Development of alginate-chitosan composite scaffold incorporation of bacterial cellulose for bone tissue engineering

On account of the excellent biocompatibility and biodegradability of natural polymers, such as alginate, chitosan (CS), and bacterial cellulose (BC), we developed the alginate/bacterial cellulose-chitosan (Alg/BC-CS) composite scaffolds through the incorporation of BC into alginate matrix and the surface coverage of CS, using hydroxyapatite/D-glucono-delta-lactone (HAP/GDL) complex as the gelling system. The effects of the addition of BC on the scaffold morphology, porosity, mechanical property, swelling, degradability, protein adsorption, and release properties, and cytocompatibility were investigated. The fabricated Alg/BC-CS composite scaffolds revealed the regular 3D morphology due to the homogeneous cross-linking by HAP/GDL complex. The incorporation of the BC significantly reduced their pore size, making Alg/BC-CS composite hydrogel more beneficial to favor tissue ingrowth and ensure mechanical integrity. Moreover, the tight fiber network structure and good barrier properties of BC and its formation of intermolecular hydrogen bonds with alginate could effectively control swelling behaviors and inhibit the degradation of Alg/BC-CS composite scaffolds. Meanwhile, the resultant Alg/BC-CS composite scaffolds showed good apatite formation ability, protein adsorption, and release performance, as well as excellent cytocompatibility, so they could exhibit great application potentials for bone tissue engineering.