Fig. 1.

Illustration of computer driven syringe pump system for the RGD concentration gradient fabrication. (A) Schematic of the gradient fabrication system, pumping of solutions A, B and cells into the mold followed by irradiation at 465 nm for 5 min. (B) Depiction of the computer controlled pumping program, inverse ramp rates for solutions A (11.5% PEGDM ~8000 g mol⁻¹) and B (11.5% PEGDM ~8000 g mol⁻¹, w/15 mM acrylated RGD) from 0 ml h⁻¹ to 53 ml h⁻¹ and the chondrocytes at a constant rate for 90 s. Both solutions were prepared containing 0.1% Irgacure 2959 as an initiating system.