In Vivo Reflectance Confocal Microscopy Evaluation of Microneedle Patch Penetration Depth.

BACKGROUND: Firstly, confirm penetration of the skin's most exclusive layer, the stratum corneum (SC), by commercially available microneedle patches using reflectance confocal microscopy (RCM). Secondly, determine the deepest layer of the skin penetrated by the microneedle patches. MATERIALS AND METHODS: In this proof-of-concept study, 3 commercially available dissolving microneedle patches with different active ingredients were included in this study. RCM images of the cheek were taken prior to patch application at 4 different layers of the skin: stratum corneum, stratum spinosum-granulosum, dermal-epidermal junction, and papillary dermis. Patches were then applied to the cheeks of participants according to manufacturer guidelines. Immediately after removal, the same area and layers were imaged using RCM and assessed for features of penetration. RESULTS: Micropores were visualized in RCM images of skin layers post-application of all patches when compared with imaging before application. Characteristics of penetration included uniformly sized, shaped, and spaced well-defined circular areas, which are the created micropores. All 3 patches penetrated the SC to the level of the papillary dermis. CONCLUSION: This study confirms that the dissolving microneedle patches penetrate the most exclusive layer of the skin, the SC, down to the level of the papillary dermis as visualized through RCM. Confirming penetration with RCM shows the potential of these patches to be used for medication transmission. While future studies are needed to assess the efficacy of microneedle patches applied for their advertised skin conditions, confirming the penetration of the microneedle technology through RCM is a significant first step in this process. J Drugs Dermatol. 2023;22(11):1107-1110     doi:10.36849/JDD.6994.

Power Amplification for Jumping Soft Robots Actuated by Artificial Muscles.

Robots composed of soft materials can passively adapt to constrained environments and mitigate damage due to impact. Given these features, jumping has been explored as a mode of locomotion for soft robots. However, for mesoscale jumping robots, lightweight and compact actuation are required. Previous work focused on systems powered by fluids, combustion, smart materials, electromagnetic, or electrostatic motors, which require one or more of the following: large rigid components, external power supplies, components of specific, pre-defined sizes, or fast actuation. In this work, we propose an approach to design and fabricate an electrically powered soft amplification mechanism to enable untethered mesoscale systems with continuously tunable performance. We used the tunable geometry of a liquid crystal elastomer actuator, an elastic hemispherical shell, and a pouch motor for active latching to achieve rapid motions for jumping despite the slow contraction rate of the actuator. Our system amplified the power output of the LCE actuator by a factor of 8.12 × 103 with a specific power of 26.4 W/kg and jumped to a height of 55.6 mm (with a 20 g payload). This work enables future explorations for electrically untethered soft systems capable of rapid motions (e.g., jumping).

Comparative seroprevalences of bovine trypanosomiasis and anaplasmosis in five states of Malaysia.

A comparative seroprevalence study on bovine trypanosomiasis and anaplasmosis was conducted. Sera of adult cattle and buffaloes of different breeds from farms from five different states in Malaysia were collected and tested for the presence of Trypanosoma evansi antibodies by CATT and Anaplasma marginale antibodies by c-ELISA. Of the 116 samples, 14.7% tested positive for bovine trypanosomiasis and 77.6% for bovine anaplasmosis.