Study On The Micro Scopic Behavior Of Natural Polysaccharide-based Preservative Materials For Drug Release

Natural polysaccharide-based materials are safe and non-toxic and renewable.By its excellent antibacterial properties and biodegradable,it has been widely research attention in the field of food preservation.In the process of its application,since the drug release is a continual process,and the microstructure of polymer materials in the process of slow release process complex and changeable.Simple and harmless ways are needed to detect the natural polysaccharide-based preservation of materials into the sustained release of the situation.In this paper,chitosan,chitin,starch and other polysaccharide natural polymer materials as a substrate,prepared sustained-release materials were used.Like ethephon/chitosan composite film,dimethyl fumarate(DMF)/crosslinked chitosan microspheres and nano-chitin-coated ascorbic acid(AA)/starch granules.We studied separately about the micro-mechanical behavior of the core material changes driven drug slow release material,the single-component carrier-driven drug release material,and the drug-sustained-release materials driven by multi-component compound carrier.The structural properties of the prepared materials and micrographic changes are characterized Using atomic force microscopy(AFM),positron annihilation lifetime(PAT),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR)The microscopic interfacial behavior of the material at different time periods during the slow release process were analyzed,explored the slow release mechanism of the material.The relationship between the microscopic performance of the material and the drug release were explained.Through the study of the mechanical properties of the materials before and after the release,a lossless judgment material slow release of the test way was found.The main conclusions are as follows:1.The ethephon/chitosan composite film is a slow release material driven by core material.At room temperature,FT-IR test showed that the composite film slowly released ethylene gas,and the chemical composition of chitosan did not change before and after sustained release.Form the AFM phase imaging;the slow release process of ethylene gas was observed,which was decomposed by the ethephon.The gas firstly aggregates in the composite film and produces small gas-holes structure in the film.Through the PAT life spectrum,the free volumes of the gas holes in the sustained-release process were increased and the peak was reached at 96-120 h.In the process of slow release,the composite film structure became more compact.The film's Young's modulus from 10.2 MPa to 7.4 GPa,and went into a rapid jump stage at 96 h.2.DMF/chitosan cross-linked microspheres are a kind of single component carrier driven drug release material.The FT-IR test showed that the crosslinked microspheres could release the DMF component slowly at room temperature,and the chemical composition of chitosan did not change before and after sustained release;By AFM and SEM imaging,microscopic changes were observed on the surface roughened chitosan microspheres in the buffer process.Including slowly released process with capillary effect on the surface condensation of water,the material swell,promote the release of DMF to the surface of microspheres;Through the PAT life spectrum,we found that the free volume of the microspheres in the microsphere was increased and reached the peak at 72 h.During the slow release process,the chitosan swelled on the surface.The microsphere's adhesion from 2.2 nN jump to 37.3 nN,and went into a smooth stage after 96h.3.Chitin nano-gel coated AA/starch composite microparticles are a multi-component composite carrier-driven drug release material.At room temperature,FT-IR test showed that the composite particles could release AA components slowly,and the chemical composition of the particles did not change before and after sustained release.The microstructure of chitin nanogels was observed by AFM and SEM imaging.The chitin nano-gel will absorb water agglomeration,then slowly stripping from the starch in the slow release process.This process exposed the internal core material,promoted AA direct contact with the environment;Through the PAT life,the free volume of composite particles were found in the process of sustained release was increased and reached the peak at 48h.During the slow release process,due to the water absorption and peeling of the nano-gel,the roughness of the surface of the microparticles decreased from 54.4 nm to 8.6 nm.At 24 h and 72 h,respectively,it went into the rapid decline in the stage.In this paper,the three different kinds driving mechanism slow release materials were studied.The mechanism of slow release of the material was investgeted,correspondence between microstructure and mechanical properties of materials and slow release behavior of materials.The research methods and results provide a useful reference for the study of the microscopic behavior of natural polysaccharide slow release materials.