Surface hydrolysis of poly(glycolic acid) meshes increases the seeding density of vascular smooth muscle cells

A procedure for surface hydrolysis of poly(gly- colic acid) (PGA) meshes was developed to increase cell seeding density and improve attachment of vascular smooth muscle cells. Hydrolysis of PGA in 1N NaOH transformed ester groups on the surface of PGA fibers to carboxylic acid and hydroxyl groups. After hydrolysis, the polymer scaffold retained its original gross appearance and dimensions while the fiber diameter decreased. A plot of fiber diameter versus the hydrolysis time showed a linear relationship, with a rate of decrease in fiber diameter of 0.65 mm/min. The molecular weight and thermal properties of the polymer did not change significantly following surface hydrolysis. In cell seeding experiments, surface-hydrolyzed mesh was seeded with more than twice as many cells as unmodified PGA mesh. Vascular smooth muscle cells attached to the surface- hydrolyzed PGA mesh both as individual cells and as cell aggregates while only cell aggregates were observed on the unmodified mesh. Control experiments indicated that ad- sorption of serum proteins onto the surface-hydrolyzed PGA fibers was correlated with the increase in cell seeding density. These results demonstrate that optimization of bio- material-cell interactions provides a strategy for increasing the initial cell seeding density for the engineering of tissues of high cell density. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 417-424, 1998.