Adsorptive removal of lead from aqueous solutions by amine–functionalized magMCM-41 as a low–cost nanocomposite prepared from rice husk: Modeling and optimization by response surface methodology

Amorphous silica that was extracted from rice husk was used to synthesize the magMCM-41 mesoporous silica. This was then functionalized by the APTMS group in order to produce NH₂-magMCM-41 as a novel and low–cost adsorbent. The XRD, VSM, N₂ adsorption–desorption, FT–IR, TGA, SEM and TEM analyses were utilized to characterize the produced materials. In order to optimize the adsorption of the Pb(II) ions, the RSM (response surface methodology) was applied by using the synthesized adsorbent in aqueous solutions. A rotatable CCD (central composite design) was adopted to carry out the experiments and RSM was used to analyze them. Three independent factors namely, initial solution pH (3–7), adsorbent dosage (0.1–2 g L^?1), and initial Pb(II) concentration (15–150 mg L^?1) were used to investigate the removal procedure. According to the obtained results, the initial solution pH of 5.22, adsorbent dosage of 0.1 g L^?1, and initial Pb(II) concentration of 150 mg L^?1 were considered as the optimum conditions with 64.32% removal of Pb(II) and an adsorption capacity of 540.64 mg g^?1. The maximum removal efficiency of Pb(II) ions was found to be 96.76%. The Sips isotherm model represents a better correlation with equilibrium data. It was reported by the kinetic study that data taken from the experiments fitted better to the pseudo–second–order model compared to the pseudo–first–order and intraparticle diffusion models. Finally, according to the thermodynamic study, the removal process strongly depends on temperature, which indicates an exothermic behavior and spontaneous nature of the adsorption.     

Systemic sclerosis and exposure to heavy metals

As a mirror image of the Roman god Janus Bifrons, the environment has a hidden face. To highlight this hidden face of the environment in the field of systemic sclerosis (SSc) will allow to identify responsible agents emerging in the future. To date, there is, in fact, a growing scientific evidence that environmental factors have a crucial impact on both alterations and modulation of epigenetic determinants, resulting in SSc onset and progression. It has been well established that there is a marked correlation between SSc onset and occupational exposure to crystalline silica and organic solvents. More recently, an association between SSc and exposure to heavy metals has further been found, including: antimony, cadmium, lead, mercury. These latter findings interestingly underscore that occupational exposure to heavy metals should be systematically checked in all SSc patients at diagnosis, as the identification of the occupational toxic agent will allow its interruption, which may result in potential improvement of SSc outcome.     

Effect of antimicrobial peptides HNP-1 and hBD-1 on Staphylococcus aureus strains in vitro and in vivo

The aims of this study were: (i) To investigate the activity of recombinant AMPs HNP-1 and hBD-1 in combination with cefotaxime against Staphylococcus aureus strains (MSSA and MRSA) in vitro using checkerboard method; (ii) To investigate the activity of HNP-1 and hBD-1 encapsulated in silicon nanoparticles (niosomes) in the treatment of MRSA-infected wound in rats. For this S. aureus strains (MSSA and MRSA) were isolated from patients with diabetic foot infection. Cefotaxime, recombinant HNP-1 and hBD-1 (in all possible combinations with each other) were used for testing by the checkerboard method. Two niosomal topical gels with HNP-1/hBD-1 were prepared to treat MRSA-infected wounds in rats. Gels were administered once a day, the control group–without treatment. Wound healing rate was calculated on the 4th, 9th and 16th days of the experiment and compared using one-way ANOVA with Bonferroni correction. MIC of HNP-1 for MSSA and MRSA was the same–1 mg/L. MIC of hBD-1 for MSSA and MRSA was also the same–0.5 mg/L. Topical gels with niosomal HNP-1 (or hBD-1) showed a significantly faster wound healing in comparison with the control. The data obtained open up prospects for use of AMPs encapsulated in silica nanoparticles for the development of new antibiotics.     

Genotoxicity of synthetic amorphous silica nanoparticles in rats following short‐term exposure. Part 1: Oral route

