Cactus thorn‑inspired Janus nanofiber membranes as a water diode for light‑enhanced diabetic wound healing

Diabetic ulcers remain a clinical nightmare: chronic exudate fuels infection, inflammation drags on, and amputation looms for one in four patients. Now, a team led by Prof. Zhigang Chen at Donghua University and Prof. Yu Chen at Shanghai University has translated the cactus thorn’s one-way water transport trick into a photonic Janus dressing that drains, disinfects and repairs all at once. Their design, published in Nano-Micro Letters, hits a 96 % healing rate in diabetic mice within 17 days.

Why a “Water Diode” Matters

· Continuous Exudate Clearance: A hydrophobic-to-hydrophilic gradient pumps fluid upward at 0.95 g cm^-2 h^-1, preventing maceration and wash-out of growth factors.

· On-Demand Sterilization: Embedded chlorin e6 converts 660 nm light into 45 °C heat and singlet oxygen, wiping out 99 % of E. coli and S. aureus without antibiotics.

· Immune Reprogramming: By drying the wound and killing bacteria, the membrane flips macrophages from pro-inflammatory M1 to pro-healing M2, cutting TNF-α and IL-6 by half.

Innovative Design and Features

· Dual-Gradient Architecture: Electro-spun PCL (large pores, 110° contact angle) topped with PAN/Ce6 (small pores, 0° contact angle) creates capillary and wetting forces that act like a diode—liquid only flows out, never back in.

· Light-Enhanced Drainage: Photothermal evaporation boosts the outward flow 1.33-fold, keeping the dressing unsaturated and the wound optimally moist.

· Single-Layer Simplicity: No pumps, batteries or hydrogel reservoirs—just a 100 µm patch that adheres gently and peels off trauma-free.

Applications and Future Outlook

· Chronic Wounds: Validated in type-2 diabetic mice, the membrane accelerates closure to 96 % versus 60 % for gauze, while restoring collagen, vessels and hair follicles.

· Scalable Manufacturing: Continuous electrospinning rolls out meter-scale Janus mats compatible with existing wound-care converters.

· Next Steps: Team is optimizing Ce6 loading for room-light activation and preparing large-animal studies toward first-in-human trials slated for 2027.

This cactus-inspired “water diode” offers a one-step, drug-free strategy to break the infection-inflammation cycle in diabetic wounds. Stay tuned for more translational advances from the Chen–Chen joint lab!