Comparative effect of ciprofloxacin and moxifloxacin on the modulation of bile acid profiles and gut microbiota in rats

Abstract Fluoroquinolones are an important class of antimicrobial agents to manage infectious diseases. However, knowledge about how host bile acids are modified by fluoroquinolones is limited. We investigated and compared the impact of fluoroquinolones on circulating bile acid profiles and gut microbiota from in vivo studies. We administered ciprofloxacin (100 mg/kg/day) or moxifloxacin (40 mg/kg/day) orally to male Wistar rats for seven days. Fifteen bile acids (BAs) from the serum and large intestine were quantified by HPLC-MS/MS. The diversity of gut microbiota after ciprofloxacin and moxifloxacin treatment was analyzed using high-throughput, next-generation sequencing technology. The two fluoroquinolone-treated groups had different BA profiles. Ciprofloxacin significantly reduced the hydrophobicity index of the BA pool, reduced secondary BAs, and increased taurine-conjugated primary BAs in both the serum and large intestine as compared with moxifloxacin. Besides, ciprofloxacin treatment altered intestinal microbiota with a remarkable increase in Firmicutes to Bacteroidetes ratio, while moxifloxacin exerted no effect. What we found suggests that different fluoroquinolones have a distinct effect on the host BAs metabolism and intestinal bacteria, and therefore provide guidance on the selection of fluoroquinolones to treat infectious diseases.

Advances in Polymer Hydrophilic Lubricating Coatings for Medical Catheters / 中国医疗器械杂志

Polymer hydrophilic lubricating coatings for medical catheters refer to highly hydrophilic coating films fixed on the surface of catheters with binding force, which can reduce the surface friction with human tissues during the use of interventional catheters, improve the patient comfort of and effectively reduce the incidence of infection. Based on the development process of medical catheter coating, this review summarizes recent advances in the field of polymer hydrophilic lubricating coatings for medical catheters from types of hydrophilic coating polymer, development of coating technology and establishment of coating performance evaluation method. Main problems in this field are analyzed and development trends in the future are prospected.

Construction and application of pharmacophore model of human carboxylesterase 2 inhibitors / 中国中药杂志

According to human carboxylesterase 2(hCE2) inhibitors reported in the literature, the pharmacophore model of hCE2 inhibitors was developed using HipHop module in Discovery Studio 2016. The optimized pharmacophore model, which was validated by test set, contained two hydrophobic, one hydrogen bond acceptor, and one aromatic ring features. Using the pharmacophore model established, 5 potential hCE2 inhibitors(CS-1,CS-2,CS-3,CS-6 and CS-8) were screened from 20 compounds isolated from the roots of Paeonia lactiflora, which were further confirmed in vitro, with the IC_(50) values of 5.04, 5.21, 5.95, 6.64 and 7.94 μmol·L~(-1), respectively. The results demonstrated that the pharmacophore model exerted excellent forecasting ability with high precision, which could be applied to screen novel hCE2 inhibitors from Chinese medicinal materials.

Preparation of hydrophilic Indigo Naturalis based on polyethylene glycol( PEG) surface film-forming method and evaluation / 中国中药杂志

Polyethylene glycol (PEG) surface film-forming method was used to prepare hydrophilic Indigo Naturalis decoction pieces with stable effect.The preparation process of modified Indigo Naturalis was optimized and its microscopic properties,hydrophilicity,antipyretic efficacy,and safety were systematically evaluated.With equilibrium contact angle as assessment index,the influence of modifier type,modifier dosage,dispersant dosage,and co-grinding time on water solubility of Indigo Naturalis was investigated by single factor test.The results showed that the optimal preparation process was as follows.The 6%PEG6000 is dissolved in 10%anhydrous ethanol solution by sonification and then the mixture is ground with Indigo Naturalis for 2 min.The resultant product is dried on a square tray in an oven at 60℃to remove ethanol and thereby the PEG-modified hydrophilic Indigo Naturalis decoction pieces are yielded.The morphological observation under scanning electron microscope (SEM) indicated that the modified Indigo Naturalis had smoother surface than Indigo Naturalis,and energy spectrometer measurement showed that the nitrogen (N),calcium(Ca),oxygen (O),and silicon (Si) on the surface of modified Indigo Naturalis powder were less than those of Indigo Naturalis powder.Modified Indigo Naturalis had the equilibrium contact angle 18.96°smaller,polar component 22.222 m J·m~(-2)more,and nonpolar component 7.277 m J·m~(-2)smaller than the Indigo Naturalis powder.Multiple light scattering technique was employed to evaluate the dispersion in water and the result demonstrated that the transmittance of Indigo Naturalis and modified Indigo Naturalis was about85%and 75%,respectively,suggesting the higher dispersity of modified Indigo Naturalis.The suspension rate of modified Indigo Naturalis in water was determined by reflux treatment.The result showed that 57%of Indigo Naturalis was not wetted after refluxing for1 h,while the modified Indigo Naturalis was all wetted and dispersed into water.The dissolution of indigo and indirubin of modified Indigo Naturalis increased and the process was more stable.Then,rats were randomized into the blank group,model group,acetaminophen group,Indigo Naturalis group,and hydrophilic Indigo Naturalis group.The temperature changes of rats were observed after administration and the concentration of IL-1βand TNF-αin serum and IL-1βand PGE_2in hypothalamus was measured.The results indicated that the temperature of Indigo Naturalis group and hydrophilic Indigo Naturalis group dropped and the IL-1βlevel of the hydrophilic Indigo Naturalis group decreased (P<0.05) as compared with those in the model group.Thus,both Indigo Naturalis and hydrophilic Indigo Naturalis had antipyretic effect,particularly the hydrophilic Indigo Naturalis.The acute toxicity test of hydrophilic Indigo Naturalis verified that it had no toxicity to rats.In this study,the hydrophilic Indigo Naturalis decoction pieces were prepared with the PEG surface film-forming method,and the antipyretic efficacy and safety were evaluated,which expanded the technological means of powder modification for Chinese medicine and provided a method for clinical use of Chinese medicine.

