See references below for related reading.10.1      Introduction and overview10.1.1    Some of the advantages of therapeutic genes10.1.2    Some of the advantages of molecular biosensor feedback control systems10.1.3    Why a nanodelivery approach is appropriate10.2      The therapeutic gene approach10.2.1    What constitutes a "therapeutic gene" ?10.2.2    Transient versus stable expression modes10.3      Molecular feedback control systems10.3.1    Drug delivery has traditionally not used feedback controls10.3.2    Why feedback control might be a very good idea!10.3.3    Positive or negative feedback?10.4      Molecular Biosensors as a component of a nanomedicine feedback control system10.4.1    What is a molecular biosensor?10.4.2    How a molecular biosensor functions as a therapeutic gene switch10.5      Building integrated molecular biosensor/gene delivery systems –some examples10.5.1    Example of a ribozyme/antivirus system10.5.2    Example of an ARE biosensor/DNA repair system10.5.3    Example of a feedback-controlled system for treatment of retinopathies