Next, the efficacy of using CU(βCD)2-Psomes as a strategy to target cervical cancers was evaluated. For this purpose, the impact of Empty-Psomes, CU(βCD)2-Psomes and CU(βCD)2-Psomes pre-treated at pH 5 was investigated on the proliferation by using Hela cervical cancer cells. A range of concentrations was studied from 50-0.125 µg mL , pursuing a compromise between a safe concentration of BCP (Empty-Psomes) and a therapeutic concentration of CU, and all samples were incubated for 24, 48 and 72 h (Fig- ). Cell proliferation was assessed by MTT assay (for consistency, concentrations for each condition are indicated as a function of BCP concentration). Firstly, it can be observed that the safest concentration of Empty-Psomes varies over time, concluding a concentration of 1 µg mL -1 as consistently safe throughout, while acceptable viability up to 25 µg mL -1 at all times. The second conclusion is that the presence of CU(βCD)2 in the loadings is slightly observed, which shows that CU complex is retained at physiological pH. This is consistent with the release profile of CU from CU(βCD)2-Psomes (Figure ) and the requested permeability characteristics of hydrophobic Psomes D membrane (Figure and S11A) for CU post-loading. Nevertheless, following short pre-treatment of CU(βCD)2-Psomes in an acidic environment, cytotoxicity of released CU from CU(βCD)2-Psomes is observed across nearly all concentrations (Figure ). This demonstrates that CU is released rapidly in response to a drastic pH change. Moreover, if the concentration of Psomes is greatly decreased, antitumor activity is still observed.