Multi-cellular tumor spheroids formation of colorectal cancer cells on Gelatin/PLCL and Collagen/PLCL nanofibrous scaffolds

Abstract

In recent years, more attention has been drawn to development of three-dimensional in-vitro tumor models, Multi Cellular Tumor Spheroids (MCTS), due to their similarity to in vivo tumors models. Interaction of tumor cells with the extracellular matrix (ECM) has an important role in stimulating microenvironmental signaling and MCTS formation. Recently, a number of scaffolds based on natural-nano pattering have been proposed which can superbly mimic the topographical and biochemical features of ECM. In this study, we investigated whether the natural-synthetic polymer nanofibers can promote the three-dimensional (3D) MCTS formation of HT29 colorectal cancer cells in compare to synthetic nanofibers. Nanofibers were fabricated by blending of collagen (Col) and gelatin (Gel) with poly (L-lactide co-ε-caprolactone) (PLCL) polymer, separately. Generally, nanofibers exhibited proper structural properties in term of morphology, hydrophilic nature and mechanical integrity. The results revealed that HT29 colorectal cancer cells can form 3D spheroids with uniform morphology and smooth surface on both Col/PLCL and Gel/PLCL nanofibers while the spheroids were unstable and irregular in shape on PLCL nanofibers. In addition, the cells were dispersed on non-coated plates as confluent cell monolayer. There were no significant differences between the number and diameter of MCTSs on both Col/PLCL and Gel/PLCL nanofibers. On the other hand, the radio resistance of cells on Col/PLCL and Gel/PLCL nanofibers was higher compared with either PLCL nanofibers or non-coated plates. In conclusion, the results showed that scaffolds provided by Col/PLCL and Gel/PLCL nanofibers can mimic the properties of ECM in case of in vitro MCTS formation so they can be suggested to use in tumor drug screening studies.