Biomimetic Synthesis Of Inorganic Micro/Nanomaterials And The Potential Applications In Anticancer Drug Deliveryand Photocatalytic Degradation Of Organic Dyes

As a serious health-threatening disease,the global cancer burden is growing at an alarming pace.Currently,the most common approaches to treat the tumor are limited to clinical-surgical therapy,chemotherapy and radiotherapy.However,these methods have a lot of shortcomings,such as high recurrence rate,strong side effects,low targeting,obvious drug resistance of the drugs and so on.The emergence of anticancer targeting agents overcomed the shortcomings bringed by common therapy approach.It can reduce the side effects to normal tissue and the doseage,improve the efficacy.Inorganic nanomaterials has found many applications due to their excellent physicochemical properties.It has been widely used in drug delivery,fluorescent tags,lithium batteries,catalysis,sewage treatment,sensing and chemical energy storage,etc.In recent years,the use of biomineralization mechanism for biomimetic synthesis becomes the hot spots in materials chemistry field.However,there is little research on the relationship between the structure,size,morphology,crystal form of the material and its cellular biological effects.Look into the future,we should strengthen the research in this direction,evaluate its scientificity,safety and effectiveness before practical application,and provide theoretical basis for the design and synthesis of inorganic nanomaterials and its application in biomedical field.In this thesis,several aspects were studied:Using water-soluble portion of pollen as organic matrix,nanoscaled porous hollow spheres of calcium carbonate were prepared.The morphology and properties of the samples were tested and characterized by a variety of different methods.The results show that the synthesized materials have uniform particle size,mesopores,internal hollow structure and large surface area.These properties can improve the drug loading capacity of the hollow spheres.The doxorubicin hydrochloride was used as a anticancer drug model for the drug loading and controlled release experiments in vitro,the as-prepared CaCO3 hollow spheres were used as drug carries in this experiment.The results showed that the synthetic porous hollow spheres has a high load capacity of91.4%.The results of controlled release experiments showed that the hollow spheres could slowly decompose into small particles under weak acidic conditions to release the drug because of the p Hsensitivity.However,the hollow sppheres was difficult to decompose under neutral and weak alkaline conditions,which could reduce the drug release around the normal cells.Additionally,the drug release from the hollow spheres exhibited the obviously sustained manner,which could obviously reduce the administration frequency.Cell biological assays showed that the specificity of DOX between normal and cancer cells can be enhanced significantly through loading into hollow spheres.Compared to the pure counterpart,the specificity of the DOX can be significantly increased by 17 times.In vitro experiments indicated that the drug loading hollow spheres could be easily internalized by cancer cells through endocytosis.Subsequently,the DOX could be released into the cancer cells.In summary,the current studies suggest that the as-prepared calcium carbonate hollow spheres might be used as anticancer drug carriers to specifically treat human cancer.In this thesis,the hollow cubes of calcium carbonate with double shells and single shell were prepared through the facile interfacial reaction.In this study,dimethyl carbonate was used as carbonate source and Ca(OH)2 was used as calcium source.The effects of reactant concentration and reaction temperature on the morphologies were evaluated.Scanning electron microscopy and transmission electron microscopy were used to characterize the as-prepared calcium carbonate cubes.The formation mechanisms of the double-shell and single shell cubes were proposed.The flower-like copper sulfide with mesoporous structure was prepared by solvothermal method.The results showed that the morphology and size of the synthesized Cu S are uniform,and the average size is about 340 nm.The synthesized CuS has excellent optical properties,and the optical bandgaps are estimated to be 1.36 e V and 2.14 eV for the indirect and direct optical bandgaps,respectively.Because of the large specific surface area and pore volume,the flower-like CuS has more active sites on the surface exhibits good photocatalytic activities for the degradation of synthetic organic dyes under visible light irradiation through the mediation of the photo-generated hydroxyl radicals(·OH).These results suggested that the flower-like Cu S prepared in this study might be used as the potential photocatalyst to efficiently treat the organic pollutants under visible light irradiation.