Chitosan based biomaterials for cartilage tissue engineering: Chondrocyte adhesion and proliferation

Multidisciplinary approaches encompassing developmental biology, tissue mechanics, cell differentiation, and nano-fabrication technology hold great promise for the effective biological repair of cartilage. In this aim, the present work proposed the use of chitosan (CS)-based fiber mats obtained by electrospinning as a scaffold for chondrocyte development in order to take advantage of the biocompatibility with native tissues. Cell viability, adhesion and proliferation were studied and compared as a function of the substrate morphology and chitosan neutralization. Fibers with two different diameters are investigated and it is shown that the cells develop better on fibers when compared with films. Early observations of cell adhesion revealed that a maximum of seeded cells is attached to the fiber substrate during the first 8 h after seeding. High ratio of living chondrocytes (>80%) was found on all types of chitosan supports examined. However, cell viability is shown to be favored on engineered CS fiber mats especially for lower diameter fibers. In that case, chondrocytes attached to thin neutralized chitosan fibers were observed to reach a proliferation ratio of 15:1 between day 14 and day 1, respectively. The influence of chitosan neutralization step on cell proliferation is also studied. Overall, CS substrates may be considered as a possible implantable scaffold for chondrocyte development, providing an adapted microenvironment for native cells to adhere, colonize, and repair the damaged tissue.