Three-dimensional printing of collagen and hyaluronic acid scaffolds with dehydrothermal treatment crosslinking

Scaffolds of collagen and collagen with hyaluronic acid were fabricated using 3D printing and crosslinked by dehydrothermal treatment. Rheological measurements of both these dispersions revealed high values of viscosity and a shear thinning behaviour. Fourier transform spectrometry indicated an increased amide bone formation when hydrothermal treatment was applied, with scanning electron microscopy revealing different pore size distributions in the scaffolds with micro- and nano-fibres. The cross-linking treatment in both scaffolds improved resistance to collagenase and elastic mechanical properties, whereas those with hyaluronic acid showed higher resistence solubilization than scaffolds without treatment in a short time at physiological conditions. The swelling ratio of all crosslinked scaffolds decreased, but this treatment prevented disintegration of collagen with hyaluronic acid scaffolds in aqueous medium. Additionally, the cytotoxicity for Vero and NIH3T3 cells showed that the collagen scaffold extracts were not cytotoxic, whereas extracts from collagen plus hyaluronic acid crosslinked scaffolds were cytotoxic only for Vero cells. In vitro evaluation using BJ cells from human skin demonstrated that all scaffolds had the ability to support cell attachment and proliferation. These results revealed that the properties of the 3D printed scaffolds based on collagen and hyaluronic acid could be modified by dehydrothermal treatment, with the materials obtained provide the support required in tissue engineering.