Chitosan microparticles for in vitro 3D culture of human chondrocytes

Chondrocytes are frequently cultured embedded in gels that provide them with a three-dimensional environment. Nevertheless cells in these constructs cannot remodel their neighbourhood when producing their own extracellular matrix. In this work we explore 3D environments that the cells can easily remodel. For this, human mature chondrocytes were cultured in the three-dimensional environment created by chitosan microparticles whose diameter is in the order of magnitude of the cell size. Chondrocytes and microparticles suspensions were mixed and the agglomerates were cultured in static tubes in chondrogenic medium. The poor adhesion between cells and chitosan surface maintained the mobility of the ensemble. In these conditions chondrocytes are viable during the 28 days of culture. The cells produce glycosaminoglycans, S100 and collagen type II up to 14 days of culture although production of type I collagen is also noticeable.