Facile fabrication of poly(ε-caprolactone)/graphene oxide membranes for bioreactors in tissue engineering

- Novel composite membranes for cell culture perfusion bioreactors were prepared.
- Poly(ε-caprolactone) was blended with graphene oxide or reduced graphene oxide.
- Phase inversion using non-toxic reductive agents and mild conditions was applied.
- The membranes showed exceptionally high water and bovine serum albumin fluxes.
- 0.1% w/w of graphene in the base membrane improved the neural cell biocompatibility.

Promising polymer membranes of blended biocompatible poly(ε-caprolactone) and graphene oxide (PCL/GO) and PCL and partially reduced graphene oxide (PCL/rGO) with outstanding water and nutrient transport properties for cell culture bioreactors were prepared using phase inversion at mild temperatures. Some of the prepared PCL/GO membranes were subjected to a 'chemical-free' GO post-reductive process using UV (PCL/GO/UV) irradiation. The PCL/rGO membranes exhibited 2.5 times higher flux than previously reported biocompatible polymer membranes for cell culture bioreactors, which was attributed to the highly interconnected porosity. On the other hand, the formation of PCL-graphene oxide composites in the PCL/GO and PCL/GO/UV membranes was not conclusive according to spectroscopic analyses, thermal analyses and mechanical characterization, probably due to the low graphene oxide loading in the membranes (0.1%w/w). The presence of graphene oxide-based nanomaterials in the polymer matrix slightly reduced the mechanical properties of the PCL-graphene oxide membranes by limiting the polymer chain mobility in comparison to that of the plain PCL membranes. However, their mechanical stability was sufficient for the applications pursued. Finally, the biocompatibility assay indicated that the incorporation of GO and rGO into the PCL matrix enhanced the uniform distribution and morphology of the glioblastoma cells on the surface of the PCL-graphene oxide membranes.