Efficient Loading and Sustained Delivery of Methotrexate Using a Tip-Swellable Microneedle Array Patch for Psoriasis Treatment

Methotrexate (MTX), a primary treatment for moderate to severe psoriasis, is limited in clinical use due to suboptimal results and severe side effects from subcutaneous (SC) injection and oral administration. Microneedles offer a promising alternative for direct MTX delivery to targeted skin lesions, but issues such as drug wastage, dosage inaccuracy, and limited drug residence time in the lesions remain. This study introduces a tip-swellable microneedle array patch (TSMAP) using photo-cross-linked methacrylated hyaluronic acid (MeHA) and biocompatible resin for effective MTX loading and sustained delivery. A two-cast micromolding with vacuum drying is employed to concentrate cross-linked MeHA in about 30% of the needle’s height at the tip, thereby ensuring that only the TSMAP tip swells. Efficient MTX loading into TSMAP tips is achieved through a 30 s drug solution immersion and 10 min drying, potentially minimizing drug waste from incomplete skin insertion due to skin elasticity. The MTX-loaded TSMAP effectively penetrates both porcine and psoriasis-like mouse skin with its tips detaching from the resin substrate and embedding deeply into the skin tissue, thereby functioning as a drug release reservoir. TSMAP significantly prolongs drug retention in skin compared with SC injection and dissolvable microneedles. The in vivo study demonstrates that TSMAP-mediated MTX delivery substantially enhances therapeutic outcomes in alleviating psoriasis symptoms and downregulating psoriasis-associated cytokines, outperforming oral administration, SC injection, and dissolvable microneedles. Thus, TSMAP could offer an efficient and user-friendly alternative for drug administration in the treatment of various skin diseases

Identification of <i>Astrotactin2</i> as a Genetic Modifier That Regulates the Global Orientation of Mammalian Hair Follicles

<div><p>Planar cell polarity (PCP) signaling controls the global orientation of surface structures, such as hairs and bristles, in both vertebrates and invertebrates. In <i>Frizzled6</i>^<i>-/-</i> (<i>Fz6</i>^<i>-/-</i>) mice, hair follicle orientations on the head and back are nearly random at birth, but reorient during early postnatal development to eventually generate a nearly parallel anterior-to-posterior array. We report the identification of a naturally occurring exon 5 deletion in <i>Astrotactin2</i> (<i>Astn2</i>) that acts as a recessive genetic modifier of the <i>Fz6</i>^<i>-/-</i> hair patterning phenotype. A genetically engineered <i>Astn2</i> exon 5 deletion recapitulates the modifier phenotype. In <i>Fz6</i>^<i>-/-</i><i>;Astn2</i>^{<i>ex5del/del</i>} mice, hair orientation on the back is subtly biased from posterior-to-anterior, leading to a 180-degree orientation reversal in mature mice. These experiments suggest that Astn2, an endosomal membrane protein, modulates PCP signaling.</p></div

Identification of <i>Astn2</i> as the <i>ridge</i> gene.

<p>(A) Whole genome multipoint LOD score for the <i>ridge</i> locus based on SNP typing of 1,449 loci. (B) Recombination mapping of the critical interval. The locations of microsatellite markers on chromosome 4 are shown above the maps of the recombinant <i>ridge</i> chromosomes, with the number of independent chromosomes of each type indicated at left. Red, region derived from the <i>ridge</i> chromosome; green, region derived from the WT chromosome; grey, region encompassing the cross-over point. Low-resolution (top) and high-resolution (bottom) maps. For the three recombinant chromosomes shown at the bottom (and indicated by asterisks in the upper part of the figure), the <i>ridge</i> phenotype was confirmed by examining at least nine progeny from each mouse that inherited the original recombination event. Black brackets demarcate the critical interval. (C) Locations of the three genes within or adjacent to the critical interval. (D) PCR amplification of <i>Astn2</i> exon 5 from <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i> and <i>Fz6</i>^<i>-/-</i><i>;ridge/+</i> siblings (each 3-digit number indicates a different sibship). All <i>Fz6</i>^<i>-/-</i><i>;ridge/+</i> samples give the expected WT PCR product and all <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i> samples give no PCR product. (E) PCR reactions in the neighborhood of <i>Astn2</i> exon 5 (locations shown by vertical arrows) show that the <i>ridge</i> allele is missing ~30 kb, consistent with an homologous recombination event between the LINE elements designated ‘I’ and ‘III’ (red arrows show location and 5’ to 3’ orientation).</p

The <i>ridge</i> phenotype.

