Electrospinning of highly porous scaffolds for cartilage regeneration.

This study presents a new innovative method where electrospinning is used to coat single microfibers with nanofibers. The nanofiber-coated microfibers can be formed into scaffolds with the combined benefits of tailored porosity for cellular infiltration and nanostructured surface morphology for cell growth. The nanofiber coating is obtained by using a grounded collector rotating around the microfiber, to establish an electrical field yet allow collection of nanofibers on the microfiber. A Teflon tube surrounding the fibers and collector is used to force the nanofibers to the microfiber. Polycaprolactone nanofibers were electrospun onto polylactic acid microfibers and scaffolds of 95 and 97% porosities were made. Human chondrocytes were seeded on these scaffolds and on reference scaffolds of purely nanofibers and microfibers. Thereafter, cellular infiltration was investigated. The results indicated that scaffold porosity had great effects on cellular infiltration, with higher porosity resulting in increased infiltration, thereby confirming the advantage of the presented method.