3D multicellular tumor spheroids used for in vitro preclinical therapeutic screening

The complex tumor microenvironment often hinders the efficient delivery of anticancer therapeutics to the individual tumor cells following three levels of drug disposition. Carrying out trials and tests using animal models for screening of anticancer pharmaceuticals and studying their pharmacokinetics is an unavoidable step before reaching it from bench-to-bedside application. However, various factors like the expenses, time needed to obtain ethical clearances and to achieve conclusive results, have added to the complications of this process. Tumor spheroids have helped in overcoming most of the above-mentioned issues for obtaining promising pre-clinical quick validations, offering a successful diffusion of anticancer pharmaceuticals, leading the testing, screening, and studying the penetration, reaction, stability, and other pharmacokinetic characteristics of anticancer therapeutics rapid, cost effective and more efficient without involving any ethical issues, making it a promising platform for screening and assessment of effectiveness of anticancer pharmaceuticals in anticancer therapy. Finally, we emphasize the impact of nanomedicine's physiochemical characteristics (size, shape, surface charge and surface modifications) on their ability to penetrate and retain within tumor spheroids. It also discusses how the inclusion of 3D in vitro models into screening protocols can improve the efficacy of nanomedicine.