Nanofluidic Implants for Better Health: More precise administration of drugs and hormones is needed to better treat chronic pathologies including diabetes, cancer, rheumatoid arthritis, HIV PrEP and others. A team led by the Houston Methodist Research Institute will describe implantable nanofluidic devices for precisely timed, highly localized, remote-controllable and sustained administration within the body. Key to these devices are robust silicon nanochannel membranes, through which the drugs and hormones are diffused. One implant, for long-term use, consisted of a nanochannel membrane affixed to a titanium reservoir, refillable through the skin via loading ports. Another, designed to deliver drugs directly into tumors, had the membrane affixed to one end of a small cylinder (1.1mm wide/3.5mm long). It was implanted in mice to deliver immunotherapeutic antibodies to a triple-negative breast cancer tumor, and its precisely targeted delivery over 14 days led to significant inhibition of tumor growth. A battery-operated implant, meanwhile, showed the ability to control drug delivery rates from outside the body. Platinum electrodes were deposited on the membrane’s surface, and application of a 1.5 V electric field generated an ionic concentration polarization on the membrane. Controllable via Bluetooth, the polarization enables the membrane’s permselectivity to be modified remotely. Finally, the researchers 3D-printed a subcutaneous cell encapsulation device with microreservoirs containing human pancreatic beta islet cells, which produce insulin. The device and the cells were connected to surrounding tissue via an array of 100µm microchannels and the sustained release of insulin from the beta islet cells was performed for more than 22 weeks in mice, with no need for pumps.
The left image shows a photo and a schematic of the internal structure of the remote-controllable drug-delivery platform.
The right image is a rendering of the implantable dell encapsulation device.
(Paper 10.1, “Nanofluidics for Cell and Drug Delivery,” N. Di Trani et al, Houston Methodist Research Institute/Politecnico di Torino)