Safe and efficient delivery of nucleic acid constructs to target cells has great potential for the treatment of genetic diseases. Non-viral gene delivery has attracted considerable attention because of large-scale production, immunogenicity and safety concerns. Whereas, non-viral gene delivery still suffered from low transfection efficiency and lack of selectivity, which is the main target on this field. The gene delivery based on cyclodextrin (CD) can offer the possibility for construction of various multi-functional gene deliveries. As a FDA approved bio-material, CDs have been extensively used for gene delivery because of their ability to stabilize the nucleic acids in biological media and their ability to destabilize and permeate biological membranes and for obviating undesirable side effects. CD is not only a widely used host molecule capable of internalizing guest molecules in water, but also a core with abundant OH groups. Therefore, a variety of nonviral vectors have been explored based on CD's host-guest interaction and core structure. Recently, CD modified gene delivery has achieved to the clinic test with remarkable result, showing great potential application. In this review the newest development of the gene delivery based on cyclodextrin is summarized. The article provides detail information about the rotaxanes type, side-chain type, star-shape type and branched type deliveries of nucleic acid. Furthermore, the advantage of CD based gene delivery is emphasized herein, which has been applied in clinical test.

Contents
1 Introduction
2 Gene delivery based on cyclodextrin
2.1 Rotaxane type gene deliveries
2.2 Side-chain type gene deliveries
2.3 Star-shape type gene deliveries
2.4 Branched type gene deliveries
2.5 Other type gene deliveries
3 Conclusion and outlook