Analysis of hydrogels for immobilisation of hepatocytes (HepG2) in 3D cell culturing systems

Abstract: In pharmaceutical development cell cultures are used as in vitro models to evaluate the function of drug candidates. In such research it is vital to have models that resemble the in vivo environment to get reliable results. In 3D models with hydrogels ECM like scaffolds are supporting the cells in a more in vivo like environment than flat 2D cultures. In this project PEG-peptide based hydrogels with cell binding RGD incorporated on one PEG-peptide type has been evaluated for culturing of HepG2 cells. Structure and viscoelastic properties were evaluated with techniques like circular dichroism spectroscopy, dynamic light scattering and rheology. Sterilisation impact was also evaluated for PEG-peptides. For cell culturing, observations in light microscope and evaluation with Live/Dead assay and albumin assay were performed. A few companies were interviewed regarding 3D culturing and interest in mechanically tuneable hydrogels. The HepG2 cells grows and forms spherical clusters in the 3D environment with hydrogels, percentage of RGD seems to not impact cell adhesion, growth or albumin secretion. UV irradiation was the most suitable sterilisation method for gel components. The most rigid gel combination formed had storage modulus of around 230 Pa. Mechanically tuneable hydrogels is interesting for the industry. The PEG-peptide based gels are suitable tor growing cells but too soft to closely resemble the in vivo rigidity of hepatocytes.