Display omitted •~6 nm β-cyclodextrin-conjugated dextran-coated magnetic Ni1.04Fe1.96O4 NPs are prepared.•Enhanced camptothecin loading and sustained release are observed.•Stimuli-responsive (pH-dependent) release of the drug from the nanocarrier occurs.•The efficacy of the drug-loaded nanocarrier is intense on cervical, breast, and lung cancer cells.•The material works as a pH-responsive and host: guest complexation-based drug vehicle. This paper fortifies the idea of smart drug vehicles, by exploring nickel ferrite nanoparticles. The material is made smart by covering with a novel biocompatible dextran fastened with a hydrophobic cavity containing molecule, β-cyclodextrin (β-CD). The approximately 6 nm MNPs, embodied with the β-CD-dextran conjugate, permit a sustained in vitro release of camptothecin. Cytotoxicity studies are done on HaCaT, 3T3, HeLa, MDA-MB-231, and A549 cell lines. It is fascinating the stacked camptothecin indicates upgraded viability against cancer cells, rendering the nanocarrier viable for transporting the anticancer drug.