Synthetic amorphous silica (SAS) in its nanosized form is now used in food applications although the potential risks for human health have not been evaluated. In this study, genotoxicity and oxidative DNA damage of two pyrogenic (NM‐202 and 203) and two precipitated (NM‐200 and ‐201) nanosized SAS were investigated in vivo in rats following oral exposure. Male Sprague Dawley rats were exposed to 5, 10, or 20 mg/kg b.w./day for three days by gavage. DNA strand breaks and oxidative DNA damage were investigated in seven tissues (blood, bone marrow from femur, liver, spleen, kidney, duodenum, and colon) with the alkaline and the (Fpg)‐modified comet assays, respectively. Concomitantly, chromosomal damage was investigated in bone marrow and in colon with the micronucleus assay. Additionally, malondialdehyde (MDA), a lipid peroxidation marker, was measured in plasma. When required, a histopathological examination was also conducted. The results showed neither obvious DNA strand breaks nor oxidative damage with the comet assay, irrespective of the dose and the organ investigated. Similarly, no increases in chromosome damage in bone marrow or lipid peroxidation in plasma were detected. However, although the response was not dose‐dependent, a weak increase in the percentage of micronucleated cells was observed in the colon of rats treated with the two pyrogenic SAS at the lowest dose (5 mg/kg b.w./day). Additional data are required to confirm this result, considering in particular, the role of agglomeration/aggregation of SAS NMs in their uptake by intestinal cells. Environ. Mol. Mutagen. 56:218–227, 2015. © 2014 Wiley Periodicals, Inc.     

Synergism through combination of chemotherapy and oxidative stress-induced autophagy in A549 lung cancer cells using redox-responsive nanohybrids: A new strategy for cancer therapy

A combination of various therapeutic approaches has emerged as a promising strategy for cancer treatment. A safe and competent nano-delivery system is thus in urgent demand to facilitate the simultaneous transport of various therapeutic agents to cancer cells and a tumor region to achieve synergistic effect. Gold nanoparticles (GNPs) and mesoporous silica nanoparticle (MSNs) were fabricated herein as potential candidates for drug delivery. Serving as gatekeepers, GNPs (5 nm in diameter) were attached onto the amino-functionalized MSNs (denoted as NMSNs) via a relatively weak gold–nitrogen bonding. The resulting nanohybrids (denoted as GCMSNs) were uptaken by cells, and the detachment of GNPs and subsequent intracellular drug release from NMSNs were achieved by competitive binding of intracellular glutathione to GNPs. In addition to the function of gatekeeping, GNPs also play another role as the oxidative stress elicitor. Our in vitro studies revealed that GCMSNs induced higher oxidative stress in lung cancer cells (A549) than in normal cells (3T3-L1). This growth inhibitory effect found in the cancer cells was likely induced by mitochondria dysfunction originated from the GCMSN-induced, oxidative stress-triggered mitochondria-mediated autophagy. The redox-responsive nanohybrids were further loaded with camptothecin and the intensified synergistic therapeutic effects were observed associated with combined chemotherapy and oxidative stress strategy. The results clearly demonstrate that such unique nanohybrids hold great promise for selective and effective cancer treatments.     

AuNP flares-capped mesoporous silica nanoplatform for MTH1 detection and inhibition

The human mutT homologue MTH1, a nucleotide pool sanitizing enzyme, represents a vulnerability factor and an attractive target for anticancer therapy. However, there is currently a lack of selective and effective platforms for the detection and inhibition of MTH1 in cells. Here, we demonstrate for the first time a gold nanoparticle (AuNP) flares-capped mesoporous silica nanoparticle (MSN) nanoplatform that is capable of detecting MTH1 mRNA and simultaneously suppressing MTH1 activity. The AuNP flares are made from AuNPs that are functionalized with a dense shell of MTH1 recognition sequences hybridized to short cyanine (Cy5)-labeled reporter sequences and employed to seal the pores of MSN to prevent the premature MTH1 inhibitors (S-crizotinib) release. Just like the pyrotechnic flares that produce brilliant light when activated, the resulting AuNP flares@MSN (S-crizotinib) undergo a significant burst of red fluorescence enhancement upon MTH1 mRNA binding. This hybridization event subsequently induces the opening of the pores and the release of S-crizotinib in an mRNA-dependent manner, leading to significant cytotoxicity in cancer cells and improved therapeutic response in mouse xenograft models. We anticipate that this nanoplatform may be an important step toward the development of MTH1-targeting theranostics and also be a useful tool for cancer phenotypic lethal anticancer therapy.     

Early immune response in large yellow croaker (Larimichthys crocea) after immunization with oral vaccine

