OBJECTIVES: This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. MATERIALS AND METHODS: Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio‑Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. RESULTS: At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resin-dentin bond strength with no significant fall. CONCLUSIONS: Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.
Adhesives* ; Ascorbic Acid ; Dentin* ; Ethyldimethylaminopropyl Carbodiimide ; Humans ; In Vitro Techniques ; Minocycline ; Molar ; Plastics ; Shear Strength ; Tooth

OBJECTIVETo establish a method for determining cyanamide in workplace air by high-performance liquid chromatography (HPLC).

METHODSAir samples were collected from the workplace using the shock absorption tube containing water solution at a rate of 2.8∼3.0 ml/min for 60 min; dansyl chloride was used as a derivatization reagent to conduct pre-column derivatization, and the procedure was as follows: acetone solution (2.5 ml), mixed solution (1.0 ml) containing 0.016 mol/L Na2CO3 and 0.184 mol/L NaHCO3, and 10 mg/ml acetone solution of dansyl chloride (0.5 ml) were added into the samples, and reaction proceeded in a water bath (50 °C) for 1 h. HPLC was performed on an ODS C18 column (250 mm × 4.6 mm, 5 üm) with a mobile phase of acetonitrile-phosphate buffer (35:65) at a flow rate of 1.0 ml/min and a column temperature of 25°C; a fluorescence detector was used at an excitation wavelength of 360 nm and an emission wavelength of 495 nm.

RESULTSThe minimum detectable concentration of cyanamide was 0.05 üg/ml; a good linear relationship was noted when the concentration of cyanamide was 0.2∼100.0 üg/ml; the intraday relative standard deviation (RSD) was 0.28%∼1.18%, and the interday RSD was 0.22∼2.16%; the recovery rate was 95.7%∼103.0%, and the sampling efficiency was 95.8%∼96.9%. Water solution of cyanamide (pH<6.5) could be stable in the dark at room temperature for 7 d.

CONCLUSIONThis method is stable, reliable, easy to operate, and highly sensitive and suitable for determination of cyanamide in workplace air.

Air Pollutants ; analysis ; Chromatography, High Pressure Liquid ; methods ; Cyanamide ; analysis ; Occupational Exposure ; analysis ; Workplace

OBJECTIVE: Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)-conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. MATERIALS AND METHODS: Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with antiVGFR2, to see a specific binding in vitro. Fluorescent cell images were taken by a confocal microscope. The human prostate cancer cells (PC3) were injected to five nude mice on hind limbs to make the xenograft tumor model. QD-antiVEGFR2 antibody complex was injected into the tumor model and fluorescence measurements were performed at 1, 4, 9, 12, 15, and 24 hours after the injection. RESULTS: The specific interaction between HUVECs and QD-antiVEGFR2 antibody was clearly shown in vitro. The in vivo fluorescence image disclosed that there was an increased signal of tumor, 12 hours after the injection of QDs. CONCLUSION: By showing endothelial cells binding with QDs-antiVEGFR2 antibodyand an experimental application of the antibody for VEGFR2 imaging in the prostate cancer xenograft mouse model, we suggests that the antibody-conjugated QDs can be a potential imaging tool for angiogenesis of the cancer.
Animals ; Carbodiimides/pharmacology ; Cell Line, Tumor ; Disease Models, Animal ; Electrophoresis, Agar Gel ; Fluorescence ; Male ; Mice ; Mice, Nude ; Microscopy, Confocal ; Neovascularization, Pathologic/*pathology ; Prostatic Neoplasms/*pathology ; *Quantum Dots ; Succinimides/pharmacology ; Transplantation, Heterologous ; Vascular Endothelial Growth Factor Receptor-2/*antagonists & inhibitors

Air Pollutants, Occupational ; analysis ; Cyanamide ; analysis ; Spectrophotometry ; Workplace

Adult ; Carbodiimides ; poisoning ; Humans ; Male ; Methylamines ; poisoning ; Occupational Exposure ; Young Adult

To establish a new immune assay for Penicillic Acid (PA) from Penicillium cyclopium, we studied the synthesis of conjugated complete antigens for penicillic acid. PA was conjugated to bovine serum album (BSA) and ovalbumin (OVA) by 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide hydrochloride (EDC). The artificial antigens PA-BSA and PA-OVA were identified by ultraviolet spectrometric scanning, SDS-PAGE and immunization. Results showed that the absorption peak of conjugation were different from that of the carrier protein alone and of the PA. The conjugated ratio of PA and BSA was 23.2:1 and that of PA and OVA was 10.4:1. Balb/c mice were immunized by the artificial antigen of PA-BSA, with PA-OVA as coating antigen. The average titer of antiserums was more than 12 800 by indirect ELISA. The obtained antigens offered a basis for developing immunoassay method.
Animals ; Antibodies ; blood ; Antigens ; immunology ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Ethyldimethylaminopropyl Carbodiimide ; analogs & derivatives ; chemistry ; Immunization ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; immunology ; Penicillic Acid ; immunology ; metabolism ; Penicillium ; immunology ; metabolism ; Serum Albumin, Bovine ; immunology

UNLABELLEDOBJECTIVE Crosslink decellularized canine carotid artery allograft by EDC [1-3-(dimethylamino)propyl-3-ethylcarbodiimide methiodide] and evaluate the biocompatibility of it.

