Hybrid functionalized coatings on Metallic Biomaterials for Tissue Engineering

The review encompasses state-of-the-art strategies for design and fabrication of smart biomaterials for tissue engineering. The focus of the work is mainly put on metallic biomaterials with hybrid coatings consisting of bioceramic and polymeric layers with hierarchical organization and drug-eluting capacity. Key technologies and steps to design hybrid smart and multifunctional coatings on metallic cores for bone regeneration implants and cardiovascular stents are outlined, including additive manufacturing of titanium and magnesium alloys for permanent and temporary implant applications. Three levels of hierarchical surface functionalization are described: i) in situ modification of the core material, incorporating bioactive inorganic species and phases by means of ceramic coatings via anodic electrochemical treatments; ii) post-treatment application of polymer layers, monolithic or with specific porous breath figure topography; and iii) application of a cellular therapy component (single cell or cell sheet). Recent progress in incorporation of drug-eluting functionality into such materials via direct or nanocarrier-assisted loading is also highlighted.