Study On Preparation And Properties Of Peanut Protein Isolate/Polylactic Acid Electrospun Fiber

Peanut Protein Isolate(PPI)is rich in resources and has high nutritional value.The materials prepared from it have excellent biocompatibility and biodegradability.Different from the traditional spinning process,in the electrospinning technology,in the process of electrospinning,the polymer solution or melt overcomes the surface tension through electrostatic interaction in the high-voltage electrostatic field to generate a charged jet.After stretching,Finally,it is solidified to form fibers in the fiber receiving device.This process is easy to operate and low in cost.It has become an important technology for preparing micron-level or nano-level fibers,and the prepared nanofibers have higher porosity and larger surface area.,Fiber uniformity and good connectivity between pores and many other advantages.In addition,adding biologically active substances to the spinning solution can prepare functional nanofibers.Nanofibers prepared by electrospinning have been widely used in many fields,such as air filtration,tissue engineering scaffolds,cosmetics industry,sustained drug release in the medical field,and food industry.The peanut protein isolate(PPI)used in this paper is made from cold-pressed peanut powder,extracted by alkali-dissolved acid precipitation method,and the high-molecular polymer poly-L lactic acid(PLLA)with good biocompatibility is used as the spinning aid.Spinning technology is used to process peanut protein isolate.Using fiber diameter as an indicator,the optimal process parameters for electrospinning PPI/PLLA nanofibers are optimized by single factor and response surface method.The results show that the diameter of PPI/PLLA nanofibers increases with the increase of the mass fraction of the blended solution.When the mass fraction of the solution is too low,beads will be produced in the PPI/PLLA nanofibers;with the increase of spinning speed and voltage,The average diameter of PPI/PLLA nanofibers decreases first and then increases.The optimal spinning conditions are determined by response surface experiments: the mass fraction of the PPI/PLLA blend solution is 10%,the voltage is 16 KV,and the spinning speed is 0.6 mL/h.Under these conditions,the model predicted value of the average diameter of PPI/PLLA nanofibers is 151 nm,the measured value is 164 nm,and the error is 7.9%.In this chapter,based on the optimal spinning conditions in Chapter 2,keep the PPI/PLLA mass fraction at 10%,prepare PPI/PLLA composite nanofibers by adjusting the mass ratio of PPI and PLLA,and composite PPI/PLLA with different mass ratios The surface morphology and structure,thermal properties,mechanical properties and hydrophobicity of nanofibers were analyzed,and the conclusions are as follows: SEM observation shows that the diameter of PPI/PLLA nanofibers decreases with the increase of PPI content,and when PPI and PPI When the mass ratio of PLLA is 50:50,the morphology of the PPI/PLLA composite nanofibers is good,no beads are found,and the diameter is relatively uniform.Fourier infrared spectroscopy and XRD tests show that PPI and PLLA have good compatibility,and there are interaction forces such as hydrogen bonds between molecules;the addition of PPI destroys the order of PLLA molecular arrangement,thereby reducing PPI /PLLA composite nanofiber crystallinity.TGA and DSC analysis showed that as the content of PPI increased,the thermal stability of PPI/PLLA nanofibers improved.The mechanical properties and contact angle tests show that in the PPI/PLLA blend system,PLLA plays a leading role in the mechanical strength of the fiber membrane.As the mass fraction of PLLA decreases,the mechanical properties of PPI/PLLA nanofibers gradually decrease;As the mass fraction increases,the hydrophobicity of PPI/PLLA nanofibers gradually increases.In this chapter,TCH is used as a model drug to prepare TCH/PPI/PLLA nanofibers with different drug loadings using electrospinning technology,and use scanning electron microscopy,Fourier infrared spectroscopy,X-diffraction,thermal analysis,and contact angle testing.Test methods such as the characterization and performance study of TCH/PPI/PLLA composite nanofibers with different drug loadings.The conclusions are as follows: SEM shows that TCH drug molecules are well dispersed in PPI/PLLA molecules.The dispersion increases,and the fiber diameter gradually decreases;DSC and Fourier transform infrared spectroscopy test results show that there is an interaction between TCH and PPI,PLLA.Thermogravimetric analysis shows that the thermal stability of the blended electrospun drug-loaded nanofiber membrane is higher than that of the PPI/PLLA nanofiber membrane.XRD results show that TCH exists in the fiber almost in an amorphous state,and has a certain composite effect with the carrier.The mechanical properties and contact angle results show that TCH is still a hydrophobic material after being compounded with PPI/PLLA and its tensile strength is higher than that of PPI/PLLA nanofibers.The results of TCH in vitro release test showed that with the increase of TCH mass fraction,the initial TCH release phenomenon of TCH/PPI/PLLA composite nanofibers was more significant,and the release mechanism of TCH was consistent with Fick diffusion.In this chapter,biological evaluations of antibacterial properties,hemolysis,in vitro cytotoxicity,skin wound healing,and other biological evaluations of PPI/PLLA nanofibers without drug and drug-loaded tetracycline hydrochloride have been carried out.The results of antibacterial experiments show that the PPI/PLLA nanofiber membrane loaded with TCH drugs has an inhibitory effect on S.aureus and E.coli,and the antibacterial effect on S.aureus is better than that of E.coli,while PPI/PLLA without drug loading The nanofiber membrane has no antibacterial effect.The hemolysis experiment and CCK-8 experiment results show that the hemolysis rate of electrospun PLLA nanofibers,PPI/PLLA composite nanofibers and drug-loaded PPI/PLLA nanofibers are all below 5%,and the TCH-loaded PPI/PLLA composite nanofibers The hemolysis rate is less than 2%.Among them,TCH drugs play an anticoagulant effect in the PPI/PLLA composite nanofibers,and have low toxicity to cells.The results of animal experiments show that the drug-loaded TCH/PPI/PLLA nanofiber membrane and the non-medicated PPI/PLLA nanofiber membrane wound dressing have better wound healing effects and speed in mice than petrolatum gauze,and the drug-loaded TCH/ The effect of PPI/PLLA nanofiber membrane is better than that of unloaded PPI/PLLA nanofiber membrane.Observation results of tissue sections of mouse skin wounds showed that granulation tissue in the wound tissues of the TCH/PPI/PLLA nanofiber group grew faster,which was consistent with the observation results of mouse skin wound healing.