Comparison Study of Cytotoxicity of Bare and Functionalized Zinc Oxide Nanoparticles

In this paper, a study of the cytotoxicity of bare and functionalized zinc oxide nanoparticles (ZnO NPs) is presented. The functionalized ZnO NPs were obtained by various types of biological methods including microbiological (intra- and extracellular with Lactobacillus paracasei strain), phytochemical (Medicago sativa plant extract) and biochemical (ovalbumin from egg white protein) synthesis. As a control, the bare ZnO NPs gained by chemical synthesis (commercially available) were tested. The cytotoxicity was measured through the use of (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) dye as well as lactate dehydrogenase (LDH) assays against murine fibroblast L929 and Caco-2 cell lines. As a complementary method, scanning electron microscopy (SEM) was performed to assess the morphology of the tested cells after treatment with ZnO NPs. The microscopic data confirmed the occurrence of apoptotic blebbing and loss of membrane permeability after the administration of all ZnO NPs. The reactive oxygen species (ROS) concentration during the cell lines’ exposure to ZnO NPs was measured fluorometrically. Additionally, the photocatalytic degradation of methylene blue (MB) dye in the different light conditions, as well as the antioxidant activity of bare and functionalized ZnO NPs, is also reported. The addition of all types of tested ZnO NPs to methylene blue resulted in enhanced rates of photo-degradation in the presence of both types of irradiation, but the application of UV light resulted in higher photocatalytic activity of ZnO NPs. Furthermore, bare (chemically synthetized) NPs have been recognized as the strongest photocatalysts. In the context of the obtained results, a mechanism underlying the toxicity of bio-ZnO NPs, including (a) the generation of reactive oxygen species and (b) the induction of apoptosis, is proposed.     

Enhanced Activity and Sustained Release of Protocatechuic Acid,a Natural Antibacterial Agent,from Hybrid Nanoformulations with Zinc Oxide Nanoparticles

Hybrid nanostructures can be developed with inorganic nanoparticles (NPs) such as zinc oxide (ZnO) and natural antibacterials. ZnO NPs can also exert antibacterial effects, and we used them here to examine their dual action in combination with a natural antibacterial agent, protocatechuic acid (PCA). To produce hybrid nanoformulations, we functionalized ZnO NPs with four types of silane organic molecules and successfully linked them to PCA. Physicochemical assessment confirmed PCA content up to ~18% in hybrid nanoformulations, with a PCA entrapment efficiency of ~72%, indicating successful connection. We then investigated the in vitro release kinetics and antibacterial effects of the hybrid against Staphylococcus aureus. PCA release from hybrid nanoformulations varied with silane surface modification. Within 98 h, only 8% of the total encapsulated PCA was released, suggesting sustained long-term release. We used nanoformulation solutions collected at days 3, 5, and 7 by disc diffusion or log reduction to evaluate their antibacterial effect against S. aureus. The hybrid nanoformulation showed efficient antibacterial and bactericidal effects that also depended on the surface modification and at a lower minimum inhibition concentration compared with the separate components. A hybrid nanoformulation of the PCA prodrug and ZnO NPs offers effective sustained-release inhibition of S. aureus growth.     

交联透明质酸衍生物的制备进展

透明质酸(Hyaluronic Acid,HA)作为滑液和细胞外基质中一种丰富的糖氨聚糖成分,具有良好的生物相容性和可降解性。但天然透明质酸的力学性能较差,降解速度快,在生物体内不稳定。利用交联反应制成交联透明质酸衍生物可制成稳定性较强的生物材料,得以广泛应用。文章综述了近年来透明质酸分子与各种交联剂交联改性制成透明质酸衍生物的研究,为开发新型透明质酸衍生物生物材料提供参考和选择。     

Food Additive Zinc Oxide Nanoparticles: Dissolution,Interaction, Fate,Cytotoxicity, and Oral Toxicity

Food additive zinc oxide (ZnO) nanoparticles (NPs) are widely used as a Zn supplement in the food and agriculture industries. However, ZnO NPs are directly added to complex food-matrices and orally taken through the gastrointestinal (GI) tract where diverse matrices are present. Hence, the dissolution properties, interactions with bio- or food-matrices, and the ionic/particle fates of ZnO NPs in foods and under physiological conditions can be critical factors to understand and predict the biological responses and oral toxicity of ZnO NPs. In this review, the solubility of ZnO NPs associated with their fate in foods and the GI fluids, the qualitative and quantitative determination on the interactions between ZnO NPs and bio- or food-matrices, the approaches for the fate determination of ZnO NPs, and the interaction effects on the cytotoxicity and oral toxicity of ZnO NPs are discussed. This information will be useful for a wide range of ZnO applications in the food industry at safe levels.     

