Determination of Intimate Composition of Theranostic Polyplexes Based on (Co)Polymers of Poly(vinyl benzyl trimethylammonium chloride)

Novel hybrid nanoparticulate systems that exhibit potential to combine therapeutic, diagnostic, and sensing modalities in a single nanoparticle are investigated. They are composed of a homopolymer of poly(vinyl benzyl trimethylammonium chloride) (or its copolymer with poly[oligo(ethylene glycol) methacrylate]), DNA, and gold nanoparticles (AuNPs). Using the approach of classic dynamic and static light scattering, parameters such as molar mass, particle size, geometry and density, and intimate composition are determined, trying to establish what the theranostic polyplexes really carry. According to the analysis, the polyplex particles are composed of up to 154 DNA molecules and 1612 (co)polymer molecules at amino‐to‐phosphate groups ratio (N/P) of 0.5 and 1 DNA and up to 252 (co)polymer molecules at higher N/P ratios. The particle morphology is consistent with “hairy surface on a compact sphere” with density that is lower than the density of the familiar copolymer micelles. The introduction of AuNPs does not influence the density and structure of the carriers, which could be related to the low number fraction of polyplex particles carrying AuNPs. Additional data from transmission electron microscopy, electrophoretic light scattering, and analytical ultracentrifugation validate the morphology, structure, and molar mass of the theranostic nanoassemblies and confirm the conclusions derived from light scattering.     

Crystallization/Melting Kinetics and Morphological Analysis of Polyphenylene Sulfide

Crystallization and melting kinetics of polyphenylene sulfide (PPS) are determined using fast scanning calorimetry. The temperature dependence of half‐time crystallization of isothermally melt‐crystallized PPS shows a downward convex curve with a minimum at 160 °C. The minimum crystallization half‐time is about 3 s. The analysis of heating rate dependence of the melting temperature reveals a zero‐entropy‐production melting temperature of the sample. The microstructure of the sample, which is prepared by fast scanning calorimetry, is investigated by small‐angle X‐ray scattering and polarizing optical microscopy. The crystallinity and lamellar thickness of the sample annealed for 400 s decrease with decreasing crystallization temperature. The size of spherulites becomes small as the isothermal temperature is decreased. Transcrystalline morphology is observed near the surface between the sample and nitrogen gas at a crystallization temperature of 120 °C. The thickness of the transcrystalline layer disappears as the isothermal temperature is increased.     

Making yttria-stabilized tetragonal zirconia translucent

ObjectiveThe aim of this study was to provide a design guideline for developing tetragonal yttria-stabilized zirconia with improved translucency.MethodsThe translucency, the in-line transmission in particular, of 3 mol.% yttria-stabilized tetragonal zirconia (3Y-TZP) has been examined using the Rayleigh scattering model. The theory predicts that the in-line transmission of 3Y-TZP can be related to its thickness with grain size and birefringence the governing parameters. To achieve a threshold value of translucency, the critical grain size of 3Y-TZP was predicted for various thicknesses (0.3–2.0 mm). The threshold value was defined by a measured average in-line transmission value of a suite of dental porcelains with a common thickness of 1 mm. Our theoretical predictions were calibrated with one of the very few experimental data available in the literature.ResultsFor a dense, high-purity zirconia, its in-line transmission increased with decreasing grain size and thickness. To achieve a translucency similar to that of dental porcelains, a nanocyrstalline 3Y-TZP structure was necessitated, due primarily to its large birefringence and high refractive index. Such a grain size dependence became more pronounced as the 3Y-TZP thickness increased. For example, at a thickness of 1.3 mm, the mean grain size of a translucent 3Y-TZP should be 82 nm. At 1.5 mm and 2 mm thicknesses, the mean grain size needed to be 77 nm and 70 nm, respectively.SignificanceA promising future for zirconia restorations, with combined translucency and mechanical properties, can be realized by reducing its grain size.     

Load cycling enhances bioactivity at the resin–dentin interface

Objectives

The purpose of this study was to evaluate if mechanical loading promotes bioactivity at the resin interface after bonding with three different adhesive approaches.

Methods

Dentin surfaces were subjected to three different treatments: demineralisation by (1) 37% phosphoric acid (PA) followed by application of an etch-and-rinse dentin adhesive Single Bond (SB) (PA + SB), (2) by 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB (EDTA + SB), (3) application of a self-etch dentin adhesive: Clearfil SE Bond (SEB). Bonded interfaces were stored in simulated body fluid during 24 h or 3 w. One half of each tooth was submitted to mechanical loading. Remineralisation of the bonded interfaces was assessed by AFM imaging/nano-indentation, Raman spectroscopy/cluster analysis, dye assisted confocal microscopy evaluation (CLSM) and Masson's trichrome staining.

