Search

Graphical abstract Highlights • Poly-3-hydroxybutyrate (PHB) films were plasma-treated in NH 3 , Ar and NH 3 /Ar mixtures. • Surface chemistry and topography changes were observed in PHB films. • A significant decrease in contact angle and an increase in free surface energy were observed. • Fibroblast cell adhesion was significantly improved after Ar plasma treatment. Abstract Poly-3-hydroxybutyrate (PHB) films were plasma-treated using pure NH 3 , pure Ar or mixtures of the two different proportions (20%, 30%, 40%, 50%, 70% NH 3 in Ar). Surface chemistry and surface topography changes of PHB films were observed after plasma processing in all plasma regimes. The XPS results confirmed the absence of chemical modification in the case of pure Ar plasma treatment. Nitrogen-containing groups (e.g., N C O) were detected on the surfaces of P3HB films treated with NH 3 -containing plasma. The surfaces of the untreated P3HB films were hydrophobic, and plasma treatment turned the surfaces hydrophilic, irrespective of the treatment. A significant decrease in the contact angle and an increase in the free surface energy were observed. An insignificant surface ageing effect was observed when P3HB samples were exposed to air for 10 days. In NIH 3T3 mice fibroblast cells, cell adhesion was significantly improved after plasma treatment in an Ar atmosphere, which is likely related to the fact that there was a surface ξ potential of 88.6 mV at neutral pH, causing a cleavage of the polymer chains and an increase in surface roughness. [ABSTRACT FROM AUTHOR]

The oxygen and ammonia radio-frequency (RF) plasma treatment of poly(3-hydroxybutyrate) P3HB films was performed. We revealed significant changes in the topography, a decrease in the surface zeta potential from −63 to −75 mV after the oxygen–plasma treatment and an increase after ammonia plasma treatment from −63 to −45 mV at a pH of 7.4. Investigations into the NIH 3T3 fibroblast adhesion and growth demonstrated the best cell vitality and a higher cell number for the ammonia plasma treatment at 150 W. [ABSTRACT FROM AUTHOR]