It is highly desirable to develop simple and rapid method to detect cancer cells. In this case, a simple method for electrochemical detecting cell numbers based cytosensor was investigated. Thioctic acid (TA) monolayer, assembled on a high conductive Au/ITO substrate to stable immobilized of Arg-Gly-Asp-Ser tetrapeptide (RGDS) by chemical bonding, was first used for construction of electrochemical cytosensor. Moreover the cytotoxicity assay also showed no cytotoxicity of TA modified electrode . The proposed cytosensor showed good performance for detection of cancer cells with a broad detection range of 3.0 × 10 2 to 1.0 × 10 7 cells/mL, and a low detection limit of 300 cells/mL. The results were obtained that can be attributed to the combination of the advantages of high conductive and biocompatible property of the modified electrode we suggested. This work demonstrated a simple strategy to prepare an electrochemical cytosensor with the property of low cost, good biocompatible, broad detection range, low detection limit, good repeatability which may have potential large-scale application for improving cancer diagnosis and treatment.
In this paper, four different kinds of mercaptan acids modified amphiphilic copolymers mPEG- b -PATMC- g -SRCOOH (R = CH 2 , CH 2 CH 2 , (CH 2 ) 10 and CH(COOH)CH 2 ) were successfully synthesized by thiol-ene “click” reaction between pendent carbon-carbon double bonds of PEG- b -PATMC and thiol groups of thioglycolic acid, 3-mercaptopropionic acid, 11-mercaptoundecanoic acid or 2-mercaptosuccinic acid. DLS and TEM measurements showed that all the mPEG- b -PATMC- g -SRCOOH copolymers could self-assemble to form micelles which dispersed in spherical shape with nano-size before and after DOX loading. The positively-charged DOX could effectively load into copolymer micelles via synergistic hydrophobic and electrostatic interactions. All DOX-loaded mPEG- b -PATMC- g -SRCOOH micelles displayed sustained drug release behavior without an initial burst which could be further adjusted by the conditions of ionic strength and pH. Especially in the case of mPEG- b -PATMC- g -S(CH 2 ) 10 COOH (P3) micelles, the suitable hydrophobility and charge density were not only beneficial to improve the DOX-loading efficiency, they were also good for obtaining smaller particle size, higher micelle stability and more timely drug delivery. Confocal laser scanning microscopy (CLSM) and MTT assays further demonstrated efficient cellular uptake of DOX delivered by mPEG- b -PATMC- g -SRCOOH micelles and potent cytotoxic activity against cancer cells.
1-Chloro-2-hydroxy-3-butene (CHB) is a possible metabolite of 1,3-butadiene, a carcinogenic air pollutant . To demonstrate its formation in vivo, it is desirable to develop a practical biomarker and the corresponding analysis method. CHB can undergo alcohol dehydrogenase- and cytochromes P450 enzymes (P450)-mediated oxidation to yield 1-chloro-3-buten-2-one (CBO), which readily forms glutathione conjugates. We hypothesized that CBO-derived mercapturic acids , which are the expected biotransformed products of CBO-glutathione conjugates, could be used as CHB biomarkers. Thus, in the present study, we investigated the in vivo biotransformation of CHB into CBO-derived mercapturic acids. Because the reaction of CBO with N -acetyl- l -cysteine yields two products, 1,4- bis ( N -acetyl- S -cysteinyl)-2-butanone (NC1) and 1-chloro-4-( N -acetyl- S -cysteinyl)-2-butanone (NC2), we first developed an isotope dilution LC/ESI − -MS-MS method to quantitate urinary NC1 and NC2, and then determined their concentrations in urine of C57BL/6 mice and Sprague-Dawley rats administered CHB. Since no NC2 was detected in samples, the LC/ESI − -MS-MS method was optimized specifically for NC1. NC1 was enriched through solid phase extraction with the recovery being 75–82%. The limits of detection and quantitation were 6.8 and 34 fmol/0.1 mL for mouse urine, and 4.5 and 7.1 fmol/0.1 mL for rat urine, respectively. In urine of animals before CHB administration, no NC1 was detected; in mice administered CHB at 10 and 30 mg/kg, and rats at 5 and 15 mg/kg, NC1 was detected and its concentrations in urine from animals given higher doses were 3–6 fold higher than those given lower doses. Moreover, the NC1 concentrations in urine during 0–8 h were 4–6 fold and 10–11 fold higher than those during 8–24 h for mice and rats, respectively. The results demonstrated that CHB could be in vivo biotransformed into NC1, which could be used as a practical CHB biomarker.
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