The synergistic effect of biomimetic electrical stimulation and extracellular-matrix-mimetic nanopattern for upregulating cell activities.

Endogenous bioelectric signaling and the extracellular matrix (ECM) are factors that have a great effect on the performance of cellular functions. Presenting an experimental platform to confirm the synergy effects of an electrical stimulation, which simulates endogenous bioelectricity, and nanopatterns that can be precisely fabricated in various patterns sizes makes it possible to consider those factors effectively. Herein, we have performed a comparison of cellular response to each of general electrical stimulation and biomimetic electrical stimulation (BES) and demonstrated the synergy effects of electrical stimulation and ECM-mimetic nanopatterns. BES has provided the most remarkable proliferation among different types of electrical stimulation and upregulated the behavior of cells through synergy effects with ECM-mimetic nanopatterns. Thus, it is believed that using the synergy effects of BES and ECM-like nanopatterns has broad applications in the biomedical field, such as cell culture with electrical stimulation, induction of cell growth, tissue repair, etc.

Snake fang-inspired stamping patch for transdermal delivery of liquid formulations.

A flexible microneedle patch that can transdermally deliver liquid-phase therapeutics would enable direct use of existing, approved drugs and vaccines, which are mostly in liquid form, without the need for additional drug solidification, efficacy verification, and subsequent approval. Specialized dissolving or coated microneedle patches that deliver reformulated, solidified therapeutics have made considerable advances; however, microneedles that can deliver liquid drugs and vaccines still remain elusive because of technical limitations. Here, we present a snake fang-inspired microneedle patch that can administer existing liquid formulations to patients in an ultrafast manner (<15 s). Rear-fanged snakes have an intriguing molar with a groove on the surface, which enables rapid and efficient infusion of venom or saliva into prey. Liquid delivery is based on surface tension and capillary action. The microneedle patch uses multiple open groove architectures that emulate the grooved fangs of rear-fanged snakes: Similar to snake fangs, the microneedles can rapidly and efficiently deliver diverse liquid-phase drugs and vaccines in seconds under capillary action with only gentle thumb pressure, without requiring a complex pumping system. Hydrodynamic simulations show that the snake fang-inspired open groove architectures enable rapid capillary force-driven delivery of liquid formulations with varied surface tensions and viscosities. We demonstrate that administration of ovalbumin and influenza virus with the snake fang-inspired microneedle patch induces robust antibody production and protective immune response in guinea pigs and mice.

Hierarchically Nanostructured CuO⁻Cu Current Collector Fabricated by Hybrid Methods for Developed Li-Ion Batteries.

We present a simple method of fabricating a hierarchically nanostructured CuO⁻Cu current collector by using laser ablation and metal mold imprinting to maximize the surface area. The laser ablation of the Cu current collector created the CuO nanostructure on the Cu-collector surface. The microstructure was transferred by subsequent imprinting of the microstructure metal mold on the Cu collector. Then, the laser-ablation nanostructure was formed. Consequently, a hierarchical structure is generated. The laser-ablated hierarchical CuO⁻Cu current collector exhibited an improved capacity while maintaining a cyclability that is similar to those of conventional graphite batteries.