Study Of The Application Of Amino Acids In The Modification Of Polylactic Nanofiber Scaffold

In this paper,thermal induced phase separation technology(TIPS)and ammonolysis method were used to prepare modified polylactic acid(PLLA)nanofiber scaffolds with higher hydrophilicity.Using 1,4-dioxane acts as solvent,serine(Ser)solution,glycine(Gly)solution,and lysine(Lys)solution act as ammonolytic agents to prepare modified PLLA nanofibers.From the fourier transform infrared spectrometer(FTIR),the modified PLLA scaffold showed an N-H bending vibration peak at 1620 cm-1,indicating that the modified PLLA scaffold prepared from Ser,Gly,and Lys had been triumphantly prepared.From GPC molecular mass and molecular weight distribution of Ser,Gly,Lys,it was found that the molecular mass was reduced and the molecular mass distribution region moved to a smaller region.The better conditions for preparation of nanofiber scaffolds were obtained from Scanning Electron Microscopy(SEM)images:PLLA concentration was 9%,Gelation temperature was-25?,Ser concentration was 20%,Solvent and non-solvent ratio=90/10,Ammonolysis reaction time was 30 min.The optimal conditions of Gly preparing nanofiber scaffold:PLLA concentration was 9%,gelation temperature was-25 ?,Gly concentration was 15%,solvent and non-solvent ratio=95/5,aminolysis reaction time was 30 min.The optimal conditions of preparing PLLA nanofiber scaffold by Lys:PLLA concentration was 9%,gelation temperature was-25?,Lys concentration was 15%,solvent and non-solvent ratio=90/10,aminolysis reaction time was 30 min.The water contact angle of modified PLLA nanofiber scaffold prepared by Ser,Gly,Lys were improved compared to the unmodified PLLA scaffold.The mechanical properties of the modified PLLA nanofiber scaffold prepared from Ser,Gly,Lys were reduced compared to the PLLA scaffold prepared from water.