Hydrogels
Water-swollen polymer networks whose softness is the point — the closest synthetic analogue to soft tissue.
A hydrogel is a crosslinked polymer network holding a large volume of water. That composition makes it mechanically similar to soft tissue, and it is why hydrogels dominate wherever the target is not bone: cells can be suspended within them in three dimensions rather than sitting on a surface.
Stiffness is a design variable, not an afterthought. Because cells read matrix mechanics — see The extracellular matrix — gel stiffness can push differentiation toward one lineage or another independently of any added factor. Hydrogels are also natural depots for controlled release, and most bioinks in bioprinting are hydrogels, chosen to balance printability against cell survival.
They can be natural (collagen, alginate, fibrin) or synthetic (PEG-based), trading biological signalling against defined, reproducible composition. In dental work they appear as injectable scaffolds for pulp regeneration, where the space to be filled is irregular and reachable only through a narrow opening.
Related articles
- BiomaterialsScaffold design principlesPorosity, strength, and degradation rate — the competing requirements every scaffold has to reconcile.
- FoundationsBiofabrication and 3D bioprintingBuilding tissue constructs layer by layer — depositing cells and matrix with spatial control.
- SignalingControlled release kineticsGetting the right signal to the right place at the right time — for the right duration.
- CellsStem cell differentiationHow an uncommitted cell chooses a fate — under chemical, mechanical, and spatial instruction.
- DentalRegenerative endodonticsRestoring a tooth's living pulp rather than replacing it with filling material — promise and present limits.
- Biomaterials3D-printed bone scaffoldsAdditive manufacturing lets scaffold architecture be specified directly — and patient-specific.