Sayed Alireza Hassani Najafabadi - Department of Chemistry, Amirkabir University of Technology, P.O. Box 1587/4413, Tehran. Iran.
Majid Abdouss - Department of Chemistry, Amirkabir University of Technology, P.O. Box 1587/4413, Tehran. Iran.
Shahab faghihi - Department of Molecular Genetic, National Institue of Genetic, P.O. Box 14965/161, Tehran. Iran.

the seaweed-derived alginate, which is a family of unbranched copolymers, composed of alternating block of 1-4 linked  -l-guluronic acid (G-block) and  -D-mannurunicacid (M-block) residues is a famous member of the hydrogel super family that has found some applications in cellencapsulation, drug delivery and macromoleculeimmobilization due to its wonderful properties [1]. With its non toxic nature and gentle sol/gel transition procedure andthe ease of its utility as an ionically cross linked polymer, its inferior biomechanical properties have limited its applicationespecially in cartilage tissue engineering. Additionally, ionically cross-linked alginate hydrogels generally lose most of their initial mechanical and swelling properties within a fewhours in biological buffers containing calcium chelators or monovalent electrolytes [2]. In the present work the synthesis and properties of newhydrophobically modified alginate hydrogels as a mesynchimal stem cells carrier was investigated.