Antibacterial effect of autologous fibrin matrices

Tissue engineering has emerged as a new treatment approach for bone repair and regeneration seeking to address limitations associated with current therapies. Local drug delivery is alternative solution to increase local drug concentrations and decreased systemic toxicity. Aim of the study was to determine antibacterial efficiency of autologous Platelet -rich fibrin (PRF) derived from a patient blood with and without vancomycin-containing microcapsules. Antibacterial efficiency was tested via the disk diffusion test. Bacterial suspension with optical density 0.5 was prepared according to the McFarland standard and were inoculated on Mueller hinton (MH) agar. Hydrogels were placed on the plates and incubated for 24 hours at 37 °C. Antibacterial properties were detected by measuring a sterile zone (diameter) around the hydrogels. Samples were transferred on fresh MH plates with bacterial inoculum, and were incubated for an additional 24 hours.  In this study 3 types of of Hydrogels were used: Fibrin/MK_Vancomycin (Vanc), Fibrin/MK_Blank (Blank micro) and Fibrin Blank_Blank (Blank O). For drug release Vancomycin hydrochloride and poly(lactic-co-glycolic acid) (PLGA) microcapsules were used as drug delivery system. Antibacterial efficiency was tested using Staphylococcus aureus (ATCC 25923) reference culture. The maximum duration of antibacterial effect in Fibrin/MK_Vancomycin samples was observed for 48 h. For the first 24 h, the mean diameter of the sterile area around the samples is 30 mm. For the next 24 h, the diameter of the sterile area is reduced by 50%. No antibacterial properties were observed for MK_Blank and Blank_Blank samples. The major release of vancomycin from the samples occurs in the first 24 h. Further work is needed to improve the method to ensure the release of all antibiotics from the samples.Acknowledgment The authors acknowledge financial support from the Latvian Council of Science research project No. lzp-2020/1-0054 “Development of antibacterial autologous fibrin matrices in maxillofacial surgery (MATRI-X)”.