Cryogenically fabricated three-dimensional chitosan scaffolds with pore size-controlled structures for biomedical applications

A cryogenic plotting system and manufacturing stage was designed to fabricate three-dimensional (3D) chitosan scaffolds for tissue regeneration applications. The combination of cryogenics and freeze-drying yielded highly porous and structurally stable 3D chitosan scaffolds. The pore size of the chitosan scaffold, which varied from 90 to 400 μm, was reproducibly dependent on processing parameters. Crosslinked chitosan scaffolds exhibited rough surfaces and were stable with regard to shapeability and pore size. During the process, changes in the dimensions of the final scaffold, due to shrinkage and swelling, were within ±10% of the dimensions specified in the initial design. MG-63 cells were cultured on the fabricated scaffolds to evaluate the structures as substrates for tissue regeneration. Cell proliferation on the structured scaffolds was higher than on conventional spongy-type chitosan scaffold. In particular, scaffolds with 200-μm mean pores exhibited the highest rate of cell proliferation.