Coordinative Synthesis Of Nanosized Arsenic Compounds Mineral Tcm And The Study Of Mechanisms

Recently, realgar and orpiment have been shown potent therapeutic efficacy intreatment of hematological malignancies, although relevant supporting pharmacologicalbasis is still limited. Novel nanosized realgar and orpiment have been prepared bynanotechnology. Recent reports said that nanosized realgar and orpiment could bereadily uptaken by experimental cancer cells with increased cytotoxicity on the cells,whilst they could emit bright fluorescence when they reached certain size limits.Pharmacological studies of these nanosized realgar and orpiment could be carried outsmoothly to give more theoretical supports for their potential applications inbiomedicine.This thesis firstly selected wild toxic ethanolamine as a coordinative agent to preparehigh quality nanosized realgar and orpiment. It has been found that acids such as formicacid and citric acid played an important role in preparing nanocrystals. The majorphysicochemical properties of these nanocrystals have been characterized by HRTEM,UV-Vis, PL etc, and the instrumental analysis showed the acids have critical effects onpreparation of nanosized realgar particularly in terms of their particle sizes anddistribution.Optimization of major preparative parameters has also been preformed in this study.Appropriate reaction temperature, pH value adjusted by addition of acids, and the timepoint of adding acids have been settle out finally.At the last stage of this thesis,3-D regular nanosized realgar/orpiment nano-structures have been made through self-assembly which have been proven by SEM andXRD.The synthesis mechanisms of nanosized arsenic compounds have been deduced asfollows: bulk realgar/orpiment could be dissolved in ethanolamine through formation ofAs-N bonds to make a molecular complex solution which was used as a syntheticprecursor. Acid induced broke down the As-N bonds to release realgar cores partially ascrystal nucleus, which finally grow to certain size limits. During the crystal growth,outside amide organic shells not only controlled crystal growth of insiderealgar/orpiment cores but also provide protection to make nanosized realgar/orpimentcomplete aqueous solubility and stability.