Mineralized Microstructure of Calcified Avian Tendons: A Scanning Small Angle X-ray Scattering Study

The micrometer level spatial distribution of the size, shape, and orientation of mineral crystallites in the calcifying matrix of tendons near the edge of the mineralizing front was investigated by scanning small angle X-ray scattering using synchrotron X-ray radiation. Using a special microbeam arrangement enabling 20 µm beam resolution and short measurement times, linear diffraction scans were made on sections from the normally calcifying tendons (tibialis cranialis) from the domestic turkey, which calcify in the distal to proximal direction. A change in shape and arrangement of mineral crystals was observed within the first 200 µm of the mineralization front, and the mineral crystal distribution was highly anisotropic with crystals aligned parallel to the fiber axis. In a cross-section of the tendon cut at right angles to the fiber axis, the orientation distribution of crystals was not azimuthally symmetric, and showed a small but nonzero anisotropy and a continuous change in mean orientation angle across the width of the tendon cross-section.     

Cardioprotective effects of saponins from Panax japonicus on acute myocardial ischemia against oxidative stress-triggered damage and cardiac cell death in rats

Aim

To study the cardioprotective effects of saponins from Panax japonicus (SPJ) on acute myocardial ischemia injury rats induced by ligating of the left anterior descending branch (LAD), on the basis of this investigation, the possible mechanism of SPJ was elucidated.

Materials and methods

SPJ was identified by high performance liquid chromatography-evaporative light scattering detection. Male Sprague-Dawley rats (200–220 g) were randomly divided into four groups: sham-operated, LAD, LAD + l-SPJ (SPJ, 50 mg/kg/day, orally) and LAD + h-SPJ (SPJ, 100 mg/kg/day, orally). Before operation, the foregoing groups were pretreated with homologous drug once a day for 7 days, respectively. After twelve hours in LAD, the cardioprotective effects of SPJ were evaluated by infarct size, biochemical values, hemodynamic, and histopathological observations and the antioxidative and antiapoptotic relative gene expressions.

Results

SPJ significantly improved heart function and decreased infarct size; remarkably decreased levels of serum lactate dehydrogenase, creatine kinase, xanthine oxide and malondialdehyde content, increased contents of serum total antioxidant capacity, superoxide dismutase (SOD), glutathione peroxidase, catalase; quantitative real-time PCR results showed that SPJ might markedly reverse the down-regulated mRNA expressions of the SOD1, SOD2 and SOD3, ameliorate the increased Bax and caspase-3 mRNA expressions and decreased Bcl-2 mRNA expression and ratios of Bcl-2 to Bax. Histopathological observations provided supportive evidence for biochemical analyses, and with the dose of SPJ increasing, the aforesaid improvement became more and more strong.

Conclusions

The studies demonstrated that in ischemic myocardium, oxidative stress caused the overgeneration and accumulation of reactive oxygen species (ROS), which was central of cardiac ischemic injury. SPJ exerted beneficially cardioprotective effects on myocardial ischemia injury rats, mainly scavenging oxidative stress-triggered overgeneration and accumulation of ROS, alleviating myocardial ischemia injury and cardiac cell death.     

HPLC-ELSD法测定人参属药材不同部位中的20(R)-25-羟基-原人参三醇

目的在人参属资源中研究20(R)-25-羟基-原人参三醇[20(R)-25-OH-PPT],为人参皂苷降血糖作用的创新和研发提供科学依据。方法色谱柱Agilent C18(250 mm×4.6 mm,5μm);流动相为甲醇-水(70∶30);柱温35℃;体积流量1.0 m L/min;ELSD气化室温度87.0℃,载气流速2.20 L/min;进样体积10μL。采用HPLC-ELSD法测定人参属植物不同部位提取物(以丙酮为溶剂,采用超声法提取)中20(R)-25-OH-PPT。结果 20(R)-25-OH-PPT在0.001~0.050 mg/m L线性关系良好,在人参茎叶、人参根、人参果、人参花、西洋参茎叶、西洋参根和三七芦头总皂苷中的量分别为3.74%、2.59%、2.37%、0.40%、0.68%、0.22%和0.39%,回收率为98.54%、97.54%、100.35%、101.46%、97.46%、99.14%和99.38%。结论20(R)-25-OH-PPT存在于人参属植物多个部位中,可作为人参皂苷降血糖作用开发利用的重要依据。     

Comparative study of protein molecular weights by size-exclusion chromatography and laser-light scattering

High-performance size-exclusion chromatography (SEC) based on UV-Vis detection is a relative technique for molecular weight determination whereas procedure based on multi-angle laser light scattering (MALLS) is both rapid and absolute. The two methods using recombinant human growth hormone (rHGH) and β-lactoglobulin samples were compared. A calibration curve for the chromatographic system was generated based on standard proteins and the data were fitted by least squares to a third order polynomial model. The molecular weight from the conventional SEC method for both proteins was higher than the reported values. The molecular weight of rHGH from MALLS was 23.1±0.57 and 21.2±0.80 kDa using differential refractive index (SEC-MALLS/RI) and UV (SEC-MALLS/UV-Vis) detectors as mass detectors. Both values agree, within experimental error with the molecular weight sequence of rHGH, 22.1 kDa. In contrast, the molecular weight from LS for β-lactoglobulin was 22.5±0.55 kDa by SEC-MALLS/RI and 23.0±1.22 kDa by SEC-MALLS/UV-Vis, respectively, values always higher than those supplied by the manufacturer, 18.4 kDa. The reproducibilty of the SEC-MALLS/UV-Vis method versus the SEC-MALLS/RI method was performed using the concordance correlation coefficient. The method′s reproducibility was accepted by assuming a precision of 98% and a 1% loss in precision.     

