Biocompatible and biodegradable doxorubicin loaded nanoparticles with targeting ability were prepared from BSA-dextran-folic acid conjugate via a pH adjustment and heating process. The BSA-dextran-folic acid conjugate was produced by an esterification reaction between folic acid and dextran and then the Maillard reaction between the modified dextran and BSA. The nanoparticles have a size about 90 nm and excellent dispersibility at pH 7.4 aqueous solution. The doxorubicin loading efficiency and loading amount of the nanoparticles are larger than 90% and 14%, respectively. The antitumor activity and toxicity of the nanoparticles were evaluated through murine ascites hepatoma H22 tumor-bearing mice. The nanoparticles allow the administration of the doxorubicin with higher dose. At doxorubicin dose of 10 mg/kg, the nanoparticles can achieve 88.9% of the tumor inhibition rate that is the same as the free doxorubicin at the dose of 5 mg/kg. Importantly, the nanoparticles can decrease the toxicity of doxorubicin that results in a significant increase of the average life time in comparison with the free doxorubicin as well as the nanoparticles without folic acid. (C) 2013 Elsevier B. V. All rights reserved.