Functionally assembled metal platform as lego-like module system for enhanced mechanical tunability and biomolecules delivery

Natural bone substituting materials derived from living organisms have been utilized to treat bone malfunctioning. However, limited sources and immune issues have led to the use of artificial scaffolds consisting of biocompatible materials. Additionally, a functionally graded porous structure has been acknowledged as an alternative to overcome reduced mechanical properties by pores and alleviate stress shielding effect. In this study, a two-body combination achieved through a densification process, in which recombinant human bone morphogenetic protein-2 (rhBMP-2) and tetracycline hydrochloride (TCH) can be simultaneously released for efficient bone regeneration, is proposed. Biomimetic titanium scaffolds (BTSs), which possess significantly different pore characteristics, are successfully fabricated. The mechanical properties of these parts are proven to be applicable as bone substitutes. The release of rhBMP-2 and TCH from the BTSs is prolonged compared to that of homogenous porous titanium scaffolds (PTSs). The prolonged release of rhBMP-2 from the BTS results in a sustained degree of pre-osteoblast differentiation. The antimicrobial properties of these scaffolds are verified using pathogens. Furthermore, various structures exhibiting different pore characteristics are obtained by mechanical interlocking between components. This study demonstrates that the novel assembled platform as customizable Lego-like building blocks, with its tunable mechanical and multi-biomolecule release properties, is promising for bone tissue engineering.