Fatemeh Yazdi Samadi - Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
Zohreh Mohammadi - Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
Maryam Yousefi - Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
Sara Majdejabbari - Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran

Chitosan is a biopolymer composed of glucosamine and N-acetylglucosamine units .hich isbiocompatible, non toxic and biodegradable, so it can be a suitable choice for drug/gene deliveryand biomedical applications. Moreover, chitosan is modifiable to improve specificity of delivery ortargeting system, due to existence of t.o functional groups on its backbone (OH and NH2). Whileabout 75% of breast cancer cells express the estrogen receptor (ER), blocking ER function canreduced the risk of advance in breast cancer. Raloxifene belongs to Selective estrogen receptormodulators (SERMs), that are a class of compounds that bind competitively .ith estrogen receptorsand depending on the structure and position, act as agonist or antagonist of these receptors.Raloxifene sho.s antagonist actcivity in breast and uterus.In this study, raloxifene-chitosanconjugate .as synthesized as a potential ER targeting vehicle to breast cancer cells. conjugation ofraloxifene to chitosan .as performed by different methods. The conjugates .ere investigated bymeans of FTIR, TGA and physical properties assessments. In addition, Cell viability .as evaluatedusing XTT assay. FTIR and TGA results confirmed that the conjugation bet.een chitosan andraloxifene occurred more efficiently .hen trimethyl chitosan in the presence of triethylamine andexcess amount of linker .as used. XTT assay on MCF-7 cell line illustrated that more than 80% ofcells .ere viable after 2g hours exposure to selected molecules. These findings confirm that theconjugation of raloxifene-chitosan can occur successfully using special synthesis condition and thisnovel chitosan derivative can be introduced as a potential drug/gene targeting agent.