European Journal of Molecular Biotechnology

117-124

Authors: Anna N. Berlina, Dmitry V. Sotnikov, Sergei A. Eremin, Liqiang Liu, Chuanlai Xu, Anatoly V. Zherdev

A novel lateral flow immunoassay based on the use of two kinds of conjugated gold nanoparticles’ preparations was developed and applied to the detection of the toxic food colorant Sudan I. The gold nanoparticles were conjugated with monoclonal antibodies specific to Sudan and a Sudan-ovalbumin conjugate. Before the immunochromatographic process, the two conjugates were incubated with a tested sample. The results obtained a direct calibration curve for the detection of low-molecular-weight antigen, in contrast to common reverse concentration dependencies. In the absence of the target compound, minimal coloration of the test line was observed. An increase in the Sudan content led to staining and the appearance of a test line, which could be observed by the naked eye. The total duration of the assay is 15 minutes. The visual limit of Sudan I detection was 0.25 ng/mL, and the instrumental limit of detection (LOD) was 7.6 pg/mL. These values were at least three-four points lower than the established permissible level of the contaminant content in foodstuffs. This reserve in sensitivity provides the possibility of working with highly diluted samples and thus excludes the influence of their matrixes on the assay results. The direct dependence of the coloration on the concentration of Sudan I in the proposed assay means it is easy to identify the presence of the contaminant at extremely low concentrations. The common nature of the proposed approach allows its use in lateral flow immunoassays of different compounds.

139-147

Authors: Valery V. Novochadov, Anna S. Krylova, Nikita A. Anikeev, Victor I. Shemonaev, Angelina O. Zekiy

The necessity to develop different approaches to increasing dental implant osseointegration should be of high prevalence of dental diseases in current world, the massive expansion of dental implantation technologies, and the advent of technical possibilities to functionalize bioactive surfaces using modern molecular biotechnology. To improve bioactive surface of dental implants by functionalization, we selected chitosan because it had the properties of biocompatibility and osteoinductive effect, also we had literature data about the possibility of its application as nano-films and nano-coating. Chitosan, applied using еру cathodic sputtering technique, significantly altered nano-surface topography of dental implants. Using atomic force microscopy it is shown that after chitosan applying, the nano-roughness parameter has 5.6-fold increase, and the developed surface area ratio has increased 3.7 times in comparison with surface properties of commercial titanium screw implant without chitosan spraying. The application of chitosan on bioactive surface of the screw titanium implants was shown to improve the morphological characteristics of osseointegration after implantation into the rat femoral bone. The bone volume fraction in osseointegration zone exceeded at different periods of the experiment the value of the same parameter in the comparison group 1.56-1.64 times. Implants with a surface chitosan-based functional coating provided the additional osteoconductive effect appeared in more intensive and rapid osteogenesis around implants, and the more expressed remodeling and thickening of the surrounding trabecular bone.

158-170

Authors: H. A. Shindy

In this paper review, some of the important characterizations and mechanisms in the chemistry of cyanine dyes were explained. This include topics like absorption spectral behaviour, general characterization of cyanine dyes, photosensitisation effects of cyanine dyes in silver halide emulsion, photosensitisation-structure correlation of cyanine dyes, colour spectrophotometric measurements of cyanine dyes, fluorescence spectra of cyanine dyes, IR and 1H NMR spectra of cyanine dyes, general view in the visible spectra of cyanine dyes, stability of cyanine dyes, cyanine dyes in photodynamic therapy, synthesis mechanisms of monomethine cyanine dyes and synthesis mechanisms of trimethine cyanine dyes. In addition, in the introduction section of this review paper some light is shed on important uses and applications of cyanine dyes. Reviewing some of the important characterizations and synthesis mechanisms in the chemistry of cyanine dyes is interesting and can be considered as a novel or patent idea to which little attention has been paid in the chemistry literature.