A critical review on multifunctional surface strategies for titanium alloys in bioactive and durable implants
Jeevadharani Murugan, Rajeswari Durairajan, Sivasakthi Sivakumar, Kartik Ravishankar, A. Manickam, G. R. Srinivasan, Surendiran Mohan
Abstract
Titanium (Ti) alloys are among the most widely used materials for orthopedic, dental, implants due to their excellent mechanical strength, corrosion resistance, and biocompatibility. However, their long-term clinical performance is often compromised by challenges such as poor osseointegration, localized corrosion, biofilm formation, and mechanical degradation under physiological loading. These limitations are further exacerbated in complex biological environments, where conventional coatings may fail due to instability or inadequate biological interaction. To address these barriers, recent research has focused on the development of multifunctional surface strategies that integrate mechanical durability with biological functionality. These include the use of nanostructured surfaces, nano organic-inorganic coatings, zwitterionic antifouling layers, and peptide-based biofunctionalization, and antibiotic-loaded to prevent implant-associated infections. In parallel, understanding and modulating early protein adsorption and subsequent cellular signaling events have emerged as critical factors in ensuring successful tissue integration. Such approaches aim to simultaneously enhance corrosion and wear resistance while supporting cellular adhesion and differentiation. This review critically analyzes these emerging surface technologies and highlights the importance of scalable fabrication methods, long-term in vivo validation, and the integration of smart or responsive functionalities to enable the next generation of bioactive, durable, and patient-specific titanium implants. • Multifunctional coatings improve Ti alloy corrosion resistance and bioactivity. • β-type Ti alloys reduce stress shielding and enhance osseointegration. • Nanostructured surfaces regulate protein adsorption and cell adhesion. • Antimicrobial layers prevent implant-associated infections effectively. • Additive manufacturing enables patient-specific implant design and function.