In Vitro Evaluation of the Antibacterial Properties and Cellular Response of Liquid-Leukocyte Platelet-Rich Fibrin Products on Barrier Membranes: A Pilot Study

<b>Background:</b> Barrier membranes (BMs) have been used in dental surgical procedures for decades, but their exposure can increase the risk of infections and compromise healing from regenerative procedures. Liquid-leukocyte platelet-rich fibrin (LPRF) products have shown antimicrobial effects and enhance wound healing. This in vitro study aimed to evaluate the antimicrobial effects and cellular responses of LPRF products as adjunctive treatments for barrier membranes, hypothesizing that the two liquid LPRF products could improve antibacterial activity against selected oral pathogen species and augment human gingival fibroblast cellular proliferation on BM. <b>Methods:</b> LPRF exudate (LPRF-EX) and liquid fibrinogen (PLyf), human LPRF products, were prepared with recommended centrifugation protocols and used to treat resorbable (Bio-gide^®) and non-resorbable (Cyto-plast™) BMs. Human gingival fibroblasts (HGFs) were cultured on the treated and untreated BMs. Scanning electron microscopy (SEM) was applied to observe cell adhesion, and CCK-8 assays were used to study cell proliferation. Oral <i>P. gingivalis</i> and <i>A. naeslundii</i> were incubated with the BMs. Bacterial adhesion was visualized using SEM, and colony-forming unit (CFU) counts were obtained. <b>Results:</b> SEM images showed markedly greater fibrin network formation after 7 days on resorbable BM (Bio-gide^®) treated with PLyF, but with no notable differences in other resorbable BM or non-resorbable BM groups with both treatments. CCK-8 assays showed non-significant effects on HGF proliferation at 3 and 5 days. SEM showed <i>A. naeslundii</i> growth inhibition in the LPRF-EX- and PLyf-treated BMs, and the greatest reduction in CFU counts of both <i>P. gingivalis</i> and <i>A. naeslundii</i> was noted with treated Cytoplast™. <b>Conclusions:</b> Within the limitations of this preliminary study, it can be concluded that the LPRF-EX and PLyf treatment of BM induced an antimicrobial effect. Their effects on cellular response were unclear due to the lack of significant findings on SEM analysis.