METHODSUse the multi-step detergent-enzyme method to construct decellularized canine carotid artery allograft and cross-link it by EDC with the weight ratio of decellularized artery to EDC 1:1 and 1:2. Evaluate the biocompatibility of it by the cytotoxical MTT test and the rat subdermal bury test.

RESULTSDecellularized canine carotid artery cross-linked by EDC has a lower degradation rate treated by collagenase type II, the result of MTT test show that the EDC cross-linked decellularized artery has no cytotoxity and the rat subdermal bury test show that crosslinking greatly enhance the ability of decellularize artery to resist the enzyme degradation and lower the immune reaction. The more the artery was cross-linked , the more effects it has.

CONCLUSIONSDecellularized canine carotid artery cross-linked by EDC has fairly good biocompatibility and ability to resist the collagenase degradation.

Animals ; Biocompatible Materials ; Carbodiimides ; Carotid Artery, Common ; transplantation ; Cross-Linking Reagents ; Dogs ; Female ; Male ; Materials Testing ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering

Lipase (EC3.1.1.3) from Candida sp. 99-125 was immobilized on chitosan by chemical covalence. Lipase was first immobilized to chitosan beads by activating its hydroxyl groups with carbodiimide followed by cross-linking more lipase to the amino groups with glutaraldehyde. In this article, different factors that influenced the immobilization were investigated, and the optimum conditions were ascertained. Comparative studies of organic solvent and thermal stability between free lipase and immobilized lipase were conducted. Immobilization enhanced the lipase stability against changes of temperature and organic solvent. Immobilization lipase can be reused in the synthesis system of palmitate hexadecyl. Operational stability tests indicated that the immobilized lipase occurs after 16 consecutive batches, the conversion rate remained 85%. Such results revealed good potential for recycling under esterification system.
Candida ; enzymology ; Carbodiimides ; chemistry ; Chitosan ; chemistry ; Cross-Linking Reagents ; Enzyme Stability ; Enzymes, Immobilized ; Lipase ; metabolism ; Palmitates ; chemistry

BACKGROUND AND OBJECTIVES: Congenital middle ear cholesteatoma (CMEC) is a rare entity that may go undiagnosed for years. Aims of this study were to assess the characteristic features and recurrence of CMEC in pediatric patients of different stages and to determine the value of preoperative CT scan in CMEC. SUBJECTS AND METHOD: Thirty cases of CMEC under 15 years old that had been treated at the hospitals of the Catholic University from 1995 through 2005 were reviewed retrospectively. The age range was from 2 to 13 with the mean age of 6.2. The main outcome measures were CT findings, surgical findings, recurrence rate and hearing assessment. RESULTS: Preoperative CT scan accurately predicted the extent of the cholesteatoma seen during surgery in 25/30 (83.3%). The recurrence rate of CMEC was 6.7% (2/30) and all of recurrent cases were belonged to stage IV. In the recurrent cases, cholesteatomas were extended to sinus tympani and facial recess at revisional operation as well as at the initial operation. CONCLUSION: Preoperative CT scan is essential in defining the extent of existing pathology. The intra-operative CMEC extension and location influence the outcome of surgery. In the higher stages, careful eradication of disease, particularly in the region of sinus tympani and facial recess, are recommended.
Adolescent ; Child* ; Cholesteatoma ; Cholesteatoma, Middle Ear* ; CME-Carbodiimide ; Ear, Middle* ; Hearing ; Humans ; Outcome Assessment (Health Care) ; Pathology ; Recurrence ; Retrospective Studies ; Tomography, X-Ray Computed

Today, the blood vessel substitutes are in large demand for coronary and peripheral bypass procedures, and the demand cannot be met by conventional sources. This problem will be solved by applying tissue-engineered blood vessel in clinics. The prefabrication of vascular scaffold will be involved in engineering a blood vessel substitute. Biological tissues are important biomaterials fabricating vascular scaffold which can offer better constructs for adhesion and growth of cells onto synthetic materials. Because of immediate degradation of biological tissues obtained from the abattoir, cadaver or patient and the presence of antigenicity in allogenic or xenogenic tissues, the fresh biological tissues can not directly be preserved and applied. The use and preservation of these natural biomaterials have typically required pre-treatment aimed at (1) reducing the antigenicity of the materials, (2) enhancing the resistance of the materials to enzymatic degradation, (3) stabilizing the structure of the tissues and maintaining their mechanical properties. Physical and chemical methods for the pre-treatment of biological tissues are available. The predominant chemical agents that have been investigated for the pre-treatment of biological tissues for vascular scaffold are glutaraldehyde, polyepoxy compound, carbodiimide, genipin and proanthocyanidin. Typical and particularly promising physical pre-treatment of biological tissues for vascular scaffold is dye-mediated photooxidation. The crosslinking mechanisms of all classes of pre-treatments and the effects of pre-treatments on antigenicity, biostability, mechanical properties, cytoxicity and calcification of treated tissues are described in this article. The advantages and disadvantages of all pre-treatments are also reviewed. The trend of pre-treatment of biological tissues is to investigate and exploit the naturally occurring crosslinking reagent with less cytoxicity. Meanwhile, dye-mediated photooxidation crosslink is also a promising pre-treatment which should be widely applied in vascular scaffold.
Biocompatible Materials ; Bioprosthesis ; Blood Vessel Prosthesis ; Cross-Linking Reagents ; Ethyldimethylaminopropyl Carbodiimide ; Glutaral ; Humans ; Iridoid Glycosides ; Iridoids ; Materials Testing ; Pyrans ; Stents ; Tissue Engineering