Stimuli-responsive gene delivery vectors.
One of the major limitations to efficient gene delivery mediated by synthetic non-viral vectors is the presence of various barriers between the site of administration and localization in the cell nucleus. Each of the barriers often demands significantly different properties from the vector. Delivery vectors that can recognize changes in the environment and that are capable of actively responding by altering their properties or behavior are therefore being developed to address the challenge of integrating the sometimes contradictory characteristics necessary for effective gene delivery. This review discusses recent developments in the area of gene delivery vectors capable of responding to various endogenous and exogenous stimuli by changing their properties or behavior.