Research On Drug Screening Model For Endothelialized Liver Cancer Based On 3D Bioprinting

As one of the common malignant tumors,liver cancer has become the third leading cause of cancer death worldwide.Currently,anti-tumor drug screening is an important part of liver cancer drug development.Traditional two-dimensional cell culture is widely used in liver cancer drug screening due to its low cost and ease of preparation.However,there is a big difference between two-dimensional culture and in vivo environment,which leads to the inaccuracy of drug efficacy evaluation.Animal models have always been considered the gold standard for drug testing,but physiological differences between species cannot be ignored.Therefore,constructing a three-dimensional liver cell culture model in vitro to reconstruct liver cancer tissue structure characteristics and microenvironmental properties is helpful to promote the progress of liver cancer drug development.Three-dimensional cell culture models can provide complex cell-cell interactions and cell-extracellular matrix(ECM)interactions,which are a new method for studying liver cancer,including in vitro drug screening or disease mechanism research.Although some progress has been made in constructing three-dimensional liver cancer models as drug screening platforms using engineering technologies such as hydrogel scaffolds and microstructure patterns,reproducing the structural architecture of native liver tumors and the microenvironment of tumor scale is still a challenge.In this study,we based on the gelatin methacryloyl(GelMA)water gel microbeads containing liver cancer cell line C3 A cells and gelatin microbeads containing human umbilical vein endothelial cells(HUVECs)were printed using gel dot extrusion printing technology(DEP)to construct a biomimetic liver lobule-like structure endothelialized liver cancer model.The preparation and performance of the liver lobule-like structure were studied from three aspects: material selection,cell growth,and model application.(1)This paper first studied the physical properties of GelMA material,optimized its printing performance,and explored the influence of material concentration on material porosity,mechanical properties,and swelling rate.Scanning electron microscopy analysis of the internal pores of the material revealed that as the GelMA concentration increased,the material pores became denser and smaller.Mechanical testing showed that the Young’s modulus increased with the material concentration.The swelling rate results showed that the swelling rate of the material decreased with the increase of the material concentration.(2)C3A cells were encapsulated in a hydrogel and printed into liver lobule-like structures with different concentrations of hydrogel,and long-term cultivation was performed to analyze the growth status of the cells during this period.The results showed that the cell growth in the 6%(w/v)GelMA hydrogel structure was better,and there were a large number of cell clusters distributed inside the structure.Compared with other high-concentration materials,the GelMA cell cluster scale was larger,indicating that the 6%(w/v)GelMA hydrogel is more suitable for C3 A cell growth.(3)Finally,based on the construction of the liver lobule-like structure layer,HUVECs were encapsulated in gelatin to print the endothelial cell layer and applied to the drug efficacy testing of the liver cancer drug sorafenib.The results showed that the endothelial cells and C3 A cells were co-cultured in the model,and the addition of HUVECs improved the drug sensitivity of the model,which provided a new idea for the design of in vitro liver cancer models.