Implantable Microchip Drug Delivery for Chronic Eye Disease Remains Preclinical After 25 Years

Patients with chronic eye diseases like age-related macular degeneration (AMD) and glaucoma require repeated drug injections into the eye — often every 4–8 weeks for years. An implantable microchip that could store and release precise drug doses on demand would eliminate this burden, but despite being invented at MIT in 1999 and generating multiple patents, $35M+ in partnerships, and a first-in-human trial in 2012, the technology has never reached commercial use. The fundamental challenge is building a device small enough to implant in ocular tissue that can hermetically seal drugs for years, release them with microdose precision, and survive the corrosive biological environment without degradation.

AMD is the leading cause of vision loss in people over 50, affecting approximately 200 million people globally. Current treatment requires anti-VEGF injections directly into the vitreous humor every 4–8 weeks, each costing $1,000–$2,000. Many patients discontinue treatment due to the burden and discomfort, leading to preventable blindness. An implantable delivery system could improve compliance, reduce clinical visits, and potentially deliver drugs more effectively through sustained local dosing rather than periodic bolus injections.

MIT's Microchips Biotech developed MEMS-based reservoir arrays etched into silicon, sealed with thin metal caps that could be ruptured wirelessly to release drug. A key manufacturing challenge was that standard hermetic sealing methods (welding, soldering) use heat that destroys the pre-loaded drugs — the team had to invent a cold-compression bonding technique. A 2012 human trial for osteoporosis drug delivery demonstrated proof-of-concept, but the ocular application proved far harder: the device must be smaller, withstand constant moisture, and deliver nanoliter-precision doses. Teva Pharmaceuticals invested $35M in 2015 but the partnership did not produce a marketed product. Microchips Biotech was acquired by Daré Bioscience in 2019 for just 3 million shares — a fraction of invested capital. As of 2025, Daré's lead product (DARE-LARC1, for contraception, not ocular) remains preclinical. The 98 patents in the portfolio could not compensate for the manufacturing, regulatory, and biological challenges.

Progress requires advances in biocompatible hermetic packaging at microscale (keeping drugs stable inside the body for years), ultra-low-power wireless communication and actuation, and biodegradable or bioresorbable reservoir materials that eliminate the need for device removal. Emerging hydrogel-based sustained-release implants (e.g., Genentech's port delivery system) represent a simpler alternative that has recently gained regulatory traction, suggesting the drug delivery problem might be better solved with materials science than with MEMS electronics.

A student team could prototype a simplified single-reservoir ocular drug delivery device using biodegradable polymer encapsulation, testing drug release kinetics in a simulated vitreous humor environment. Alternatively, a team could design a benchtop model comparing controlled-release profiles from MEMS-like pulsatile delivery versus polymer-based sustained release. Skills in biomedical engineering, microfabrication, polymer chemistry, and pharmacokinetics would be most relevant.