Electron‑Integrated Controlled Transdermal Drug Delivery - Three High‑quality Papers from Nature‑Family Journal

Microneedle arrays represent a promising minimally‑invasive medical technique for nearly pain‑free transdermal drug delivery. Microneedles penetrate the stratum corneum to build drug transport pathways while avoiding dermal blood vessels and nerve endings to minimize pain and bleeding. To date, chemical modification and physical structural optimization have greatly improved the performance of microneedle‑mediated drug delivery.

Nevertheless, most existing microneedle systems operate in a passive release mode, where drug release is governed mainly by material swelling or dissolution. Dynamic and precise tuning of administration timing and dosage remains challenging. Integrating microneedle arrays with electronic control systems to achieve active, on‑demand transdermal delivery has become a critical bottleneck and a major development direction for next‑generation microneedle medical devices.

This article features three high‑impact papers published in Microsystems & Nanoengineering (a Nature journal). The studies are from the research group of Prof. Peter B. Lillehoj (Rice University, USA), the research team led by Prof. Lelun Jiang (School of Biomedical Engineering, Sun Yat‑sen University), and Prof. Lingqian Chang's group (School of Biological Science and Medical Engineering, Beihang University). They cover three cutting‑edge directions: blood‑free rapid‑diagnostic microneedle skin patch, smartphone‑powered iontophoresis‑microneedle array for controlled transdermal delivery, and micro‑nanodevices for stomatological and ophthalmological diagnosis and therapy. These works provide valuable references for microneedle‑based diagnosis, intelligent drug delivery and expanded cross‑scenario applications.

---Excellent papers worth reading---

01 Microneedle‑based skin patch for blood‑free rapid diagnostic testing

Authors: Jiang, X., Lillehoj, P.B. Journal: Microsyst Nanoeng, 6, 96 (2020) Link: https://www.nature.com/articles/s41378‑020‑00206‑1 (Images courtesy of the authors)

This study presents a hollow‑microneedle integrated skin patch. Instead of blood collection, the device extracts dermal interstitial fluid via microneedles and performs visual protein‑biomarker detection by coupling with colloidal‑gold lateral‑flow test strips. Taking Plasmodium falciparum histidine‑rich protein 2 (PfHRP2, malaria biomarker) as the proof‑of‑concept target, the assay achieves a detection limit down to 8 ng/mL within less than 20 min without bulky instruments. This work demonstrates for the first time the combination of microneedles and lateral‑flow immunoassay, offering a new blood‑free POCT solution for resource‑limited regions.

02 Smartphone‑powered iontophoresis‑microneedle array patch for controlled transdermal delivery

Authors: Yang, J., Li, Y., Ye, R. et al. Journal: Microsyst Nanoeng, 6, 112 (2020) Link: https://www.nature.com/articles/s41378‑020‑00224‑z (Images courtesy of the authors)

Different from conventional passive‑release microneedles, this work develops an IMAP patch combining microneedle arrays with iontophoresis. Powered by a smartphone, it implements an integrated "penetration‑diffusion‑iontophoresis" drug‑administration workflow. After piercing the stratum corneum, microneedles retract; iontophoresis drives insulin‑loaded nanovesicles through skin microchannels. Drug dosage can be dynamically regulated by adjusting electric current intensity. In type‑1‑diabetic rat models, the system sustains normoglycemia for a long time and reduces hypoglycemia risk compared with subcutaneous injection. This work validates that electronic‑microneedle integration enables active, on‑demand transdermal delivery of macromolecular therapeutics.

03 Micro/nanodevices for assessment and treatment in stomatology and ophthalmology

Authors: Sheng, A., Lin, L., Zhu, J. et al. (Corresponding author: Prof. Lingqian Chang) Journal: Microsyst Nanoeng, 7, 11 (2021) Link: https://www.nature.com/articles/s41378‑021‑00238‑1

Moving beyond cutaneous transdermal scenarios, this review extends microneedles and diverse micro‑nanodevices to special mucosal tissues for stomatology and ophthalmology. It systematically summarizes material fabrication, device‑design principles and biosafety considerations of micro‑nanodevices, covering biochemical sensing from cellular to tissue levels, as well as therapeutic strategies targeting oral cancer, keratitis, periorbital wrinkles and oral infectious diseases. Key translational bottlenecks are also discussed. The review calls for interdisciplinary collaboration between clinicians and engineering researchers to accelerate clinical translation of micro‑nano medical devices for oral and eye careNature