Albany 2013: Book of Abstracts

category image Albany 2013
Conversation 18
June 11-15 2013
©Adenine Press (2012)

Encapsulation of Antitumor Drugs Tamoxifen, 4-Hydroxytamoxifen and Endoxifen by Chitosan Nanoparticles

Synthetic polymers are often used as drug delivery systems in vitro and in vivo (Shi et al., 2009). Here, we used biodegradable chitosan of different sizes to encapsulate antitumor drug tamoxifen (tam) and its metabolites 4-hydroxytamoxifen (hydroxytam) and endoxifen (end). The interactions of tamoxifen and its metabolites with chitosan 15, 100 and 200 KD were investigated in aqueous solution, using FTIR, fluorescence spectroscopic methods and molecular modeling. The structural analysis showed that tamoxifen and its metabolites bind chitosan via both hydrophilic and hydrophobic contacts with overall binding constants of


with the number of drug molecules bound per chitosan (n) 2.8 to 0.5. The order of binding is ch-100>200>15 KD with stronger complexes formed with 4-hydroxytamoxifen than tamoxifen and endoxifen. The molecular modeling showed the participation of polymer charged NH2 residues with drug OH and NH2 groups in the drug-polymer adducts. The free binding energies of -3.46 kcal/mol for tamoxifen, -3.54 kcal/mol for 4-hydroxytamoxifen and -3.47 kcal/mol for endoxifen were estimated for these drug-polymer complexes. The results show chitosan 100 KD is a stronger carrier for drug delivery than chitosan-15 and chitosan-200 KD, which is consistent with our recent report on doxorubicin-chitosan complexes (Sanyakamdhorn et al., 2013).


    M. Shi, K. Ho, A. Keating and M. S. Shoichet. Doxorubicin-conjugated immuno-nanoparticles for intracellular anticancer drug delivery. Adv. Funct. Mater. 19, 1689-1696 (2009).

    S. Sanyakamdhorn, D. Agudelo and H. A. Tajmir-Riahi. Encapsulation of antitumor drug doxorubicin and its analogue by chitosan nanoparticles. Biomacromolecules in press (2013).

H. A. Tajmir-Riahi*
D. Agudelo
S. Sanyakamdhorn

Departement de Chemistry-Biology
University of Québec in Trois-Rivières
C. P. 500, Trois-Rivières (Québec), G9A 5H7, Canada