Factors affecting the location of sphenoid sinus ostium: a binary logistic regression analysis.

BACKGROUND: Sphenoid sinus is a type of sinus surrounded by critical structures so that its injury potential to induce complications during surgery. The purpose of this study was to investigate the factors affecting the location of the sphenoid sinus natural ostium (SSO) to provide valuable data for endoscopic sinus surgery. METHODS: Ostiomeatal unit (OMU) computerized tomography (CT) was performed on 198 subjects. Across the left and right sides, 396 evaluation results were obtained. The vertical distance to determine the location of the SSO was analyzed based on Lines 1, 2 and 3 on the sagittal image. The horizontal distance was analyzed based on Lines 4 and 5 on the axial image. The upper, lower, medial and non-medial borders were defined according to the location of the SSO. The presellar, sellar and postsellar types were categorized according to the level of sphenoid sinus pneumatization (SSP) on the sagittal image. The presence and absence of Onodi cells were defined on the coronal image. Binary logistic regression analysis was performed to investigate each factor. RESULTS: As the rostrum width of the SSO on the horizontal position increased, the position toward non-medial boarder increased by 4.902 times so that the natural ostium showed a trend of lateralization. For the postsellar type, compared to the presellar type, the position toward the non-medial boarder decreased by 0.223 times, indicating that the postsellar type had the natural ostium showing a trend of medialization. In the presence of Onodi cells, the position toward the lower boarder increased by 2.599 times with a significant association. CONCLUSIONS: The results in this study indicated that the presellar type of SSP had the natural ostium exhibiting lateralization with an increase in the rostrum width, whereas the postsellar type had the natural ostium exhibiting medialization with a decrease in the rostrum width. Based on these findings, the methods to widen the natural ostium may be diversified.

Upconversion Nanoparticle-Based Förster Resonance Energy Transfer for Detecting DNA Methylation.

Aberrant methylation of a crucial CpG island is the main mechanism for the inactivation of CDKN2A in the early stages of carcinogenesis. Therefore, the detection of DNA methylation with high sensitivity and specificity is important, and various detection methods have been developed. Recently, upconversion nanoparticles (UCNPs) have been found to display a high signal-to-noise ratio and no photobleaching, making them useful for diagnostic applications. In this pilot study, we applied UCNPs to the detection of CDKN2A methylation and evaluated the feasibility of this system for use in molecular diagnostics. DNA PCR was performed using biotinylated primers, and the PCR amplicon was then intercalated with SYTOX Orange dye, followed by incubation with streptavidin-conjugated UCNPs. Fluorescence detection of the Förster resonance energy transfer (FRET) of the UCNPs (MS-UC-FRET) was then performed, and the results were compared to those from real-time PCR (RQ-PCR) and pyrosequencing. Detection by MS-UC-FRET was more sensitive than that by either RQ-PCR or pyrosequencing. Our results confirmed the success of our MS-UC-FRET system for detecting DNA methylation and demonstrated the potential application of this system in molecular diagnostics.

Fabrication of Magnetic Upconversion Nanohybrid for Luminescent Resonance Energy Transfer-Based Detection of Glutathione.

This study introduces the facile fabrication of a bimodal nanohybrid for the luminescent ON/OFF detection of glutathione. The proposed nanosensor consists of magnetic (Fe3O4) and upconversion nanoparticles (UCP) co-encapsulated in a silica matrix, and decorated with gold nanoparticle (AuNP) as a luminescent quencher. The detection mechanism is based on the Luminescent Resonance Energy Transfer (LRET) between the donor (UCP) and the acceptor (AuNP) with the help of a disulfide bond as a bridging element. In the presence of glutathione, the disulfide bridges between AuNPs and Fe3O4/UCP@SiO2 was cleaved and the amount of glutathione could be traced by the restored luminescence (ON state) of the nanohybrids after magnetic separation.

Gold nanoparticle silica nanopeapods.

