Osteoblastic cellular responses on ionically crosslinked chitosan-tripolyphosphate fibrous 3-D mesh scaffolds

Tripolyphosphate (TPP) crosslinked chitosan (CH)-based fibrous matrices have potential as bioactive scaffolds for bone tissue engineering. This study describes mechanical, biomineralization, and in vitro bone cell growth and differentiation properties of CH-TPP (chitosan-tripolyphosphate) fibrous scaffolds and compared with that of uncrosslinked CH one. The hydrated CH-TPP scaffolds were viscoelastic in nature and their compressive strength was ~2.9 MPa, which is greater than recent polymer experimental bone scaffolds. This improvement in mechanical properties of CH-TPP scaffold may be beneficial toward cancellous bone graft application. Furthermore, CH-TPP fibers supported in vitro biomineralization with phosphate as nucleation site; however, no significant difference in biomineralization morphology was observed with uncrosslinked CH fibers. Interestingly, a significant improvement in cellular responses (>33% increase in cell number based on DNA quantification) was observed when osteoblast like cells were cultured on the CH-TPP scaffolds than that of CH scaffolds without phosphate group. Enhanced osteoblastic differentiation of MG63 cells on CH-TPP scaffolds was also evidenced. Altogether, the results show that the CH-TPP fibrous scaffolds are encouraging for bone tissue engineering.