Superficial venous morphometry in the antecubital fossa: An autonomous robotic ultrasound-based analysis.

BACKGROUND: The antecubital fossa is an important site for venepuncture and intravenous procedures. The size and location of a vein can affect the success of venepuncture and intravenous access. Several studies have investigated the superficial vein morphometry, but they had small sample sizes or focused on specific populations or groups. Therefore, we conducted a prospective study with large participants in general population to analyse the morphology of the antecubital superficial vein and identify the association of sex, age and body mass index (BMI) with the size and location of the vein. METHODS: This study collected images of superficial veins prospectively using autonomous robotic ultrasound on the antecubital area between October and November 2020. We measured the superficial vein depth, vertical diameter and horizontal diameter at the antecubital area, extracted population characteristics (sex, age and BMI), and analysed a relationship between the vein dimensions and the characteristics. RESULTS: In this study, data from 461 participants (201 males and 260 females) with mean age of 41.1 years were produced. The mean vein depth, mean vertical diameter and mean horizontal diameter (±standard deviation) were 4.81 (±2.17), 3.01 (±1.10) and 4.46 (±1.60) mm, respectively. We found significant differences in vein dimensions between males and females, with males having larger vertical and horizontal diameters than females (p < 0.001). The study also revealed significant differences in vein depth and dimensions among age groups and BMI subgroups (p < 0.001). CONCLUSIONS: These findings revealed that the superficial vein in the antecubital area was oval, with a larger horizontal diameter than vertical diameter. Morphometry revealed differences in sex, age and BMI. Understanding variations in vein dimensions among different subgroups can help medical professionals improve success rate of venous access and patient safety.

Real-time cancer diagnosis of breast cancer using fluorescence lifetime endoscopy based on the pH.

A biopsy is often performed for the diagnosis of cancer during a surgical operation. In addition, pathological biopsy is required to discriminate the margin between cancer tissues and normal tissues in surgical specimens. In this study, we presented a novel method for discriminating between tumor and normal tissues using fluorescence lifetime endoscopy (FLE). We demonstrated the relationship between the fluorescence lifetime and pH in fluorescein using the proposed fluorescence lifetime measurement system. We also showed that cancer could be diagnosed based on this relationship by assessing differences in pH based fluorescence lifetime between cancer and normal tissues using two different types of tumor such as breast tumors (MDA-MB-361) and skin tumors (A375), where cancer tissues have ranged in pH from 4.5 to 7.0 and normal tissues have ranged in pH from 7.0 to 7.4. To support this approach, we performed hematoxylin and eosin (H&E) staining test of normal and cancer tissues within a certain area. From these results, we showed the ability to diagnose a cancer using FLE technique, which were consistent with the diagnosis of a cancer with H&E staining test. In summary, the proposed pH-based FLE technique could provide a real time, in vivo, and in-situ clinical diagnostic method for the cancer surgical and could be presented as an alternative to biopsy procedures.

Photoinduced electron transfer upon supramolecular complexation of (porphyrinato)Sn-viologen with cucurbit[7]uril.

The synthesis of (porphyrinato)Sn-viologen, 1, and its supramolecular complexation with cucurbit[7]uril (CB[7]) were studied. 1H NMR spectroscopic studies obviously reveal that 1 forms a 1 : 2 supramolecular complex with CB[7] through the inclusion of viologen moieties of 1 into the cavity of CB[7]. The cyclic voltammetric study supports that the binding affinity of the radical cation forms is comparable to that of the di-cation viologen toward CB[7]. The fluorescence arising from the porphyrin moiety is significantly quenched upon the complexation of 1 with CB[7]. The ps-time-resolved fluorescence and ns-transient absorption spectroscopic studies reveal that the photoinduced electron transfer (PET) between viologen and Sn(iv) porphyrin of 1 takes place from the first excited singlet (S1) state and the second excited triplet (T2) state of the porphyrin moiety upon complexation with CB[7], while the PET from the S1 state is negligible in the absence of CB[7].

