Highly sensitive near-infrared SERS nanoprobes for in vivo imaging using gold-assembled silica nanoparticles with controllable nanogaps

Abstract Background To take advantages, such as multiplex capacity, non-photobleaching property, and high sensitivity, of surface-enhanced Raman scattering (SERS)-based in vivo imaging, development of highly enhanced SERS nanoprobes in near-infrared (NIR) region is needed. A well-controlled morphology and biocompatibility are essential features of NIR SERS nanoprobes. Gold (Au)-assembled nanostructures with controllable nanogaps with highly enhanced SERS signals within multiple hotspots could be a breakthrough. Results Au-assembled silica (SiO2) nanoparticles (NPs) (SiO2@Au@Au NPs) as NIR SERS nanoprobes are synthesized using the seed-mediated growth method. SiO2@Au@Au NPs using six different sizes of Au NPs (SiO2@Au@Au50–SiO2@Au@Au500) were prepared by controlling the concentration of Au precursor in the growth step. The nanogaps between Au NPs on the SiO2 surface could be controlled from 4.16 to 0.98nm by adjusting the concentration of Au precursor (hence increasing Au NP sizes), which resulted in the formation of effective SERS hotspots. SiO2@Au@Au500 NPs with a 0.98-nm gap showed a high SERS enhancement factor of approximately 3.8 × 106 under 785-nm photoexcitation. SiO2@Au@Au500 nanoprobes showed detectable in vivo SERS signals at a concentration of 16μg/mL in animal tissue specimen at a depth of 7mm. SiO2@Au@Au500 NPs with 14 different Raman label compounds exhibited distinct SERS signals upon subcutaneous injection into nude mice. Conclusions SiO2@Au@Au NPs showed high potential for in vivo applications as multiplex nanoprobes with high SERS sensitivity in the NIR region. Graphical Abstrac

Depression in Adolescence and Brain-Derived Neurotrophic Factor

Copyright © 2022 Lee, Shin, Song and Chang.The incidence of depression among adolescents has been rapidly increasing in recent years. Environmental and genetic factors have been identified as important risk factors for adolescent depression. However, the mechanisms underlying the development of adolescent depression that are triggered by these risk factors are not well understood. Clinical and preclinical studies have focused more on adult depression, and differences in depressive symptoms between adolescents and adults make it difficult to adequately diagnose and treat adolescent depression. Brain-derived neurotrophic factor (BDNF) is known to play a critical role in the pathophysiology of many psychiatric disorders, including depression. However, there are still few studies on adolescent depression. Therefore, in this review paper, the causes and treatment of adolescent depression and the function of BDNF are investigated.11Nsciescopu

Isoegomaketone Alleviates the Development of Collagen Antibody-Induced Arthritis in Male Balb/c Mice

In this study, we attempted to identify and assess effects of isoegomaketone (IK) isolated from Perilla frutescens var. crispa on the development of rheumatoid arthritis (RA). RA was induced in male Balb/c mice by collagen antibody injection. Experimental animals were randomly divided into five groups: normal, collagen antibody-induced arthritis (CAIA), CAIA + IK (5 mg/kg/day), CAIA + IK (10 mg/kg/day), and CAIA + apigenin (16 mg/kg/day) and respective treatments were administered via oral gavage once per day for four days. Mice treated with IK (10 mg/kg/day) developed less severe arthritis than the control CAIA mice. Arthritic score, paw volume, and paw thickness were less significant compared to the control CAIA mice at day seven (73%, 15%, and 14% lower, respectively). Furthermore, histopathological examination of ankle for inflammation showed that infiltration of inflammatory cells and edema formation were reduced by IK treatment. Similarly, neutrophil to lymphocyte ratio (NLR) in whole blood was lower in mice treated with IK (10 mg/kg/day) by 85% when compared to CAIA mice. Taken together, treatment with IK delays the onset of the arthritis and alleviates the manifestations of arthritis in CAIA mice

Isoegomaketone from Perilla frutescens (L.) Britt Stimulates MAPK/ERK Pathway in Human Keratinocyte to Promote Skin Wound Healing

