~ 45 ~ ORIGINAL ARTICLE Theoretical Study on Physicochemical and Geometrical Properties of Doxorubicin-PEG-FOL Nanoparticles and Daunorubicin-PEG-FOL Nanoparticles S.M. Hassani 1 and S. Bagheri 2* 1 Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, Shahrood, Iran 2 Department of Chemistry, Quchan Branch, Islamic Azad University, Quchan, Iran * E-mail: s_bagheri1316@yahoo.com ABSTRACT The physicochemical properties of Doxorubicin–PEG–FOL and Daunorubicin-PEG-FOL ( Doxorubicin and Daunorubicin conjugated to polyethylene glycol–folate nanoparticles) have been estimated using Density functional Theory (DFT) and Hartree Fock(HF) calculations.In this report some geometrical parameters of Doxorubicin-PEG-FOL complex of the conjugated complex and Daunorubicin–PEG–FOL complex of the conjugated complex were investigated using computational methods and physicochemical properties such as Gibbs free energy of solvation (ΔGsolvation),binding energy, partition coefficient, and Dipole Moment (DM) of complexes were investigated. Our results indicate that water-solubility of Doxorubicin–PEG-FOL and Daunorubicin–PEG–FOL are higher than that of Doxorubicin and Daunorubicin. Keywords: Anti-cancer drugs; Molecular geometry; Doxorubicin-PEG-FOL; nanoparticles; Daunorubicin-PEG-FOL. INTRODUCTION Daunorubicin (or daunomycin) and Doxorubicin (or adriamycin or 14-hydroxydaunomycin) are well-known drugs used in cancer chemotherapy. Biochemical data confirms that these drugs make complexes with DNA thereby blocking the any replication or transcription [1-4]. Fig. 1: Structures of Doxorubicin (R = OH) and Daunorubicin (R = H) Some other researchers have illustrated in experimental studies that nano-particulate drug delivery systems containing anti-cancer agents have received much attention due to their unique behavior of accumulating at the tumor site [5-7]. Enhanced Permeation and Retention (EPR) effect has come in focus these days as a major mechanism for its unique bio-distribution profile in the tumor tissue [8, 9]. For selective delivery in a passive targeting approach of the different anti- cancer agents at the tumor, many nano-particulate carriers, such as, polymer conjugates, polymeric micelles, nanoparticles, and liposomes, are used [10, 11]. However, it has been felt that a more effective and active targeting system is needed to further improve the intracellular uptake of medicine in nano-carriers within cancerous cells at the site of tumor [12]. Various targeting moieties or ligands against tumor-cell-specific receptors have been rendered immobile on the surface of nano-particulate carriers in order to deliver them within cells via receptor-mediated endocytosis. For instance, vitamin folic acid (folate) has been utilized broadly as a targeting moiety for various anti-cancer drugs [13-17]. Folate binding protein, a glycosylphosphatidylinositol (GPI) Advances in Bioresearch Volume 3 [2] June 2012: 45 - 48 ISSN 0976 – 4585 © Society of Education, INDIA A A B B R R www.soeagra.com/abr/abr.htm