Photopolymerized thermosensitive hydrogels: synthesis, degradation, and cytocompatibility
Tina Vermonden1, Natalja E Fedorovich, Daphne van Geemen
1Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands. T.Vermonden@uu.nl
Biomacromolecules
|February 22, 2008
Summary
This study enhances thermosensitive hydrogels for tissue engineering by adding covalent cross-links via photopolymerization. This improves mechanical strength and stability, making them suitable for cell encapsulation and differentiation.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Tissue Engineering
Background:
- Thermosensitive hydrogels offer in situ formation for tissue engineering but lack mechanical stability.
- Physical cross-links limit their application due to insufficient gel strength and rapid degradation.
Purpose of the Study:
- To enhance the mechanical properties and stability of thermosensitive hydrogels.
- To investigate the potential of photopolymerization for creating covalent cross-links in these systems.
- To assess the cytocompatibility and differentiation capacity of encapsulated cells.
Main Methods:
- Triblock copolymers with thermosensitive poly(N-(2-hydroxypropyl) methacrylamide lactate) and poly(ethylene glycol) blocks were synthesized.
- Methacrylate groups were attached to the polymer side chains.
- Photopolymerization was performed above the polymer's lower critical solution temperature (LCST) to form covalent cross-links.
Main Results:
- Photopolymerization significantly improved hydrogel mechanical properties and stability, extending degradation from 2 days to 10–25 days.
- Encapsulated goat mesenchymal stem cells remained viable and demonstrated differentiation potential, confirmed by alkaline phosphatase expression and collagen I production.
- The degree of cross-linking influenced the degradation rate of the photopolymerized hydrogels.
Conclusions:
- Photopolymerized thermosensitive hydrogels exhibit enhanced mechanical properties, prolonged stability, and adequate cytocompatibility.
- These improved hydrogels show high potential for various tissue engineering applications.
- Covalent cross-linking via photopolymerization is an effective strategy to overcome the limitations of physically cross-linked thermosensitive hydrogels.