Skin wound healing is essential for recovery from injury, and delayed or impaired wound healing is a severe therapeutic challenge. Keratinocytes, a major component of the epidermis, play crucial roles in reepithelialization during wound healing including cell proliferation. Recent studies have shown that compounds from natural products have candidates for healing skin injury. Isoegomaketone (IK), isolated from leaves of Perilla frutescens var. crispa (Lamiaceae), has various bioactivities. However, the effect of IK on cutaneous wound healing processes has not been studied yet. In this study, we demonstrated that IK exhibits therapeutic wound healing effects using the human keratinocyte cell line HaCaT. Notably, IK promoted cell proliferation and migration in a dose-dependent manner in vitro, and treatment with 10 μM IK upregulated these processes by approximately 1.5-fold after 24 h compared with the control. IK induced the activation of the MAPK/ERK pathway and cell cycle progression to the S and G2/M phases. Thus, this study demonstrates IK as a potential candidate to upregulate wound healing that may provide therapeutic benefits to patients with delayed wound healing

A New Monoterpene from the Leaves of a Radiation Mutant Cultivar of Perilla frutescens var. crispa with Inhibitory Activity on LPS-Induced NO Production

The leaves of Perilla frutescens var. crispa (Lamiaceae)—known as ‘Jureum-soyeop’ or ‘Cha-jo-ki’ in Korean, ‘ZI SU YE’ in Chinese, and ‘Shiso’ in Japan—has been used as a medicinal herb. Recent gamma irradiated mutation breeding on P. frutescens var. crispa in our research group resulted in the development of a new perilla cultivar, P. frutescens var. crispa (cv. Antisperill; PFCA), which has a higher content of isoegomaketone. The leaves of PFCA were extracted by supercritical carbon dioxide (SC-CO2) extraction, and phytochemical investigation on this extract led to the isolation and identification of a new compound, 9-hydroxy-isoegomaketone [(2E)-1-(3-furanyl)-4-hydroxy-4-methyl-2-penten-1-one; 1]. Compound 1 exhibited inhibitory activity on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW264.7 cells with an IC50 value of 14.4 μM. The compounds in the SC-CO2 extracts of the radiation mutant cultivar and the original plant were quantified by high-performance liquid chromatography with diode array detection

Rhizoplane and Rhizosphere Fungal Communities of Geographically Isolated Korean Bellflower (<i>Campanula takesimana</i> Nakai)

Fungal communities in the rhizoplane (RP) and rhizosphere (RS) of geographically isolated C. takesimana habitats in different environments such as oceanic (Seodo, the Dokdo Islands), coastline (Sadong, Ulleungdo Island), and inland (Taeha, Ulleungdo Island) regions were analyzed by MiSeq sequencing. In total, 1279 operational taxonomic units (OTUs) were obtained and they were further classified into 185 genera belonging to five phyla. The total number of fungal taxa in the RP samples was lower than those in the RS samples in all the sampled locations, providing an indication of the existence of a certain level of the selective pressures from the host plant. The richness of the RP in the Dokdo Islands was higher than that of Ulleungdo Island, but the richness of the RS in the Dokdo Islands was lower than that of Ulleungdo Island. These results suggest evidence for strong effects of a harsh geo-climate on the RP and RS fungal diversities in the Dokdo Islands. Additionally, a total of 82 fungal genera were identified in all three RP samples and 63 genera (77%) were uniquely found in each of the geographical regions and 43 genera (52.4%) showed high dependency on the C. takesimana vegetation. It was found that the genus Mortierella was the most dominant taxon in all the samples. The geo-ecological isolation of the Korean bellflower may have caused unique formation of the RP and RS fungal communities in the natural habitats

Quantitative Analysis of the Efficiency of OLEDs

We present a comprehensive model for the quantitative analysis of factors influencing the efficiency of organic light-emitting diodes (OLEDs) as a function of the current density. The model takes into account the contribution made by the charge carrier imbalance, quenching processes, and optical design loss of the device arising from various optical effects including the cavity structure, location and profile of the excitons, effective radiative quantum efficiency, and out-coupling efficiency. Quantitative analysis of the efficiency can be performed with an optical simulation using material parameters and experimental measurements of the exciton profile in the emission layer and the lifetime of the exciton as a function of the current density. This method was applied to three phosphorescent OLEDs based on a single host, mixed host, and exciplex-forming cohost. The three factors (charge carrier imbalance, quenching processes, and optical design loss) were influential in different ways, depending on the device. The proposed model can potentially be used to optimize OLED configurations on the basis of an analysis of the underlying physical processes

