Zinc-Doped Bioactive Glass/Polycaprolactone Hybrid Scaffolds Manufactured by Direct and Indirect 3D Printing Methods for Bone Regeneration.

A novel organic-inorganic hybrid, based on SiO2-CaO-ZnO bioactive glass (BG) and polycaprolactone (PCL), associating the highly bioactive and versatile bioactive glass with clinically established PCL was examined. The BG-PCL hybrid is obtained by acid-catalyzed silica sol-gel process inside PCL solution either by direct or indirect printing. Apatite-formation tests in simulated body fluid (SBF) confirm the ion release along with the hybrid's bone-like apatite forming. Kinetics differ significantly between directly and indirectly printed scaffolds, the former requiring longer periods to degrade, while the latter demonstrates faster calcium phosphate (CaP) formation. Remarkably, Zn diffusion and accumulation are observed at the surface within the newly formed active CaP layer. Zn release is found to be dependent on printing method and immersion medium. Investigation of BG at the atomic scale reveals the ambivalent role of Zn, capable of acting both as a network modifier and as a network former linking the BG silicate network. In addition, hMSCs viability assay proves no cytotoxicity of the Zn hybrid. LIVE/DEAD staining demonstrated excellent cell viability and proliferation for over seven weeks. Overall, this hybrid material either non-doped or doped with a metal trace element is a promising candidate to be translated to clinical applications for bone regeneration.

The Use of Antibiotic Impregnated Cement Spacers in the Treatment of Infected Total Joint Replacement: Challenges and Achievements.

Two stage total hip arthroplasty revision surgery includes foreign material debridment, insertion of antibiotic impregnated cement spacer, and finally, reimplantation of the prosthesis. This review has aimed to evaluate the efficacy of antibiotic impregnated cement spacers in infection control and eradication in arthroplasties. A total of 85 articles on total hip arthroplasty were used in this narrative literature review. High concentrations of the antibiotic in targeted drug delivery by means of using antibiotic impregnated cement spacers is effective against infections while reduces the side effects of systemic antibiotic therapy. This results in prevention of bone and muscle atrophy as well as size discrepancy. Also, antibiotic impregnated cement spacers reduce dead space and help stabilize the limb in total hip arthroplasty. Despite all reported drawbacks, antibiotic impregnated cement spacers seem effective in eradicationg infections, although a consensus has not been yet achieved.