Honeycomb-patterned poly(L-lactic) acid on plasma-activated FEP as cell culture scaffold

Abstract

The main aim of our work was to design a simple approach for preparation of a specific pattern with a honeycomb-like structure on a solid polymer substrate and to evaluate its cytocompatibility. We have chosen poly-(L-lactic) acid (PLLA) as a source material for formation of the honeycomb-like pattern and perfluorethylenepropylene (FEP) as underlying substrate material. The PLLA pattern formation was induced by improved phase separation with application of a dip-coating technique. Surface morphology, chemistry and wettability of the patterned structure were strongly affected by the initial pretreatment parameters of the FEP substrate, i.e., by the plasma power and exposure time. The pattern formation was unsuccessful without plasma pretreatment. Surface morphology of the PLLA pattern was studied by both of atomic force and scanning electron microscopies. Surface chemistry was analyzed by energy dispersive spectroscopy. The wettability and ability to change electrolyte flow, which might be important for cell-material interaction, were studied by goniometry and zeta-potential, respectively. Due to the morphology and roughness of the prepared pattern, human cells derived from osteosarcoma (U-2 OS) were chosen to evaluate the material cytocompatibility WST-1 assay. Moreover, morphology of cells growing on the honeycomb-like pattern was studied in detail by fluorescence and scanning electron microscopies. We have been able to determine such combination of substrate plasma pre-treatment and honeycomb-like pattern formation on the basis of different amount of target material (PLLA) that led to construction of an excellent scaffold for U-2 OS cell culture.