A subnanometer gap-separated linear chain gold nanoparticle (AuNP) silica nanotube peapod (SNTP) was fabricated by self-assembly. The geometrical configurations of the AuNPs inside the SNTPs were managed in order to pose either a single-line or a double-line nanostructure by controlling the diameters of the AuNPs and the orifice in the silica nanotubes (SNTs). The AuNPs were internalized and self-assembled linearly inside the SNTs by capillary force using a repeated wet-dry process on a rocking plate. Transmission electron microscopy (TEM) images clearly indicated that numerous nanogap junctions with sub-1-nm distances were formed among AuNPs inside SNTs. Finite-dimension time domain (FDTD) calculations were performed to estimate the electric field enhancements. Polarization-dependent surface-enhanced Raman scattering (SERS) spectra of bifunctional aromatic linker p-mercaptobenzoic acid (p-MBA)-coated AuNP-embedded SNTs supported the linearly aligned nanogaps. We could demonstrate a silica wall-protected nanopeapod sensor with single nanotube sensitivity. SNTPs have potential application to intracellular pH sensors after endocytosis in mammalian cells for practical purposes. The TEM images indicated that the nanogaps were preserved inside the cellular constituents. SNTPs exhibited superior quality SERS spectra in vivo due to well-sustained nanogap junctions inside the SNTs, when compared to simply using AuNPs without any silica encapsulation. By using these SNTPs, a robust intracellular optical pH sensor could be developed with the advantage of the sustained nanogaps, due to silica wall-protection.

Silica nanotube surface modification for multiplex detection of pathogenic bacteria.

This study described the prospect of silica nanotube surface modification in simultaneous detection of pathogenic bacteria by coupling cation exchange magnetic separation with quantum dot labeling. The outer surface of magnetic nanoparticles embedded long silica nanotube (capturing SNT) was modified with poly-L-lysine to serve as a cation exchange magnetic nano-complex to capture and isolate Escherichia coli (E. coli) O157:H7 and Salmonella enteritis typhimurium (S. typhimurium) in aqueous phase. Antibody conjugated quantum dot-embedded short SNT (reporting SNT) was used to simultaneously detect both bacteria, giving a high intensity and photo-stable fluorescent image that can detect single leveled bacterium binding on the capturing SNT. The fluorescent intensity generated from the capturing of both bacteria at different concentration was in the range of 10(2)-10(5) CFU/ml for both E. coli and S. typhimurium.

Upconversion nanoparticles in bioassays, optical imaging and therapy.

Rare-earth doped nanoparticle (RE), termed upconversion nanoparticle (UCNP), is a new generation of phosphorescence which has recently attracted significant research interest. Due to the unique upconversion properties, UCNP has been considered to be an excellent alternative for conventional fluorescence. Since its first emergence in mid-1960s, UCNPs have been studied in a wide range of fields, including those in biological applications. Owing to its suitable size distribution and biocompatibility, UCNP could be conjugated with various kinds of biomolecules, resulting in the development of numerous biological platforms such as biodetection assays and therapeutic modalities. The unique optical properties of UCNP such as prominent luminescence, deep penetration to biological tissues without damaging the cells, low background and high resistance to photo-bleaching enhance UCNP prospects as an excellent contrast agent in both in vitro and in vivo. In this review, we discuss the recent developments of UCNP in bioassays, optical imaging, and therapy, also the prospects and challenges of UCNP-based detection in the development of biomedical science.

Fabrication of dual dye-doped silica nanotube as a fluorescent ratiometric pH sensor.

