Once CSHNs are fully characterized, cell-based in vitro experiments can be initiated to evaluate the therapeutic efficacy of encapsulated drugs and to understand how nanocarriers behave in the biological environment. For this reason, cellular uptake and cytotoxicity assays using various analytical techniques are required to evaluate the efficacy of the developed systems on the desired cell lines. In this context, in vitro cytotoxicity and cellular uptake studies are the most basic in vitro assays that reveal the specificity and efficacy of drug-loaded CSHNs against target cells before in vivo assays are performed. Some of these assays include flow cytometry, MTT or MTS cell proliferation assays, trypan blue staining, clonogenic assays, ATPLite1 step luminescence, and ATP detection assays. Determination of the inhibitory potential of core-shell nanoparticles against various cancer cell lines and their uptake capacity by cells are fundamental approaches that provide information on the efficacy and cytotoxic profile of CSHNs before in vivo studies .