Emerging properties of hydrogels in tissue engineering

Abstract

Hydrogels are three-dimensional polymeric networks filled with water and mimic tissue environments. Therefore, they are considered optimal to deliver cells and engineer damaged tissues. The hydrogel networks have been significantly modified to endow biochemical functionality with adhesive ligands, growth factors, or degradable sites that are helpful to drive proper cell functions. Recently, some of the biophysical properties of hydrogels have emerged as key players in dictating cell fate. Beyond static stiffness, time-dependent stress/strain changes in the interaction with cells and the cell-mediated degradation and matrix synthesis have been demonstrated to shape cell status and tissue repair process. We highlight here the emerging biophysical properties of hydrogels that can motivate tissue engineers to design and develop hydrogels optimally for tissue regeneration.

Keywords: Hydrogels; biophysical parameters; cell fate; stiffness; tissue regeneration.

Figure 1.

Schematic diagram showing the key parameters in hydrogel–cells’ dynamic interactions. Beyond the static physical–chemical properties of hydrogels (e.g. stiffness, ligand density, porosity), dynamic changes (stress relaxation, matrix degradation and matrix formation) with time (f(t)), induced by the interactive cells, are considered as critical factors in determining cell fate and tissue regeneration.