Molecular Interactions between a Novel Soybean Oil-Based Polymer and Doxorubicin

Authors: ABDEKHODAIE, MOHAMMAD - University Of Toronto; Liu, Zengshe - Kevin; Erhan, Sevim; WU, XIAO - University Of Toronto

Submitted to: American Association of Pharmaceutical Scientists
Publication Type: Abstract Only
Publication Acceptance Date: 11/8/2009
Publication Date: 11/8/2009
Citation: Abdekhodaie, M.J., Liu, Z., Erhan, S.Z., Wu, X.Y. 2009. Molecular Interactions between a Novel Soybean Oil-Based Polymer and Doxorubicin [abstract]. American Association of Pharmaceutical Scientists.

Interpretive Summary:

Technical Abstract: A novel soybean oil-based polymer, hydrolyzed polymers of epoxidized soybean oil (HPESO), was developed and investigated for drug delivery. This work was aimed at determining the molecular interactions between HPESO and doxorubicin (DOX), an anticancer drug. Powder X-ray diffraction, ATR-FTIR and 1H-NMR spectroscopy were used to examine the molecular interactions between HPESO and doxorubicin. To load doxorubicin into HPESO, 20 mg of DOX was added to 2 ml of 5 mg/ml HPESO solution at 60 deg C and mixed for 30 minutes. The resultant mixture was lyophilized to obtain a powder of HPESO loaded with DOX (HPESO-DOX) for further analyses. The self diffusion coefficients of HPESO-DOX, HPESO and DOX were measured using PGSE-NMR spectroscopy. Powder X-ray diffraction patterns of HPESO, HPESO-DOX, and pure DOX were obtained. The diffraction peaks associated with crystal structures of the drug or HPESO were observed. However, these peaks were absent in the HPESO-DOX, indicating that HPESO-DOX powder existed in an amorphous form probably due to complexation of DOX with HPESO. The absence of the characteristic peaks of functional groups of DOX in the FTIR spectrum demonstrated the drug-polymer interactions at the position of the amino group. Comparing 1H-NMR spectrum of DOX with HPESO-DOX revealed significant changes in the chemical shifts and the shape of the peaks. For example the chemical shift of 3-NH2 proton changed from 3.5 to 3.7 ppm while the chemical shift of aromatic proton resonance changed from 7.3 to 7.6. The resonance at ca. 2.75 ppm in the spectrum of HPESO disappeared in that for HPESO-DOX. The diffusion coefficient of HPESO-DOX was much lower than that of HPESO and the diffusion coefficient of HPESO was smaller than that of DOX. Since diffusion coefficient depends on the size of molecule, the difference between the diffusion coefficient of HPESO loaded with drug and HPESO demonstrated the presence of aggregates formed by HPESO and DOX. Powder X-ray diffraction, ATR-FTIR, 1H-NMR, and PGSE-HMR spectroscopy confirmed the presence of molecular interactions between HPESO and DOX.