Compared with traditional drug delivery methods, transdermal drug delivery has many advantages in avoiding the side effects in gastrointestinal tract, reducing the fluctuations in drug concentration, and improving patients’ compliance. Among them, electrically controlled drug delivery is a promising solution. The work of Liu et al. (2020) presents a wireless, battery-free and wearable device with electrically controlled drug delivery capability. With the help of smartphone, the device could wirelessly obtain energy and implement data transmission. The drug delivery component is a paper-based electrode modified with polypyrrole, in which non-steroidal anti-inflammatory drug sodium salicylate was encapsulated. The drug release dose and release rates could be controlled by applying potentials with different amplitudes and durations through this device. It provided a minimalized wearable transdermal drug delivery platform for monitoring diseases such as gout.
Joo et al. (2021) studied a novel treatment system for neurological medical emergencies, such as status epilepticus, a fatal epileptic condition that requires immediate treatment, using a soft implantable drug delivery device (SID). The SID is integrated wirelessly with wearable devices for monitoring electroencephalography signals and triggering subcutaneous drug release through wireless voltage induction. Because of the wireless integration, bulky rigid components such as sensors, batteries, and electronic circuits can be moved from the SID to wearables, and thus, the mechanical softness and miniaturization of the SID are achieved (see the featured image above; Photo credit: Hyunwoo Joo, Seoul National University). The efficacy of the prompt treatment could be demonstrated with animal experiments in vivo, in which brain damages were reduced and survival rates were increased.
The emerging trends and latest innovations of wearable glucose monitoring and implantable insulin delivery technologies for diabetes management have been recently reviewed by Zhang et al. (2021). Wearable glucose sensors implanted within diverse platforms including skin or on-tooth tattoos, skin-mounted patches, eyeglasses, contact lenses, fabrics, mouthguards, and pacifiers have enabled noninvasive, unobtrusive, and real-time analysis of glucose excursions in ambulatory care settings. These wearable glucose sensors can be integrated with implantable drug delivery systems, including an insulin pump, glucose responsive insulin release implant, and islets transplantation, to form self-regulating closed-loop systems.
As far as we know there are no wearable drug delivery systems with cyclodextrins. A cellulose/β-cyclodextrin nanofiber patch as a wearable epidermal glucose sensor was developed by Kim et al. (2019). The cellulose/β-cyclodextrin electrospun immobilized glucose oxidase enzyme patch was used for noninvasive monitoring of interstitial fluid (ISF) glucose levels with reverse iontophoresis. CD is a stabilizer of the enzyme and also a shuttle of electrons between the enzyme and the electrode. The sensor makes possible continuous glucose monitoring overcoming the limitations of finger-stick blood sampling.
Joo,H., Lee, Y., Kim, J. et al. (2021) Soft implantable drug delivery device integrated wirelessly with wearable devices to treat fatal seizures. Sci. Adv. 7, eabd4639. https://doi.org/10.1126/sciadv.abd4639
Kim, K.O., Kim, G.J., Kim J.H. (2019) A cellulose/β-cyclodextrin nanofiber patch as a wearable epidermal glucose sensor. RSC Adv., 2019,9, 22790-22794. https://doi.org/10.1039/C9RA03887F
Liu, J., Liu, Z., Li, X. et al. (2020) Wireless, battery-free and wearable device for electrically controlled drug delivery: sodium salicylate released from bilayer polypyrrole by near-field communication on smartphone. Biomed Microdevices 22, 53. https://doi.org/10.1007/s10544-020-00511-6
Jinyuan Zhang, Jian Xu, Jongcheon Lim, James K. Nolan, Hyowon Lee, Chi Hwan Lee (2021) Wearable Glucose Monitoring and Implantable Drug Delivery Systems for Diabetes Management. Adv. Healthcare Mater. https://doi.org/10.1002/adhm.202100194