A poly(dimethylsiloxane) (PDMS) soft mold was made from a micro- or nano-patterned template by soft lithography, as previously described [38 (link)]. Briefly, the PDMS 10:1 elastomer and curing agent mixture was degassed, dispensed onto the masters and cured at 65 °C.
PLLA films were made by solvent casting using 3% w/v PLLA (Sigma Aldrich, St. Louis, MO, USA) dissolved in chloroform on the PDMS soft mold. The films were dried at room temperature covered with a glass dish. PLLA films were vacuum dried in a desiccator for 5 min to remove any residual solvent before demolding. The PLLA films were trimmed to 1.0-cm2 squares and sterilized with 70% ethanol (v/v) and ultraviolet irradiation.
To verify the surface morphology and fidelity of the micro- and nano-topography replication process, PLLA films were sputter coated with gold (JEOL JFC 1600 Fine Gold Coater, JEOL Ltd., Tokyo, Japan) and examined by scanning electron microscopy (SEM, Quanta FEG 200 and JEOL JSM-5600LV Scanning Microscope, JEOL Ltd., Tokyo, Japan).
PLLA films were made by solvent casting using 3% w/v PLLA (Sigma Aldrich, St. Louis, MO, USA) dissolved in chloroform on the PDMS soft mold. The films were dried at room temperature covered with a glass dish. PLLA films were vacuum dried in a desiccator for 5 min to remove any residual solvent before demolding. The PLLA films were trimmed to 1.0-cm2 squares and sterilized with 70% ethanol (v/v) and ultraviolet irradiation.
To verify the surface morphology and fidelity of the micro- and nano-topography replication process, PLLA films were sputter coated with gold (JEOL JFC 1600 Fine Gold Coater, JEOL Ltd., Tokyo, Japan) and examined by scanning electron microscopy (SEM, Quanta FEG 200 and JEOL JSM-5600LV Scanning Microscope, JEOL Ltd., Tokyo, Japan).