Abstract
The in-vitro experimental model for the development of cancer therapeutics has always been challenging. Recently, the scientific revolution has improved cell culturing techniques by applying three dimensional (3D) culture system, which provides a similar physiologically relevant in-vivo model for studying various diseases including cancer. In particular, cancer cells exhibiting in-vivo behavior in a model of 3D cell culture is a more accurate cell culture model to test the effectiveness of anticancer drugs or characterization of cancer cells in comparison with two dimensional (2D) monolayer. This study underpins various factors that cause resistance to anti-cancer drugs in forms of spheroids in 3D in-vitro cell culture and also outlines key challenges and possible solutions for the future development of these systems.