Mesoporous silica nanoparticles (MSNs) have been used in the field of biomedicine as antigen carriers and adjuvants for protective antigens. In the present study, an oral nanovaccine against Vibrio alginolyticus was prepared employing MSNs as carriers. The uptake of the dihydrolipoamide dehydrogenase (DLDH) antigens in the intestine of large yellow croaker was evaluated using an immunohistochemistry assay. Additionally, the effects of the nanovaccine on the early immune response in large yellow croaker were investigated via oral vaccination. The presence of the antigens was detected in the mucosa and lamina propria of the foregut, midgut, and hindgut of large yellow croaker at 3 h following oral immunization. The expression levels of cytokines (i.e., lysozyme, IFN-γ, IFITM, TNF-α, IL-1β, IL-2, IL-4, IL-10, and IL-13) in the intestine, spleen, and head kidney tissues of large yellow croaker before and after the immune challenge were determined via RT-qPCR assay. The obtained results revealed that the expression levels of lysozyme, IFN-γ, IFITM, TNF-α, IL-1β, IL-2, IL-4, IL-10, and IL-13 in the intestine and head kidney of the vaccinated large yellow croaker, as well as the expression of lysozyme, IL-1β, and IL-10 in the spleen, exhibited time-dependent oscillation regulation patterns. Notably, the nanovaccine immunization could induce early (6 h) and high expression of IFN-γ in the spleen and kidney tissues after the bacterial infection. The current study supplements the available data on the early immune response to fish nanovaccines. It also provides a valuable theoretical basis for the future development of large yellow croaker oral vaccines.     

硅溶胶的浓度对磷酸盐包埋料性能的影响

目的 评价硅溶胶浓度对包埋料性能的影响。方法 分别使用SiO2含量为0％、10％、20％、30％、40%的硅溶胶调拌包埋同一包埋料，检测气孔率、抗压强度、凝固膨胀率和热膨胀率．并包埋铸造100个钴铬合金帽状修复体，检测边缘浮出量。结果 当硅溶胶的浓度小于20％时，随着硅溶胶浓度的提高，凝固膨胀和热膨胀明显增大，铸件的边缘浮出量明显减小；当硅溶胶浓度在20％-40％时，随着硅溶胶浓度的提高，抗压强度明显增大，铸件的边缘浮出量变化不大。结论 使用SiO2含量为30％左右的硅溶胶所得的包埋料各方面性能都较优良，建议使用30％左右的硅溶胶。     

自体肋软骨联合硅胶假体鼻整形效果探讨

目的:探讨自体肋软骨联合硅胶假体在鼻整形中的应用效果。方法:回顾性分析2015年5月-2017年5月笔者医院接受鼻整形的105例就医者临床资料,通过治疗方式不同分为观察组55例和对照组50例,对照组使用硅胶假体隆鼻,观察组使用自体肋软骨联合硅胶假体隆鼻,比较两组手术情况、鼻部塑形效果、二次手术率及并发症发生情况。结果:两组手术成功率、愈合时间比较,差异无统计学意义(P>0.05);观察组手术时间明显长于对照组,差异有统计学意义(P<0.05)。和术后3个月时比较,观察组术后12个月时鼻根高、鼻面角、鼻尖角、鼻额角差异无统计学意义(P>0.05);对照组术后12个月时鼻根高、鼻面角、鼻尖角均明显降低(P<0.05),且术后12个月时,观察组鼻根高、鼻面角、鼻尖角均明显高于对照组(P<0.05)。观察组二次手术率为3.64%(2/55)明显低于对照组的16.00%(8/50),差异有统计学意义(χ^2=4.646,P=0.031)。观察组术后并发症总发生率为14.55%明显低于对照组的32.00%,差异有统计学意义(P<0.05)。结论:和单用硅胶假体相比,自体肋软骨联合硅胶假体用于鼻整形中效果更加显著,具有鼻部塑形效果满意、二次手术率低、并发症少等特点,临床应用价值高。     

原人参二醇类皂苷(PPD)在酶反应中转化动态及其产物稀有皂苷的制备

目的为了生物转化低成本制备人参稀有皂苷,利用Aspergillus g.848菌的粗酶与市售的原人参二醇类皂苷(PPD)混合皂苷反应,制备人参稀有皂苷C-K、C-Mc、F_2单体和4种异构体的Rh2组皂苷。方法酶与PPD皂苷反应,生成稀有皂苷;用HPLC法测定PPD皂苷原料和产物皂苷的组成,用硅胶柱法分离产物中的单体皂苷,用NMR法确认产物单体皂苷结构;用UPLC-MS法确认产物Rh2组。结果原料PPD中含有人参皂苷Rb_1、Rd、Rb_2、Rc和4种异构体的人参皂苷Rg3组;酶反应时,若生产以F_2为主的皂苷时,最佳反应时间为1.5~2.0h;若生产以C-K为主的皂苷时,反应时间为24.0~30.0h;若生产以Rh2组为主的皂苷时,反应6.0~12.0h时,Rg_3组产量低而Rh_2组产量高。以C-K为主的皂苷生产中,从30 g的PPD皂苷酶反应得到20 g产物,经硅胶柱分离,得到8.16 g的C-K、1.01 g的C-Mc、0.45 g的F_2单体和0.19 g的Rh_2组皂苷,并以NMR和UPLC-MS法核对了其结构。结论 PPD皂苷经酶转化成功地制备了高活性C-K、C-Mc、F_2和Rh_2组皂苷。