: SAGE Publications
• Year: 2004
• Tongue: English
• Weight: 191 KB
• Volume: 19
• Category: Article
• ISSN: 0883-9115
• DOI: 10.1177/0883911504041608

✦ Synopsis

A relatively low-molecular weight sample of hyaluronic acid (HA) was chemically modified by means of a cross-linking reaction with water-soluble carbodiimide and L-lysine methyl ester to form a chemical hydrogel. FT-IR analysis performed on the precursors and on the cross-linked hydrogel indicated the formation of ester bonds between different HA molecules that led to an intermolecular cross-linking. Hydrogel swelling kinetics as well as equilibrium sorption properties were evaluated. A swelling ratio of 250 was observed after immersion in distilled water for 7 h. Rheological measurements by means of a plate–plate rheometer of the cross-linked sample showed non-Newtonian and pseudoplastic behavior, while the uncross-linked HA showed Newtonian behavior and a viscous characteristic. Morphological analysis of these microstructures by scanning electron microscopy indicated that the freeze-dried crosslinked hydrogel presents a more closed-pore structure and higher density of pores than the freeze-dried original HA.