Effect of bioreactor system on chondrocyte proliferation using cell adhesive PLLA-PAA-RGD scaffolds

Abstract

Porous poly(L-lactic acid)(PLLA) scaffolds were prepared and then grafted with acrylic acid(AAC) using in situ direct plasma treatment to obtain hydrophilic PLLA-PAA. The obtained PLLA-PAAc was coupled with Gly-Arg-Asp-Gly(GRGD.) as a ligand peptide to get cell-adhesive PLLA-PAAc-RGD. The prepared AA-grafted and RGD-immobilized PLLA films were confirmed from various surface, analyses. Chondrocyte, isolated front rabbit knee articular cartilages was passaged twice before, cell seeding on the PLLA scaffolds. Once seeded on either PLLA scaffolds, they were placed in a multi-functional bioreactor system and an intermittent hydrodynamic pressure(IHP) was applied in 3 bars, while turned on for 2 min and off for 28 min during 3-weeks Culture. Chondrocyte adhesion increased with time and the order of the adhesion was PLLA control < PLLA-PAAc < PLLA-PAAc-RGD. In addition, the contents of total collagen and glycosaminoglycans(GAG) increased in dynamic Culture system as compared with static one. This suggests that the bioreactor may significantly enhance the adhesion and proliferation of chondrocytes irrespective of kinds of PLLA scaffolds.