<p>(A) Side and top views of a <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i> mouse at approximately one month of age. Arrows indicate the single transverse ridge hair pattern on the back. (B-D) Hair orientation (red arrows) on flat-mounted back skins from WT, <i>Fz6</i>^<i>-/-</i>, and <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i> mice at P8. Images to the right of each flat mount correspond to the boxed regions labeled a-c and illustrate the correlation between vector scoring (red arrows) and the raw data (montage images showing follicle orientations). Rostral is at the top; caudal is at the bottom. The narrow slits and oval holes correspond to the locations of the eyes and ears, respectively. WT follicles are almost perfectly aligned in an anterior-to-posterior direction (B). Most <i>Fz6</i>^<i>-/-</i> follicles are aligned in an anterior-to-posterior direction, except for a region in the mid-back (C). <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i> follicles in the caudal half of the back exhibit a uniformly reversed (i.e. posterior-to-anterior) orientation (D). White scale bars, 1 mm.</p

Origin of the <i>Astn2</i> exon 5 deletion.

<p>(A) PCR analysis of genomic DNA in the neighborhood of <i>Astn2</i> exon 5, as shown in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005532#pgen.1005532.g002" target="_blank">Fig 2E</a>. The ~30 kb deletion is present in 129X1/SvJ mice and R1 ES cells, but is absent from C57Bl6/J, 129S1/SvlmJ, and 129S6/SvEvTac mice. (B) The <i>Astn2</i> locus from the three 129 mouse lines shown in (A) was bred to homozygosity in a <i>Fz6</i>^<i>-/-</i> background. The <i>ridge</i> phenotype was observed only in the presence of the 129X1/SvJ <i>Astn2</i> locus; mice were photographed at P14.</p

Targeted deletion of <i>Astn2</i> exon 5 and quantitative analysis of hair follicle orientations in early postnatal back skins.

<p>(A) PCR analysis of genomic DNA in the neighborhood of <i>Astn2</i> exon 5 (left) and gross appearance of P14 mice (right). Red arrow indicates the exon 5 PCR product. <i>Fz6</i>^<i>-/-</i><i>;Astn2</i>^{<i>ex5fl/fl</i>} mice (with an intact <i>Astn2</i> exon 5) lack a ridge, whereas <i>Fz6</i>^<i>-/-</i><i>;Astn2</i>^{<i>ex5del/del</i>} mice (lacking <i>Astn2</i> exon 5) have a ridge. (B) By in situ hybridization, <i>Astn2</i> is expressed in hair follicles beginning at the placode stage (E15.5; arrow) and continuing throughout the period of follicle maturation. Scale bars, 0.1 mm. (C) Flat mount head and lower back skin of the indicated genotypes at P3. Quantifications of follicle angles are shown for each genotype beneath the flat mount images (n = 3 mice per genotype). For each skin, 81 follicle angles were determined for a set of follicles closest to the grid points on a 9 x 9 grid (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005532#sec003" target="_blank">Methods</a> for further details). Zero degrees corresponds to anterior-to-posterior; 180 and -180 degrees corresponds to posterior-to-anterior. Scale bars, 0.5 mm. <i>Astn2</i> exon 5 deletion has no effect on follicle orientation in a <i>Fz6</i>^<i>+/-</i> background. <i>Fz6</i>^<i>-/-</i><i>;Astn2</i>^{<i>ex5del/del</i>} is indistinguishable from <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i>. (D) Quantification of follicle orientations on the lower backs of eight <i>Fz6</i>^<i>-/-</i>, five <i>Fz6</i>^<i>-/-</i><i>;ridge/ridge</i>, and nine <i>Fz6</i>^<i>-/-</i><i>;Astn2</i>^{<i>ex5del/del</i>} mice at P3. Left, histograms shows all of the follicles quantified per genotype (n). Follicles with an anterior-to-posterior direction are shown in black; follicles with a posterior-to-anterior direction are shown in red. The ratio of the two classes is indicated above each histogram. Right, scatter plot showing the percent of follicles with a reversed (i.e. posterior-to-anterior) orientation for each skin. P-value was calculated with a student’s t-test.</p

Iron Oxide Nanoparticle-Powered Micro-Optical Coherence Tomography for in Situ Imaging the Penetration and Swelling of Polymeric Microneedles in the Skin