Gold nanorods-conjugated TiO2 nanoclusters for the synergistic combination of phototherapeutic treatments of cancer cells.

BACKGROUND: Recently, a combination of photodynamic therapy (PDT) and photothermal therapy (PTT) to generate reactive oxygen species (ROS) and heat to kill cancer cells, respectively has attracted considerable attention because it gives synergistic effects on the cancer treatment by utilizing the radiation of nontoxic low-energy photons such as long wavelength visible light and near IR (NIR) penetrating into subcutaneous region. For the effective combination of the phototherapies, various organic photosensitizer-conjugated gold nanocomplexes have been developed, but they have still some disadvantages due to photobleaching and unnecessary energy transfer of the organic photosensitizers. RESULTS: In this study, we fabricated novel inorganic phototherapeutic nanocomplexes (Au NR-TiO2 NCs) by conjugating gold nanorods (Au NRs) with defective TiO2 nanoparticle clusters (d-TiO2 NP clusters) and characterized their optical and photothermal properties. They were observed to absorb a broad range of visible light and near IR (NIR) from 500 to 1000 nm, exhibiting the generation of ROS as well as the photothermal effect for the simultaneous application of PDT and PTT. The resultant combination of PDT and PTT treatments of HeLa cells incubated with the nanocomplexes caused a synergistic increase in the cell death compared to the single treatment. CONCLUSION: The higher efficacy of cell death by the combination of PDT and PTT treatments with the nanocomplexes is likely attributed to the increases of ROS generation from the TiO2 NCs with the aid of local surface plasma resonance (LSPR)-induced hot electrons and heat generation from Au NRs, suggesting that Au NR-TiO2 NCs are promising nanomaterials for the in vivo combinatorial phototherapy of cancer.

Simultaneous multicolor imaging of wide-field epi-fluorescence microscopy with four-bucket detection.

We demonstrate simultaneous imaging of multiple fluorophores using wide-field epi-fluorescence microscopy with a monochrome camera. The intensities of the three lasers are modulated by a sinusoidal waveform in order to excite each fluorophore with the same modulation frequency and a different time-delay. Then, the modulated fluorescence emissions are simultaneously detected by a camera operating at four times the excitation frequency. We show that two different fluorescence beads having crosstalk can be clearly separated using digital processing based on the phase information. In addition, multiple organelles within multi-stained single cells are shown with the phase mapping method, demonstrating an improved dynamic range and contrast compared to the conventional fluorescence image. These findings suggest that wide-field epi-fluorescence microscopy with four-bucket detection could be utilized for high-contrast multicolor imaging applications such as drug delivery and fluorescence in situ hybridization.

Fabrication of ZnO nanoplates for visible light-induced imaging of living cells.

Visible light-sensitive ZnO nanoplates (ZnO NPls) were successfully synthesized using a hydrothermal sol-gel method and their structures were characterized by using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmitting electron microscopy (TEM), atomic force microscopy (AFM) and FT-IR analysis. From these studies it was found that the nanoplates have excellent crystallinity and a perfect nanoplate morphology with diameter ranging from 50 nm to 250 nm and a thickness of ∼10 nm. Surfaces of the ZnO NPls were further conjugated with hydrophilic amino groups such as aminopropyl triethoxysilane (APTES) to enhance the biocompatibility and cell penetrations. The resultant APTES-modified ZnO NPls showed excellent colloidal stability in various aqueous media, exhibiting stable and strong red fluorescence emission (∼650 nm) under visible light-excitation at 405 nm. They also exhibited strong red emission even after being penetrated into living cells with negligible cytotoxicity. Therefore, the APTES-modified ZnO NPls should be promising alternative nanomaterials to the traditional quantum dots as well as previously reported ZnO cellular labelling agents which exhibit green emission by UV-excitation.

Visible light-sensitive APTES-bound ZnO nanowire toward a potent nanoinjector sensing biomolecules in a living cell.