This study described a novel fabrication of fluorescence co-encapsulating silica nanotubes (F@SNT) and the further application of the as-synthesized nanostructure as a ratiometric pH sensor in buffer solution. Silica nanotubes (SNTs) embedded anodic alumina oxide (AAO) template was fabricated by sol-gel technique, tetramethyl rhodamine (TMR-the reference dye) was incorporated directly onto silica layer via hydrophobic interaction. Subsequently, fluorescent isothiocyanate (FITC-pH sensitive dye) was encapsulated inside poly-dimethylsiloxane (PDMS) matrix and the FITC-PDMS nanocomposite was doped into the hollow structure of SNT using nano-molding lithography. On removing AAO, free-standing SNTs were obtained and were subsequently applied as a ratiometric pH sensor in phosphate buffer solution. The dual dye-doped SNTs showed excellent fluorescence and a good pH sensing performance from pH 5.2-8.0. The results were distinguishable by the emission spectra and by fluorescent visualization. High photostability, sensitivity, biocompatibility with adjustable sizes make dual dye doped-SNT a promising nanostructure for bioapplications.

Effect of Maxillary Sinus Pneumatization on the Ease of Access to Prelacrimal Recess.

OBJECTIVE: Prelacrimal recess approach can be used to access lesions of the anterior wall of the maxillary sinus (MS). Moreover, the longer the prelacrimal recess window distance (PLRWD), the easier it is to access the anterior wall. This study aimed to define the correlation between maxillary sinus pneumatization (MSP) and PLRWD, a previously defined anatomic factor predictive of the ease of prelacrimal recess approach (PLRA). METHODS: In total, 506 sides of 253 participants were studied. In the axial image, the PLRWD, the distance between the anterior wall of the MS and the lacrimal duct, was measured through radioanatomical analysis and classified as type I (<3 mm), type II (3-7 mm), or type III (>7 mm). On the coronal image, the distance between the nasal floor and the lower end of the MS was measured. When MSP did not reach the nasal floor, it was classified as grade I, as grade II when MSP reached the nasal floor, and grade III when the MS was pneumatized below the nasal floor. RESULTS: Type I included 115 sides (22.7%); type II, 277 sides (54.7%); and type III, 114 sides (22.5%). Grade I was observed in 58 sides (11.5%), grade II in 38 sides (7.5%), and grade III in 410 sides (81.0%). The mean PLRWD of grade I was 2.35 ± 2.41 mm, II was 3.37 ± 2.46 mm, and III was 5.55 ± 2.54 mm, showing a significant difference (P < .001). Post hoc analysis showed significant differences in the mean PLRWD among grades I, II, and III. Two anatomical factors, the MSP and PLRWD, were positively correlated (r = .507, P < .001). CONCLUSIONS: This study demonstrates a correlation between the feasibility of MSP and PLRA. Both MSP and PLRWD are essential diagnostic parameters for preoperative planning and better surgical outcomes.

Subppb level monitoring and UV degradation of triclosan pollutants using ZnO multipod and Ag nanocomposites.

A unique nanomaterial platform was developed for trace detection and efficient degradation of triclosan (TCS). A facile spectroscopic technique for surface-enhanced Raman scattering (SERS)-supported identification and ultraviolet (UV) degradation of TCS using a SERS template based on silver spherical nanoparticle (AgNP)-modified ZnO multipods (ZnO@Ag) is reported. Core-shell composite materials of ZnO multipods with a dimension of around 3 µm and AgNPs with an average diameter of ∼27 nm was designed not only as a substrate for TCS degradation up to ∼92% upon UV irradiation (λ = 365 mm, 300 µW/cm2) but also as a monitoring platform sensitive to TCS at a detection limit as low as 10-9 M (≈0.3 ppb). Herein, the first investigation into ZnO@Ag bimetallic composites is established for both the SERS-based detection and UV-assisted degradation of environmental TCS pollutants. The calibration curve was estimated to be linear at R2 > 0.97. The validated technology was successfully used to determine the antibacterial agent and TCS in distilled or river water. The advantages of the ZnO@Ag template are highlighted over conventional detection and excellent degradation.

Transparent Oil-Water Separating Spiky SiO2 Nanoparticle Supramolecular Polymer Superhydrophobic Coatings.

