Carbon-carbon composite material as a potential basis for orthopedic implants

Aim . To determine the cytocompatibility of carbon-carbon composite materials (CCCM) and assess their ability to be impregnated with vancomycin. Materials and Methods. The study included samples of carbon-carbon composite materials (CCCM). The cytocompatibility of CCCM blocks was evaluated using a culture of eukaryotic cells (Vero cell line). Biofilms of S. aureus ATCC 29213 (MSSA), S. aureus ATCC 43300 (MRSA), S. epidermidis ATCC 12228 (MSSE), and S. epidermidis ATCC 29887 (MRSE) were formed by immersing sterile test samples of CCCM into a nutrient medium which contained bacteria. After 24-hour incubation, the samples were washed, placed in an ultrasonic bath, and sonication fluid was inoculated using the sector method. To saturate the CCCM blocks with antibiotics, they were placed into a vancomycin solution and then lyophilized under negative pressure with gradual heating. The antimicrobial activity of the resulting blocks was studied using the cup plate method against the same reference cultures of staphylococci. The dynamics of vancomycin elution from CCCM was investigated using high-performance liquid chromatography. Results . Vero cells maintained their viability in the presence of the tested material. Considering the highly porous structure of CCCM and variable diameter of the pores, we suggested a good osteointegration potential of this material. On the samples without an impregnation with an antibacterial drug, reference strains of staphylococci were able to form a biofilm with a sufficient number of bacterial cells to initiate an infectious process. The duration of antimicrobial activity of the antibioticim-pregnated samples against the reference staphylococcal strains was up to 3 days. The majority of the antibiotic eluted from the CCCM into the incubation medium during the first two days. Conclusion . The cytocompatibility and porosity of CCCM in combination with a vancomycin impregnation makes this material promising for the fabrication of implants with antimicrobial activity as well as tissue engineering constructs.