Key to Indigo Naturalis' oral effectiveness: in vivo and in vitro verification of bile action / 中国中药杂志

Indigo Naturalis( IN) is mainly composed of 10% organic matter and 90% inorganic matter,with a poor wettability and strong hydrophobicity. Indigo,indirubin and effective ingredients are almost insoluble in water. And how it exerts its effect after oral administration still needs to be revealed. For this reason,this study put forward the hypothesis that " Indigo Naturalis forms a slightly soluble calcium carbonate carrier in a strong acid environment of gastric fluid,and organic substances are solubilized in the bile environment of intestinal fluid",and then verified the hypothesis. First,the dissolution apparatus was used to simulate the change process of IN in different digestive fluid,and the effects of low-dose and normal bile on the dissolution of inorganic substances and the release of organic substances were compared. After the surface morphology and element changes of IN in different digestive fluid were observed,it was found that bile is the key to promoting the dissolution of organic and inorganic substances in IN. Furthermore,the rat fever model induced by 2,4-dinitrophenol was used to study the antipyretic effect of IN in normal rats and bile duct ligation rats. It was found that the antipyretic effect of IN on normal rats was better than that of bile duct ligation rats. The above results indicated that after oral administration of IN,the calcium carbonate carrier was transformed into a slightly soluble state in acidic gastric fluid,and a small amount of organic matter was released. When IN entered the intestinal fluid mixed with bile,the carrier dissolved in a large amount,and indigo and indirubin were dissolved in a large amount,so as to absorb the blood and exert the effect. This study has a certain significance for guiding clinical application of IN. For patients with insufficient bile secretion( such as bile duct resection),oral administration with IN may not be effective and shall be paid attention.

Nanostructured lipid carriers as a novel tool to deliver sclareol: physicochemical characterisation and evaluation in human cancer cell lines

Sclareol (SC) is arousing great interest due to its cytostatic and cytotoxic activities in several cancer cell lines. However, its hydrophobicity is a limiting factor for its in vivo administration. One way to solve this problem is through nanoencapsulation. Therefore, solid lipid nanoparticles (SLN-SC) and nanostructured lipid carriers (NLC-SC) loaded with SC were produced and compared regarding their physicochemical properties. NLC-SC showed better SC encapsulation than SLN-SC and was chosen to be compared with free SC in human cancer cell lines (MDA-MB-231 and HCT-116). Free SC had slightly higher cytotoxicity than NLC-SC and produced subdiploid DNA content in both cell lines. On the other hand, NLC-SC led to subdiploid content in MDA-MB-231 cells and G2/M checkpoint arrest in HCT-116 cells. These findings suggest that SC encapsulation in NLC is a way to allow the in vivo administration of SC and might alter its biological properties

Lipophilicity Descriptors Correlate Uniquely with Pharmacokinetic and Blood-Brain Barrier Penetration Parameters for Selected Antipsychotic Drugs

