A new therapeutic trial based on the self-healing potential of cells to naturally induce tissue regeneration, has been recently noted. To realize this regenerative medical therapy, it is highly required to efficiently combine cells with their local environment which basically allows cells to survive and biologically function in vivo through the essential interaction. Tissue engineering is a biomedical technology or methodology to create the local environment which promotes the proliferation and differentiation of cells to induce tissue regeneration. There are some cases where tissue regeneration can be induced only by supplying a cell scaffold of biomaterials. Drug delivery system (DDS) with biomaterials enhanced the in vivo biological activities of un-stable growth factor and gene for cell-induced tissue regeneration. The controlled release technology enabled growth factors to achieve the regeneration of various tissues experimentally and clinically. The DDS technology also augmented the biological functions of plasmid DNA and small interference RNA. The cells genetically engineered by the DDS gene system showed an enhanced therapeutic efficacy in cell-based tissue regeneration (cell-gene hybrid therapy). By making use of DDS technology, it is possible to suppress the deterioration and proceeding of chronic fibrotic diseases based on the self-healing potential inherently equipped in the living body. This paper emphasizes significance of biomaterials in tissue engineering for regenerative medical therapy.