A potential application of spiky SiO2 nanoparticles (NPs) with tubular and rough surfaces is investigated as superhydrophobic coatings, for their unique transparent, fluorinate-free, and environmentally friendly properties. This study demonstrates a facile method for the successful fabrication of superhydrophobic coatings and SiO2 @polydimethylsiloxane (PDMS) using spiky SiO2 NPs, N-coordinated boroxines, and PDMS. Combined with spray coating technology, this method of superhydrophobic coating can be simply applied to both hydrophilic and hydrophobic surfaces, including wood, fabric, glass, metal, sponge, and paper. The nanocomposite coating on the glass surface showed both excellent superhydrophobicity and high transparency, with a contact angle of 165.4 ± 1.0° and 96.93% transmittance at 550 nm, respectively. SiO2 @PDMS-modified glass substrate is found to be resilient to UV irradiation, water, and high temperature treatments at ambient conditions. Experimental data demonstrated that the simple but effective combination of N-boroxine-PDMS and spiky SiO2 NPs produces a layered coating material that exhibits many good integrated surface properties, including stability, transparency, superhydrophobicity, and oil-water separation.

Advanced microplastic monitoring using Raman spectroscopy with a combination of nanostructure-based substrates.

Micro(nano)plastic (MNP) pollutants have not only impacted human health directly, but are also associated with numerous chemical contaminants that increase toxicity in the natural environment. Most recent research about increasing plastic pollutants in natural environments have focused on the toxic effects of MNPs in water, the atmosphere, and soil. The methodologies of MNP identification have been extensively developed for actual applications, but they still require further study, including on-site detection. This review article provides a comprehensive update on the facile detection of MNPs by Raman spectroscopy, which aims at early diagnosis of potential risks and human health impacts. In particular, Raman imaging and nanostructure-enhanced Raman scattering have emerged as effective analytical technologies for identifying MNPs in an environment. Here, the authors give an update on the latest advances in plasmonic nanostructured materials-assisted SERS substrates utilized for the detection of MNP particles present in environmental samples. Moreover, this work describes different plasmonic materials-including pure noble metal nanostructured materials and hybrid nanomaterials-that have been used to fabricate and develop SERS platforms to obtain the identifying MNP particles at low concentrations. Plasmonic nanostructure-enhanced materials consisting of pure noble metals and hybrid nanomaterials can significantly enhance the surface-enhanced Raman scattering (SERS) spectra signals of pollutant analytes due to their localized hot spots. This concise topical review also provides updates on recent developments and trends in MNP detection by means of SERS using a variety of unique materials, along with three-dimensional (3D) SERS substrates, nanopipettes, and microfluidic chips. A novel material-assisted spectral Raman technique and its effective application are also introduced for selective monitoring and trace detection of MNPs in indoor and outdoor environments.

Nano barcoding cell-based biosensor using fluorophor-embedded silica nanotubes.

A simple and reliable drug screening method was developed using peptide hydrogel cell beads coded by quantum dot-embedded silica nanotubes. Very long silica nanotubes were fabricated upon a nanoporous alumina template using sol-gel techniques. The physical shapes of the nanotubes were measured by TEM (Transmission Electron Microscope). Green and red quantum dots embedded in silica nanotubes were applied to peptide hydrogel cell beads as coding materials. This was confirmed by confocal microscopy that examined fluorescence levels and quantum dot shapes. The peptide hydrogel cell beads coded with silica nanotubes were loaded into a PDMS single chamber in order to assess the effect of doxorubicin on HMEC and MCF-7 cells, which was measured in hydrogel cell beads by live and dead cell staining using coding materials. As a result, MCF-7 cancer cells were more affected by doxorubicin than HMEC; however, doxorubicin induced HMEC cell death at a relatively high concentration (> 5 microg/ml).

Surface-Enhanced Raman Sensing of Semi-Volatile Organic Compounds by Plasmonic Nanostructures.

