Growth factors and scaffold composition influence properties of tissue engineered human septal cartilage implants in...

Several surgical disciplines apply cartilage grafts for reconstructive purposes and have to overcome the scarcity of donor sites for this unique tissue. Employing the techniques of tissue engineering, cartilage might be generated in reasonable amounts for clinical purposes. Application of growth factors together with biochemical and biomechanical scaffold properties influence the process of ex vivo transplant production. The aims of this study are: 1) to investigate the influence of IGF-1 and TGFbeta-2 on tissue engineered human septal cartilage in vitro and in vivo after transplantation in nude mice; 2) to analyse the effect of the polydioxanone (PDS) content of the biodegradable Ethisorb E210 scaffold on the properties of the implanted constructs. Cells were three-dimensionally cultured on biodegradable Ethisorb E210 (PGA-PLA-copolymer fleeces with polydioxanone (PDS) adhesions), or on E210 scaffolds with a reduced polydioxanone content. Wet weight (ww), GAG-, and hydroxyprolin-content, as well as the cellularity of the neocartilage constructs were quantitatively evaluated. Additionally, the in vivo resorption of the two types of cell carriers was monitored. Addition of growth factors clearly increased the wet weight of the in vitro cultured constructs before transplantation. After transplantation, high PDS content improved the in vivo stability and macroscopic morphometric appearance of the tissue engineered specimens and led to enhanced deposition of glycosaminoglycans in transplanted constructs. Hydroxyproline content of the implants was not affected by either growth factors or PDS content. These data suggest a role for IGF-1 and TGFbeta-2 in preparative in vitro culture of chondrocytes before implantation, while PDS content of the scaffold is important for in vivo properties of the implanted material.