Importance of integrin β1-mediated cell adhesion on biodegradable polymers under serum depletion in mesenchymal stem cells and chondrocytes

To evaluate the predominant mechanism of chondrogenic cell [mesenchymal stem cells (MSCs) and chondrocytes] adhesion under serum free conditions, we measured the surface roughness and wettability of poly(lactic acid:polyglycolic ACID=75:25) (PLGA), poly(lactic acid) (PLA), and poly(-epsilon-caprolactone) (PCL)-coated glass plates. Also to evaluate the biological reactions involved in cell–polymer interactions, integrin β1, one of the cell adhesion molecules, was blocked with monoclonal antibody. In cell attachment test, MSCs and chondrocytes adhesion to synthetic polymers in 1 h were very low and ranged from 2.8% to 8.0%. In present study, the correlation between attachment rate and surface roughness, contact angle, or integrin β1 blocking on PLGA, PLA and PCL-coated plates could not be proved. However, we found that -arginine-coated PLA highly increased the attachment rates of MSCs (30.2%) and of chondrocytes (26%), whereas integrin β1 blocking significantly decreased these attachment rates to 5.6% and 7.4%, respectively, suggesting that increased cell adhesion to -arginine-coated plates is mediated by integrin β1.