Review of craniofacial regeneration in China

Abstract

Craniofacial defect is frequently caused by inflammation, trauma, and tumour etc The damaged tissues cannot be fully reconstituting the integrated matrix and regenerate native surface due to the complexity of craniofacial tissues, although with good intrinsic healing capacity. Till now, many approaches, such as manufacturing prosthesis, have obtained limited results. Tissue engineering has been recognised as one of the most effective means to replace or repair damaged tissues, which aims at forming a new viable tissue for a medical purpose. Such approaches need scaffolds that support the attachment, growth and proliferation of cells. With the development of modern medicine, the research of biomaterials has undergone a process from bio-inert materials to bioactive or degradable materials. The first generation of biomaterials was bio-inert materials with high strength, which included the metallic materials, ceramic materials, and polymeric materials. Whereas second-generation biomaterials were designed to be either resorbable or bioactive, the new biomaterials converged the separate concepts of bioactive materials and resorbable materials. Ideally, the scaffold must be of good biocompatibility and suitable physical and mechanical properties, furthermore, the scaffold must possess three-dimensional and properly porous network to allow cell adhesion, and controlled rate of degradation to match new tissue growth in vitro and in vivo. 1,2 Besides, the mechanism of tissue repair is complex and involves several important bioactive factors, 3,4 which function as inductive signals to provide cells with sufficient stimulus to migrate into tissues or biomaterials. Utilisation of growth factors, peptides or small molecules that associated with a natural matrix or biomaterial carrier has been extensively studied. Tissue engineering also utilises living cells as engineering materials, and cells became available as engineering materials when Bodnar et al 5 discovered how to extend telomeres in 1998, producingimmortalised cell lines. Stem cells are self-renewing and multipotent, with unique capacity to regenerate