Preparation And Properties Of Oriented Electrospun Composite Pelvic Floor Patch

Pelvic floor dysfunctional diseases(PFD)are common in middle-aged and elderly women.The main symptoms are pelvic organ prolapse(POP)and urinary incontinence(SUI),which have a great impact on women’s quality of life.The traditional surgical treatment is to remove the bulged tissue,but the pelvic tissue has not been repaired and is easy to recur.The use of pelvic floor patch can help pelvic floor tissue repair to achieve the purpose of treatment.The commonly used pelvic floor patch materials in clinic are polypropylene(PP),polyvinylidene fluoride(PVDF),etc.Although they have high mechanical strength,they have the shortcomings of hard materials,non degradablility,etc.,which are easy to cause complications.Therefore,the development of soft,degradable,biocompatible,and pelvic floor patch with less complications has become a research hotspot.In this study,oriented nanofiber membrane was prepared by electrospinning from regenerated silk fibroin(RSF)and polyvinyl alcohol(PVA)and then compounded with SF warp knitted patch to prepare composite patch,which provides reference for the preparation and optimization of pelvic floor patch.Firstly,RSF and PVA were blended in formic acid for electrospinning to prepare RSF/PVA oriented nanofiber membranes.The spinning parameters were optimized to explore the properties of RSF/PVA oriented nanofiber membranes prepared under the optimized spinning parameters.The results showed that when formic acid was used as solvent,the roller speed of the drum was 2400 rpm,the mass concentration of spinning solution was 0.16g/L,the spinning voltage was23 k V,the liquid outflow rate was 0.6m L/h,and the receiving distance was 17 cm,the RSF/PVA oriented nanofiber membrane had the most regular morphology,the highest degree of orientation,and the average fiber diameter was 0.25 μm.The proportion of 45 °~135 ° fiber is up to 90%,and the proportion of 70 °~110 °fiber is up to 56%.Compared with RSF/PVA non-oriented nanofiber membrane,it has better tensile properties and biocompatibility.Secondly,genipin and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride(EDC)/N-hydroxysuccinimide(NHS)were used to crosslink the RSF/PVA oriented nanofiber membrane respectively.The single factor test was used to optimize the crosslinking process and explore the performance of the RSF/PVA oriented nanofiber crosslinked membrane prepared under the optimized crosslinking process.The results showed that when EDC/NHS crosslinking is adopted,the optimized mass concentration of genipin was 5g/L.At this mass concentration,the morphology of nanofiber membrane was regular,the breaking stress increased to 111.66% of the un-crosslinked membrane,and the breaking elongation increased to 110.37% of the un-crosslinked membrane;When EDC/NHS crosslinking is adopted,the ratio of ethanol and water is 9:1,and the mass concentration of EDC/NHS is 30g/L.Under this crosslinking process,the breaking stress of the membrane is increased to 102.37% of the un-crosslinked membrane,and the breaking elongation is increased to 128.22% of the un-crosslinked membrane.The crosslinking using genipin and EDC/NHS can increase the initial degradation temperature of RSF/PVA oriented nanofiber membranes by 17.81 ℃ and 12.88 ℃,respectively,and the fastest degradation temperature can be increased by 5 ℃.In addition,genipine and EDC / NHS crosslinking can improve the hydrophilic properties of RSF / PVA oriented nanofiber membranes.Finally,RSF/PVA oriented nanofiber membrane direct spinning composite patch(composite patch A),RSF/PVA oriented nanofiber membrane medical adhesive composite patch(composite patch B),RSF/PVA oriented nanofiber membrane suture composite patch(composite patch C),RSF/PVA oriented nanofiber cross-linked membrane suture composite patch(composite patch D),four kinds of composite patches,and explore their performance.The results showed that composite patch A was soft,but its peeling strength was almost zero;The density of composite patch B is the highest,the peel strength is only 0.14 N,and the softness is the lowest;The peel strength of composite patch C and D is high,reaching 2.39 N and 0.21 N respectively,and the softness is high.The longitudinal fracture strengths of composite patches B,C and D are lower than their latitudinal fracture strengths,while the longitudinal fracture elongation is higher than latitudinal fracture elongation,which is determined by the structural characteristics of SF warp knitted patches.After one week of degradation,composite patch B,C and D have different degrees of shrinkage and mass loss.The shrinkage of composite patch B after degradation is the smallest,only17.50%,and the mass loss of composite patch D is the smallest,only 1.16%.The composite patch D prepared with cross-linked film has the best thermal stability.