Hair Thickness Growth Effect of Adenosine Complex in Male-/Female-Patterned Hair Loss via Inhibition of Androgen Receptor Signaling.

Aging (senescence) is an unavoidable biological process that results in visible manifestations in all cutaneous tissues, including scalp skin and hair follicles. Previously, we evaluated the molecular function of adenosine in promoting alopecia treatment in vitro. To elucidate the differences in the molecular mechanisms between minoxidil (MNX) and adenosine, gene expression changes in dermal papilla cells were examined. The androgen receptor (AR) pathway was identified as a candidate target of adenosine for hair growth, and the anti-androgenic activity of adenosine was examined in vitro. In addition, ex vivo examination of human hair follicle organ cultures revealed that adenosine potently elongated the anagen stage. According to the severity of alopecia, the ratio of the two peaks (terminal hair area/vellus hair area) decreased continuously. We further investigated the adenosine hair growth promoting effect in vivo to examine the hair thickness growth effects of topical 5% MNX and the adenosine complex (0.75% adenosine, 1% penthenol, and 2% niacinamide; APN) in vivo. After 4 months of administration, both the MNX and APN group showed significant increases in hair density (MNX + 5.01% (p < 0.01), APN + 6.20% (p < 0.001)) and thickness (MNX + 5.14% (p < 0.001), APN + 10.32% (p < 0.001)). The inhibition of AR signaling via adenosine could have contributed to hair thickness growth. We suggest that the anti-androgenic effect of adenosine, along with the evaluation of hair thickness distribution, could help us to understand hair physiology and to investigate new approaches for drug development.

Aqueous synthesis of highly monodisperse sub-100 nm AgCl nanospheres/cubes and their plasmonic nanomesh replicas as visible-light photocatalysts and single SERS probes.

Despite the distinctive electrochemical and photocatalytic properties of nanostructured silver chloride (AgCl), the shape- and size-dependence of their properties have not been thoroughly investigated to date. The most substantial reason responsible for this incomplete study and the subsequent limited applications is the failure in controlling the structure of AgCl nanomaterials, mainly owing to the challenging synthetic conditions including organic phase and high reaction temperature. In this work, we reported a rapid one-pot room-temperature aqueous synthesis of highly monodisperse sub-100 nm AgCl nanomaterials with various shapes and sizes by controlling the precursor (Ag+ and AuCl4 -) ratios. The remaining unreacted metal precursors (Ag+ and AuCl4 -) used to produce AgClNC were subsequently reduced by ascorbic acid on the surface of the synthesized AgCl nanomaterials to form Ag/Au bimetallic nanomesh structures (AgClNC#AuAgCMs and SMs). After the removal of the AgCl nanotemplates, only nanomesh structures (AuAgCMs and SMs) were obtained. Importantly, we successfully decreased the size of the AgCl nanomaterials which were replicated into bimetallic spherical and cubic nanomesh structures that were small enough (∼100 nm) to show intense surface-plasmon-absorption bands. Based on these unique chemical and physical properties, we could take advantage of the plasmonic photocatalysis properties of the complex comprising semiconducting AgCl/metallic nanomesh replica for the complete removal of the environmentally harmful Cr6+ in the presence of sacrificial agents such as formic acid. Finally, the novel bimetallic nanomesh structures proved themselves to exhibit intense surface-enhanced Raman scattering properties in a single-particle enhancing the electromagnetic field.

Synthesis of Gold Nanoparticle-Embedded Silver Cubic Mesh Nanostructures Using AgCl Nanocubes for Plasmonic Photocatalysis.

A novel room-temperature aqueous synthesis for gold nanoparticle-embedded silver cubic mesh nanostructures using AgCl templates via a template-assisted coreduction method is developed. The cubic AgCl templates are coreduced in the presence of AuCl4- and Ag+ , resulting in the reduction of AuCl4- into gold nanoparticles on the outer region of AgCl templates, followed by the reduction of AgCl and Ag+ into silver cubic mesh nanostructures. Removal of the template clearly demonstrates the delicately designed silver mesh nanostructures embedded with gold nanoparticles. The synthetic mechanism, structural properties, and surface functionalization are spectroscopically investigated. The plasmonic photocatalysis of the cubic mesh nanostructures for the degradation of organic pollutants and removal of highly toxic metal ions is investigated; the photocatalytic activity of the cubic mesh nanostructures is superior to those of conventional TiO2 catalysts and they are catalytically functional even in natural water, owing to their high surface area and excellent chemical stability. The synthetic development presented in this study can be exploited for the highly elaborate, yet, facile design of nanomaterials with outstanding properties.

Recent advances in chemical functionalization of nanoparticles with biomolecules for analytical applications.

