Electrospun cell infiltration

Baker BM et al (2008) The potential to improve cell infiltration in composite fiber-aligned electrospun scaffolds by the selective removal of sacrificial fibers. Biomaterials 29(15) 2348-2358... 

Guimaraes A et al (2010) Solving cell infiltration limitations of electrospun nanofiber meshes for tissue engineering applications. Nanomedicine 5(4) 539-554... 

FIGURE 11.10 Permeation of hMSCs on (a) nonfunctionalized PCL and (b) PCL electrospun fibers functionalized by a 2% solution of PNEAmHi. Cells were allowed to culture for 4 weeks to obsawe cell infiltration. Functionalization promoted cell infiltration from the scaffold surface. Scaffold seeded at 30,000 cells per 1 x 1 cm scaffold. Scale bars=1000pm. 

Unique fiber collector designs have been attempted to loosen the electrospun scaffold to improve cell infiltration. The principle of the collector design is to reduce the fiber intersections. For example, a half-ball collector containing pillars was designed to achieve cotton ball-like fibrous scaffolds by changing the fiber deposition space (Figure 19.5(a)) [22]. An ethanol bath was used as a collector to obtain low-density electrospun polycaprolactone scaffolds (Figure 19.5(b)) [23]. The ethanol quickly stabilizes the polymer fiber surface to reduce the intersections between fibers. 

Blakeney BA, TambraUi A, Anderson JM, Andukuri A, Lim DJ, Dean DR, et al. Cell infiltration and growth in a low density, uncompressed three-dimensional electrospun nanofibrous scaffold. Biomaterials 2011 32 1583-90. 

The pore size of an electrospun scaffold will essentially dictate whether it is viewed as a 2-dimensional mat or a 3-dimensional scaffold by cells. Depending on the application either might be desirable. Additionally, the ability to engineer scaffolds with a desired pore size distribution may allow for the use of nanofibrous scaffolds without limiting cell infiltration, combining the advantages of both micro-and nanofibrous scaffolds. 

Baker, B. M., et al.. The Potential to Improve Cell Infiltration in Composite Fiber-Aligned Electrospun Scaffolds by the Selective Removal of Sacrificial Fibers. National Center for Biotechnology Information, 2008,29(15), 2348-2358. 

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],... 

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