Property Regulation Of Pectin Nanofiber Mats For Wound Dressing Applications

Pectin is a kind of natural anion polysaccharide with good biocompatibility,biodegradation and high hydrophilicity.The structure of nanofiber mats prepared by electrospinning is similar to that of natural extracellular matrix with high specific surface area and large porosity.In recent years,our group has developed"periodate oxidation-electrostatic spinning-adipate hydrazide(ADH)crosslinking"methods,succeessfully prepared of pectin nanofiber mats materials which can keep stability of water environment,and this material can combine the material characteristics of pectin with the structure characteristics of nanofiber,can quickly absorb a large number of wound exudates,keep moist wound,and promote cell growth,is expected to be used as a kind of high-performance wound dressings.In practical application,different wound conditions,and the required dressing properties are also different.The purpose of this paper is to study the effects of preparation conditions on the properties of pectin nanofiber mats,so as to obtain a means to regulate the properties of wound dressing,to meet the needs of different wound treatment.The detailed work content and results of this paper are as follows:First,we study the effect of polymer concentration in the process of electrospinning on the related properties of pectin nanofiber mats prepared by the method of"periodate oxidation-electrospinning-ADH crosslinking"for wound dressing application.The results found that with the polymer concentration increases from 5%to 10%,the average diameter of electrospinning pectin nanofibers gradually rising from 103 nm to 225 nm,the average diameter after crosslinking gradually rising from 225 nm to 353 nm,the absorption ability of interfibrillary pores gradually decrease from 18.1 times to 10.2 times,immersion in simulated body fluids in 14 days remaining quality gradually increases from 65.6%to 80.0%.The polymer concentration had no significant effect on the crosslinking density(ADH residue content 20.0%),the absorbability(3.6 times),the mechanical strength(2.2 MPa)and the air permeability[0.25 g/(cm~2·24h)]of the fibers.Second,we study the effects of crosslinking conditions on the application properties of pectin nanofiber mats prepared by"periodate oxidation-electrospinding-ADH crosslinking"method were studied.Results show that with the increase of ADH amount from oxidation of pectin aldehyde group 1 and gradually increased to 40 times,average diameter of fiber increased gradually from 323 nm to 353 nm,crosslinking density increase gradually(ADH residue content increased from 11.8%to 21.0%),fiber liquid absorption ability gradually decrease from 28.0 times to 13.6 times,the tensile strength of the fiber mats gradually rising from 1.5 MPa to 2.2 MPa,the elongation decreased from 70.0%to 42.4%,the remaining 14days in simulated body fluid to cultivate quality gradually increases from 0 to 80.8%.As the crosslinking time extended from 8 hours to 48 hours and crosslinking temperature increased from 25 ~oC to 37 ~oC,the average fiber diameter increased respectively from 225 nm to 352nm and 385 nm,crosslinking density increase(ADH residue content from 15.6%up to 17.1%and 18.4%respectively),fiber liquid absorption capacity from 22.5 times dropped to 18.9times and 14.7 times respectively,the tensile strength of the fiber mats from 1.8 MPa up to 1.9MPa and 2.1 MPa,respectively,elongation decreased respectively from 48.8%to 47.5%and42.8%.The residual mass increased from 7.8%to 50.0%and 55.2%,respectively,after 14days of simulated body fluid culture.The crosslinking conditions had no significant effect on the air permeability of the pectin nanofiber mats,which were about 0.25 g/(cm~2·24h).In general,this paper found that regulation in the process of spinning polymer concentration can regulate the"periodate oxidation-electrostatic spinning-ADH crosslinking"preparation of pectin nanofibers size,but not change its crosslinking density,and regulating the crosslinking process of crosslinking agent amount,crosslinking time and crosslinking temperature affect the crosslinking density and the fibre size,fiber size and crosslink density change may further affect pectin nanofiber mats absorption liquid and wound dressing properties of strength,stability etc.,but does not affect its permeability.The results of this work provide guidance for the properties regulation of pectin nanofiber mats and lay the foundation for their application as wound dressings.