Lipophilicity is an important physicochemical parameter of biological relevance; although its in- vivo predictive capability is dependent on accuracy and reliability of platforms used for its determination. This work examines biomimetic attribute of isocratic chromatographic hydrophobicity index (ICHI), experimental logarithm of octanol ­ water partition coefficient (LogP) and some computed lipophilicity indices for eight (8) selected antipsychotic agents and their predictive capability in drug discovery. The retention behavior of 5 first-generation and 3 second-generation antipsychotics was determined on reversed-phase chromatographic platform using methanol-phosphate buffer (pH 6.8) mobile phase. The retardation factor obtained was transformed to Rm, and plotted against volume fraction of organic modifier in the mobile phase to generate linear graph whose x- intercept is ICHI. Experimental LogP values were curled from literature while computed LogP were obtained using respective software. The experimentally determined LogPoctanol/water and ICHI were first correlated with index of brain permeability (BBB); before all lipophilicity indices were comparatively evaluated and correlated with in-vivo-normalized pharmacokinetic parameters curled from literature. ICHI gave better correlation with BBB index (r = 0.976) compared to Log Poctanol/water (r = 0.557). Comparative lipophilicity evaluation shows clustered pattern for second generation antipsychotics compared to first generation. In vivo correlation was poorer for the 8 drugs (r < 0.7), better with subset of phenothiazine homologues (r = 0.51 to 0.97). The ALogP, LogPoctanol/water, cLogP and ICHI gave highest correlation with the pharmacokinetic parameters. The biomimetic attributes of ICHI is better than for LogPoctanol/water in predicting brain permeability, but lower for in-vivo pharmacokinetic prediction.

Métodos de extração, estabilidade e biodisponibilidade da guanitoxina em cultivos de Sphaeropermopsis torques-reginae analisadas por espectrometria de massas / Methods of extraction, stability, and bioavailability of guanitoxin in Sphaeropermopsis torques-reginae cultures analyzed by mass spectrometry

A guanitoxina (GNT) é uma neurotoxina produzida por algumas cepas de cianobactérias dos gêneros Dolichospermum e Sphaerospermopsis>. A GNT é o único organofosforado natural, capaz de causar a morte de animais selvagens e domésticos devido à inibição irreversível da acetilcolinesterase. Apesar de sua alta toxicidade, o diagnóstico da GNT em amostras biológicas ainda é um grande desafio. A dificuldade para sua detecção está diretamente ligada à sua instabilidade em altas temperaturas e pH alcalino, tornando difícil seu monitoramento em corpos d'água. Por isso, esta pesquisa objetivou estudar a estabilidade e biodisponibilidade da GNT em amostras aquosas, com intuito de obter mais informações sobre a natureza química e biológica dessa potente neurotoxina. Para realizar este estudo, a cepa ITEP-24 (S. torques-reginae) produtora de GNT foi cultivada em laboratório sob condições controladas, para obter biomassa para os experimentos de extração, semi-isolamento, estabilidade, ensaio in vitro e identificação por LC-MS/MS. Primeiramente foram realizados testes de extração da GNT partir de células liofilizadas da cepa ITEP-24 utilizando água, metanol e etanol em pH ácido. Depois utilizou-se dois métodos de extração em fase sólida (SPE) com cartuchos preenchidos com fases estacionarias C18 em fase reversa e sílica gel em fase normal, com objetivo de avaliar qual método de SPE seria melhor para extrair e concentrar a GNT. Nós também testamos métodos para lisar as células com sondas de ultrassom, misturador e centrifugação. Além dos métodos de extração, nós avaliamos a estabilidade da toxina em diferentes temperaturas, para isso a biomassa seca contendo a GNT ficou condicionada a 4 °C, 23 °C, -20 °C, -80 °C durantes seis meses, e análises de identificação foram realizadas dentro período de 150 dias em uma sequência de 30 dias. A estabilidade da toxina foi analisada também a partir de extrações em soluções com diferentes valores de pH (1,5; 3,0; 5,0; 7,0; 8,5; 10,5) e temperatura (23 ºC e 37 ºC). Depois, analisou-se a biodisponibilidade da GNT em células frescas da linhagem ITEP-24 através de teste de dissolução in vitro. O objetivo deste teste foi avaliar a liberação da toxina intracelular em meio simulado do conteúdo gástrica e intestinal com e sem enzimas digestivas para compreender e estimar a disponibilidade da GNT in vivo. Os resultados de todos experimentos descritos neste estudo, foram obtidos a partir de análises por cromatografia líquida de interação hidrofílica (HILIC) acoplado ao espectrômetro de massas do tipo triplo quadrupolo LC-QqQ-MS/MS utilizando as transições 253>58, 253>159 e 159>58 [M+H]+ utilizando coluna com fase estacionária zwitteriônica (ZIC). A identificação da GNT foi realizada também por cromatografia líquida acoplada ao espectrômetro de massas de alta resolução (LC-HR-QTOF-MS) com coluna Luna C18, Hydro-RP C18 e ZIC-HILIC. Dos protocolos de extração testados, a combinação de metanol/água (70:30 v/v) com ácido acético (0.3%) extraiu maior quantidade relativa da GNT a partir de células frescas e liofilizadas da cepa ITEP-24 e a concentração da toxina foi maior em amostras de células frescas. Em relação aos métodos de lise celular, as extrações realizadas em sonda de ultrassom com banho-maria e centrifugação por 1h foram estatisticamente significantes para liberar a toxina intracelular. Não houve diferença significativa entre os testes de SPE, no entanto, a semipurificação da toxina foi melhor com cartucho preenchido com sílica gel em fase normal e adaptação desse método em coluna aberta permitiu obter uma fração enriquecida com GNT. A GNT mostrou ser mais estável em pH ácido, sendo o pH 3,0 o melhor para manter e extrair a toxina em amostras aquosas e a toxina intracelular presente em células secas podem degradar em temperatura de 23 °C por um período de 150 dias mesmo em solução com pH 3,0. Durante os testes de extração e purificação foi observado também a degradação da toxina em processos de secagem e ressuspensão. As análises realizadas no LC-HR-QTOF-MS com diferentes métodos cromatográficos possibilitou a identificação da GNT, porém o método realizado com coluna ZIC-HILIC mostrou melhor resolução cromatográfica dos picos relativos m/z e tempo de retenção de toxina. Os resultados obtidos nos testes de dissolução in vitro mostraram que a GNT fica mais disponível no simulado gástrico com e sem a enzima pepsina, mas também pode ser absorvida no intestino. Portanto, o teste de dissolução in vitro pode ser uma ferramenta útil para a avaliação de risco de cianotoxinas in vivo, devido ao seu potencial de monitorar qualitativa e quantitativamente substâncias dissolvidas em fluidos gastrointestinais. Os resultados apresentados neste estudo fornecem informações valiosas para uma melhor compreensão da estabilidade e biodisponibilidade do GNT. Além disso, os métodos apresentados neste estudo podem ser úteis para diversas aplicações projetadas para identificar a toxina em amostras ambientais, bem como orientações para procedimentos de purificação da GNT

