Fabrication Of Aligned Electrospun Fibers And Its Biomineralization Study

Bone is a hierarchically structured organic-inorganic composite consisted of uniaxiallyoriented nanocrystals of hydroxyapatite(HAP) embedded within and aligned parallely to thecollagen fibril axes. Type I collagen in bone provides organization framework and spatialconstraint for crystal deposition，while noncollagenous proteins(NCPs) might be involved in thecontrol of nucleation and growth of the nineral phase during the bone formation and regeneration.To date, there is no clear understanding of the mechanism of this process. To uncover thismechanism, electrospinning were applied to fabricate aligned fibrous scaffolds collected bycontinuous parallel plates for the biomineralization in the double diffusion system in the presentstudy. The effect of different electrospinning parameters on fiber properties was explored bySEM, FTIR, EDS and Universal Testing Machine. After the successful fabrication of alignedPCL/Gelatin fibrous mats with electrospinning, the mats were placed in a double diffusionsystem designed in our lab. And the synergic effect of β-GP and fiber mats on biomineralizationwas investigated. The composition and morphology of the obtained minerals were characterizedby XRD, FTIR, EDS, SEM, TEM and HRTEM. The aim of this work is to reveal the possiblemechanism of the formation of HAP in bone, and provide theoretical basis of the design andfabrication of scaffolds for bone tissue engineering. The results were listed as follows:1. The diameter of PCL fibres decreases as the increase of the distance between two platesand the voltage; and fibre diameter increases with the increase of feed rate; the fibre collectiondistance has no significant influence on fibre diameter.2. The diameters of aligned fibre are smaller than that of random fibre. The tensile strengthof aligned fibre is27.63±0.75MPa which is232%stronger than that of random fibre. The elasticmodulus of aligned fibre is almost the same as random fibre, but the elongation at brakedecreased obviously.3. The minerals formed in the double diffusion system on the fibrous mat are combinationof HAP and DCPD. The incorporation of β-GP onto the fibres can effectively promote theformation of HAP crystals.4. There are no significant differences among minerals formed on the aligned and random fibrous mats. Both are compounds of DCPD and HAP. However, the flower-like minerals formedon the aligned fibrous mats are clustered along the alignment of fibres.The present work innovatively designed electrospining device and double diffusion systemand verified that the minerals grow along the alignment of fibers.