3D cancer tumor models for evaluating chemotherapeutic efficacy

The in vitro evaluation of chemotherapeutic delivery systems is essential as a prediction of in vivo chemotherapeutic efficacy. Generally, the in vitro therapeutic efficacy of chemotherapeutic agents is evaluated by using cellular monolayers cultured in a flat-bottomed plastic culture dish prior to expensive and arduous in vivo studies. Despite its ease of handling, cellular monolayers have provided poorly correlated outcomes of in vivo chemotherapeutic efficacy. Morphological differences among the tumor cells and lack of cell-cell and cell-extracellular matrix (ECM) interactions in two-dimensional (2D) culture environment contribute to the discrepancies in cellular drug responses; in vivo cells are exposed to a 3D microenvironment that is regulated with respect to interactions with the surrounding cells, growth factors, and other biomolecules. Hence, there is a strong need for the development of in vitro 3D tumor models that closely mimic the in vivo microenvironment. A successfully developed in vitro tumor model will provide predictable outcomes of efficiencies of new drug delivery systems. It will also improve the understanding of drug delivery mechanisms to develop more efficient drug delivery systems.