Stimuli-Responsive Polymer-Based Micro- and Nanoscale Theranostics

Most conventional chemotherapeutics have narrow therapeutic windows, and thus their delivery remains challenging and often raises safety and efficacy concerns. Theranostic platforms, with simultaneous encapsulation of therapeutic and diagnostic agents, have been proposed as next-generation formulations which can overcome this issue. We have shown in recent studies that co-encapsulation of superparamagnetic iron oxide nanoparticles (potent magnetic resonance imaging [MRI] contrast agents) and chemotherapeutic active ingredients into nanoscale fibers and nano-microscale particles produces formulations from which drug release can be directly quantified from the MRI signal. We have, using a range of polymer processing technologies (electrospinning, electrospraying, spray drying), generated systems appropriate for oral and implant delivery. The incorporation of pH-responsive and/or thermoresponsive polymers allows both drug and contrast agent release to be controlled via endogenous or exogenous stimuli. This presentation will summarize our recent findings in this field, exploring the effect of formulation composition and morphology on the functional performance.