Preparation Of Electrospun Composite Nanomaterials And Its Application In Drug Delivery

Electrospun nanofibers are increasingly used as drug carrier materials due to their controllable fiber size,large specific surface area,high porosity and three-dimensional network structure.The controlled release of drugs can be achieved by changing the morphology,porosity and composition of the fiber scaffold,and the electrostatic spinning fiber drug loading system can realize the localized drug release of human body.Due to the flexibility of electrostatic spinning nanofibers in the application of drug delivery system,it has attracted wide attention.This paper aims to study an electrospun nanofiber scaffold that can be used in pharmaceutical science.In view of the sudden release phenomenon of common drug formulations such as nanoparticles,micelles,liposomes and some electrospun drug-loaded nanofibers,multi-level sustained release structures such as inorganic/organic blended fibers and electrospun nanofibers embedded with nanospheres were prepared to achieve the goal of sustained drug release.The main contents of this paper are as follows:The first part: The polymer polylactic acid-glycolic acid(PLGA)and polyurethane(PU)with good biocompatibility are used as electrospun fiber matrix,illite as drug carrier and danshensu(DSS)as drug model.The PLGA/PU/drug-loaded illite composite nanofibers were prepared by electrospinning using illite loaded DSS and then mixed with spinning solution.The drug-loaded illite was characterized by XRD and FTIR.It was found that the drug was successfully loaded on the surface of illite.The morphology,diameter,hydrophilicity/hydrophobicity,mechanical properties,biocompatibility and drug release properties of drug-loaded composite nanofibers were analyzed by SEM,contact angle,mechanical properties test,cell activity test and drug release test in vitro.The results showed that the drug-loaded illite was successfully loaded into PLGA/PU fibers,and the addition of drug-loaded illite had no obvious influence on the morphology and contact angle of the nanofibers.The average diameter of the composite fibers was 1091±265 nm,which was smaller than that of pure PLGA/PU nanofibers.This may be due to the increase in the conductivity of the spinning solution caused by the addition of drug-loaded illite.In addition,the addition of illite enhanced the mechanical properties of the composite fibers.Cell activity tests showed that the addition of drug-loaded illite did not significantly inhibit the growth of HUVECs compared with pure PLGA/PU fibers;the in vitro drug release test results of the composite drug-loading fiber membrane show that DSS@CS-Ilt/PLGA/PU composite nanofibers have sustained drug release effect.In the second part,hydrotalcite(LDH)was used as the drug carrier,and LDH was stripped into positively charged nanosheets by formamide,and then recombined with DSS to prepare drug-LDH nanohybrids.PLGA was used as the carrier,and PLGA/LDH drug-loaded composite microspheres were prepared by emulsion-solvent evaporation method.XRD and FTIR results of drug-loaded LDH showed that the drug DSS was successfully inserted into the LDH layer,and the drug loading of LDH was 32.6%.The encapsulation efficiency,surface morphology and particle size distribution of the microspheres were characterized.The PLGA/DSS-LDH composite microspheres showed higher encapsulation efficiency compared with the pure PLGA microspheres,and the surface of the composite microspheres was rougher with obvious holes.In hemolysis experiment,the hemolysis rate of DSS-LDH and microspheres were both lower than 5%,showing good biocompatibility.In the third part,the PLGA/DSS-LDH composite nanospheres were combined with electrospun fiber membrane based on previous research.The prepared drug-loaded composite nanospheres were added into polyvinyl alcohol(PVA)aqueous solution to prepare PVA nanofibers embedded with the drug-loaded nanospheres by electrospinning.The morphology,diameter,hydrophilicity/hydrophobicity,mechanical properties and drug release properties of PVA composite drug-loaded nanofibers were analyzed by SEM,contact angle,mechanical properties and in vitro drug release tests.The results show that the nanospheres can be uniformly dispersed in the composite nanofibers and have no obvious influence on the hydrophilicity of PVA fibers.With the addition of nanospheres,the Young’s modulus of the PVA composite fiber membrane is obviously reduced.In addition,in vitro drug release tests show that the PVA nanofibers embedded with drug-loaded nanospheres effectively weaken the phenomenon of drug release and can well delay drug release.The combination of composite nanospheres and PVA nanofibers is a promising local drug delivery system.