Three-Dimensional Collagen/Alginate Hybrid Scaffolds Functionalized with a Drug Delivery System (DDS) for Bone Tissue Regeneration

Biomedical scaffolds have recently evolved into various functional materials, including drug delivery systems (DDS). Here, we report the development of a new, highly porous scaffold based on a layer-by-layer collagen scaffold coated with an alginate polymer, which shows improved mechanical properties and controllable drug release without loss of the original biological function of the collagen scaffold. In particular, the scaffold (75 vol % alginate in a collagen scaffold with a porosity of 88%) attained a Young's modulus of 30 MPa, which is similar to 9 times the value for the pure collagen scaffold (porosity = 98%). Although the scaffolds are highly porous, the drug release and initial burst were well-controlled with an appropriate volume fraction of alginate. Osteoblast-like cells (MG63) readily proliferated and migrated into the interior of the scaffolds, and calcium and phosphate on the cell surfaces were well-formed, similarly on pure collagen and alginate/collagen scaffolds, within only 7 days of culture. The alginate/collagen scaffolds with a drug delivery function have potential as biomedical scaffolds for clinical use in soft and hard tissue regeneration.