Preparation And Properties Of Drug Sustained-release Functional Materials Based On Apocynum Venetum Nanocellulose

Drug slow-release materials are an important part of the slow-release system,which can regulate the drug release rate and improve the drug efficacy.However,large energy consumption may be generated in the preparation process.Therefore,it has become a research hotspot to find slow-release materials that can be loaded with drugs,have good biocompatibility and have low energy consumption.Xinjiang special plant--Apocynum venetum has natural antibacterial properties,can be prepared into nanocellulose(CNF)with high aspect ratio and high specific surface area;Sea-buckthorn extract is natural and non-toxic,which can reduce the drug resistance caused by the abuse of antibiotics.The new antibacterial biomaterials with high biocompatibility and excellent sustained-release effect can be prepared through the load of emulsion electrospinning,which provides a new idea for the development of new nanocellulose drug-loaded sustained-release materials.In this paper,apocynum as a raw material was used to prepare and compare nanocellulose prepared by TEMPO oxidation method and acid hydrolysis method.The optimized process was selected,and then the screened CNF was combined with PLA to obtain a nanofiber membrane with antibacterial function.In order to enhance the functionality and application scope of the nanofiber membrane,CNF and sea buckthorn extracts were added to the PVP aqueous phase,and then coated by emulsion electrospinning to successfully prepare a drug-loaded sustained-release nanofiber membrane with a shell-core structure.The specific research content is as follows:(1)The apocynum phloem and straw CNF were prepared by TEMPO oxidation method and acid hydrolysis method,respectively,and its preparation process was explored.The diameter distribution of nanocellulose prepared by two different methods is mainly concentrated between 30-90nm.However,the diameter distribution was slightly different:compared with TEMPO nanocellulose,the acidolysis nanocellulose filament was thinner and the diameter distribution was more uniform.After by FTIR,XRD analysis,the two methods to non-cellulosic substances such as hemicellulose,retained completeⅠcrystal type of cellulose.(2)The PLA/CNF nanofiber membrane prepared by electrospinning of apocynum phloem and straw nanocellulose was compared.Adding CNF to the membrane changed the permeability of the membrane,and the contact angle was reduced by 30°,the permeability is as high as 4658 g/(m~2·d).In addition,the nanofiber membrane has good antibacterial activity against both E.coli and S.aureus,and the maximum antibacterial activity increased by 71.58%.Apocynum straw has the same excellent performance as the phloem,and can be regarded as a promising raw material for the preparation of CNF.It can fully utilize the apocynum resources and expand its application.(3)Prcyanidin extract(SBTP)was successfully extracted from seabuckthorn,and a double-layer nanostructured drug delivery system with PVP water phase as the core and PLA as the shell loaded with SBTP and s CNF was constructed.The nanofiber membrane was composed of smooth and uniform fibers with core-shell structure,and the encapsulation efficiency was over 83.84%,showed strong antioxidant capacity,which the clearance rate of DPPH was as high as 88.62%.The continuous and lasting release of SBTP was achieved by adding s CNF into SBTP,with the maximum cumulative release reaching 75.41%.This system proved that the emulsion electrospun nanofiber membrane with SBTP and s CNF has the drug sustained release function.In summary,this article successfully prepared apocynum nanocellulose and PLA/CNF nanofiber membranes with different systems and studied their properties.At the same time,the application of apocynum nanocellulose membrane as a drug-loaded sustained-release medical application of explorations and analyses have been done.The successful preparation of apocynum phloem and straw CNF exists more selectivity for the raw materials for preparing nanocellulose.At the same time,the process parameters and conclusions of this topic provide corresponding support for the research and application data of nanocellulose,preliminary exploration of the application of slow-release nanofiber membrane loaded with seabuckthorn extract,and a certain expansion of the application range of Apocynum venetum.