Ion-responsive alginate based macroporous injectable hydrogel scaffolds prepared by emulsion templating.
Shengzhong Zhou1, Alexander Bismarck, Joachim H G Steinke
1Department of Chemical Engineering, Polymer & Composite Engineering (PaCE) Group, Imperial College London, South Kensington Campus, London SW7 2AZ, UK. a.bismarck@imperial.ac.uk.
Journal of Materials Chemistry. B
|April 9, 2020
Summary
Researchers developed ion-responsive, biocompatible macroporous hydrogels using high internal phase emulsion templating. These alginate hydrogels offer tunable properties and can be reformed into scaffolds after extrusion, showing promise for tissue engineering.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Tissue Engineering
Background:
- Developing advanced hydrogels with controlled porosity and ion responsiveness is crucial for biomedical applications.
- Alginate-based materials are widely explored due to their biocompatibility and tunable properties.
Purpose of the Study:
- To synthesize ion-responsive, biocompatible macroporous hydrogels using high internal phase emulsion (HIPE) templating.
- To investigate the tunability of hydrogel properties (dimensions, pore size, water uptake) via calcium ion (Ca 2+ ) concentration.
- To assess the injectability, reformability, and biocompatibility of the developed alginate polyHIPE hydrogels.
Main Methods:
- Synthesis of macroporous hydrogels via oil-in-water (o/w) HIPE templating using methacrylate-modified alginate.
- Crosslinking of alginate in the aqueous phase, followed by removal of the oil phase to form hydrogel monoliths.
- Evaluation of ion-responsive behavior, mechanical properties (storage moduli up to 20 kPa), cytotoxicity, injectability, and scaffold reformation capabilities.
Main Results:
- Macroporous alginate polyHIPE hydrogels with interconnected pore structures were successfully synthesized.
- Hydrogel properties, including pore size and water uptake, were controllably tuned by Ca 2+ ion concentration.
- The ionic crosslinks were reversible, allowing dissolution with sodium citrate and reformation of hydrogel fragments into scaffolds.
- Cytotoxicity assays confirmed the biocompatibility of the hydrogels.
- Extrusion resulted in small fragments (1-3 mm) that retained pore morphology and could be reformed into coherent scaffolds.
Conclusions:
- Ion-responsive alginate polyHIPE hydrogels with tunable properties and interconnected porosity can be fabricated using HIPE templating.
- The reversible ionic crosslinking and ability to reform into scaffolds after injection make these hydrogels promising for minimally invasive tissue engineering applications.
- The demonstrated biocompatibility and mechanical properties further support their potential use in regenerative medicine.
