Han Wu

Mg-based implants with a sandwiched coating simultaneously facilitate antibacterial and osteogenic properties due to the synergistic biological effects of TCS and Mg²⁺.

To improve the bio-performances of porous polyetheretherketone (PPK) for bone repair, silicon nitride coated PPK (CSNPPK) was prepared by a method of suspension coating and melt binding. The results revealed that as compared with PPK, the surface roughness, compressive strength and water absorption of CSNPPK increased while the pore size and porosity of CSNPPK exhibited no obvious changes. In addition, the cellular responses (including attachment, proliferation and differentiation as well as osteogenic related gene expressions) of the MC3T3-E1 cells to CSNPPK were remarkably promoted compared with PPK and dense polyetheretherketone in vitro. Moreover, in the model of rabbit femoral condyle defects, the results of micro-CT, histological and mechanical evaluation revealed that the ingrowth of new vessels and bone tissues into CSNPPK were significantly more than PPK in vivo. Furthermore, the load-displacement and push-out loads for CSNPPK with bone tissues were higher than PPK, indicating good osseointegration. In short, CSNPPK not only promoted vascularization but also enhanced osteogenesis as well as osseointegration in vivo. Therefore, it can be suggested that CSNPPK with good biocompatibility, osteogenic activity and vascularization might be a promising candidate as an implant for bone substitute and repair.

A hierarchical nanostructural coating of amorphous SN on a PEEK surface was prepared by ICPECVD which exhibited excellent cytocompatibility and antibacterial activity.

To improve the antibacterial and osteogenic activities of polyetherketoneketone (PEKK), concentrated sulfuric acid (H2SO4) suspension with silicon nitride (SN) microparticle was utilized to modify PEKK surface. Through sulfonation reaction, microporous coatings of PEKK/SN composites were created on PEKK surface, which were integrated with PEKK substrate. The results showed that the content of SN in the microporous coatings increased with the increase of SN content in H2SO4 suspension (PKS without SN, PKSC5 and PKSC10 with 5wt% and 10wt% SN content in H2SO4) and the surface roughness and hydrophilicity of microporous coatings on PEKK were significantly improved with the SN content increasing. In addition, the microporous coating of PKSC10 with high SN content exhibited excellent antibacterial activity due to the synergistic action of the presence of amino (-NH2) and sulfonic acid (-SO3H) groups as well as the improvement of protein absorption. Moreover, the microporous coating of PKSC10 obviously stimulated adhesion, proliferation and osteogenic differentiation of rat bone mesenchymal stem cells. Furthermore, histological and push-out load evaluation indicated that the microporous coating of PKSC10 significantly promoted osteogenesis and osseointegration in vivo. The results suggested that the microporous coatings of PKSC10 with high SN content display good biocompatibility, antibacterial and osteogenic activities and osseointegration ability, which would have great potential for bone substitutes.