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Updated: Jun 4, 2026
3D Hydrogel Scaffolds for Articular Chondrocyte Culture and Cartilage Generation
Published on: October 7, 2015
Degradation improves tissue formation in (un)loaded chondrocyte-laden hydrogels
Justine J Roberts1, Garret D Nicodemus, Eric C Greenwald
1Department of Chemical and Biological Engineering, University of Colorado-Boulder, ECCH 111, Campus Box 424, Boulder, CO 80309, USA.
Background:
Photopolymerizable poly(ethylene glycol) (PEG) hydrogels offer a platform to deliver cells in vivo and support three-dimensional cell culture but should be designed to degrade in sync with neotissue development and endure the physiologic environment.
Questions/Purposes:
We asked whether (1) incorporation of degradation into PEG hydrogels facilitates tissue development comprised of essential cartilage macromolecules; (2) with early loading before pericellular matrix formation, the duration of load affects matrix production; and (3) dynamic loading in general influences macroscopic tissue development.
Methods:
Primary bovine chondrocytes were encapsulated in hydrogels (n = 3 for each condition). The independent variables were hydrogel degradation (nondegrading PEG and degrading oligo(lactic acid)-b-PEG-b-oligo(lactic acid) [PEG-LA]), culture condition (free swelling, unconfined dynamic compressive loading applied intermittently for 1 or 4 weeks), and time (up to 28 days). The dependent variables were neotissue deposition through biochemical contents, immunohistochemistry, and compressive modulus.
Results:
Degradation led to 2.3- and 2.9-fold greater glycosaminoglycan and collagen contents, respectively; macroscopic cartilage-like tissue formation comprised of aggrecan, collagen II and VI, link protein, and decorin; but decreased moduli. Loading, applied early or throughout culture, did not affect neotissue content in either hydrogel but affected neotissue spatial distribution in degrading hydrogels where 4 weeks of loading appeared to enhance hydrogel degradation resulting in tissue defects.
Conclusions:
PEG-LA hydrogels led to macroscopic tissue development comprised of key cartilage macromolecules under loading, but hydrogel degradation requires further tuning.
Clinical Relevance:
PEG-LA hydrogels have potential for delivering chondrocytes in vivo to replace damaged cartilage with a tissue-engineered native equivalent, overcoming many limitations associated with current clinical treatments.
