In Vivo/external Drug Loading Performance Of Calcium Phosphate Coated Nano-silver Composites

In recent years,some precious metal nanometer materials have always been a research focus to some researchers.Simple noble metal nanomaterials can be cytotoxic to organisms,which greatly limits its application,And calcium phosphate have a good biocompatibility as the main inorganic component of vertebrate bone and teeth,the nano silver coated with appropriate thickness of calcium phosphate layer to overcome the silver toxicity,nano-silver coated Calcium phosphate layer composite material has a good application in surface enhanced Raman spectra(SERS),but also has a lower Cytotoxicity.This paper is mainly about the preparation of calcium phosphate-silver nano composite materials of different calcium layer thickness with chemical precipitation method,And we choose halogen salts as fluorescent quencher to achieve the fluorescence quenching effect for sodium citrate caused.In last chapter of this paper,we review a concept that spatially offset Raman spectroscopy that can detect deep subsurface analysis of biological tissues.Main content contains several aspects as follows:1.The preparation,characterization of biocompatible silver/calcium phosphate nano composite for in vivo/in vitro SERS performance research.Use silver nitrate as the source of silver,sodium citrate as reducing agent in the first step and ascorbic acid as reducing agent in the next step without any surface active agent.We achieved flower-like nano silver at room temperature.On the basis of this nano composite,it can form a layer of inorganic calcium phosphate on the surface layer and gain calcium phosphate-silver nano composite materials of different calcium layer thickness with calcium lactate as the calcium source and trisodium phosphate as the phosphorus source.The obtained CaP/Ag nano composites with an ultra-thin CaP layer(～6nm)were used to conduct SERS research.With 5-fluorouracil(5-Fu)and doxorubicin hydrochloride(Dox)as a probe molecule,we discussed the the performance of the CaP/Ag nano composites which are used as SERS active substrate.The minimum detection limit(LOD)to 5-Fu,Dox is 5×10-8 mol/L,5×10-7 mol/L.Furthermore,the LOD of 5-Fu and Dox with CaP/Ag nano composites were chosen for in-vivo SERS research.We detected the 5-Fu and Dox LOD about 5h of transcutaneous in the rat.2.Fluorescence quenching in surface-enhanced Raman spectroscopyOn the basis of CaP/Ag nano composites obtained in the first chapter,fluorescence is caused by sodium citrate in the early stages of the rection,resulting the fluorescence effects on the SERS Raman signal is more serious in our study,so we use some Method to achieving fluorescence quenching while enhancing the Raman signal.We choose halogen salt(CuCl2、KI)as fluorescent quencher,And we can conclude that CuC12 quenching effect is far less than KI even no SERS,the quencher concentration with a 200μL were shown to the highly fluorescence quenching and simultaneous Raman enhancement,and the 0.02mol/L KI can significantly increase efficiency of quencher.3.Research of Raman spectroscopy to Detect ingredient of subcutaneous boneIn this chapter the traditional Raman spectroscopy and spatially offset spatially Raman device were used to measure and compare the foreskin metaphyseal signals on the calf surface of the chicken and the calf transcutaneous,we review a concept that spatially offset Raman for deep subsurface analysis of biological tissues unlocks new prospects for medical diagnosis and monitoring of various biological conditions.This part reviews these concepts and discusses their emerging medical applications including bone disorder detection.The measurement and contrast of subcutaneous bone of chicken toe were carried out through conventional portable Raman spectroscopy configuration and spatially offset Raman spectroscopy configuration individually.The results show that the Raman shift peak strengthened and then weakened with the increasing of the offset △S,and the SORS peak of the bone is the strongest when the offset△S is 2.5 mm.Then,the surface and transcutaneous(5-Fu,Dox,R-6G)signals were measured and compared in order to detect the absorption of the drug without damaging the skin,and obtained the strongest SORS peak of 5-Fu,Dox,R-6G,when the offset △S is 1.0mm,2.0mm,1.Omm.The action mechanism why the spatially offset Raman spectroscopy can effectively detect the subcutaneous bone signals was analyzed.The spatially offset Raman spectroscopy broke through the limitation of detection depth of conventional Raman spectroscopy is small and the ingredient of the subsurface under the skin can not be detected.The measurement and identification of the subcutaneous bone of chicken toe were realized.