Hr mb l and hr 3.0 columns

The molecular weight of the unprocessed PLGA and printed PLGA was determined by GPC using a Waters Alliance Separations Module e2695, Waters 2414 Refractive Index Detector, and Waters HSPgel columns in series (HR MB-L and HR 3.0 columns, 6.0 mm ID × 15 cm) (Waters, Milford, MA) [18 (link)]. For printed PLGA, scaffold was fabricated using conditions summarized in table 2, then a small piece of the printed scaffold was cut and dissolved in tetrahydrofuran for the test. Polystyrene standards were used to report the relative molecular weights. The standard curve was generated from a 10-point calibration using Agilent EasiCal polystyrene standards. The data analysis was performed using Waters Empower 3 Chromatography Data software. Three samples of each composition were performed for statistical analysis.

The molecular weight of printed and stock PS was determined by GPC (Waters Alliance Separations Module e2695, Waters 2414 Refractive Index Detector, and Waters HSPgel columns in series (HR MB-L and HR 3.0 columns, 6.0 mm ID × 15 cm), Waters, Milford, MA). Three samples of each were dissolved in tetrahydrofuran with molecular weight determined against PS standards in at least technical duplicate.