Enhancing Antibacterial Efficacy and Patient Biocompatibility in Spinal Fusion Cages with Novel Cage Design

Introduction: Spinal fusion utilizes cage structures to provide mechanical stability and alleviate chronic back pain. Current Polyetheretherketone (PEEK) cages have a high rate of implant failure, low bioactivity, and bacterial infections. The integration of novel bioactive ceramics with Fused Filament Fabrication (FFF) may enhance osseointegration while reducing the risk of implant failure and infection. Here, we evaluate the biocompatibility, bioactivity, and antibacterial attributes of Bio-PEEK as a potential solution.

Methods: Biocompatibility was assessed using an inductively coupled plasma (ICP) analysis. Mouse pre-osteoblasts were seeded directly onto the filaments. The cages were immersed in Simulated Body Fluid (SBF) at 37°C for 7 days; the amount of bone-like apatite deposited was compared to determine bioactivity. Cell growth kinetics were determined using a Thiazolyl blue tetrazolium bromide (MTT) assay. Antimicrobial properties were assessed using LIVE/DEAD analysis. Inhibition of biofilm formation was confirmed using scanning electron microscopy (SEM) images, comparing the adherence of S. aureus on Bio-PEEK to that on bare PEEK.

Results: Bio-PEEK demonstrated improved biocompatibility and bioactivity compared to PEEK, as the number of cells adhered to Bio-PEEK and the amount of bone-like apatite deposited on Bio-PEEK was higher following experimentation. Bio-PEEK also exhibited faster cell growth kinetics and LIVE/DEAD analyses indicated lower bacterial growth compared to bare PEEK, while the number of dead bacteria was higher. SEM image analysis demonstrated Bio-PEEK’s ability to inhibit biofilm formation, as fewer staphylococcus aureus adhered to Bio-PEEK compared to bare PEEK.

Conclusion : The results suggest that Bio-PEEK demonstrates improved biocompatibility, bioactivity, and antibacterial properties compared to PEEK. These cages could minimize the use of expensive bone-stimulating proteins, lower the risk of infections, and lead to the development of multi-functional implants with reconstructive applications. These advances set the stage for personalized implants with wider reconstructive potential. Building upon advancements in material science and fabrication techniques, Bio-PEEK offers a promising future.