Degradative properties and cytocompatibility of a mixed-mode hydrogel containing oligo[poly(ethylene glycol)fumarate] and poly(ethylene glycol)dithiol

✍ Scribed by Kelly S. Brink; Peter J. Yang; Johnna S. Temenoff

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 421 KB
• Volume: 5
• Category: Article
• ISSN: 1742-7061
• DOI: 10.1016/j.actbio.2008.09.015

✦ Synopsis

Our laboratory is currently exploring synthetic oligo(poly(ethylene glycol)fumarate) (OPF)-based biomaterials as a means to deliver fibroblasts to promote regeneration of central/partial defects in tendons and ligaments. In order to further modulate the swelling and degradative characteristics of OPF-based hydrogels, OPF crosslinking via a radically initiated, mixed-mode reaction involving poly(ethylene glycol) (PEG)-diacrylate and PEG-dithiol was investigated. Results demonstrate that mixed-mode hydrogels containing OPF can be formed and that the presence of 20 wt.% PEG-dithiol increases swelling and decreases degradation time vs. 10 wt.% PEG-dithiol and non-thiol-containing hydrogels (20% thiol fold swelling 28.7 ± 0.8; 10% thiol fold swelling 11.6 ± 1.4; non-thiol 8.7 ± 0.2; 20% thiol-containing hydrogels degrade within 15 days in vitro). After encapsulation, tendon/ligament fibroblasts remained largely viable over 8 days of static culture. While the presence of PEG-dithiol did not significantly affect cellularity or collagen production within the constructs over this time period, image analysis revealed that the 20% PEG-dithiol gels did appear to promote cell clustering, with greater values for aggregate area observed by day 8. These experiments suggest that mixed-mode OPF-based hydrogels may provide an interesting alternative as a cell carrier for engineering a variety of soft orthopedic tissues, particularly for applications when it is important to encourage cell-cell contact.