The Preparation Of Aggregation-induced Emission/polymer Composite Fibers And Its Application As The Tissue Engineering Scaffold

As one of the core elements of tissue engineering,tissue engineering scaffold provides not only attachment points for cells,but also a good and reliable environment for cell growth,proliferation and other life activities as well as the substances exchange of cells with the environment.It is especially important for the tissue engineering to investigate the affinity of scaffolds to cells and observe the growth of cells on scaffolds.Most of the previous methods used fluorescent materials to dye cells or dye cells and scaffolds at the same time.However,the common fluorescent materials always have the possibility of aggregated-caused quenching,which not only brings inconvenience to the observation process,but may even encounter the lack of experimental data because of the fluorescence quenching.To this end,we use a special fluorescent substance named aggregation-induced emission(AIE)molecules as the dye,using electrospinning technology to prepare fiber scaffolds containing AIE molecules,explore it as a scaffold for tissue engineering,and investigate the release of AIE molecules in the fiber carrier meanwhile.Polylactic Acid(PLA)and Polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene(SEBS)three block copolymer were used as polymer materials to prepare fiber scaffol-ds,and 2,3-dicyano-5,6-di-(4-diphenylamino-biphenyl-4-yl)-pyrazine(2CNP2TPA),1,1,2,3,4,5-hexaphenylsilole(HPS),1,3-(4-bromoethyl quaternary ammonium salt)diphenyl-2,4-diphenylethene,(TPE-2N~+),the three types of AIE molecules with one aggregation-cau sed quenching(ACQ)molecule which named Rhodamine 6G(R6G)were selected as t he dye.The Specific contents are as follows:(1)Using electrospray/electrospinning to prepare pure PLA and SEBS different products at different concentration.Add four different fluorescent materials to the origin PLA and SEBS gradient concentration solutions,research the morphology and properties of composite fibers.The experiment showed that the morphology and structure of the fiber and several properties can be greatly affected by the addition of different fluorescent substances.(2)Preparing the AIE/polymer composite fiber with core shell structure and construct the random,uniaxial orientation as well as cross orientation composite fiber scaffold by electrospinning.Through the observation of SEM and FM respectively,confirmed the structure of core-shell fiber and composite fiber with different topological.The co-culture of the cells showed that the composite fibers had good biocompatibility.Experiments show that different topology structure of fibers can be obtained by adjusting the parameters of electrospinning.AIE molecules used as the dye in biological imaging field has huge potential,and it also can be used as an effective tool for the characterization of the structure of the fiber.(3)Regarding the AIE molecules as model drug,investigating the efficiency release ratio of the fat-soluble AIE molecule 2CNP2TPA and the water-soluble AIE molecule TPE-2N~+in PLA fibers and SEBS fibers,observing whether it can be absorbed by cells at the same time.The results showed that AIE molecules can be effectively released in polymer fiber matrix and be absorded by cells,observing fiber structure and cells via AIE moleculars at the same time.