Prof. Jin Nam and colleagues from the University of California, Riverside have developed a stimulus-responsive drug delivery system, based on electrospun piezoelectric nanofibrous membranes. The drug release characteristics of these nanofibers can be fine-tuned by modulating their piezoelectric properties via fiber size control, thus the sensitivity of the material to the magnitude and frequency of the applied pressures. In this regard, stimuli-responsive drug delivery systems are promising methods in overcoming the pharmacogenetics associated vulnerabilities in response to systemic drug administration, by controlling when, where, and how much drug is released to accommodate a more personalized therapy. Fig 1: Model drug release from nanofibrous membranes composed of 70 nm average fiber diameter in vivo in response to mechanical stimulation. The membranes were conjugated with a fluorescence dye (Vivotag) and implanted under vastus lateralis near femur in rats. The release of the drug under non-invasive mechanical activation was determined by in vivo fluorescence imaging. ** indicates p < 0.01.