Guanitoxin (GNT) is a neurotoxin produced by some strains of cyanobacteria of the genus Dolichospermum and Sphaerospermopsis. GNT is the only natural organophosphate, capable of causing the death of animals from wild and domestic animals due to irreversible inhibition of acetylcholinesterase. Despite its high toxicity, the diagnosis of GNT in biological samples is still a significant challenge. The difficulty in its detection is directly linked to its instability at high temperatures and alkaline pH, making it difficult to monitor in bodies of water. Therefore, this research aimed to study the stability and bioavailability of GNT in aqueous samples to provide more information about the chemical and biological nature of this molecule. The strain ITEP-24 (S. torques-reginae) producing GNT was grown in the laboratory under controlled conditions to obtain biomass for the extraction, semi-isolation, stability, in vitro tests, and toxin identification by LC-MS/MS. Firstly, tests were carried out to extract GNT from lyophilized cells strain ITEP-24 using water, methanol, and ethanol at acidic pH and, two SPE methods in cartridges with stationary phases of C18 reverse phase and normal phase gel silica, to evaluate which would be better to extract and concentrate the GNT. We also tested different methods of cell lysis, such as ultrasound probes, mixers, and centrifugation. In addition to the extraction methods, the stability of the toxin was evaluated at different temperatures, for this, the dry biomass containing the toxin was conditioned at 4 °C, 23 °C, -20 °C, -80 °C for 150 days and analysis of the identification of the GNT was carried out within that period in a sequence of 30 days. The toxin stability was also analyzed from extractions in solutions with different pH values (1.5; 3.0; 5.0; 7.0; 8.5; 10.5) and temperature (23 ºC and 37 ºC). In addition, we performed dissolution tests with fresh cells of the ITEP-24 strain to evaluate the bioavailability of GNT in simulated gastric and intestinal fluids with and without digestive enzymes to understand and estimate the availability of GNT in vivo. The results of all experiments described in this study were obtained from analyzes by hydrophilic interaction liquid chromatography (HILIC) coupled to the LC-QqQ-MS/MS triple quadrupole mass spectrometer using the transitions m/z 253> 58, m/z 253> 159 and m/z 159> 58 [M + H]+ using a column with the zwitterionic stationary phase (ZIC). Liquid chromatography coupled to the high-resolution mass spectrometer (LC-HR-QTOF-MS) with Luna column C18, Hydro-RP C18, and ZIC-HILIC carried out the identification of the GNT. From the extraction protocols tested, the combination of methanol/water (70:30 v/v) with acetic acid (0.3%) extracted a greater relative amount of GNT from fresh and lyophilized ITEP-24 cells, and the concentration of the toxin is higher previously fresh. Concerning cellular methods, the ultrasound probe with a water bath and centrifugation for 1h ware statistically significant to release the intracellular toxin. There was no significant difference between the SPE tests. However, the semi-purification of the toxin was better with a cartridge filled with gel silica in the normal phase and adaptation of this method in an open column allowed to obtain a fraction enriched with GNT. GNT was more stable at acid pH, with pH 3.0 being the best to maintain and the intracellular toxin present in dry cells can degrade at a temperature at 23 °C for 150 days even in pH 3.0 solution. The toxin can also hydrolyze in the drying and resuspension processes. The analyzes carried out in LC-HR-QTOF-MS with different chromatographic methods made it possible to identify the GNT itself, however, the ZIC-HILIC column method showed excellent chromatographic resolution of the relative m/z peaks and toxin retention time. The results obtained in the in vitro dissolution tests showed that GNT is more available in the gastric simulation with and without the enzyme pepsin, but it can also be absorbed in the intestine. Thus, in vitro dissolution tests can be used as a useful tool for the risk assessment of cyanotoxins in vivo due to their potential to qualitatively and quantitatively monitor substances dissolved in gastrointestinal fluids. The results presented in this study provide valuable information for a better understanding of the stability and bioavailability of GNT. Besides, the methods presented in this study can be useful for various applications designed to identify the toxin in environmental samples, as well as guidance on procedures for purifying GNT

