Improving culture conditions for temporomandibular joint disc tissue engineering.

The temporomandibular joint (TMJ) is extremely important for activities like eating and talking, which can become painful and difficult for patients with TMJ dysfunction. Tissue engineering is a potential alternative to current surgical interventions through replacement of diseased or injured tissue with a functional construct. Since research with TMJ disc cells began relatively recently, optimal culturing conditions must be determined. Metabolic additives, L-glutamine, L-alanyl-L-glutamine, sodium pyruvate, and insulin, were examined for their effects on TMJ disc cells in monolayer. Effects of L-proline were examined in three-dimensional (3-D) culture at concentrations of 0, 25 and 100 mg/l. The combination of L-glutamine, sodium pyruvate, and insulin improved cell proliferation rates without affecting collagen production or gene expression. No differences were observed in mechanical properties of the engineered constructs; however, collagen and glycosaminoglycan quantities normalized to cell number decreased at the highest concentration of L-proline. This work identified supplements for 2-D monolayer expansion. Other supplements or culture conditions still need to be investigated for 3-D tissue production. This work improves upon porcine TMJ disc cell culturing conditions, taking us closer to being able to engineer the TMJ disc.