Results

Loading cycling for 3 w promoted an increase of mechanical properties at the resin–dentin interface. Cluster analysis demonstrated an augmentation of the mineral–matrix ratio in SB-loaded specimens. CLSM showed an absent micropermeability and nanoleakage after loading EDTA + SB and SEB specimens. Trichrome staining reflected a narrow demineralised dentin matrix after loading, almost not observable in EDTA + SB and SEB.

Significance

In vitro mechanical loading promoted mineralization in the resin–dentin interfaces, at 24 h and 3 w of storage.     

Photodynamic therapy-mediated hypericin-loaded nanostructured lipid carriers against vulvovaginal candidiasis

Introduction and Aim: The indiscriminate use and adverse effects of the main conventional antifungal agents compromise the effectiveness of treating vulvovaginal candidiasis (VVC), mainly caused by the species Candida albicans. This study evaluated the effectiveness of photodynamic therapy (PDT) and the in vitro and in vivo anti-candida potential of the hypericin (HYP)-loaded nanostructured lipid carriers (NLC). Materials and Methods: Empty NLC and NLC-HYP were characterized by the dynamic light scattering technique and transmission electron microscopy to evaluate the average particle size distribution and its morphologies. The in vitro inhibition photodynamic effect of the systems was tested to reduce the planktonic viability of C. albicans. The therapeutic assay photodynamic of the systems was performed to treat VVC in mice. Results: Empty NLC and NLC-HYP presented values of average hydrodynamic diameter, polydispersity index, and ζ-potential from 136 to 133 nm, 0.16 to 0.22, and -18 to -30 mV, respectively, on day 30. Microscopically, the systems showed spherical morphologies and nanoscale particles. Furthermore, in the in vitro inhibition assay, the treatment of PDT with NLC-HYP (NLC-HYP+) showed a significant reduction of the C. albicans planktonic viability compared to YNB negative control after 5 min of LED light irradiation. In the in vivo therapeutic assay, the antifungal group (vaginal antifungal cream) and NLC-HYP+ evaluated in the dark and by PDT, respectively, had a significant log₁₀ reduction in fungal burden compared to the infected group on day 8 of the VVC treatment. Conclusion: Due to the in vitro and in vivo anti-candida potential, PDT-mediated systems can be an effective strategy in VVC therapy.     

飞行时间质谱技术在食管鳞癌血清学诊断中的应用

目的：用蛋白质质谱分析法寻找食管鳞状细胞癌相对特异的生物标志物。方法：用金属亲和表面（IMAC3）芯片和表面增强激光解析／电离飞行时间质谱仪（SELDI-TOF-MS）检测44例食管鳞癌患者、42例正常人血清的蛋白质质谱。应用Bio-marker Pattem软件建立决策树分类模型,经交叉验证得到该分类模型对测试组病变人群的诊断率。结果：用食管鳞癌患者与正常人质荷比为M9479．43的一种蛋白质建立的决策树分类模型,在学习模式下44例食管鳞癌患者中有43例被正确诊断,42例正常人有40例被诊断正常,诊断准确率为96．5％（83／86）,敏感性和特异性分别为97．7％（43／44）、95.2％（40／42）;在检测模式下44例食管鳞癌患者中有42例被正确诊断,42例正常人中有40例被正确分组,敏感性和特异性分别为95.4％（42／44）、95．2％（40／42）。结论：该方法可快速、准确检测食管鳞癌,敏感性、特异性高。     

Role of artificial intelligence and vibrational spectroscopy in cancer diagnostics

ABSTRACT

Introduction

Raman and Infrared spectroscopic techniques are being used for the analysis of different types of cancers and other biological molecules. It is possible to identify cancers from normal tissues both in fresh and fixed tissues. These techniques can be used not only for the early diagnosis of cancer but also for monitoring the progression of the disease. Furthermore, chemical pathways to the progression of the disease process can be understood and followed.     

Flow cytometry evaluation of in vitro cellular necrosis and apoptosis induced by silver nanoparticles

Particles possess unique properties in the nanoscale, e.g., enhanced catalytic activity, high surface area, and light emission/absorption properties, that might result in interference with colorimetric in vitro cytotoxicity assays such as MTT, XTT or MTS. Alternatively, assays that do not use spectrophotometric detection, such as trypan blue exclusion or flow cytometry (FC) based assays, are less likely to be influenced by nanoparticle interference. The aim of this study was to evaluate FC assays to assess the cytotoxicity of three different sizes (10, 100, or 200 nm) of silver nanoparticles (AgNPs) at different mass concentrations (1, 25, or 50 ug/ml) in L-929 fibroblast cells. After 4 h and 24 h exposure, cell necrosis and apoptosis were assessed using 7-AAD and Annexin V dyes, respectively, with FC. The data indicate that cell necrosis and apoptosis in AgNP-exposed fibroblasts depends on dose, exposure time, and AgNP size. The data indicate that AgNPs produced a dose- and time-dependent decrease in cell viability; however, 10 nm AgNPs were significantly more toxic than larger-sized particles. Thus, standard FC assays can be utilized to assess apoptosis and necrosis in response to nanomaterial exposure.