Prceparation And Properties Of Polyphenol Microcapsules Engineered By Templating Method

Microcapsules with a hollow structure have shown their potential in biomedical applications.In recent years,polymer microcapsules have attracted great interests as micro-or nano-carriers for drug delivery due to their good biocompatibility and specific physicochemical properties(e.g.,pH and light responsiveness).Many methods have been developed for the preparation of microcapsules and the templating method is one of the most used approach for the preparation of microcapsules with tunable shapes and sizes.In this thesis,a series of microcapsules with tunable sizes,shapes and thicknesses were fabricated by layer-by-layer(LbL)method and one-step assembly of metal-phenol network(MPN)using cuprous oxide(Cu2O)and zeolitic imidazolate framework(ZIF-8)particles as templates.The properties and applications of these microcapsules were also explored.The research contents of this paper are listed below.Chapter ? reviews the basic concept,characteristics,classification,and preparation methods of microcapsules.The LbL microcapsules and MPN microcapsules assembled by templating method and the functionalities and biological applications of these microcapsules are introduced as well.In Chapter ?,Cu2O particles were used as the templates for LbL assembly of cubic,tetradecahedral and spherical microcapsules.Cu2O particles could be removed by sodium thiosulfate(Na2S2O3)under mild condition.The resulted microcapsules retained the size and shape of the templates with an average size of 1 ?m.Cell experiments indicated that the toxicity ofthe microcapsules was negligible and cubic microcapsules resulted in higher cell association than that of tetradecahedral and spherical microcapsules due to the higher contact area between cells and cubic microcapsules.In Chapter ?,MPN microcapsules were synthesized using metal organic frameworks(MOFs)of ZIF-8 with an average size of200 nm as templates.The ZIF-8 particles can be removed using EDTA solution under mild condition,which is a good candidate as templates.The thickness of the microcapsules wall was controlled by changing the concentration of metal ions and polyphenol as well as the reaction time.The photothermal effects,pH-responsiveness,and the capacity of drug loading of microcapsules indicated their great potential in theropeutic delivery.