In Vivo Bone Regeneration Induced by a Scaffold of Chitosan/Dicarboxylic Acid Seeded with Human Periodontal Ligament Cells.

Chitosan/dicarboxylic acid (CS/DA) scaffold has been developed as a bone tissue engineering material. This study evaluated a CS/DA scaffold with and without seeded primary human periodontal ligament cells (hPDLCs) in its capacity to regenerate bone in calvarial defects of mice. The osteogenic differentiation of hPDLCs was analyzed by bone nodule formation and gene expression. In vivo bone regeneration was analyzed in mice calvarial defects. Eighteen mice were divided into 3 groups: one group with empty defects, one group with defects with CS/DA scaffold, and a group with defects with CS/DA scaffold and with hPDLCs. After 6 and 12 weeks, new bone formation was assessed using microcomputed tomography (Micro-CT) and histology. CS/DA scaffold significantly promoted in vitro osteoblast-related gene expression (RUNX2, OSX, COL1, ALP, and OPN) by hPDLCs. Micro-CT revealed that CS/DA scaffolds significantly promoted in vivo bone regeneration both after 6 and 12 weeks (p < 0.05). Histological examination confirmed these findings. New bone formation was observed in defects with CS/DA scaffold; being similar with and without hPDLCs. CS/DA scaffolds can be used as a bone regenerative material with good osteoinductive/osteoconductive properties.

Multi-functional carboxylic acids for chitosan scaffold.

In general, CS scaffold is prepared by lyophilizing CS hydrogel which traditionally can be prepared by dissolving CS in acetic acid and crosslinking with dialdehyde. However, this method expresses unpleasant odor and toxicity leading to obstruct the practical applications. Here, the aqueous solution of multi-functional carboxylic acids is considered as the alternative and ordorless solvents to provide dual functions, i.e. (i) protonation of CS for the dissolution, and (ii) providing the preferable structure to give crosslink networks under amide bond through the conjugation reaction. The present work demonstrates the potential use of multi-functional carboxylic acids for preparation of CS scaffold and shows the tunable physicochemical and mechanical properties. The work also extends to the basic studies on biological properties to propose as the potential material for dental tissue engineering.