Facile detection of indoor semi-volatile organic compounds (SVOCs) is a critical issue to raise an increasing concern to current researchers, since their emissions have impacted the health of humans, who spend much of their time indoors after the recent incessant COVID-19 pandemic outbreaks. Plasmonic nanomaterial platforms can utilize an electromagnetic field to induce significant Raman signal enhancements of vibrational spectra of pollutant molecules from localized hotspots. Surface-enhanced Raman scattering (SERS) sensing based on functional plasmonic nanostructures has currently emerged as a powerful analytical technique, which is widely adopted for the ultra-sensitive detection of SVOC molecules, including phthalates and polycyclic aromatic hydrocarbons (PAHs) from household chemicals in indoor environments. This concise topical review gives updated recent developments and trends in optical sensors of surface plasmon resonance (SPR) and SERS for effective sensing of SVOCs by functionalization of noble metal nanostructures. Specific features of plasmonic nanomaterials utilized in sensors are evaluated comparatively, including their various sizes and shapes. Novel aptasensors-assisted SERS technology and its potential application are also introduced for selective sensing. The current challenges and perspectives on SERS-based optical sensors using plasmonic nanomaterial platforms and aptasensors are discussed for applying indoor SVOC detection.

Nanostructured Raman substrates for the sensitive detection of submicrometer-sized plastic pollutants in water.

We prepared novel Raman substrates for the sensitive detection of submicron-sized plastic spheres in water. Anisotropic nanostar dimer-embedded nanopore substrates were prepared for the efficient identification of submicron-sized plastic spheres by providing internal hot spots of electromagnetic field enhancements at the tips of nanoparticles. Silver-coated gold nanostars (AuNSs@Ag) were inserted into anodized aluminum oxide (AAO) nanopores for enhanced microplastic (MP) detection. We found that surface-enhanced Raman scattering (SERS) substrates of AuNSs@Ag@AAO yielded stronger signals at the same weight percentages for polystyrene MP particles with diameters as small as 0.4 µm, whereas such behaviors could not be observed for larger MPs (diameters of 0.8 µm, 2.3 µm, and 4.8 µm). The detection limit of the submicrometer-sized 0.4 µm in our Raman measurements were estimated to be 0.005% (∼0.05 mg/g =50 ppm) along with a fast detection time of only a few min without any sample pretreatments. Our nano-sized dimensional matching substrates may provide a useful tool for the application of SERS substrates for submicrometer MP pollutants in water.

Nanopatterned Polymer Molds Using Anodized Aluminum Templates for Anti-Reflective Coatings.

This work introduces a facile geometry-controlled method for the fabrication of embossed and engraved polymeric moth-eye-inspired nanostructures in imprinting molds using anodic aluminum oxide (AAO) templates, resulting in a novel anti-reflective transparent coating. The moth-eye nanostructures are prepared directly on the surface of a flexible polyethylene terephthalate (PET) substrate. As a prerequisite procedure, a UV-curable polyurethane acrylate resin is spun on the PET. The shape of the moth-eye nanostructures can then be adjusted by controlling the size and shape of the nanopores in the AAO templates. Both embossed and concaved polymer moth-eye nanostructures were successfully mounted on a PET substrate. Embossed polymer replica molds were prepared using the AAO master templates in combination with an imprinting process. As revealed by field-emission electron microscope (FE-SEM) images, conical nanopatterns in the AAO template with a diameter of ~90 nm and a depth of ~100 nm, create a homogeneous embossed morphology in the polymer moth-eye nanostructure. The polymeric molds with the depths of 300 and 500 nm revealed the amalgamated structures in their apexes. In addition, a dip-imprinting process of the polymeric layers was implemented to yield a concaved mold by assembly on the surface of the 100 nm embossed polymer mold substrate. Considering that the embossed structures may be crumbled due to their protuberant shapes, the concaved geometries can have an advantage of stability in a certain application concerning physical degradation along with a higher transmission by ~2%, despite somewhat nonuniform structure. The experimental and theoretical results of this study indicate that this polymer layer has the potential for use in anti-reflective coating applications in transparent films.

