Pressure-Triggered Microfluidic Contact Lens for Ocular Drug Delivery

Abstract

Microfluidic technology has been used for precise drug delivery for many years, but microfluidic wearable devices have mostly been used for skin drug delivery. The application of eye drops is currently one of the most common ways to treat eye diseases. However, due to their low corneal bioavailability and short residence time in tears, topical eye drops must be applied multiple times a day. Contact lenses, as a wearable device for the eye, are a good platform for drug delivery. In this paper, we propose a type of microfluidic contact lens that integrates a microchannel and a micropump and uses a pressure source to trigger the release of a drug. Here, a flat microfluidic chip component is first fabricated by photolithography and then cast into a curved surface by secondary thermosetting. Through experiments, the outlet check valve opening pressure and liquid flow test were studied to prove that the liquid release is controllable. In addition, the microfluidic contact lens has good flexibility, light transmittance, and biocompatibility. Finally, we demonstrate through fluorescence experiments that the microfluidic contact lens can be loaded with different types of drugs in different regions. In general, liquid exchange between the eye and the contact lens can be realized through the mechanical action of blinking without using electronic components, meaning more safety and stability. The mechanical characteristics of a blink can be artificially regulated to a large extent; thus, it is also possible to achieve specific, personalized medicine.

Smart Contact Lenses as Wearable Ophthalmic Devices for Disease Monitoring and Health Management

“…This mechanism enables controlled and localized drug delivery directly to the eye, providing therapeutic efficacy and reducing the need for frequent application of eye drops or systemic drug administration. Du et al conducted experiments to confirm that the release of liquid can be controlled . They investigated the opening pressure of the outlet check valve and conducted liquid flow tests.…”

“…Du et al conducted experiments to confirm that the release of liquid can be controlled. 403 They investigated the opening pressure of the outlet check valve and conducted liquid flow tests. They developed a microchannel and circular micropump to ensure effective drug release.…”

Nanocarrier‐Based Drug Delivery Systems using Microfluidic‐Assisted Techniques

“…B) Reproduced with permission. [ 113 ] Copyright 2022, American Chemical Society. A) Wireless‐controlled drug‐releasing mechanism.…”

“…[ 112 ] A microfluidic‐based contact lens was fabricated by Du et al for ocular drug delivery. [ 113 ] They demonstrated that the contact lens delivered drugs to the eye in a safer and more controllable way without the use of any electronic components (Figure 7B). As per literature reviews, not many microfluidic drug delivery in vitro systems based on a mechanically controlled pressure‐driven approach are reported, and none of them have been demonstrated in vivo.…”

“…Copyright 2021, Springer Nature. B) Reproduced with permission [113]. Copyright 2022, American Chemical Society.…”