Ocotea pulchellaas an alternative against schistosomiasis: chemical analysis, development of nanoemulsion and biological control activity / Ocotea pulchellacomo una alternativa ante esquistosomiasis: análisis químico, desarrollo de una nanoemulsión y actividad en control biológico

The aim of this work was to evaluate the potential of the essential oil (EO) from Ocotea pulchella leaves as an alternative in the control of schistosomiasis. It was tested O. pulchella EO nanoformulation to assess its activity against adult Biomphalaria glabrata, their spawning and Schistossoma mansoni cercariae. Additionally, the EO chemical composition was investigated by gas-chromatography. Nanoemulsion were elaborated by the low energy method. The adult mollusks, their spawning and cercariae were placed in contact with nanoemulsion to calculate lethal concentrations. Myristicin, bicyclogermacrene and α-Pinene were the main substances in the EO. Nanoemulsion caused mortality of adult B. glabrata, its egg embryos and S. mansoni. These results suggest the use of this nanoemulsion as an alternative in the control of the schistosomiasis cycle.

El objetivo de este trabajo fue evaluar el potencial de los aceites esenciales (AE) de las hojas de Ocotea pulchellacomo una alternativa en el control de esquistosomiasis. Se probó una nanoformulación de AE de O. pulchellapara evaluar su actividad ante adultos de Biomphalaria glabrata, sus huevos y cercarías de Schistossoma mansoni. La nanoemulsión fue elaborada por el método de baja energía. Los moluscos adultos, sus huevos y cercarías se colocaron en contacto con la nanoemulsión para calcular concentraciones letales. Los compuestos mayoritarios en el AE fueron miristicina, biciclogermacreno y α-pineno. La nanoemulsión causó mortalidad en adultos de B. glabrata, sus huevos y a S. mansoni. Los resultados sugieren el uso de esta nanoemulsión como una alternativa en el control del ciclo de esquistosomiasis.

Improvement of the alkali stability of Penicillium cyclopium lipase by error-prone PCR

BACKGROUND: Lipases are extensively exploited in lots of industrial fields; cold-adapted lipases with alkali-resistance are especially desired in detergent industry. Penicillium cyclopium lipase I (PCL) might be suitable for applications of detergent industry due to its high catalytic efficiency at low temperature and relatively good alkali stability. In this study, to better meet the requirements, the alkali stability of PCL was further improved via directed evolution with error-prone PCR. RESULTS: The mutant PCL (N157F) with an improved alkali stability was selected based on a high-throughput activity assay. After incubating at pH 11.0 for 120 min, N157F retained 70% of its initial activity, which was 23% higher than that of wild type PCL. Combined with the three-dimensional structure analysis, N157F exhibited an improved alkali stability under the high pH condition due to the interactions of hydrophilicity and ß-strand propensity. Conclusions: This work provided the theoretical foundation and preliminary data for improving alkali stability of PCL to meet the industrial requirements, which is also beneficial to improving alkali-tolerance ability of other industrial enzymes via molecular modification.

Conversion of renewable substrates for biosurfactant production by Rhizopus arrhizus UCP 1607 and enhancing the removal of diesel oil from marine soil

BACKGROUND: The use of agro-industrial wastes to produce high value-added biomolecules such as biosurfactants is a promising approach for lowering the total costs of production. This study aimed to produce biosurfactants using Rhizopus arrhizus UCP 1607, with crude glycerol (CG) and corn steep liquor (CSL) as substrates. In addition, the biomolecule was characterized, and its efficiency in removing petroderivatives from marine soil was investigated. RESULTS: A 22 factorial design was applied, and the best condition for producing the biosurfactant was determined in assay 4 (3% CG and 5% CSL). The biosurfactant reduced the surface tension of water from 72 to 28.8 mN/m and produced a yield of 1.74 g/L. The preliminary biochemical characterization showed that the biosurfactant consisted of proteins (38.0%), carbohydrates (35.4%), and lipids (5.5%). The compounds presented an anionic character, nontoxicity, and great stability for all conditions tested. The biomolecule displayed great ability in dispersing hydrophobic substrates in water, thereby resulting in 53.4 cm2 ODA. The best efficiency of the biosurfactant in removing the pollutant diesel oil from marine soil was 79.4%. CONCLUSIONS: This study demonstrated the ability of R. arrhizus UCP1607 to produce a low-cost biosurfactant characterized as a glycoprotein and its potential use in the bioremediation of the hydrophobic diesel oil pollutant in marine soil

