Interactions of chondrocytes with methacrylate copolymers

Copolymers of poly(ethylmethacrylate) (PEMA) and tetrahydrofurfurylmethacrylate (THFMA) have been shown to exhibit potential as a biomaterial for use in cartilage repair. However, the interactions of chondrocytes with the polymer surface is not well understood. A series of novel methacrylate copolymers containing PEMA, THFMA and hydroxyethylmethacrylate (HEMA) were prepared and the ability of these various copolymers to support chondrocytes attachment in vitro has been assessed by the Alamar blue assay for cell number and environmental scanning electron microscopy (ESEM). As the mole fraction of HEMA in PEMA/THFMA/HEMA copolymers increased, chondrocyte attachment to the polymer surface in 24 h decreased. Chondrocytes maintained a rounded morphology and were strongly attached on the THFMA/PEMA polymer surface, but as the mole fraction of HEMA increased the cells present became much smaller with fewer cell to cell interactions. The effect of pre-adsorbing fibronectin on to the polymer surface on cell attachment was assessed both in the presence and absence of serum. Chondrocyte attachment was significantly reduced in serum-free medium. Pre-adsorption of fibronectin on to the copolymer surface substantially increased cell attachment in all cases. In conclusion, chondrocyte attachment and proliferation on these copolymers may be controlled by changes in the polymer surface chemistry and is highly sensitive to the presence of proteins either in the culture media or pre-adsorbed on to the copolymer surface.