Synergistic Regulation of Osteogenesis and Angiogenesis on Titanium Implants via Laser-Etched Micronano Structures...

The limited bioactivity of titanium (Ti) implants often impedes osseointegration and the coordinated regulation of osteogenesis and angiogenesis. To address this, we engineered multifunctional Ti surfaces by integrating laser-etched periodic micronano arrays with zinc oxide (ZnO) coatings via sol-gel spin-coating. Two fabrication sequences were compared: applying the ZnO coating before laser etching (as the TZ-A series) and performing laser etching before the ZnO coating (TZ-B series). For both series, periodic micronano arrays with controlled spacings of 0.05, 0.175, and 0.5 mm were fabricated. The TZ-B series exhibited superior surface integrity and sustained Zn²⁺ release, leading to enhanced contact-dependent antibacterial activity. In vitro studies revealed that TZ-A surfaces favored early MC3T3-E1 cell proliferation, while TZ-B─especially TZ-B0.05─promoted late-stage osteogenic differentiation, upregulating ALP, COL-I, OPN, OCN, and Runx2. Additionally, TZ-B0.05 significantly enhanced angiogenic activity in HUVECs, evidenced by improved tube formation and the upregulation of VEGF, CD31, and VE-cadherin. These findings demonstrate that combining surface microtopography with Zn²⁺ release provides synergistic and phase-specific modulation of osteogenesis and angiogenesis. This approach offers a promising strategy for developing advanced Ti implants for bone regeneration and vascularized tissue repair.