The Research Of Solid Phase Extraction And Nano-drug Delivery System Based On Molecular Interaction

Non-bonded interaction is one of the intermolecular interactions common in nature.Substances have relationships to each other through the interaction.All kinds of interactions have been used in various analytical science areas.The concept of “3S”(sensitivity,selectivity,speediness)and “3A”(accuracy,automatics,application)of analytical science(including analytical chemistry and pharmaceutical analysis)become more and more important for scientific research.Solid phase extraction(SPE)is a vital part in sample preparation process.It bases on the interaction between extraction materials and analytes.Thus,efficient extraction methods,novel extraction materials and advanced devices of SPE are the main development direction in this field.Firstly,the extraction method is developed in this work.The two kinds of molecular imprinted polymers(MIPs)are considered,which have different binding intensity with templates and the expected different orientations of templates into MIPs cavities.Then,a novel method based on two steps of SPE with the two MIPs(TSPE-TMIPs)is established to extract targeted compounds in complex matrix.Through this method,the unique compounds were extracted,which improved the selectivity of extraction.Further,the adsorption properties of two MIPs were revealed by comparing their molecular recognition ability.The recognition mechanism was analyzed by using the Scatchard equation.The results show that the TMIPs-TSPE method is higher selectivity of MIPs and the molecular recognition mechanism may rely on two important factors: 1)the intensity of binding sites between functional monomers and imprinted molecules;2)the spatial orientation of molecules when entering into the cavity of MIPs.Secondly,one novel extraction materials are firstly explored,which is based on the biologic interactions between living microorganism and molecules.In this work,the living bacteria was used as bio-extraction materials to extract ofloxacin.These living bacteria was adhered to the inner wall of the capillary tube to develop one in-tube SPME device.The device was able to perform all the steps including extraction,washing and elution.The bacteria in the tube showed selective ability for the extraction of ofloxacin.Thirdly,the syringe solid phase micro extraction-liquid chromatography(Syringe SPME-LC)is explored for the goal of simplicity and sensitivity.The Syringe SPME-LC showed good abilities of extraction and analysis to the phthalate in water.This technique realized the whole sample preparation and analysis process of extraction,elution and injection without any requisition of modification of the LC sample injection interface.Back to the nature of SPE,the research focuses on the relationship of interaction between analytes and extraction phase(solid phase)or the extreated phase(liquid phase),which is similar with nano-drug delivery system.The system contains the relationship of interactions between drugs and nanocarriers(solid phase)or the environment in body(including the environment under delivery and release,usually liquid phase).These relationships of nano-drug delivery system are the whole research process.Thus,in the work,curcumin-loaded galatosylated BSA nanoparticles(Gal-BSA-Cur NPs)were successfully synthesized and evaluated.Compared with pure curcumin,the release behavior in vitro of Gal-BSA-Cur NPs showed relatively long release time and better release ability.During the delivery process of nano-drugs,using the Caco-2 cells and the intestine adsorption model of Ussing chamber revealed that Gal-BSA-Cur NPs showed better intestinal absorption with dual intestinal absorption mechanisms including clathrin-mediated endocytosis and passive transport.The pharmacokinetic study in rats indicated that the plasma concentration of Gal-BSA-Cur NPs was higher than that of curcumin,which could improve the oral bioavalability of curcumin.During the release of nano-drug,the research mainly focused on the anti-cancer activity of Gal-BSA-Cur NPs.The nano-drugs could inhibit the proliferation of Hep G2 cells,induce the cell apoptosis and inhibit the cell migration.The effects of Gal-BSA-Cur NPs on Hep G2 were associated with the inactivation of the protein level of NF-κB-p65.In conclusion,the various interactions in SPE and nano-drug delivery system are similar.The drug loading is equivalent to the extraction process of analytes.And the drug release is equal to the elution step from the extraction phase.Although their similarity,nano-drug delivery system is more complex than that of SPE.The reason is due to the more interaction types of biology.The research based on several interactions points out some interesting research ideas.