Cytotoxicity of free curcumin, curcumin/PEG5K-FTS2 (L), and curcumin/PEG5K-FTS2 (S) against mouse breast cancer cell line, 4T1.2 (a) and human prostate cancer cell lines, DU145 (b), and PC3 (c). Cells were treated for 96 h and cytotoxicity was determined by MTT assay. Values are reported as the means ± standard deviation for triplicate samples