Quantum Dots Drug Nanocapsules Preparation And Performance Study

This dissertation focuses on the nanopackaging of quercetin and camptothecin.Quercetin is a poorly water-soluble drug.In order to improve its water solubility,quercetin is encapsulated with water-soluble gelatin to obtain nanocapsules;The distribution of capsules in the body,the introduction of carbon dots,the preparation of three-layer structure of secondary encapsulated nanocapsules;Camptothecin is a fluorescent drug,insoluble in water,nanocapsules obtained after packaging it still has strong fluorescence.Finally,the operation and release behavior of two fluorescent nanocapsules in vivo were investigated.The first part first introduced the basic properties of nanocapsules,common preparation methods,morphology characterization and performance analysis methods,main functions,and applications in the field of medicine.Secondly,the basic properties of fluorescent carbon dots,their common preparation methods and their application in medicine are introduced.Finally,the properties and pharmacological effects of quercetin and camptothecin are introduced.The purpose and significance of this work were discussed.The second part describes the preparation of quercetin nanocapsules.In order to improve the water solubility of quercetin,gelatin encapsulated quercetin was used to prepare nanocapsules.The optimum conditions for synthesis were as follows: quercetin 4.0 mg,gelatin 0.2 g,formaldehyde 1.0 mL,and the mixing time was 30 min..The size of the nanocapsules was characterized by dynamic light scattering,scanning electron microscopy,and transmission electron microscopy.The diameter of the nanocapsules was found to be about 100 nm,which was spherical or ellipsoidal,and the pH was measured by UV spectroscopy.The in vitro release behavior and sustained release effect of the nanocapsules in the buffer;and have a significant sustained release effect at pH=9.0.In the third part,the carbon dots were introduced into quercetin nanocapsules to prepare nanocapsules coated with three-layer structure containing sub-dots.The capsule has a carbon dot as the core,the second layer is quercetin,and the third layer is gelatin.carbon dots were prepared by hydrothermal method.The diameters of the capsules were about 3 nm.After the preparation of the nanocapsules,the dynamic particle scattering,SEM and TEM were used.The diameter of the capsules was about 89 nm.The morphology was spherical or ellipsoidal.The average value of the encapsulation rate was determined by ultraviolet spectrophotometry to be about 64%.the carbon quanta before and after encapsulation were measured.The point of fluorescence loss is about 50%,and it can realize the timely detection of nanocapsules' operating regularity and release behavior in vivo.In the fourth part,the distribution of quercetin nanocapsules containing carbon dots was studied in vivo.The distribution of blood and tissues in 0.5-4 h was measured by fluorescence spectroscopy,and it was concluded that the nanocapsules showed a slow decline in the blood.Trend,blood concentration gradually decreased,accumulated most in the liver,with liver targeting,the fluorescence intensity of the nanocapsules in the order of 1h was: liver> plasma> kidney> heart> lung> spleen.The fifth part introduces the nano-packaging of the fluorescent drug camptothecin.Camptothecin is hardly soluble in water.In order to increase its water solubility,water-soluble gelatin is selected,and camptothecin is nano-packed using an initial microcrystalline method.The optimal synthesis conditions were as follows: camptothecin 0.5 mg,gelatin 0.2 g,formaldehyde 200 ?L,and the cyst formation time was 20 min.The morphology and properties of camptothecin nanocapsules were characterized by dynamic and static scattering,scanning electron microscopy,and transmission electron microscopy.The average particle size of the camptothecin nanocapsules was about 90 nm,which was spherical or ellipsoidal.The fluorescence spectra of camptothecin nanocapsules was studied.Sustained release action,stimulated drug release under different pH buffer conditions,the sustained release ability was 7.4> 9.0> 5.0 in order;subsequently,the fluorescence properties of the nanocapsules will be used to explore the transport and tissue distribution of the nanocapsules,visualization of behavior.