Study on galactosylated sodium alginate for enhancing HepG2 Cells adhesion and 3D printability

Sodium alginate is a polyanionic natural polysaccharide polymer widely used in tissue engineering. However, the lack of binding domains for interaction with cells limits its application in regenerative medicine. This study designed a kind of galactosylated sodium alginate (G-SA) material with improved galactose grafting rate by EDC/NHS activation of carboxyl groups in MES buffer and subsequently cross-linking by Ca²⁺ aims to enhance the adherence behavior of HepG2 cells on alginate substrate. The synthesized G-SA was characterized by Fourier transform infrared spectra and nuclear magnetic resonance spectroscopy. G-SA exhibited good biocompatibility and significantly enhanced the adhesion behavior of HepG2 cells on its surface. Furthermore, we demonstrated that the effect of G-SA concentration in enhancing cell adhesion was diminished at higher than 2% w/v. Finally, the suitability of G-SA material is investigated for 3D printing, demonstrating that HepG2 cells could maintain high viability and excellent printability in the interior of the gel. In addition, cells could multiply and grow into cell spheroids with an average size of 200 μm in G-SA scaffolds. These results indicated that galactosylated sodium alginate material could be used as a 3D culture system that could be effective for engineering liver cancer models.