用废硫酸和锌灰制取微细氧化锌

以钛白生产的废硫酸和镀锌厂的下脚料锌灰为主要原料,以尿素作为沉淀剂,采用液相法制备微细氧化锌.尿素水解速率较低,可缓慢释放出OH-,从而生成粒径分布均匀的微细氧化锌.用透射电子显微镜和比表面积测定仪对微细氧化锌进行了表征,结果表明,制备出的氧化锌晶体属于圆柱状六方晶系,直径20-100nm,长200nm;其比表面积为85.3m2/g,接近纳米级氧化锌.     

纳米氧化锌光催化十八烷酸脱羧的研究

利用纳米氧化锌作催化剂,在较低温度、氢气氛围、紫外光照射条件下,对十八烷酸脱羧制备十七烷,研究光催化十八烷酸脱羧反应的影响因素及最佳脱羧反应条件。利用气相色谱对产物进行定性与定量分析,探讨光催化十八烷酸脱羧的最佳反应条件。结果表明催化剂含量为5 mg/mL,在175℃、汞灯光照1 h时,十八烷酸转化率最高,为18.6%。     

碱性镀锌中氧化锌及氯化钾镀锌中硼酸的分析

对碱性镀锌溶液中氧化锌的分析，采用氟化氢铵为掩蔽剂，以二甲酚橙为指示剂的分析方法，克服了以铬黑T为指示剂时干扰元素对指示剂的封闭现象。在氯化钾镀锌的硼酸分析中，对通常造成测定结果偏高的原因进行了阐述，并给出了矫正的方法。     

Nanoarchitectonics of Cerium Oxide/Zinc Oxide/Graphene Oxide Composites for Evaluation of Cytotoxicity and Apoptotic Behavior in HeLa and VERO Cell Lines

Journal of Inorganic and Organometallic Polymers and Materials - Using the ultrasonic approach, we produced a morphology involving a cerium oxide/ zinc oxide/graphene oxide nanocomposite-based...     

闪锌矿-软锰矿湿法浸出制备MnO2、ZnO

通过正交试验,研究了浸出时间、温度、矿比、酸用量对闪锌矿、软锰矿两矿浸出的影响。研究结果表明:温度是对两矿浸出率影响最主要因素,其次是酸用量。最佳工艺参数:温度为95℃、两矿比为1︰3.0、浸出时间为6h、20%酸用量80mL时,锰矿浸出率平均值达到91.69%,锌矿浸取率平均值为92.92%左右。     

In-Vitro Release Study of Metoprolol Succinate from the Bioadhesive Films of Pullulan-Polyacrylamide Blends

In the present work, an attempt has been made to investigate the drug release profile of pullulan-polyacrylamide blend films with metoprolol succinate as a model drug. The drug diffusion behavior of pullulan/polyacrylamide films has been established by an open glass diffusion cell at 37 ± 1°C. The diffusion rate of the drug was determined by UV/visible spectroscopy. The kinetics of drug release are fitted to the Higuchi and Koresmeyer–Peppas model. The drug release kinetics for the blend was found to be fast and follows Fickian mechanism. This blend could be a promising approach for formulating a transdermal drug delivery system for immediate release with good film-forming property.     

透明质酸的性能及生产

叙述了生化药物透明质酸的化学结构、性质及两种不同的生产方法.     

透明质酸的应用及生产

透明质酸具有特殊的生理作用、独特的流变学性质和极强的保湿能力,在化妆品工业、医学研究、临床治疗等领域有着广泛的应用.本文综述了透明质酸的制备方法及应用方面的进展.     

氧化锌硫化溴化丁基橡胶的性能研究

试验研究硫化剂氧化锌和硬脂酸用量对溴化丁基橡胶(BIIR)性能的影响。结果表明:当硬脂酸用量为1份时,随着氧化锌用量的增大,BIIR胶料的门尼粘度总体增大,硫化特性、交联密度和物理性能变化不大;当氧化锌用量为1份时,随着硬脂酸用量的增大,BIIR胶料的门尼粘度总体减小,硫化时间缩短,硫化胶的交联密度先增大后减小,物理性能呈下降趋势。     

Development of Graphene Oxide Nanosheets as Potential Biomaterials in Cancer Therapeutics: An In-Vitro Study Against Breast Cancer Cell Line

Journal of Inorganic and Organometallic Polymers and Materials - Recent advances in nanotechnology and nano biomaterials have attracted considerable attention in the field of cancer therapy. The...     

