Preparation of poly(Ԑ-Caprolactone)/gelatin nanofibers by dual-electrospinning for tissue engineering applications

Electrospinning of hybrid polymers is one of the effective methods for providing desirable nanofibrous biocomposite by taking biological properties of natural polymers and mechanical properties of synthetic polymers, for particular applications in tissue engineering. Blending of poly(ԑ-caprolactone) (PCL) and gelatin is one of the widely used biocomposites, applied in tissue engineering, due to its desired cell adhesion and mechanical properties. Nowadays, electrospinning of PCL and gelatin is carried out, using hexafluoro-2-propanol (HFP) or 2,2,2-trifluoroethanol (TFE), as co-solvent. However, these cytotoxic residues of solvents may remain in the nanofibers, which might affect the cell viability. To overcome the mentioned problem, in this study, we dissolved PCL and gelatin in chloroform/DMF and acetic acid/water solution, respectively, and fabricated the electrospun PCL/Gelatin biocomposite fibrous scaffolds by dual-electrospinning technique. Three samples with different ratio of flow rate for PCL and gelatin solution were prepared, 5:1, 1:1 and 1:5 (PCL:gelatin). Chemical and mechanical properties of nanofibrous scaffolds were evaluated using FTIR, FE-SEM, tensile measurements and contact angle. FE-SEM analysis of nanofibrous scaffolds showed uniform and beads-free fibers, with no evidence for phase segregation in all samples. Our data exhibited that with increasing the flow rate of gelatin (from 0.1 to 0.5 ml/hr), the average blended fiber diameter was reduced from 346±132 nm to 255±68 nm (p<0.01) and elastic modules increased from 3.42±1.2 MPa to 96.5±21.4 MPa (P<0.05). The result of contact angle revealed that increasing the gelatin amount in fibrous scaffolds increase hydrophilicity from 45ᴼ±5 to 15ᴼ±3 (p<0.01). Overall, our result indicated that the hybrid nanofibers of PCL/gelatin, which fabricated by dual-electrospinning with cytotoxic-free solvent, in this study, might provide a well suited biocompatible scaffolds for tissue engineering.

Keywords:

Nanofibers , Tissue engineering , Biocomposite , Dual-electrospinning