Abstract:
Growing cells on 3D scaffolds is far superior to the conventional 2D monolayer culture method. In this
study, a novel 3D thermoresponsive poly(propylene-g-N-isopropylacrylamide) (PP-g-PNIPAAm) nonwoven
fabric (gNWF) was developed for cell culture using oxyfluorination-assisted graft polymerisation
(OAGP). New polar functional groups were detected on the oxyfluorinated NWF (oNWF), and PNIPAAm
was confirmed in the gNWF by attentuated total-reflectance Fourier transform infrared (ATR-FTIR) and
scanning X-ray photoelectron spectroscopy (S-XPS). Scanning electron microscopy (SEM) revealed a
rough surface morphology and confinement of the PNIPAAm graft layer to the surface of the fibres in
the gNWF. The OAGP method did not affect the crystalline phase of bulk PP, however, twin-melting
thermal peaks were detected for the oNWF and gNWF indicating crystal defects. Contact angle studies
showed that the surface of the gNWF exhibited a thermoresponsive behaviour. Hepatocyte cells attached
onto gNWF disks in a bioreactor at 37 ◦C and remained viable for 10 days in culture. Upon cooling the cell
culture media to 20 ◦C, cells were spontaneously released as 3D multi-cellular constructs without requiring
destructive enzymes. The development of 3D thermoresponsive scaffolds capable of non-invasive 3D
cell culture could provide a more reliable in vitro model for cells.
