ABSTRACT
With the development of polymeric materials and nanotechnology, the potential application of nanoscaled drug delivery system (NDDS) is gradually manifested in the field of pharmaceutics. Especially, NDDS has the obvious advantages in the delivery of gene or drug. Comparing to the delivery system of single-drug, co-delivery system of gene and drug can significantly improve the therapeutic effects by enhancing transfection efficiency of gene and reversing multidrug resistance, etc. The co-delivery systems of gene and drug, which had the triggered release characteristics in the inner and outer of tumor, could be constructed by introducing the environment-responsive (pH-responsive, redox-responsive and light-responsive, etc) groups into the co-delivery system. The antitumor activity was further improved. In the present paper, the environment- responsive delivery systems in the application of co-delivery gene and drug in recent years were reviewed, and their remarkable properties in the antitumor activity were analyzed and summarized.