Electrospun method

The obtained polymer solution was then sprayed by the electrospun method schematically represented in Fig. 8.26. In the electrospinning process, a high electric field is applied to the viscous polymer solution, held in a capillary tube, inducing a charge density on the liquid surface. The distance between the tip of the needle and the substrate was optimized to 20 cm with a voltage of 15 kV. 

Early reports on electrospun scaffolds described poor cellular infiltration [175], Frequently, cells adhered at the surface and thus coated the nano- or submicrometer-scaled electrospun meshes due to the small pore size. In order to overcome this limitation, pore sizes were increased by combining ES with other methods. These approaches included the coating of microfibers with nanofibers [183], Other strategies combine ES with leaching [184, 185], freeze-drying [186], blowing agents [187], or ice templates [188],... 

Another popular method for creating electrospun ceramic/polymer composites is to blend HAp nanoparticles directly into the polymer solution prior to... 

The last method to be discussed, which is used to form polymer/ceramic composites by electrospinning, is extremely different to the methods previously described, but worth mentioning. Zuo et al. [129] used a method to create a composite scaffold that is actually the reverse of what most people are doing. Instead of mineralizing the nanofibers, Zuo et al. actually incorporated electrospun polymer nanofibers into a ceramic bone cement in order to form a composite scaffold. It was found that by incorporating electrospun nanofibers into the cement, the scaffold became less brittle and actually behaved similarly to that of a ductile material because of the fibers. Composite scaffolds with different polymers and fiber diameters were then tested in order to determine which scaffold demonstrated the most ideal mechanical properties. However, no cell studies were conducted and this method would most likely be used for a bone substitute instead of for bone regeneration applications. 

Others have combined electrospun scaffolds with scaffolds created by other techniques to create a 3D bone-1 ike scaffold for bone regeneration. For instance, Martins et al. [62] combined both electrospinning and rapid prototyping in order to create a 3D bone-like structure. This method is very similar to the layer-by-layer... 

Sisson K et al (2009) Evaluation of cross-linking methods for electrospun gelatin on cell growth and viability. Biomacromolecules 10(7) 1675-1680... 

Liu LH, Dzenis YA (2008) Analysis of the effects of the residual charge and gap size on electrospun nanoflber alignment in a gap method. Nanotechnology 19(35) 355307... 

Madhugiri S et al (2003) Electrospun MEH-PPV/SBA-15 composite nanoflbers using a dual syringe method. J Am Chem Soc 125(47) 14531—14538... 

Johnson J et al (2009) Quantitative analysis of complex glioma cell migration on electrospun polycaprolactone using time-lapse microscopy. Tissue Eng Part C Methods 15(4) 531-540... 

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