Study On Preparation Process And Bioactivity Of Carbon Dots Of Ginseng

Objective:Total ginsenosides,the main active ingredients of Chinese medicinal ginseng,were selected as the raw materials to synthesis different carbon dots product solutions of ginseng by controlling the orthogonal hydrothermal reaction conditions（reaction temperature,reaction time,reaction concentration）.With the change of reaction conditions,the obtained product also has different physical and chemical properties.Then the law of change was summarized,and the research on its biological activity and medicinal effect was discussed.It is prospective to obtain carbon nanodots（carbon dots）from ginseng nanomedicine products with fluorescent labeling function and excellent bioactivity.Methods:1.An exploratory screening study on the preparation process of carbon dots from ginseng:total ginsenosides,the important active components of ginseng,were used as the reaction raw materials.The reaction temperature,time and concentration were used as variables to control the different hydrothermal reaction conditions to obtain a series of product solutions prepared under different conditions.After coarse filtration of the solution with a 0.22μm filter membrane,it was separated and purified by an ultrafiltration device to obtain ginseng carbon dot product.2.The product solutions obtained under different reaction conditions were tracked and characterized dynamically by Ultraviolet absorption spectroscopy and fluorescence spectroscopy.According to the analysis results,a ginseng carbon dots product with typical physical and chemical properties was screened out,and its reaction conditions were determined.3.Characterization of physicochemical properties of ginseng carbon dots:the putative structure was explained by Fourier transform infrared spectrometer（FTIR）and triple quadrupole liquid chromatography mass spectrometer（TSQ）results combined with ultraviolet absorption（UV）,fluorescence spectroscopy（PL）,and high-resolution projection electron microscopy（TEM）results.4.Bioactivity of ginseng carbon dots:Using CCK-8 method,different types of cells such as rat adrenal pheochromocytoma cells（PC12 cells）,human cervical carcinoma cells（He La cells）,human hepatoma cells（Hep G2 cells）,human neuroblastoma cells（SH-SY5Y cells）were used to investigate the biological activity of ginseng carbon dots.The prepared ginseng carbon dots were used as fluorescent probes to perform fluorescence imaging experiments of cells by fluorescence imaging technology.The apoptosis of carbon dots from ginseng was detected using apoptosis kit and flow cytometry.Results:1.A series of different carbon dots products of ginseng were prepared by one-step hydrothermal method using total ginsenosides as the carbon source by controlling orthogonal hydrothermal reaction conditions.After performing UV mapping and fluorescence spectral dynamic tracking analysis of ginseng carbon dot solution,a ginseng carbon dots products with typical physicochemical properties was screened out and the reaction conditions were determined:the reaction concentration of total ginsenosides was1.5 mg/m L,the reaction temperature was 170℃,and the reaction time was 8 h.2.After membrane filtration and purification treatment by ultrafiltration,the concentrated ginseng carbon dots products were characterized by UV,PL and TEM.The results showed that the prepared ginseng carbon dots had a certain fluorescence emission property with uniform size distribution,average particle size of 4.13±0.50 nm,better dispersion and less aggregation.3.FTIR spectroscopy characterization analysis showed that the surface of ginseng carbon dots is rich in hydroxyl groups,which is beneficial for its subsequent efficient interaction with organisms through functional groups.Mass spectrometric elucidation revealed that the structures of ginsenoside Rg₁,ginsenoside F₂,and ginsenoside Rd were still contained within the prepared ginseng c-dots.It indicated that the main body of ginseng carbon dots is combined with ginsenosides,which are not only nano-sized in size,but also may preserve the biological activity of ginseng.4.Cell viability experiments proved that the prepared ginseng carbon dots have a specific inhibitory effect on SH-SY5Y cells in the concentration range of 50μg/m L-150μg/m L.On the other hand,ginseng carbon dots can be used as fluorescent probes by SH-SY5Y cells uptake.The experimental results confirmed that the longer the carbon dots interact with the cells（8 h）,the greater the intake of cells,the more fluorescently labeled cells,and the stronger the fluorescence intensity displayed in the cells.Moreover,compared with the blank control group,the total apoptosis rate of SH-SY5Y cells treated with ginseng carbon dots solution was significantly increased.Conclusion:Ginseng carbon dots prepared by hydrothermal method under certain conditions have small size,uniform distribution,abundant surface groups,good fluorescent properties,which can be used as an effective cell fluorescent probe.Additionally,the main body of ginseng carbon dots are combined with ginsenosides,showing good biological activity,showing specific cytosolic inhibition to SH-SY5Y cells,providing a good research foundation for the subsequent preparation and development of traditional Chinese medicine nanomedicine and application prospects.