Gene vectors are of great importance in gene therapy .Non-viral gene vectors gain most attention as viral gene vectors have shown a series of safety problems during clinical application .Chitosan is one of the best potential non-viral gene vectors because of its excellent physico-chemical and biological properties .In recent years

a lot of works have been done on chitosan and its modification for gene delivery

and valuable progresses have been achieved .In this paper

recent progress in chitosan and its modification for gene delivery are reviewed in detail in terms of size

stability

specific targeting ability and transfection efficiency of chitosan/DNA complex for different cells .