Magnetoelectric Nanoengineered PEEK Implant for Accelerated Osseointegration

Polyetheretherketone (PEEK) offers advantages for orthopedic implants but suffers from inherent bioinertness and poor osseointegration. To overcome these limitations, we engineered an electromagnetic active nanoengineered surface on PEEK (PEEK@MSN) that synergistically integrates magnetoelectric activation, bioactive nanotopography, and controlled release of alendronate to direct bone regeneration. In vitro, PEEK@MSN exhibited exceptional osteogenic capabilities, significantly enhancing the differentiation of bone marrow stromal cells (BMSCs), the expression of alkaline phosphatase (ALP), and calcium deposition. We elucidated the osteogenic synergy observed on the nanoengineered surface: the gold layer generates responsive currents in response to a magnetic field, activating voltage-gated calcium channels (VGCC) and directly modulating osteogenic signaling. Meanwhile, the nanotopography of the silica layer (MSN) facilitates cell recruitment and adhesion, while the sustained release of alendronate loaded in MSN delivers potent pharmacological osteogenic stimulation. PEEK@MSN demonstrated superior osseointegration versus pristine PEEK, achieving 4.1-fold higher calcium deposition (2.67% → 16.30%) in vitro and 492% greater trabecular bone formation (0.075 → 0.308 mm) in vivo. This work establishes a strategy for smart orthopedic implants, where magnetoelectrically generated currents, nanotopographical cues, and controlled pharmacological release act cooperatively to achieve actively guided mineralization and bone regeneration.