Polycaprolactone (PCL) electrospun scaffolds have been widely investigated for cartilage repair application. However, their hydrophobicity and small pore size has been known to prevent cell attachment, proliferation and migration. Here, PCL was blended with gelatin (GEL) combining the favorable biological properties of GEL with the good mechanical performance of the former. Also, polyethylene glycol (PEG) particles were introduced during the electrospinning of the polymers blend by simultaneous electrospraying. These particles were subsequently removed resulting in fibrous scaffolds with enlarged pore size. PCL, GEL and PEG scaffolds formulations were developed and extensively structural and biologically characterized. GEL incorporation on the PCL scaffolds led to a considerably improved cell attachment and proliferation. A substantial pore size and interconnectivity increase was obtained, allowing cell infiltration through the porogenic scaffolds. All together these results suggest that this combined approach may provide a potentially clinically viable strategy for cartilage regeneration.

There is a growing need to develop strategies capable of engineering the anisotropic cartilagino us fibrous network in vitro and consequently overcome the anatomical and functional restrictions of the standard medical procedures used for cartilage regeneration. In this work, we suggest a fabrication procedure that uses two complementary electrospinning set ups to build 3D multilayered fibrous scaffolds with adjustable fibre orientation features, matching the topographic cues of the three cartilaginous zones. Polycaprolactone (PCL) was used as bulk material for the differe nt electrospun layers (horizontally, randomly and vertically aligned) that were assembled and then structurally maintained by a biocompatible graphene-oxide-collagen (GO-collagen) microporous network. To validate the resourcefulness of the technique, four PCL-GO-collagen scaffolds with different anisotropic properties were produced and characterized by analysing their depth dependent morphological and mechanical anisotropy. The results confirmed that each electrospun layer presents a similar topography relatively to its natural counterpart and that changing the fibre orientation modifies the compressive behaviour of the scaffold, which is specially influenced by the presence of the vertically aligned fibres. Overall, the presented fabricating technique offers the opportunity to easily tune the anisotropy of 3D electrospun scaffolds towards the enhancement of both static and dynamic cell culture protocols concerning cartilage tissue engineering (TE).

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