The recent synthetic development of a variety of nanoparticles has led to their widespread application in diagnostics and therapeutics. In particular, the controlled size and shape of nanoparticles precisely determine their unique chemical and physical properties, which is highly attractive for accurate analysis of given systems. In addition to efforts toward controlling the synthesis and properties of nanoparticles, the surface functionalization of nanoparticles with biomolecules has been intensively investigated since the mid-1990s. The complicated yet programmable properties of biomolecules have proved to substantially enhance and enrich the novel functions of nanoparticles to achieve "smart" nanoparticle materials. In this review, the advances in chemical functionalization of four types of representative nanoparticle with DNA and protein molecules in the past five years are critically reviewed, and their future trends are predicted.

Divalent metal ion-mediated assembly of spherical nucleic acids: the case study of Cu(2.).

Despite the critical functions of divalent metal ions (M(2+)s) in association with duplex DNA, fundamental and general interactions of M(2+)s with spherical nucleic acids (SNAs) composed of single-stranded DNA have rarely been investigated. We have explored that the coordinative nature of the M(2+)-SNA binding mediates the temperature- and base composition-dependent reversible assemblies of SNAs even without the need of complementary counterparts for duplex-interconnection, additional monovalent metal ions for charge screening, or pre-designed sequences for any non-Watson-Crick base-pairing, all of which are essential for the conventional assembly of SNAs. Cu(2+) has been identified to maximize the reversible assembly properties in relation to this M(2+)-mediated DNA bond, and has been further qualitatively and quantitatively investigated in detail as a model system.

Library approach for reliable synthesis and properties of DNA-gold nanorod conjugates.

We developed a library-based approach to chemically stabilize cetyltrimethylammonium bromide (CTAB)-coated gold nanorods for the synthesis of polyvalent DNA-gold nanorod conjugates (DNA-AuNRs). Eleven chemical reagents were carefully chosen to constitute an additive library and screened by UV-vis spectroscopy to evaluate their stabilizing capability for the CTAB-coated AuNRs. Interestingly, 5-bromosalicylic acid (5-BrSA) was determined to most significantly stabilize the AuNRs by inducing additional adsorption of CTAB on the rod. Importantly, these stabilized AuNRs with 5-BrSA were conjugated with thiol DNA in an exceptionally reproducible and reliable method, which led to the systematic investigation of their cooperative assembly and disassembly properties under various conditions, including different types and lengths of the DNA sequences.

Wrapping AgCl Nanostructures with Trimetallic Nanomeshes for Plasmon-Enhanced Catalysis and in Situ SERS Monitoring of Chemical Reactions.

Selective chemical control of multiple reactions is incredibly important for the fabrication of sophisticated nanostructures for functional applications. A representative example is the synthesis of plasmonic nanomaterial-silver chloride (AgCl) conjugates, where metal ions should be selectively reduced into metallic nanostructures for plasmon-enhanced catalytic activity, while the reducible AgCl nanomaterials remain intact despite the presence of a chemical reductant. In addition to the selectively controlled reduction, the plasmonic nanostructures should be appropriately designed for the high stability and photoefficiency of catalysts. In this study, we demonstrate how AgCl nanocubes and nanospheres could be comprehensively wrapped by plasmonic three-dimensional nanomesh structures consisting of gold, silver, and palladium by the selective reduction of their ionic precursors while the AgCl nanostructures remain intact. Complete trimetallic wrapping provided the absorption of visible light, while the porosity of the nanomesh structures exposed the photocatalytic AgCl surface to catalyze desired reactions. Platinum in place of palladium was examined to demonstrate the versatility of the wrapping scheme, resulting in an extraordinary catalytic activity. Importantly, the detailed chemical mechanism behind the trimetallic wrapping of the AgCl nanostructures was systematically investigated to understand the roles of each reaction component in controlling the chemical selectivity. The synthesized AgCl-trimetal nanoconjugates excellently exhibit both metal-based and plasmon-enhanced catalytic properties for the removal of environmentally harmful Cr6+. Moreover, their applications as surface-enhanced Raman-scattering (SERS) probes for the in situ monitoring of catalytic reduction in real-time and as single-nanoparticle SERS probes for molecular detection are thoroughly demonstrated.

In vivo photothermal treatment by the peritumoral injection of macrophages loaded with gold nanoshells.

Photothermal treatment methods have been widely studied for their target specificity and potential for supplementing the limitations of conventional surgical treatments. In this study, we conducted in vivo photothermal treatments using macrophages containing nanoshells as live vectors. We injected macrophages at the peritumoral sites and observed that they had penetrated into the tumor approximately 48 hours after injection. Afterwards, we irradiated with a near-infrared laser for 2 minutes at 1 W/cm(2), causing cancer cell death. Our study identified the optimal conditions of the photothermal treatment and confirmed the feasibility of its use in in vivo treatments.