Seeding cells into needled felt scaffolds for tissue engineering applications

Tissue engineering methods are under development that will enable the repair or replacement of a variety of tissues, including articular cartilage and bone. To engineer functional tissue it is necessary that scaffolds initially be seeded with a large number of cells distributed evenly throughout the scaffold structure. It previously has been shown that, compared to static seeding conditions, seeding scaffolds under dynamic conditions facilitates high seeding densities and even distributions of cells (Li et al., Biotechnology Progress 2001;17:935-944). The efficiency of seeding HOSTE85 cells and bovine chondrocytes into needled felt scaffolds following agitation at different speeds was determined. Seeding efficiency was determined using the Hoechst 33258 assay, and cell viability was assessed using the Alamar Blue trade mark assay. The distribution of cells within the scaffolds was imaged using scanning electron microscopy. It was found that the optimum seeding conditions varied for HOSTE85 cells and bovine chondrocytes, with different agitation speeds leading to different seeding efficiencies, cell viabilities, and distributions of cells within scaffolds. The optimum agitation speeds for seeding a high number of viable cells into scaffolds so that they were arranged evenly were 300 rpm for HOSTE85 cells and 200 rpm for bovine chondrocytes.