Serum albumin-based nanoparticles (NPs) are commonly used for drug delivery due to their stability, biodegradability, ease of particle size control and no toxicity. In this study, bovine serum albumin (BSA) was functionalized with catechol-containing dopamine (D) to synthesize D-BSA NPs using pH responsive catechol-metal coordination bonds. Instead of using glutaraldehyde, V(III) ion was used as a cross-linker for synthesizing NPs. Catechol-V(III) coordination bonds provided pH responsive NPs due to their different stoichiometry of catechol-metal complexes (e.g. mono-, bis- or tris-) at different pH values. For the synthesis of D-BSA NPs, desolvation method was used with acetone as desolvating agent. Uniformly sized NPs were synthesized with an average of 294 nm with a PDI value of 0.15. Doxorubicin is loaded to NPs with a 15:1 DOX:D-BSA molar ratio. DOX encapsulation efficiency and drug loading capacity of D-BSA NPs were found to be 98% and 10%, respectively. Conversion to bis- and/or mono- catechol-V(III) complexes in acidic medium resulted in degradation of NPs and rapid release of the loaded doxorubicin (DOX). DOX releases reached to 51, 76 and 95% at pH values 7.4, 5.5 and 4.2, respectively at the end of 80 hours. Furthermore, the cytotoxic effects of prepared D-BSA NPs, in comparison to free DOX were studied with MCF-7 cells. Increasing D-BSA concentrations up to 0.2 mg/mL did not affect the cell viability, significantly. But, upon cell (MCF-7) uptake in vitro, DOX-loaded D-BSA NPs and free DOX reduced cell viability by 75% and 20% in 24 hours, respectively.