Phytochemical Composition and Antioxidant Activities of Two Different Color Chrysanthemum Flower Teas

Chrysanthemum morifolium Ramat is a perennial flowering plant widely cultivated for use in a tea infusion and as a popular beverage. To identify and evaluate the tea infusion made with a &gamma;-irradiated mutant chrysanthemum cultivar with dark purple petals (cv. ARTI-Dark Chocolate), its phytochemical composition and antioxidant activity were tested and compared with those of the commercially available chrysanthemum cultivar with yellow petals (cv. Gamguk) by HPLC-DAD-ESIMS, as well as DPPH and ABTS radical scavenging assays. The purple chrysanthemum tea contained anthocyanins and linarin, which were not detected in the yellow chrysanthemum tea and the content of chlorogenic acid, acacetin-7-O-&beta;-glucoside, and luteolin was higher compared with the yellow chrysanthemum tea. In contrast, the yellow chrysanthemum tea had higher luteolin-7-O-&beta;-glucoside, 3,5-dicaffeoylquinic acid, apigenin-7-O-&beta;-glucoside, and apigenin contents in comparison with the purple chrysanthemum tea. In addition, the content and antioxidant activity of the two chrysanthemum teas were investigated according to different water temperatures and infusing time. The yellow chrysanthemum tea did not show any significant differences according to infusing time and temperature, while the purple chrysanthemum tea was more influenced by the infusing time than water temperature, showing the highest total compound content in the infusing condition of 100 &deg;C and 4 min. Moreover, the floral scent volatiles of the two chrysanthemum tea sources were analyzed using HS-SPME-GC-MS. In the DPPH radical scavenging assay, the purple chrysanthemum tea broadly showed greater antioxidant activity than did the yellow chrysanthemum tea, corresponding to the high content of anthocyanins known as the powerful antioxidant. Further, both chrysanthemum flower teas exhibited strong ABTS radical scavenging effects ranging from 76% to 61% under all infusing conditions. Therefore, the purple chrysanthemum cultivar, ARTI-Dark Chocolate, is worthy of breeding as a new tea cultivar

Preparative Separation of Three Monoterpenes from Perilla frutescens var. crispa Using Centrifugal Partition Chromatography

Three monoterpenes, namely, 9-hydroxy isoegomaketone (1), isoegomaketone (2), and perilla ketone (3), were successfully separated from the supercritical carbon dioxide (SC-CO2) extract of the leaves of Perilla frutescens var. crispa (cv. Antisperill; Lamiaceae) by centrifugal partition chromatography (CPC). To obtain large quantities of these materials required for studies on their mechanism of action and in vivo effectiveness in inflammation, we used CPC because of its high loading capacity and reproducibility to purify the three compounds. Compound 1 (2.60 mg, 96.7% purity at 254 nm) was purified from 500 mg of the SC-CO2 extract of P. frutescens var. crispa (cv. Antisperill), using a two-phase solvent system comprising n-hexane/ethyl acetate/ethanol/water (5:5:5:5 v/v) in a descending mode. As compounds 2 (56.1 mg, 97.6% purity at 254 nm) and 3 (78.6 mg, 96.1% purity at 254 nm) are highly volatile and difficult to recover from an aqueous mobile phase after purification during the drying process, they were obtained from the same amount of the processed extract in an ascending mode using the upper organic phase as the mobile phase (n-hexane/ethyl acetate/ethanol/water, 8:2:8:2 v/v). The structures of compounds 1–3 were confirmed by 1H- and 13C-NMR analysis. Thus, based on our findings, we recommend centrifugal partition chromatography as a powerful technique for purifying the active principal compounds 1 and 2 from the leaves of P. frutescens var. crispa