Spectral ami ht

To visualize the drug release mechanics in vivo, we used a fluorescent imaging system (Spectral AMI HT, Spectral Instruments Imaging, LLC., Tucson, AZ, USA). We fabricated three devices with 20 μL of indocyanine green dye (ICG, Fisher Scientific, Waltham, MA, USA). To aid in the quantification of released drug amount, we created a standard curve using the ICG dye with concentrations ranging from 2 μg/mL to 25 μg/mL (SI Fig. 2). We subcutaneously implanted each device into 3 male C57BL/6 mice obtained from an in-house colony. Each animal was anesthetized with an initial injection of Buprenorphine (0.05–0.1 mg/kg) and with 1–3% Isoflurane in 1 L/min O₂ during the implantation, device activation, and imaging. For implantation, a 1-mm incision was made in the left dorsum and the skin was separated from underlying connective tissue to create a subcutaneous pocket. The device was then inserted into the pocket and the incision sutured closed. After the implantation, mice were imaged every 10 min for 40 min prior to the activation of the implanted device to quantify any drug leakage. We then activated each device for 60 s using our bespoke magnetic field generator, and each animal was imaged for an additional 30 min post-activation. All procedure were performed with approval from the Purdue Animal Care and Use Committee.