Nanoscale cell injection techniques combined with nanoscopic photoluminescence (PL) spectroscopy have been important issues in high-resolution optical biosensing, gene and drug delivery and single-cell endoscopy for medical diagnostics and therapeutics. However, the current nanoinjectors remain limited for optical biosensing and communication at the subwavelength level, requiring an optical probe such as semiconductor quantum dots, separately. Here, we show that waveguided red emission is observed at the tip of a single visible light-sensitive APTES-modified ZnO nanowire (APTES-ZnO NW) and it exhibits great enhancement upon interaction with a complementary sequence-based double stranded (ds) DNA, whereas it is not significantly affected by non-complementary ds DNA. Further, the tip of a single APTES-ZnO NW can be inserted into the subcellular region of living HEK 293 cells without significant toxicity, and it can also detect the enhancement of the tip emission from subcellular regions with high spatial resolution. These results indicate that the single APTES-ZnO NW would be useful as a potent nanoinjector which can guide visible light into intracellular compartments of mammalian cells, and can also detect nanoscopic optical signal changes induced by interaction with the subcellular specific target biomolecules without separate optical probes.

Highly fluorescent peptide nanoribbon impregnated with Sn-porphyrin as a potent DNA sensor.

Highly fluorescent and thermo-stable peptide nanoribbons (PNRs) were fabricated by solvothermal self-assembly of a single peptide (D,D-diphenyl alanine peptides) with Sn-porphyrin (trans-dihydroxo[5,10,15,20-tetrakis(p-tolyl)porphyrinato] Sn(IV) (SnTTP(OH)2)). The structural characterization of the as-prepared nanoribbons was performed by transmitting electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM), FT-IR and Raman spectroscopy, indicating that the lipophilic Sn-porphyrins are impregnated into the porous surface formed in the process of nanoribbon formation through intermolecular hydrogen bonding of the peptide main chains. Consequently the Sn-porphyrin-impregnated peptide nanoribbons (Sn-porphyrin-PNRs) exhibited typical UV-visible absorption spectrum of the monomer porphyrin with a red shifted Q-band, and their fluorescence quantum yield was observed to be enhanced compared to that of free Sn-porphyrin. Interestingly the fluorescence intensity and lifetimes of Sn-porphyrin-PNRs were selectively affected upon interaction with nucleotide base sequences of DNA while those of free Sn-porphyrins were not affected by binding with any of the DNA studied, indicating that DNA-induced changes in the fluorescence properties of Sn-porphyrin-PNRs are due to interaction between DNA and the PNR scaffold. These results imply that Sn-porphyrin-PNR will be useful as a potent fluorescent protein analogue and as a biocompatible DNA sensor.

Optical waveguiding and lasing action in porphyrin rectangular microtube with subwavelength wall thicknesses.

Lasing action by planar-, fiber-, or ring-type waveguide has been extensively investigated with different types of microcavities such as thin films, wires, cylindrical tubes, or ribbons. However, the lasing action by sharp bending waveguide, which promises efficient interconnection of amplified light in the photonic circuits, remains unexplored. Here, we report the first observation of microcavity effects in the organic rectangular microtubes (RMTs) with sharp bends (ca. 90°) and subwavelength nanoscale wall thicknesses, based on single crystalline and themostable tetra(4-pyridyl)porphyrin (H(2)TPyP)-RMTs synthesized by the VCR process. A bright tip emission is observed from the sharp bending edges of a single RMT upon laser excitation, demonstrating a clear waveguiding behavior in RMT. The appearance of a peak from the (0-1) band at a threshold tube length and the gradual decrease of its full width at half-maximum (fwhm) suggest that amplification of spontaneous emission (ASE) is developed by stimulated emission along the walls of the RMTs. The ehancement of the ASE peak together with the narrowing of its fhwm over a threshold pump power and the tube size (width and length) dependence of the mode spacing strongly support vibronic lasing action in the RMTs. The stimulated emission by the subwavelength bending waveguide demonstrates that the organic RMTs can be applied as new building blocks for micromanipulation of optical path and amplification in the integrated circuits for efficient photonic devices.