Plasmonic nanorod array for effective photothermal therapy in hyperthermia.

Optical properties of anisotropic gold nanorod arrays inside anodic aluminium oxide substrates enhance the longitudinal absorption intensities and the hyperthermia cancer cell killing at 42.1 °C under photothermal laser exposures at 671 nm.

Mechanical capping of silica nanotubes for encapsulation of molecules.

Multifunctional silica nanotubes (SNTs) are being widely used for many biomedical applications due to their structural benefits. Controlling the structure of the open end of an SNT is a crucial step for drug/gene delivery and for fabrication of multifunctional SNTs. We developed a mechanical capsulation method to fabricate caps at the ends of SNTs. A thin layer of malleable capping materials (Au, Ag, PLGA) was deposited onto the surface of an SNT-grown AAO template. Capped SNTs were then obtained by hammering with alumina microbeads. For a proof-of-concept experiment, we demonstrated dye-encapsulated SNTs without any chemical functionalizations. Since a mechanical approach is free of the issue of chemical compatibility between cargo molecules and capping materials, the method can provide an effective platform for the preparation of smart multifunctional nanotubes for biomedical applications.

TEM-based metrology for HfO2 layers and nanotubes formed in anodic aluminum oxide nanopore structures.

Nanotubes are fabricated by atomic layer deposition (ALD) into nanopore arrays created by anodic aluminum oxide (AAO). A transmission electron microscopy (TEM) methodology is developed and applied to quantify the ALD conformality in the nanopores (thickness as a function of depth), and the results are compared to existing models for ALD conformality. ALD HfO2 nanotubes formed in AAO templates are released by dissolution of the Al2O3, transferred to a grid, and imaged by TEM. An algorithm is devised to automate the quantification of nanotube wall thickness as a function of position along the central axis of the nanotube, by using a cylindrical model for the nanotube. Diffusion-limited depletion occurs in the lower portion of the nanotubes and is characterized by a linear slope of decreasing thickness. Experimentally recorded slopes match well with two simple models of ALD within nanopores presented in the literature. The TEM analysis technique provides a method for the rapid analysis of such nanostructures in general, and is also a means to efficiently quantify ALD profiles in nanostructures for a variety of nanodevice applications.

Inorganic hollow nanoparticles and nanotubes in nanomedicine Part 1. Drug/gene delivery applications.

Recent cytotoxicity studies on carbon nanotubes have shown that the biocompatibility of nanomaterial might be determined mainly by surface functionalization, rather than by size, shape, and material. Although the cytotoxicity for individual inorganic hollow nanomaterials should be extensively tested in vitro and in vivo, potential safety concerns about the use of inorganic nanomaterials in biomedical applications could be alleviated with proper surface treatment. Inorganic hollow nanoparticles and nanotubes have attracted great interest in nanomedicine because of the generic transporting ability of porous material and a wide range of functionality that arises from their unique optical, electrical, and physical properties. In this review, we describe recent developments of hollow and porous inorganic nanomaterials in nanomedicine, especially for drug/gene delivery.

Inorganic hollow nanoparticles and nanotubes in nanomedicine Part 2: Imaging, diagnostic, and therapeutic applications.

Inorganic nanoparticles, such as carbon nanotubes, quantum dots and gold nanoshells, have been adopted for biomedical use, due to their unique optical and physical properties. Compared to conventional materials, inorganic nanomaterials have several advantages such as simple preparative processes and precise control over their shape, composition and size. In addition, inorganic porous nanomaterials are fundamentally advantageous for developing multifunctional nanomaterials, due to their distinctive inner and outer surfaces. In this review, we describe recent developments of hollow and porous inorganic nanomaterials in nanomedicine, especially for imaging/diagnosis and photothermal therapy.