Research progress of visualization methods and localization techniques of the cardiac conduction system / 中国胸心血管外科临床杂志

@#The cardiac conduction system (CCS) is a set of specialized myocardial pathways that spontaneously generate and conduct impulses transmitting throughout the heart, and causing the coordinated contractions of all parts of the heart. A comprehensive understanding of the anatomical characteristics of the CCS in the heart is the basis of studying cardiac electrophysiology and treating conduction-related diseases. It is also the key of avoiding damage to the CCS during open heart surgery. How to identify and locate the CCS has always been a hot topic in researches. Here, we review the histological imaging methods of the CCS and the specific molecular markers, as well as the exploration for localization and visualization of the CCS. We especially put emphasis on the clinical application prospects and the future development directions of non-destructive imaging technology and real-time localization methods of the CCS that have emerged in recent years.

Enzyme-responsive fluorescent probes for bacteria imaging / 药学学报

Fluorescent probes are potential fluorophores that display signals based on the changes in tissue microenvironment, interactions with analytes or specific biochemical reactions. Metabolic enzymes are the most important protein involved in bacteria activities. Complex dynamics of biological processes in bacteria are elucidated by these metabolic enzymes-based fluorescent probes with high spatial resolution and sensitivity. Here, we review recent advances in metabolic enzyme-responsive fluorescent probes for bacteria imaging. It was organized according to enzyme classification systems, focused on fluorescence masking strategies, molecular mechanisms of enzyme activation, and bio-related applications.

Effects of zinc gluconate carbon dots in cell imaging and inducing osteoblastic differentiation in vitro / 吉林大学学报(医学版)

Objective: To synthesize the zinc gluconate carbon dots (Zn-CDs) by one-step hydrothermal method, and to investigate their effects on the cell imaging and inducing osteoblastic differentiation of preosteoblasts in the mice. Methods: The Zn-CDs were synthesized by one-step hydrothermal method, and the characteristics were observed and detected by transmission electron microscope (TEM), Fourier transform-infrared spectrum (FT-IR) and fluorescence spectrometer. The MC3T3-E1 cells were divided into blank control group and experimental groups; different concentrations (0.01, 0.10, 1.00, 10.00, 100.00, 1 000 mg middot; L-1) of Zn-CDs were added into the cells in experimental groups, and nothing was added into the cells in blank control group. MTT assay was used to determin the relative growth rate (RGR) of MC3T3-E1 cells in various groups; the imaging characteristics of MC3T3-E1 cells were observed under confocal microscope; the relative expression levels of Runt-relateed transcription factor-2 (Runx2), alkaline phosphatase (ALP) and osteocalcin (OC) mRNA in the MC3T3-E1 cells in various groups were detected by qRT-PCR; the number of calcified nodules was detected by alizarin red staining. Results: The TEM results showed that the particle size of Zn-CDs was about 5. 25 nm. The fluorescence spectrometer results showed that the Zn-CDs had the fluorescence properties of 360 nm ultraviolet excited light and 450 nm blue emission light, and the Zn-CDs showed the characteristics of excitation wavelength dependence. The FT-IR results showed that the surface of Zn-CDs was mainly composed of carboxyl groups and hydroxyl groups. Compared with blank control group, the RGR of MC3T3-E1 cells in 1 000. 00 mg middot; L-1 Zn-CDs group was decreased significantly at 24 h after co-culture (P<0. 01). The results of fluorescence imaging showed that the blue, green and red fluorescence in the MC3T3-E1 cells, the outline was clear, and the fluorescence intensity of the cytoplasm was stronger than that of the nucleus after co-cultured with Zn-CDs. The qRT-PCR results showed that the relative expression levels of Runx2, ALP and OC mRNA were significantly increased with the increasing of Zn-CDs concentration. The alizarin red staining results showed that the number of calcium deposits in the MC3T3-E1 cells in different concentrations of Zn-CDs groups were more than that in blank control group after induced for 21 d. Conclusion: Zn-CDs can effectively perform the fluorescence imaging in the MC3T3-E1 cells, and Zn-CDs have a certain ability to promote the osteoblastic differentiation of the MC3T3-E1 cells.

Application of Nucleic Acid Aptamers in Polypeptides Researches / 分析化学

Polypeptides play a vital role in physiological processes of life. The pharmacological and medical value of polypeptides has attracted the attention of researchers in recent years. Aptamers are short, single stranded DNA or RNA which developed by an in vitro process called systematic evolution of ligands by exponential enrichment ( SELEX ) . Aptamers can bind targets with high affinity and specificity. Hence, aptamer is also called "chemical antibody" or "chemist's antibody". To date, there are two main application aspects for polypeptides-targeted aptamers. First, aptamer can be used as specific affinitive elements based on their ability of recognition, which would be applied to polypeptides detection or imaging. The other one is that aptamer can also be used as antagonists based on their ability of inhibiting, which can restrict the activity of polypeptides and block the downstream signaling pathways in vivo, thus can be used to treat the disease associated with polypeptides. In this review, we summarize the numbers of polypeptides-targeted aptamers and the related applications in vitro and in vivo. Current issues and development trends throughout the screening, characterizing and applying of polypeptides-targeted aptamers are also discussed.

Applications and research of quantum dots in biological imaging / 国际生物医学工程杂志

More and more attention has been drawn on nano-materials in the application of molecular imaging and targeted cancer therapy. Quantum dots, due to their rich surface chemical properties and bright stable fluorescence, have been used as a new type of nano-probes and widely used in molecular, cellular and vivo biological imaging. In recent years, many inspiring achievements have been obtained in the study on quantum dots surface modification and biological imaging in cell and animals. In this article, current status and the latest developments of the study and the application are reviewed.