Development of a purification tag to produce thermostable fused protein / 生物工程学报

Self-assembling amphipathic peptides (SAPs) have alternating hydrophilic and hydrophobic residues and can affect the thermal stabilities and catalytic properties of the fused enzymes. In this study, a novel multifunctional tag, S1vw (HNANARARHNANARARHNANARARHNARARAR) was developed to modify fused enzymes. After fusing S1vw at the enzymes/proteins N-terminus through a PT-linker, the crude enzymatic activities of polygalacturonate lyase and lipoxygenase were enhanced 3.1- and 1.89-fold, respectively, compared to the wild-type proteins. The relative fluorescence intensity of the green fluorescent protein was enhanced 16.22-fold. All the three S1vw fusions could be purified by nickel column with high purities and acceptable recovery rates. Moreover, S1vw also induced the thermostabilities enhancement of the fusions, with polygalacturonate lyase and lipoxygenase fusions exhibiting 2.16- and 3.2-fold increase compared with the corresponding wild-type, respectively. In addition, S1vw could enhance the production yield of green fluorescent protein in Escherichia coli and Bacillus subtilis while the production of GFP and its S1vw fusion changed slightly in Pichia pastoris. These results indicated that S1vw could be used as a multifunctional tag to benefit the production, thermal stability and purification of the fusion protein in prokaryotic expression system.

Fabrication of hydrophilic medical catheter with hydrogel grafting and the in vivo evaluation of its histo-compatibility / 生物医学工程学杂志

The biocompatible hydrogel was fabricated under suitable conditions with natural dextran and polyethylene glycol (PEG) as the reaction materials. The oligomer (Dex-AI) was firstly synthesized with dextran and allylisocyanate (AI). This Dex-AI was then reacted with poly (ethyleneglycoldiacrylate) (PEGDA) under the mass ratio of 4∶6 to get hydrogel (DP) with the maximum water absorption of 810%. This hydrogel was grafted onto the surface of medical catheter via diphenyl ketone treatment under ultraviolet (UV) initiator. The surface contact angle became lower from (97 ± 6.1)° to (25 ± 4.2)° after the catheter surface was grafted with hydrogel DP, which suggests that the catheter possesses super hydrophilicity with hydrogel grafting. The evaluation after they were implanted into ICR rats subcutaneously verified that this catheter had less serious inflammation and possessed better histocompatibility comparing with the untreated medical catheter. Therefore, it could be concluded that hydrogel grafting is a good technology for patients to reduce inflammation due to catheter implantation, esp. for the case of retention in body for a relative long time.

Rapid chemical profiling of Artemisiae Scopariae Herba using reversed phase liquid chromatography-hydrophilic interaction liquid chromatography-predictive multiple reaction monitoring / 中国中药杂志

Chemical profiling of a given herbal medicine( HM) is the prerequisite for clarifying the effective material basis and therapeutic mechanisms,and it is an important integral part of traditional Chinese medicine chemical biology( TCMCB). In current study,we aimed to propose a new strategy for fast chemical characterization of HM by using reversed phase liquid chromatography-hydrophilic interaction chromatography-predictive multiple reaction monitoring( RPLC-HILIC-p MRM),and Artemisiae Scopariae Herba was employed in this study to illustrate the entire strategy. In response to wide polarity spanning of the diverse chemical clusters in Artemisiae Scopariae Herba,RPLC and HILIC were coupled in series to retain and separate hydrophilic and hydrophobic components simultaneously by identifying the characteristics of chromatographic separation. Most of the chemical constituents in traditional Chinese medicine can be predicted by summarizing the results of chemical constituents of the same genera and introducing primary metabolites and possible substitution reaction types. Therefore,we constructed predictive ion pairs to rapidly identify the chemical constituents of Artemisiae Scopariae Herba. After comparison with control products,discussion on fragmentation pattern,and access to relevant information from literature and databases,a total of 139 components were detected and structurally annotated by matching the obtained spectral data with the information of authentic compounds. Above all,RPLC-HILIC-p MRM could be used as an eligible analytical tool for the chemical profiling of HMs.

Bioactive characteristics of an implant surface coated with a pH buffering agent: an in vitro study

PURPOSE: The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation.METHODS: Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted.RESULTS: In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively).CONCLUSIONS: SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings.

