Preparation And Research Of Electrostatic Spun Degradable Polyurethane Nanofibrous Membrane

The degradation of natural high polymer drug carrier material is too fast,failing to meet the material requirements for certain drugs.For example,enteric system drugs,we need them not to be degraded and absorbed in the stomach,but natural macromolecule material,stability is poorer,can be degraded in the stomach absorb,so we need to improve the degradation properties of the drug carrier material,so that the drug can get to the intestine smoothly.In general,we mix the natural drug carrier material with the synthetic drug carrier material,the drug-carrying materials were prepared.The poly ester urethane,or PEEUU,is an important member of the polyurethane family,PEEUU has good mechanical strength,machinability and biocompatibility,and after the degradation will not produce harmful products to human cells or tissues,it can be used as an ideal biological material.Therefore,biodegradable polyurethane was mixed with natural materials,and nanofiber scaffolds were prepared by electrostatic spinning,so that the scaffolds could meet the requirements of drug release on material properties.The purpose of this paper is to study a biodegradable nanofiber drug carrier material which can be used in drug sustained-release systems.In this study,PEEUU was first prepared by solution polymerization,in which the soft segment consisted of polyethylene glycol(PEG)and polycaprolactone diol(PCL,Mn=200),The hard part was hexamethylenediisocyanate(HDI),and the chain extender was 1,4-butanediazine.According to PEEUU's infrared analysis,the molecule contains a large number of carbamate groups,and does not contain reactive groups-NCO and-OH,it shows that the synthesis of PEEUU is successful.Synthesis of danshensu hydrotalcite drug(dss-ldh)by stripping and recombination.First,the multilayer hydrotalcite(LDH)was separated into a single-layer LDH by formamide,and then the drug danshesin(DSS)was hybridized with a single-layer LDH,synthesis of DSS-LDH nanocomplexes.After the drugloading analysis of DSS-LDH,it can be known that the drug loading of DSS-LDH is31.5%,indicating that the drug loading performance of LDH is good.The XRD and FTIR test results of DSS-LDH indicate that DSS was successfully inserted into the layers of LDH.The main research contents are as follows:Chapter 2 and chapter 3: in this experiment,PEEUU was physically mixed with gelatin(GE)and silk fibroin(SF)and electrospun,5 kinds of PEEUU /GE mixtures with different mass ratios were prepared(The mass ratio of PEEUU /GE is respectively:0:100?30:70?50:50?70:30,100:0,they're called GE100,GE70,GE50,GE30,GE0),and 5different mass ratios of PEEUU /SF mixtures(PEEUU /SF= 0:100?30:70?50:50?70:30,100:0,they're called SF100,SF70,SF50,SF30,and SF0).SEM images showed that the fiber distribution of PEEUU /SF was more uniform than that of PEEUU /GE.The FTIR of PEEUU indicated that the compound had been successfully synthesized.In terms of mechanical properties,GE30,GE100 and SF30 and SF100 have the best mechanical properties.TG analysis results showed that with the increase of GE and SF content,the initial decomposition temperature of PEEUU /GE composite nanofiber membrane and PEEUU /SF composite nanofiber membrane decreased significantly.The main content of chapter 4: the prepared DSS-LDH was compounded with composite nanofiber membrane with better performance in PEEUU/SF and PEEUU/GE,then the solution was electrospun to obtain the optimized drug-loading nanofiber membrane.SEM,mechanical properties test and drug loading performance analysis were performed on the drug-loading nanofiber membrane.The results showed that dss-ldh could be uniformly dispersed in the drug-loaded composite nanofiber membrane,the mechanical properties of the nanofiber membrane were decreased,the hydrophilic and hydrophobic properties were unchanged,and the slow-release properties of the drug were increased.To sum up,combining the advantages of dss-ldh and nanofiber membrane,dss-ldh package is embedded in nanofiber membrane,which has a broad application prospect in the field of drug sustained release.According to the experimental results,the drug-loaded composite nanofiber membrane can effectively prolong the sustained release period of drugs,it can maintain a certain concentration of the drug in the human body for a long period of time and reduce the number of times the drug is administered to patients with cardiovascular disease,it has a good application prospect for patients,With the continuous development of medical level,people have higher and higher requirements on the performance of drugs,so there will be better drug-carrying composite nanofiber scaffolds,and even other types of sustained-release systems will be discovered.