The efficacy of LED microneedle patch on hair growth in mice.

Light penetration depth in the scalp is a key limitation of low-level light therapy for the treatment of androgenetic alopecia (AGA). A novel light emitting diode (LED) microneedle patch was designed to achieve greater efficacy by enhancing the percutaneous light delivery. The study aimed to investigate the efficacy and safety of this device on hair growth in mice. Thirty-five male C57BL/6 mice which their dorsal skin was split into upper and lower parts to receive either LED irradiation alone or LED irradiation with a microneedle patch. Red (629 nm), green (513 nm), and blue light (465 nm) at an energy dose of 0.2 J/cm2 were applied once daily for 28 days. Outcomes were evaluated weekly using digital photographs. Histopathological findings were assessed using a 6 mm punch biopsy. A significant increase in hair growth was observed in the green light, moderate in the red light, and the lowest in the blue light group. The addition of the microneedle patch to LED irradiation enhanced greater and faster anagen entry in all the groups. Histopathology showed an apparent increase in the number of hair follicles, collagen bundles in the dermis, angiogenesis, and mononuclear cell infiltration after treatment with the green-light LED microneedle patches. No serious adverse effects were observed during the experiment. Our study provides evidence that the newly developed green-light LED microneedle patch caused the optimal telogen-to-anagen transition and could lead to new approaches for AGA. Microneedle stimulation may aid percutaneous light delivery to the target hair follicle stem cells.

Efficacy of a novel microneedle patch for rejuvenation of the nasolabial fold.

BACKGROUND: Skin rejuvenation plays a significant role in the esthetic medicine market. Microneedle patches have been developed for a wide range of applications based on the principles of transdermal drug delivery; however, clinical trials of microneedle patches for skin rejuvenation remain limited. AIMS: This study was conducted to examine the efficacy of microneedle patches for improving nasolabial folds. METHODS: A total of 23 Thai women completed this prospective clinical trial. The participants were treated according to a split-face design, with application of microneedle patch plus 1.8% hyaluronic acid solution to the right nasolabial fold and microneedle patch alone to the left nasolabial fold. The treatments were applied to the nasolabial fold for 8 weeks. The test areas were measured before treatment and at 2, 4, 8, 12, and 16 weeks after the use of the test product. RESULTS: Combination treatment using the microneedle patch plus hyaluronic acid solution and use of the microneedle patch alone both significantly improved the Merz esthetic scales for nasolabial folds. Measurement of the nasolabial fold showed an improvement in the two groups, with no significant differences between the groups. No adverse effects were reported during the study period. CONCLUSIONS: Application of a microneedle patch with 1.8% hyaluronic acid solution or a microneedle patch alone were both effective treatments for improving facial wrinkles in the nasolabial folds.

Piezoelectric-Induced Triboelectric Hybrid Nanogenerators Based on the ZnO Nanowire Layer Decorated on the Au/polydimethylsiloxane-Al Structure for Enhanced Triboelectric Performance.

Here, we demonstrate a novel device structure design to enhance the electrical conversion output of a triboelectric device through the piezoelectric effect called as the piezo-induced triboelectric (PIT) device. By utilizing the piezopotential of ZnO nanowires embedded into the polydimethylsiloxane (PDMS) layer attached on the top electrode of the conventional triboelectric device (Au/PDMS-Al), the PIT device exhibits an output power density of 50 µW/cm2, which is larger than that of the conventional triboelectric device by up to 100 folds under the external applied force of 8.5 N. We found that the effect of the external piezopotential on the top Au electrode of the triboelectric device not only enhances the electron transfer from the Al electrode to PDMS but also boosts the internal built-in potential of the triboelectric device through an external electric field of the piezoelectric layer. Furthermore, 100 light-emitting diodes (LEDs) could be lighted up via the PIT device, whereas the conventional device could illuminate less than 20 LED bulbs. Thus, our results highlight that the enhancement of the triboelectric output can be achieved by using a PIT device structure, which enables us to develop hybrid nanogenerators for various self-power electronics such as wearable and mobile devices.