Fabrication of rough surface on titanium using electrochemical treatment in NaCl electrolyte / 대한치과재료학회지

It is difficult to get sufficient roughness on titanium implant surface using traditional electrochemical treatments. In this study, we have developed a new method which provides a hybrid structured titanium surface having micro/nano roughness using electrochemical treatment in NaCl electrolyte and hydrothermal treatment. Titanium disks were anodically oxidized (ANO) in 0.15M NaCl electrolyte by applying positive electric pulses. The oxide compounds loosely attached to the surface were removed by ultrasonic cleaning (ANO group). These specimens were hydrothermally (HT) treated in an alkaline solution (ANO-HT group). ANO group showed the dimpled grain surfaces with a diameter of approximately 30 µm, and its roughness (Ra) was about 2.4 µm. The nano-sized crystallites which had an anatase TiO₂ crystalline structure were uniformly distributed on the surface of ANO-HT group. This group still retained high roughness (~2.7 µm) similar to ANO group and showed high hydrophilicity. Titanium surface with high roughness and hydrophilicity was fabricated using new electrochemical treating method and hydrothermal treatment. This surface modification method could be used for enhancing the osteoconductivity of the titanium implants.

Surface characterization of calcium phosphate coating formed on chitosan and alkali-treaDted titanium metal / 대한치과재료학회지

The calcium phosphate coating on various pretreated metals was prepared by soaking in modified simulated body fluid (m-SBF) solution. The coating structure and its surface morphologies were determined by x-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results revealed significant differences in morphology and composition of the calcium phosphate coatings with and without chitosan and NaOH-pretreated commercially pure titanium (cp-Ti) substrate. The calcium phosphates formed on chitosan coated-Ti pretreated with NaOH were ~ 350 nm-sized resulting in strong bonding of the apatite layer with the substrates and a uniform gradient of stress transfer from coating materials to the Ti-substrate. After NaOH pretreatment, the hydroxyl groups bind to Ca²⁺ to attract PO₄³⁻ anions, eventually resulting in a continuous layer of calcium phosphate on chitosan coated-Ti substrate during immersion in m-SBF solution. The chitosan coated-Ti showed hydrophobic surface while NaOH pretreatment resulted in maximum hydrophilicity to the Ti substrate. Due to improved wettability of Ti by NaOH pretreatment before chitosan coating, aggregation of calcium phosphate was prevented and size-controlled composite materials were obtained.

The effects of saline soaking on the removal torque of titanium implants in rabbit tibia after 10 days / 대한치과보철학회지

PURPOSE: The aim of this study was to confirm if Laser-treated implants were soaked in 0.9% NaCl solution for 2 weeks could increase the surface hydrophilicity, and the Remoal Torque of each implant that inserted in rabbit tibia for initial healing period of 10 days. MATERIALS AND METHODS: Twenty machined titanium surface screws were produced with a diameter 3 mm, length 8 mm. Ten screws had their surface treated with a laser only (laser treated group), and the other 10 were soaked in saline for 2 weeks after surface treatment with a laser (laser treated + saline soaked group). Implants were inserted in rabbit tibia (ten adult New Zealand white rabbits), and the RTQ of each implant was measured after 10 days. The wettability among implants was compared by measuring the contact angle. Surface composition and surface topography were analyzed. RESULTS: After 10 days, the laser treat + soaking group implants had a significantly higher mean RTQ than the laser treated implants (P = .002, < .05). There were no significant morphological differences between groups, and no remarkable differences were found between the two groups in the SEM analysis. CONCLUSION: Saline soaking implants is expected to produce excellent RTQ and surface analysis results.

Caracterização interna de materiais restauradores indiretos com diferentes condicionamentos de superfície / Internal characterization of indirect restorative materials with different surface etching protocols

Objetivo: O objetivo do estudo foi avaliar o efeito da aplicação de ácido fluorídrico com diferentes tempos e concentrações na superfície de materiais restauradores indiretos obtidos a partir de blocos utilizados na tecnologia CAD-CAM. Materiais e Métodos: Amostras dos materiais restauradores indiretos medindo 4x4x0,8mm foram obtidos a partir de blocos CAD para cada material estudado: resina nanocerâmica Lava Ultimate (3M Espe), monossilicato de lítio reforçado por zircônia Celtra Duo (Dentsply) e cerâmica híbrida Vita Enamic (Vita). Os materiais foram submetidos à aplicação de ácido fluorídrico com concentração de 5% ou 10%, sendo o mesmo aplicado pelos tempos de 20, 40, 60 ou 90 segundos. Um grupo controle para cada material foi avaliado, sem nenhum tratamento de superfície, contabilizando nove grupos de cada material (n=10). As amostras foram avaliadas em relação à rugosidade de superfície (Ra e Rz), avaliadas em microscopia óptica confocal; ângulo de contato (θ), energia de superfície (s) e energia livre total de interação (∆G) avaliados em goniômetro, e resistência de união ao cimento resinoso avaliada através do teste de microcisalhamento. Imagens das amostras foram obtidas em microscopia eletrônica de varredura (MEV), microscopia óptica confocal e microscopia de força atômica. Os dados de rugosidade de superfície, ângulo de contato, energia de superfície, energia livre total de interação e resistência de união foram submetidos à ANOVA dois fatores e teste de Tukey (p<0,05). Resultados: Os resultados mostraram que, de maneira geral, o monosilicato de lítio reforçado por zircônia Celtra Duo apresentou melhores resultados quando submetido ao condicionamento com ácido fluorídrico 10% por 40 ou 60 segundos de aplicação. A resina nanocerâmica Lava Ultimate apresentou melhor performance quando condicionada com ácido fluorídrico 10% por 20 ou 40 segundos, enquanto que a cerâmica híbrida Vita Enamic apresentou melhores resultados quando condicionada com ácido fluorídrico 5% por 90 segundos. Conclusão: Cada material interagiu de maneira diferente ao condicionamento com ácido fluorídrico, sendo que o conhecimento do adequado protocolo para cada material é essencial para garantir melhorias nos processos de adesão e durabilidade das restaurações indiretas. Celtra Duo apresentou de maneira geral propriedades mecânicas superiores aos demais. Relevância clínica: Recomenda-se protocolos específicos de tratamento de superfície com ácido fluorídrico de acordo com a composição de cada material restaurador indireto(AU)

