Bio-inspired design of a magnetically active trilayered scaffold for cartilage tissue engineering

An important topic in cartilage tissue engineering is the development of biomimetic scaffolds which mimic the depth-dependent material properties of the native tissue. We describe an advanced trilayered nanocomposite hydrogel (ferrogel) with a gradient in compressive modulus from the top to the bottom layers (p < 0.05) of the construct. Further, the scaffold was able to respond to remote external stimulation, exhibiting an elastic, depth-dependent strain gradient. When bovine chondrocytes were seeded into the ferrogels and cultured for up to 14 days, there was good cell viability and a biochemical gradient was measured with sulphated glycosaminoglycan increasing with depth from the surface. This novel construct provides tremendous scope for tailoring location-specific cartilage replacement tissue; by varying the density of magnetic nanoparticles, concentration of base hydrogel and number of cells, physiologically relevant depth-dependent gradients may be attained.