Nanotextured and drug loaded Neovius Ti6Al4V ELI scaffolds with osteogenesis and anti-cancer potential

Abstract

Introduction: The use of Ti6Al4V for orthopedic implants though widely accepted, is 10X stiffer than bone, that leads to stress shielding and aseptic loosening. Further, oral delivery demands significantly large dosage of drugs. To address these twin challenges, we have fabricated open cell porous scaffolds capable of sustained dual drug delivery. Drug delivery from open cell porous Ti6Al4V implants is a promising approach for in situ delivery in orthopedic and dental implant applications. Methodology: In this study, selective laser melting technology was used to fabricate open cell porous Ti6Al4V ELI scaffolds of 50 % volume fractions with Neovius architecture (NOCL). Electrochemical anodization was used to create micro and nano scale surface features for efficient drug loading. The two payloads: an osteogenic agent (Baicalein) and an anti-cancerous drug (Paclitaxel) were then loaded to different levels for differential release. An osteogenic agent was loaded in the nano reservoirs while paclitaxel was mixed with poloxamer and coated over the scaffold. Results: The mechanical stiffness of the designed NOCL lattices is approximately 1.29 ± 0.05 GPa, which is comparable to the human bone. This helps to reduce stress shielding effect. The scaffolds loaded with baicalein and paclitaxel yielded a sustained drug release profiles, releasing 57 % and 79 % of the pharmaceuticals over a 7-day period, respectively. Additionally, the baicalein-loaded nano reservoirs promote osteoblast differentiation in mesenchymal stem cells. As a result, bio-inspired 3D-printed open cell porous titanium scaffolds loaded with dual drugs offer a workable solution to the problems associated with orthopedic implants.

Keywords

• Dual drug delivery
• Open cell lattices
• Multiscale surface topography
• Neovius architecture
• Additive manufacturing
• Ti6Al4V ELI