Purpose: The aim of this study was to evaluate the effect of different times and concentration of hydrofluoric acid etching on the surface of indirect restorative materials obtained from blocks used in CAD-CAM technology. Methods and Materials: Samples of indirect restorative materials measuring 4x4x0.8mm were obtained for each restorative material studied: Lava Ultimate nanoceramic resin (3M Espe), Celtra Duo zirconia-reinforced lithium silicate ceramic (Dentsply) and Vita Enamic polymer-infiltrated ceramic-network material (Vita). The materials were submitted to etching with 5% or 10% hydrofluoric acid for 20, 40, 60 or 90 seconds. A control group for each material was evaluated without any surface treatment, totaling nine experimental groups for each material (n = 10). The samples were evaluated in relation to surface roughness (Ra and Rz), evaluated by confocal optical microscopy; contact angle (θ), surface energy (s) and total free interaction energy (∆G) evaluated by goniometer; and microshear bond strength to resin cement. Sample images were obtained by scanning electron microscopy (SEM), confocal optical microscopy and atomic force microscopy. Data of surface roughness, contact angle, surface energy, total free interaction energy and bond strength were submitted to two-way ANOVA and Tukey test (p<0.05). Results: The results showed that, in general, the Celtra Duo zirconia-reinforced lithium silicate ceramic showed better results when subjected to etching with 10% hydrofluoric acid for 40 or 60 seconds. Lava Ultimate nanoceramic resin showed better performance when etched with 10% hydrofluoric acid for 20 or 40 seconds, while Vita Enamic polymer-infiltrated ceramic-network showed better results when etched with 5% hydrofluoric acid for 90 seconds. Conclusion: Each material showed different characteristics after etching with hydrofluoric acid, and the knowledge of the proper protocol for each material is essential to ensure improvements in the adhesion process and durability of indirect restorations. Celtra Duo presents general ways of mechanical properties superior to the others. Clinical relevance: Specific surface treatment protocols with hydrofluoric acid are recommended based on the different compositions of indirect restorative materials(AU)

UV induced surface modification on improving the cytocompatibility of metallocene polyethylene

ABSTRACT Demand for medical implants is rising day by day as the world becomes the place for more diseased and older people. Accordingly, in this research, metallocene polyethylene (mPE), a commonly used polymer was treated with UV rays for improving its biocompatibility. Scanning electron microscopy (SEM) images confirmed the formation of crests and troughs, which depicts the improvement of surface roughness of mPE substrates caused by UV etching. Accordingly, the contact angle measurements revealed that the wettability of mPE-2.5 J/cm2 (68.09º) and mPE-5 J/cm2 (57.93º) samples were found to be increased compared to untreated mPE (86.84º) indicating better hydrophilicity. Further, the UV treated surface exhibited enhanced blood compatibility as determined in APTT (untreated mPE- 55.3 ± 2.5 s, mPE-2.5 J/cm2 - 76.7 ± 4.1 s and mPE-5 J/cm2 - 112.3 ± 2 s) and PT (untreated mPE - 24.7 ± 1.5 s, mPE- 2.5 J/cm2 - 34.3 ± 1.1 s and mPE-5 J/cm2 - 43 ± 2 s) assay. Moreover, the treated mPE-2.5 J/cm2 (4.88%) and mPE-5 J/cm2 (1.79%) showed decreased hemolytic percentage compared to untreated mPE (15.40%) indicating better safety to red blood cells. Interestingly, the changes in physicochemical properties of mPE are directly proportional to the dosage of the UV rays. UV modified mPE surfaces were found to be more compatible as identified through MTT assay, photomicrograph and SEM images of the seeded 3T3 cell population. Hence UV-modified surface of mPE may be successfully exploited for medical implants.