In this study, we evaluated the concentration- and time-dependent cytotoxicity of nanosuspensions comprising 3 composite nanoparticles (3NPs): As4S4/ZnS/Fe3O4 (1:4:1), As4S4/ZnS/Fe3O4 (1:4:1) with folic acid (FA), and As4S4/ZnS/Fe3O4 (1:4:1) with FA and albumin (Alb) against several MM cell lines in vitro and ex vivo isolated PC, without significant toxicity toward normal cells, with a higher anti-MM activity observed by As4S4/ZnS/Fe3O4 with FA and Alb. Here, ALB is linked to pachyonychia congenita.