Ultrathin Metal Crystals: Growth on Supported Graphene Surfaces and Applications.

Controlled nucleation and growth of metal clusters in metal deposition processes is a long-standing issue for thin-film-based electronic devices. When metal atoms are deposited on solid surfaces, unintended defects sites always lead to a heterogeneous nucleation, resulting in a spatially nonuniform nucleation with irregular growth rates for individual nuclei, resulting in a rough film that requires a thicker film to be deposited to reach the percolation threshold. In the present study, it is shown that substrate-supported graphene promotes the lateral 2D growth of metal atoms on the graphene. Transmission electron microscopy reveals that 2D metallic single crystals are grown epitaxially on supported graphene surfaces while a pristine graphene layer hardly yields any metal nucleation. A surface energy barrier calculation based on density functional theory predicts a suppression of diffusion of metal atoms on electronically perturbed graphene (supported graphene). 2D single Au crystals grown on supported graphene surfaces exhibit unusual near-infrared plasmonic resonance, and the unique 2D growth of metal crystals and self-healing nature of graphene lead to the formation of ultrathin, semitransparent, and biodegradable metallic thin films that could be utilized in various biomedical applications.

Fourth dose of microneedle array patch of SARS-CoV-2 S1 protein subunit vaccine elicits robust long-lasting humoral responses in mice.

The COVID-19 pandemic has underscored the pressing need for safe and effective booster vaccines, particularly in considering the emergence of new SARS-CoV-2 variants and addressing vaccine distribution inequalities. Dissolving microneedle array patches (MAP) offer a promising delivery method, enhancing immunogenicity and improving accessibility through the skin's immune potential. In this study, we evaluated a microneedle array patch-based S1 subunit protein COVID-19 vaccine candidate, which comprised a bivalent formulation targeting the Wuhan and Beta variant alongside a monovalent Delta variant spike proteins in a murine model. Notably, the second boost of homologous bivalent MAP-S1(WU + Beta) induced a 15.7-fold increase in IgG endpoint titer, while the third boost of heterologous MAP-S1RS09Delta yielded a more modest 1.6-fold increase. Importantly, this study demonstrated that the administration of four doses of the MAP vaccine induced robust and long-lasting immune responses, persisting for at least 80 weeks. These immune responses encompassed various IgG isotypes and remained statistically significant for one year. Furthermore, neutralizing antibodies against multiple SARS-CoV-2 variants were generated, with comparable responses observed against the Omicron variant. Overall, these findings emphasize the potential of MAP-based vaccines as a promising strategy to combat the evolving landscape of COVID-19 and to deliver a safe and effective booster vaccine worldwide.

Clinical efficacy of dissolvable microneedles armed with anti-melanogenic compounds to counter hyperpigmentation.

BACKGROUND: Hyperpigmentation is a complex physiological process associated with alterations of skin color due to melanin overproduction and distribution. Both intrinsic and extrinsic factors influence discoloration with the involvement of multiple pathways in cooperative manners. Restoring natural skin color requires a multi-targeted approach. Latest advances in anti-melanogenic compounds and microneedle delivery system have presented opportunities for tackling hyperpigmentationsuccessfully. AIMS: This work was aimed at assessing the dermal tolerability and efficacy of hyaluronic acid-based microneedle patches loaded with anti-melanogenic actives for improvements of skin discoloration. PATIENTS/METHODS: The test products consist of hyaluronic acid with niacinamide, ascorbic acid 2-glucoside, tranexamic acid, resveratrol, 4-n-butyl-resorcinol, and Halidrys siliquosa extract. In a monocentric 12 weeks clinical trial, the HA-MNs patches were applied to the affected areas of the faces on subjects with hyperpigmented skin. The color properties of the skin were analyzed spectrophotometrically. RESULTS: The products were tolerated remarkably; none of the subjects informed any primary or cumulative skin responses. Evaluation of color related measurable skin properties provided insight into the general effectiveness: The individual topology measurements showed 51.4% noticeable improvements in hyperpigmented zones, which were also in good agreement with the personal impressions of the subjects determined by questionnaires before and after the treatments. CONCLUSIONS: The concentrated blends of actives in microneedle patches act in a multi-targeted manner, and they could be worked in a complementary fashion for the improvement of skin color and appearance. The study has established the overall convenience of the HA-MNs with the formulation of anti-melogenic compounds against skin discoloration.

Efficacy of bioactive peptides loaded on hyaluronic acid microneedle patches: A monocentric clinical study.

BACKGROUND: Aging skin is a gradual physiological process associated with functional and structural changes of the skin. Both intrinsic and extrinsic factors influence skin aging by the involvement of multiple pathways. Restoring natural skin conditions requires a multi-targeted approach. Recent developments in both bioactive peptides and microneedle delivery system have presented an opportunity for tackling premature skin aging. AIMS: This study was aimed at evaluating the dermal tolerability and efficacy of hyaluronic acid-based microneedle patches loaded with bioactives for restoration of the skin properties including hydration, wrinkle reduction, density, and thickness. PATIENTS/METHODS: The test product of HA-MNs comprises arginine/lysine polypeptide, acetyl octapeptide-3, palmitoyl tripeptide-5, adenosine, and seaweed extracts. In the monocentric 12-week clinical trial, the HA-MNs patches were applied to the outer corner of the right and left eye and a defined area on the volar forearm on healthy subjects with aged skin. Instrumental analysis of skin properties was determined. RESULTS: The product was tolerated excellently; none of the subjects reported any primary or cumulative skin reactions. Assessment of measurable skin properties provides insight into the general effectiveness: The fine lines/wrinkles showed 25.8% noticeable decrease; the skin hydration measurements demonstrated 15.4% improvement; the skin density and thickness in the dermis increased 14.2% and 12.9%, respectively. CONCLUSIONS: The composition of the microneedle patches works in a multi-targeted manner and all ingredients might possibly be acted synergistically for the improvement of skin structure, function, and appearance. The study has demonstrated the overall usefulness of the HA-MNs with careful formulation for skin care applications.