In recent years, polymeric microneedles (MNs) have attracted keen interests among researchers because of their applicability in transdermal drug delivery and interstitial skin fluid (ISF) extraction. When designing and characterizing such devices, it is critical to monitor their real-time in vitro and in vivo performances to optimize the desired effects, yet most of the existing methods are incapable of such functions. To address this unmet need, we develop a real-time noninvasive imaging methodology by integrating iron oxide (Fe₃O₄) nanoparticles into polymeric MNs to enhance image contrast for micro-optical coherence tomography (μOCT) imaging. Using the Fe₃O₄-integrated polystyrene-<i>block</i>-poly­(acrylic acid) (PS-<i>b</i>-PAA) MNs as an example, we evaluate the influences of Fe₃O₄ concentrations on contrast enhancement in μOCT imaging and visualize the real-time swelling process of polymeric MNs in biological samples for the first time. Our results show that a concentration of ∼4–5 wt % Fe₃O₄ nanoparticles not only helps achieve the best contrast-to-noise ratio in μOCT imaging, which is 10 times higher than that without Fe₃O₄ nanoparticles in air and hydrogel, but also enables the real-time changes in the profile of MNs to be observed clearly in their swelling process in skin tissues. On the basis of such findings, we utilize the optimized concentration of Fe₃O₄ nanoparticles to further quantitatively study the swelling kinetics of PS-<i>b</i>-PAA MNs in agarose hydrogel and fresh skin tissues, which lasts ∼20 and ∼30–35 s, respectively. The suitability of such a methodology for enhancing μOCT imaging would greatly facilitate the development and clinical translation of MN-based medical technologies

Green Synthesis of Carbon Quantum Dots and Carbon Quantum Dot-Gold Nanoparticles for Applications in Bacterial Imaging and Catalytic Reduction of Aromatic Nitro Compounds

This study delves into the green synthesis and multifaceted applications of three types of carbon quantum dots (CQDs), namely, CQDs-1, CQDs-2, and CQDs-3. These CQDs were innovatively produced through a gentle pyrolysis process from distinct plant-based precursors: genipin with glucose for CQDs-1, genipin with extracted gardenia seeds for CQDs-2, and genipin with whole gardenia seeds for CQDs-3. Advanced analytical techniques, including X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR), were employed to detail the CQDs’ structural and surface characteristics, revealing their unique functional groups and surface chemistries. The study further explores the CQDs’ bioimaging potential, where confocal fluorescence microscopy evidenced their swift uptake by Escherichia coli bacteria, indicating their suitability for bacterial imaging. These CQDs were also applied in the synthesis of gold nanoparticles (AuNPs), acting as reducing agents and stabilizers. Among these, CQD3-AuNPs were distinguished by their remarkable stability and catalytic efficiency, achieving a 99.7% reduction of 4-nitrophenol to 4-aminophenol in just 10 min and maintaining near-complete reduction efficiency (99.6%) after 60 days. This performance notably surpasses that of AuNPs synthesized using sodium citrate, underscoring the exceptional capabilities of CQD3-AuNPs. These insights pave the way for leveraging CQDs and CQD-stabilized AuNPs in bacterial imaging and catalysis, presenting valuable directions for future scientific inquiry and practical applications

Cucurbit[8]uril Supramolecular Assembly for Positively Charged Ultrathin Films as Nanocontainers

The design of positively charged ultrathin films for surface modification is of crucial importance for biomedical applications. Herein, we report the layer-by-layer assembly of pure positively charged ultrathin films based on the host–guest interaction of cucurbit[8]­uril (CB[8]). Two positively charged poly­(ethylenimine)­s (PEI) functionalized with guest moieties methyl viologen (MV) and indole (ID) were alternately assembled with the formation of CB[8] ternary complex under basic conditions. The growth of the (PEI-MV@CB[8]/PEI-ID) films was monitored by spectroscopic ellipsometry and quartz crystal microbalance. The morphology and structure of the films were characterized by scanning electron microscopy and UV–vis spectroscopy, respectively. These positively charged (PEI-MV@CB[8]/PEI-ID) films were very stable in the pH range from 4 to 9 but disassembled immediately when subjected to a competitive guest adamantylamine. Finally, the films were successfully employed as nanocontainers for DNA loading and subsequent directing the transfection of the adhered cells

Supplemental material for Detection of Bacteria in Water with β-Galactosidase-Coated Magnetic Nanoparticles

<p>Supplemental material for Detection of Bacteria in Water with β-Galactosidase-Coated Magnetic Nanoparticles by Mingyue Cui, Hao Chang, Yang Zhong, Min Wang, Tianze Wu, Xiao Hu, Zhichuan J. Xu, and Chenjie Xu in SLAS Technology</p