Fabrication Of Electrospun PLA/CNF Composite Nanofiber Scaffold And Its Mineralization

Applied as matrix of seeding cells and repairing the tissues,the tissue engineering scaffold has now become one of the major braches in tissue engineering field.An ideal porous scaffold should have the following characteristics:high porosity,suitable mechanical strength,an interconnected porous structure and biocompatible.Thus,how to fabricate the ideal three dimensional porous scaffolds is a front subject in the field of tissue engineering.This study mainly pays attention on the relationships among the preparation techniques,morphologies,and properties.The influences of processing technology on the morphology,thermal properties,water wettability,mechanical property and biocompatibility were studied.Additionally,the surface of scaffold was modified by using surface coating and biomineralization method to improve its biocompatibility.The main works are as follow:1.Poly(lactic acid)(PLA)/cellulose nanofibrils(CNF)composite nanafiber scaffold was prepared using electrospinning.The influence of CNF content on the microstructure,thermal properties,hydrophilicity,and mechanical properties of PLA/CNF scaffold were investigated.The results showed that the PLA/CNF composite nanafiber with fine fibirous morphology was prepared in this study.Additionally,PLA/CNF composite nanafiber scaffold showed significantly improved on the thermostability,crystallinity,hydrophilicity,and mechanical properties compared to the PLA scaffold.Hence,PLA/CNF composite nanafiber scaffold was expected to exhibit a better biocompatibility than that of PLA scaffold.2.Poly(lactic acid)(PLA)/cellulose nanofibrils(CNF)composite nanafiber scaffold was prepared using electrospinning,and then the surface of PLA/CNF scaffold was modified by PDA coating method.The influence of CNF content and coating time on the thermal properties,hydrophilicity and mechanical properties of PLA/CNF scaffold.The results showed that PDA particles were successfully deposited the surface of PLA/CNF scaffold,and the hydrogen bonding was formed between PDA and CNF particles.The PDA particles on the surface of scaffold increase with the increase of CNF content and coating time.The PLA/CNF-PDA scaffold exhibited better hydrophilicity and mechanical properties than that of uncoated PLA scaffold.Additionally,the deposition rate of PDA particles on the surface of scaffold was significantly improved due to the introduction of CNF particles.3.The biocompatibility of PLA/CNF and PLA/CNF-PDA composite nanofiber scaffold was studied by cell cuture in vitro and biomineralization methods.the results of cell culture test showed that PDA coating could stimulate the attachment,proliferation and growth of cells on PLA/CNF-PDA scaffold,indicating its excellent biocompatibility.The results of biomineralization showed that the deposition rate and amount of hydroxyapatite on the PLA/CNF-PDA composite nanofiber scaffold is larger than that of on the PLA/CN scaffold,which indicated that the ability of biomineralization for composite nanofiber was increased due to the introduction of PDA coating,and the biocompatibility of scaffold further improved.