Effect of electrical charge on chondrocyte attachment

Our goal in this study is to develop hydrogels which serve as a substrate for chondrocyte attachment, proliferation and differentiation. We used oligo(poly(ethylene glycol) fumarate (OPF) as matrix of the hydrogels and incoporated charged molecules, sodium 2-Sulfoethyl methacrylate (SEMA) for negative and [2-(methacryloyloxy) ethyl]-trimethylammonium chloride (MAETAC) for positive charge. Swelling ratio of hydrogels was measured in PBS and deionized water at 37degC. In general, the negatively charged hydrogels showed a higher swelling ratio than positive or neutral charged. Both negatively and positively charged hydrogels had higher swelling ratio in deionized water as opposed to the PBS. Further we characterized the surface chemical structure of the hydrogels using Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FTIR) Spectroscopy. The results showed incorporation of the charged molecules on the surface of the hydrogels. To investigate the effect of electrical charge on chondrocyte attachment, chondrocytes were seeded on the hydrogels at the density of 20,000 cells/cm². At desired time points, cells were stained for viability and morphology. Our results showed that chondrocyte behavior is influenced by the type and density of electrical charge incorporated into the hydrogels.