Osteoblast cell response to a CO2 laser modified polymeric material

Lasers are an efficient technology, which can be applied for the surface treatment of polymeric biomaterials to enhance insufficient surface properties. That is, the surface chemistry and topography of biomaterials can be modulated to increase the biofunctionality of that material. By employing CO2 laser patterning and whole area processing of nylon 6,6 this paper details how the surface properties were significantly modified. Samples, which had undergone whole area processing, followed the current theory in which the advancing contact angle, θ, with water decreased and the polar component, γp, increased upon an increase in surface roughness. For the patterned samples it was observed that θ increased and γP decreased. This did not follow the current theory and can be explained by a mixed-state wetting regime. By seeding osteoblast cells onto the samples for 24 h and 4 days the laser surface treatment gave rise to modulated cell response. For the laser whole area processing, θ and γP correlated with the observed cell count and cover density. Owed to the wetting regime, the patterned samples did not give rise to any correlative trend. As a result, CO2 laser whole area processing is more likely to allow one to predict biofunctionality prior to cell seeding. Moreover, for all samples, cell differentiation was evidenced. On account of this and the modulation in cell response, it has been shown that laser surface treatment lends itself to changing the biofunctional properties of nylon 6,6.

► CO2 lasers can be used to modify the wettability characteristics of a polymer. ► Patterning gave rise to increased θ, attributed to a mixed-state wetting regime. ► Laser whole area processing gave rise to a decrease in θ, following the current theory. ► For whole area processing, θ and γP correlated with the osteoblast cell response. ► Trends and cell differentiation show potential of use in regenerative medicine.