Interpenetrating Polymer Networks Based on Gelatin and Poly(Vinyl Pyrollidone): Evaluation of Degradation,Histocompatibility, Cytotoxicity,and Drug Release

Interpenetrating polymer networks (IPNs) based on crosslinked gelatin [Gx] and poly(vinyl pyrrolidone) [PVPx] were synthesized using gamma irradiation. Degradability of IPNs was found to be dependent on the irradiation dose and crosslinker concentration as well as on the composition of IPNs. Samples prepared at dose of 0.07 and 0.14 Mrad degraded within 15 days in comparison to samples prepared at higher doses [0.20, 0.25 Mrad, and 0.30 Mrad]. Cell viability and histocompatibility studies suggest that IPNs based on gelatin and PVPx can be used as biodegradable drug delivery devices.     

New Hyaluronic Acid from Plant Origin to Improve Joint Protection—An In Vitro Study

Background: In recent decades, hyaluronic acid (HA) has attracted great attention as a new treatment option for osteoarthritis. Classical therapies are not able to stop the cartilage degeneration process nor do they favor tissue repair. Nowadays, it is accepted that high molecular weight HA can reduce inflammation by promoting tissue regeneration; therefore, the aim of this study was to verify the efficacy of a new high molecular weight HA of plant origin (called GreenIuronic^®) in maintaining joint homeostasis and preventing the harmful processes of osteoarthritis. Methods: The bioavailability of GreenIuronic^® was investigated in a 3D intestinal barrier model that mimics human oral intake while excluding damage to the intestinal barrier. Furthermore, the chemical significance and biological properties of GreenIuronic^® were investigated in conditions that simulate osteoarthritis. Results: Our data demonstrated that GreenIuronic^® crosses the intestinal barrier without side effects as it has a chemical–biological profile, which could be responsible for many specific chondrocyte functions. Furthermore, in the osteoarthritis model, GreenIuronic^® can modulate the molecular mechanism responsible for preventing and restoring the degradation of cartilage. Conclusion: According to our results, this new form of HA appears to be well absorbed and distributed to chondrocytes, preserving their biological activities. Therefore, the oral administration of GreenIuronic^® in humans can be considered a valid strategy to obtain beneficial therapeutic effects during osteoarthritis.     

Modification of Starch by Grafting Acetylsalicylic Acid: Synthesis,Characterization, and Application in Drug Release Domain

A series of modified starches were prepared by grafting acetylsalicylic acid (AsA) into starch by an esterification reaction then coated with poly(vinylalcohol).The structure of Starch-graft-AsA was confirmed by FTIR, NMR, and DSC. The release of AsA occurred via a retroesterification reaction of this modified coated starch (SAC) during 76 h at different pHs and AsA contents. The diffusion coefficient of AsA in the SAC matrix followed a Fickian model. The effect of AsA amount grafted on starch revealed that the higher AsA amount released was reached with SAC containing 16.18 mol% of AsA at pH 7.     

ICP-OES法测定除尘灰中锌、氧化钙、氧化镁含量

除尘灰高温灰化除碳后,转入聚四氟乙烯烧杯,加盐酸、硝酸、氢氟酸溶解,加高氯酸冒烟驱氟,补加盐酸煮沸溶解盐类。通过锌、钙、镁元素的谱线选择、样品消解、称样量、元素线性等方面做了条件试验,实验结果表明在最佳条件下,配制合适含量高纯铁打底的工作曲线,该方法准确度高、周期短,适用于除尘灰中锌、钙、镁元素的快速测定。     

氧化镁和氧化锌对PVC的热稳定作用研究

用HAAKE流变仪评价了氧化镁和氧化锌的热稳定作用。研究结果表明,氧化锌具有较好的初期稳定作用,但对长期热稳定反而不利;氧化镁的作用则相反。用不同规格的氧化镁和氧化锌的研究还表明,不同规格氧化镁主要影响PVC的初期色相,而不同规格氧化锌对初期和长期稳定性都有影响。最后,不同温度条件下的测试表明,采用这种稳定体系时,设备的温度不宜超过180℃。