Hydroxyl Functionalization of a Titanium Implant Drug Carrier Channel Modified by Vacuum Drying-Assisted Laser Texturing to Achieve Delayed Release of CIP-PLGA Microsphere Suspension

Titanium alloys are commonly used for bone grafting, but in mandibular defect repair, implantation possibly fails due to bacterial infection. The establishment of a long-acting drug delivery system through microspheres and titanium channels can reduce the risk of infection. However, there is insufficient research on the mechanism of microsphere attachment and microsphere-liquid two-phase flow in the hydroxyl-functionalized titanium implantation channel modified by a vacuum-drying-assisted laser texturing. In this paper, poly(lactic- co -glycolic acid) (PLGA) loaded with ciprofloxacin (CIP) was attached to the titanium channel by vacuum drying-assisted laser texturing. Titanium macroscopic flow channels and microscopic texture morphology were designed; three mathematical models of titanium substrate–microsphere–droplet interactions were developed, and the hydroxyl-based surface functionalization mechanism and the effect of laser texture parameters on microsphere adhesion and microsphere-liquid two-phase flow on titanium channels were investigated. The results showed that vacuum drying-assisted laser texture can control the bonding degree of the PLGA hydroxyl group to the titanium channel, which affects the adhesion of microspheres. The laser texture modification can control the flow rate of the microsphere suspension in the titanium channel to achieve a dynamic adjustment of the release effect. The CIP-PLGA microsphere drug delivery system, based on vacuum drying-assisted laser texturing, enables sustained local drug release, providing a potential strategy to suppress inflammation around the implant and reduce the risk of postoperative infection.