Accumulative Rolling Mg/PLLA Composite Membrane with Lamellar Heterostructure for Enhanced Bacteria Inhibition and Rapid Bone Regeneration

Abstract

Developing composite materials with optimized mechanics, degradation, and bioactivity for bone regeneration has long been a crucial mission. Herein, a multifunctional Mg/Poly‐l‐lactic acid (Mg/PLLA) composite membrane based on the “materials plain” concept through the accumulative rolling (AR) method is proposed. Results show that at a rolling ratio of 75%, the comprehensive mechanical properties of the membrane in the rolling direction are self‐reinforced significantly (elongation at break ≈53.2%, tensile strength ≈104.0 MPa, Young's modulus ≈2.13 GPa). This enhancement is attributed to the directional arrangement and increased crystallization of PLLA molecular chains, as demonstrated by SAXS and DSC results. Furthermore, the AR composite membrane presents a lamellar heterostructure, which not only avoids the accumulation of Mg microparticles (MgMPs) but also regulates the degradation rate. Through the contribution of bioactive MgMPs and their photothermal effect synergistically, the membrane effectively eliminates bacterial infection and accelerates vascularized bone regeneration both in vitro and in vivo. Notably, the membrane exhibits outstanding rat skull bone regeneration performance in only 4 weeks, surpassing most literature reports. In short, this work develops a composite membrane with a “one stone, four birds” effect, opening an efficient avenue toward high‐performance orthopedic materials.

Dual Mg-Reinforced PCL Membrane with a Janus Structure for Vascularized Bone Regeneration and Bacterial Elimination

“…The Transwell assay was used to evaluate the barrier function of our membranes against fibroblasts, as reported by our previous study. 25 In detail, 3 × 10 4 cells were dispersed in 100 μL of serum-free culture medium and placed onto the membranes, which were then closely attached to the top chamber of the Transwell insert (Corning 3422). The insert was then transferred to a 24-well plate filled with 500 μL of culture medium containing 10% FBS.…”