Description of a novel approach to engineer cartilage with porous bacterial nanocellulose for reconstruction of a human auricle

In this study, we investigated the effects of human primary chondrocytes, derived from routine septorhino- and otoplasties on a novel nondegradable biomaterial. This biomaterial, porous bacterial nanocellulose, is produced by Gluconacetobacter xylinus. Porosity is generated by paraffin beads embedded during the fermentation process. Human primary chondrocytes were able to adhere to bacterial nanocellulose and produce cartilaginous matrix proteins such as aggrecan (after 14 days) and collagen type II (after 21 days) in the presence of differentiation medium. Cells were located within the pores and in a dense cell layer covering the surface of the biomaterial. Cells were able to re-differentiate, as cell shape and extra cellular matrix gene expression showed a chondrogenic phenotype in three-dimensional bacterial nanocellulose culture. Collagen type I and versican expression decreased during three-dimensional culture. Variations in pore sizes of 150-300 mu m and 300-500 mu m did not influence cartilaginous extra cellular matrix synthesis. Varying seeding densities from 9.95x10(2) to 1.99x10(3)cells/mm(2) and 3.98x10(3)cells/mm(2) did not result in differences in quality of extra cellular matrix neo-synthesis. Our results demonstrated that both nasal and auricular chondrocytes are equally suitable to synthesize new extra cellular matrix on bacterial nanocellulose. Therefore, we propose both cell sources in combination with bacterial nanocellulose as promising candidates for the special needs of auricular reconstruction