Photo-Cross-Linked PLA-PEO-PLA Hydrogels from Self-Assembled Physical Networks: Mechanical Properties and Influence of Assumed Constitutive Relationships

Sanabria-DeLong, Naomi and Crosby, Alfred J. and Tew, Gregory N.. (2008) Photo-Cross-Linked PLA-PEO-PLA Hydrogels from Self-Assembled Physical Networks: Mechanical Properties and Influence of Assumed Constitutive Relationships. Biomacromolecules, 9 (10). pp. 2784-2791. ISSN 1525-7797

Full text not available from this repository. (Request a copy)

Abstract

Poly(lactide)-block-poly(ethylene oxide)-block-poly(lactide) (PLA-PEO-PLA) triblock copolymers are known to form physical hydrogels in water as a result of the polymer’s amphiphilicity. Their mechanical properties, biocompatibility, and biodegradability have made them attractive for use as soft tissue scaffolds. However, the network junction points are not covalently cross-linked, and in a highly aqueous environment these hydrogels adsorb more water, transform from gel to sol, and lose the designed mechanical properties. In this article, a hydrogel was formed by the use of a novel two-step approach. In the first step, the end-functionalized PLA-PEO-PLA triblock was self-assembled into a physical hydrogel through hydrophobic micelle network junctions, and in the second step, this self-assembled physical network structure was locked into place by photo-cross-linking the terminal acrylate groups. In contrast with physical hydrogels, the photo-cross-linked gels remained intact in phosphate-buffered solution at body temperature. The swelling, degradation, and mechanical properties were characterized, and they demonstrated an extended degradation time (65 days), an exponential decrease in modulus with degradation time, and a tunable shear modulus (1.6−133 kPa). We also discuss the various constitutive relationships (Hookean, neo-Hookean, and Mooney−Rivlin) that can be used to describe the stress−strain behavior of these hydrogels. The chosen model and assumptions used for data fitting influenced the obtained modulus values by as much as a factor of 3.5, which demonstrates the importance of clearly stating one’s data fitting parameters so that accurate comparisons can be made within the literature.

Item Type: Article
Additional Information: Reprinted with permission from "Tew et.al.'Photo-Cross-Linked PLA-PEO-PLA Hydrogels from Self-Assembled Physical Networks: Mechanical Properties and Influence of Assumed Constitutive Relationships', BIOMACROMOLECULES Volume: 9 Issue: 10 Pages: 2784-2791." Copyright 2008 American Chemical Society.
InterNano Taxonomy: Nanoscale Objects and Nanostructured Materials > Nanostructured Materials > Block copolymers
Nanomanufacturing Processes > Biological Techniques > Biolinker assembly
Informatics and Standards
Nanoscale Objects and Nanostructured Materials > Other Nanostructured Materials > Self assembled monolayers
Collections: Nanomanufacturing Research Collection > Nanomanufacturing Nanoscale Science and Engineering Centers > Center for Hierarchical Manufacturing
Nanomanufacturing Research Collection
Depositing User: Moureen Kemei
Date Deposited: 25 Jan 2010 20:57
Last Modified: 19 Sep 2011 21:13
URI: http://eprints.internano.org/id/eprint/230

Actions (login required)

View Item View Item