Molecularly Imprinted Polymer-modified Microneedle Array for Smart Active Triggered Drug Release

The skin, the largest organ in the human body, provides several benefits for drug delivery. These advantages stem from its expansive surface area and the avoidance of the first-pass metabolism in the gastrointestinal tract. This, in turn, enhances drug bioavailability and minimizes potential side effects [1]. Currently, transdermal drug delivery (TDD) relies on topical products or transdermal patches. However, these methods face limitations due to the physio-chemical properties that impede their permeation through the lipophilic stratum corneum (SC) and their slow diffusion rate through the skin. To overcome these challenges, microneedles (MNs) have been developed. These microneedles penetrate the SC in a minimally invasive manner, creating "micro-conduits" that facilitate the transport of drugs into the skin tissue from the skin surface [2].

Herein, we have developed a microneedle array modified with molecularly imprinted polymers (MIPs) able to entrap bovine serum albumin (BSA) and insulin labeled with fluorescein isothiocyanate (FITC). Several MIPs based on the co-polymerization of o-phenylendiamine and gallic acid (1:1, 1:3 and 1:10) were tested in order to ensure the formation of hydrogen bonds between the polymer and the target. The target release was triggered by an electrochemical and bioelectrochemical oxygen reduction reaction (ORR) occurring at the electrode surface [3].

References

1. Fakhraei Lahiji, S., Kim, Y., Kang, G., Kim, S., Lee, S., & Jung, H. Tissue interlocking dissolving microneedles for accurate and efficient transdermal delivery of biomolecules. Sci. rep. 9(1), 7886 (2019).
2. Oliveira, D., Correia, B. P., Sharma, S., & Moreira, F. T. C. Molecular imprinted polymers on microneedle arrays for Point of Care transdermal sampling and sensing of inflammatory biomarkers. ACS omega, 7(43), 39039-39044 (2022).
3. Bollella, P., Sharma, S., Cass, A. E. G., & Antiochia, R. Minimally‐invasive microneedle‐based biosensor array for simultaneous lactate and glucose monitoring in artificial interstitial fluid. Electroanalysis, 31(2), 374-382 (2019).