A wear-resistant and spatially compartmentalized “valley–ridge” titanium surface for combined infection control and angiogenesis-supported bone regeneration

Abstract

Implant-associated infection and inadequate osseointegration remain major obstacles to successful implantation. To overcome these challenges, we developed a multifunctional titanium surface featuring a mechanically robust micro-“valley–ridge” architecture, incorporating LL37-loaded nanotubes in the valleys for early postoperative antibacterial activity (within 72 h) with a TaCu coating on the ridges that provides intermediate-to-late phase (beyond 72 h, up to 28 days) angiogenic and osteogenic stimulation. The surface architecture was fabricated by coating the titanium substrate with a TaCu layer via magnetron sputtering, followed by laser lithography micropatterning and anodization to selectively produce TaCu nanotubes, after which a polydopamine coating was applied and the LL37 peptide was introduced to infill the nanotubes. The architectural system showed early postoperative LL37 release(~90% within 72 h) alongside sustintermediate-to-late phaseained Cu2+ release over 28 days. It exhibited combined antibacterial activity (>89% reduction against Staphylococcus aureus and Escherichia coli), enhanced expression of angiogenic markers, and promotion of osteogenesis in vitro. In vivo evaluation in a rabbit bone-defect and infection model demonstrated potent antibacterial activity, decreased inflammation, and enhanced bone regeneration compared with control implants. By integrating rapid antibacterial protection with sustained angiogenic and osteogenic support, this spatially compartmentalized architectural surface effectively controls infection while promoting angiogenesis-supported bone regeneration, underscoring its potential as a versatile strategy to enhance titanium implant success in infection-prone or delayed-healing conditions.