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2022, Vol. 26 ›› Issue (16): 2557-2561Evaluation on the preparation and performance of lysine modified polylactic acid nanofiber stentLi Yu, Pan Yuancheng, Lin Ran, Chen Shunyou
Abstract: BACKGROUND: Polylactic acid as a biodegradable polymer has been made into nanofiber stent, widely used in tissue regeneration. However, as a scaffold material, polylactic acid has some limitations, such as slow degradation rate and poor biocompatibility. OBJECTIVE: To prepare lysine-polylactic acid stents to study the structure and properties of stents by controlling different lysine concentrations. METHODS: With 1, 4-dioxane as solvent system and lysine as an ammonia solution, thermally induced phase separation technology was used to prepare the lysine-polylactic acid stents. Lysine concentrations were 5%, 10%, 15%, 30%, respectively. The detection of Fourier transform infrared spectrometer, scanning electron microscope, differential scanner thermal analyzer, contact angle and mechanical performance analysis were carried out with the unaltered polylactic acid bracket as the control. RESULTS AND CONCLUSION: (1) Fourier transform infrared spectral analysis showed that the polylactic acid stent was successfully modified by lysine ammonia. (2) The scanning electron microscope showed that when the non-solvent phase was deuterium depleted water, the fiber mesh structure of the bracket was poor and no three-dimensional structure was formed. When the concentration of lysine was 5%, the stent was flaky, ribbon or a large number of reunion phenomenon, and no good three-dimensional fiber network structure was formed. With the increase of lysine concentration, the nanofiber structure of the stent gradually formed. When the concentration of lysine was 10%, the prepared stent still had flaky and reunion phenomenon. When the concentration of lysine was 15%, the stent had a relatively uniform distribution of nanofiber structure. However, when the concentration of lysine was 30%, the structure of stent fiber collapsed and large areas reunited. (3) With the increase of lysine concentration, the water contact angle of the stent was reduced and the strength of pressure was reduced. (4) With the increase of lysine concentration, the melting temperature of the stent decreased slightly, but there was no obvious change, and the crystallization increased. (5) The results show that the introduction of lysine improves the mesh fiber structure, hydrophobicity and crystallization of polylactic acid stent and reduces the mechanical properties of the bracket. Key words: polylactic acid, nanofiber, stent, lysine, thermal induced phase separation technology, tissue engineering |