Fish cell lines as a tool for the ecotoxicity assessment and ranking of engineered nanomaterials

Risk assessment of engineered nanomaterials (ENMs) is being hindered by the sheer production volume of these materials. In this regard, the grouping and ranking of ENMs appears as a promising strategy. Here we sought to evaluate the usefulness of in vitro systems based on fish cell lines for ranking a set of ENMs on the basis of their cytotoxicity. We used the topminnow (Poeciliopsis lucida) liver cell line (PLHC-1) and the rainbow trout (Oncorhynchus mykiss) fibroblast-like gonadal cell line (RTG-2). ENMs were obtained from the EU Joint Research Centre repository. The size frequency distribution of ENM suspensions in cell culture media was characterized. Cytotoxicity was evaluated after 24 h of exposure. PLHC-1 cells exhibited higher sensitivity to the ENMs than RTG-2 cells. ZnO-NM was found to exert toxicity mainly by altering lysosome function and metabolic activity, while multi-walled carbon nanotubes (MWCNTs) caused plasma membrane disruption at high concentrations. The hazard ranking for toxicity (ZnO-NM > MWCNT ≥ CeO₂-NM = SiO₂-NM) was inversely related to the ranking in size detected in culture medium. Our findings reveal the suitability of fish cell lines for establishing hazard rankings of ENMs in the framework of integrated approaches to testing and assessment.     

High-content analysis for mitophagy response to nanoparticles: A potential sensitive biomarker for nanosafety assessment

Mitophagy, a selective autophagy of mitochondria, clears up damaged mitochondria to maintain cell homeostasis. We performed high-content analysis (HCA) to detect the increase of PINK1, an essential protein controlling mitophagy, in hepatic cells treated with several nanoparticles (NPs). PINK1 immunofluorescence-based HCA was more sensitive than assays and detections for cell viability and mitochondrial functions. Of which, superparamagnetic iron oxide (SPIO)-NPs or graphene oxide-quantum dots (GO-QDs) was selected as representatives for positive or negative inducer of mitophagy. SPIO-NPs, but not GO-QDs, activated PINK1-dependent mitophagy as demonstrated by recruitment of PARKIN to mitochondria and degradation of injured mitochondria. SPIO-NPs caused the loss of mitochondrial membrane potential, decrease in ATP, and increase in mitochondrial reactive oxide species and Ca²⁺. Blocking mitophagy with PARKIN siRNA aggravated the cytotoxicity of SPIO-NPs. Taken together, PINK1 immunofluorescence-based HCA is considered to be an early, sensitive, and reliable approach to evaluate the bioimpacts of NPs.     

Silicone Oil-Free Polymer Syringes for the Storage of Therapeutic Proteins

Prefilled syringes are a popular choice for the delivery of biopharmaceuticals. However, glass syringes might not be the optimal primary packaging material for all biopharmaceuticals. There is evidence that the necessary lubricant silicone oil in glass syringes can interact with proteins and can be shed from the surface into the product solution. In recent years, silicone oil-free polymer syringes were developed. Despite several advantages, however, a major shortcoming of these polymer systems is their relatively high gas permeability, which might be a limitation for the storage of oxygen sensitive biopharmaceuticals. So far, no long-term protein stability studies regarding such polymer systems have been published. In this study, 2 therapeutic proteins were stored in glass syringes and in silicone oil-free polymer syringes. In addition, polymer syringes stored in nitrogen-filled aluminum pouches or covered with oxygen-tight labels were included. Similar chemical protein stability was achieved at 4°C for all syringes. However, in contrast to the polymer syringes, high particle counts were observed in the glass syringes. Polymer syringes stored in nitrogen-filled aluminum pouches presented a promising alternative for the storage of biopharmaceuticals as they do not expose patients to silicone oil and silicone oil-protein aggregates.     

高灵敏共振瑞利散射技术快速检测药物中的美司那

目的 建立快速、准确测定药物中美司那的高灵敏共振瑞利散射（resonance Rayleigh scattering,RRS）新方法。方法 在BR弱碱性溶液中,亮绿与美司那以静电作用生成的缔合物使RRS信号显著增强,RRS强度在最大RRS峰处与美司那的浓度有线性关系。检测波长为344 nm。结果 在pH 7.75 BR缓冲溶液中,亮绿与美司那结合生成绿色二元离子缔合物,产生以294,344,468 nm为特征峰的新RRS光谱。最大RRS峰位于344 nm,线性范围为0.006~0.41 mg·L^-1,检出限为0.005 2 mg·L^-1。该法用于市售美司那药物中美司那的测定,加样回收率和相对标准偏差（RSD,n=6）分别为98.3%~103%和1.6%~2.3%。结论 该法简便、快速,有高灵敏度和高选择性,可用于实际药物中美司那的测定。     

Particle Size Distribution Analysis of OTC Aerosol or Powder Drug Products With Potential for Inadvertent Inhalation Exposure to Consumers

The potential for inadvertent inhalation of over-the-counter (OTC) aerosol/powder drug products for topical application requires understanding of the characteristic size distributions of the airborne particles or droplets generated when these products are used as per the directions on the product label. Particle/droplet size is an important factor in determining the depth of particle penetration into the respiratory system after inhalation. Because particles penetrating beyond the larynx into the lung may lead to adverse respiratory effects, OTC aerosol or powder drug product particle size distribution is important to characterize. In this study, laser diffraction was used to analyze the particle size distribution of 32 currently marketed OTC drug products as emitted after actuation or air dispersion from their final package. Among the products surveyed were sunscreens, antiperspirants, topical analgesics, skin protectants, and acne products. The results may be useful to the U.S. Food and Drug Administration in its mission to protect as well as promote public health.