Preparation And Property Characterization Of Magnetic Biomaterial And Scaffolds

Inducing cell alignment can promote the regeneration of tissue or organs.Externally magnetic field can align a variety of cells effectively, but itsapplication was limited due to its shortcomings. Magnetic biomaterial with aninternal magnetic field prepared by mixing magnetic material with goodbiocompatible and biomaterial, can be used for inducing cell alignment in vitroor vivo.Firstly, novel strontium ferrite (SrFe₁₂O₁₉) particle reinforced PCL （PS）composites were obtained, and the effects of SrFe₁₂O₁₉particle content on themechanical properties, micro-structure and wettability of PS composites werestudied. Then PS composites were magnetized for preparing magnetic PScomposites （MPS composites）, and the effects of SrFe₁₂O₁₉particle content onthe magnetic properties of MPS composites were analyzed. The results showthat not only the tensile modulus, flexural modulus and flexural strength, butalso wettability of PCL were obviously improved by the addition of SrFe₁₂O₁₉particle. The saturated magnetized MPS composites can be prepared by ourmagnetization process, and the remanent magnetism of MPS composites increased linearly with increasing SrFe₁₂O₁₉particle content.Secondly, PCL and PS composites porous scaffolds were fabricated byFused Deposition Modeling （FDM）, which have controllable structure andperformance. The pore size and porosity of porous scaffolds can be controlledfrom150to1100μm and30%to80%, respectively. Porous scaffolds have goodpore interconnectivity, and the structure and properties of them are anisotropic.Not only mechanical properties, but also wettability of PCL porous scaffoldswere improved by the addition of SrFe₁₂O₁₉particle.Furthermore, Too formulaand Gibson-Ashby formula can be used for describing and predicting therelationship between FDM processing parameters and scaffold structure, andbetween structure and mechanical properties of scaffolds, respectively. Thus, thecontrollability and predictability of the structure and properties of porousscaffolds were achieved.Finally, the cytotoxicity of PS composites and MPS composites and thefeasibility of using MPS composites for inducing cell alignment wereinvestigated. The results show that PS composites and MPS composites have noacute toxicity. And most of Schwann cells seeded on the MPS50compositesalign parallel to the direction of magnetic field, indicating MPS50compositescan align Schwann cells efficiently. These research results above providetheoretical and experimental evidences for further applications of magnetic biomaterial and inner magnetic field in biomedical field.