A novel and homogeneous scaffold material: preparation and evaluation of alginate/bacterial cellulose nanocrystals/collagen composite hydrogel for tissue engineering

Alginate is a well-known biomaterial which has been widely used in tissue engineering due to its excellent property. However, there are still several drawbacks, such as weak mechanical strength, the lack of cell recognition sites for cell adhesion, extensive swelling and uncontrolled degradation that limit its practical application. Therefore, the internal gelation using CaCO₃–GDL complex and the incorporation of bacterial cellulose nanocrystals (BCNs) and type I collagen (COL) as the reinforcing component into alginate matrix were proposed to prepare the novel and homogeneous alginate/bacterial cellulose nanocrystals/collagen composite scaffold (ALG/BCNs/COL). The morphology, porosity, mechanical property, swelling and degradation behavior, and cytotoxicity of the resultant scaffold were investigated. The experimental results showed that ALG/BCNs/COL revealed good three-dimensional (3D) architecture as well as lamellar and porous morphologies. The incorporation of BCNs into alginate matrix obviously decreased the pore size and maintained the porosity of ALG/BCNs/COL, which was in favour of mechanical integrity. FT-IR spectra and XRD analysis revealed that the components of ALG/BCNs/COL, such as SA, BCNs and COL were combined together by intermolecular hydrogen bonds, which could effectively inhibit large swelling and retard the biodegradation of the composite scaffold. Finally, cell studies results indicated that both MC3T3-E1 and h-AMS cells were viable and proliferate well on the composite scaffold.