Antimicrobial Effects of Novel Triple Antibiotic Paste–Mimic Scaffolds on Actinomyces naeslundii Biofilm

Abstract

Introduction Actinomyces naeslundii has been recovered from traumatized permanent teeth diagnosed with necrotic pulps. In this work, a triple antibiotic paste (TAP)–mimic scaffold is proposed as a drug-delivery strategy to eliminate A. naeslundii dentin biofilm. Methods Metronidazole, ciprofloxacin, and minocycline were added to a polydioxanone (PDS) polymer solution and spun into fibrous scaffolds. Fiber morphology, mechanical properties, and drug release were investigated by using scanning electron microscopy, microtensile testing, and high-performance liquid chromatography, respectively. Human dentin specimens (4 × 4 × 1 mm3, n = 4/group) were inoculated with A. naeslundii (ATCC 43146) for 7 days for biofilm formation. The infected dentin specimens were exposed to TAP-mimic scaffolds, TAP solution (positive control), and pure PDS (drug-free scaffold). Dentin infected (7-day biofilm) specimens were used for comparison (negative control). Confocal laser scanning microscopy was done to determine bacterial viability. Results Scaffolds displayed a submicron mean fiber diameter (PDS = 689 ± 312 nm and TAP-mimic = 718 ± 125 nm). Overall, TAP-mimic scaffolds showed significantly (P ≤ .040) lower mechanical properties than PDS. Within the first 24 hours, a burst release for all drugs was seen. A sustained maintenance of metronidazole and ciprofloxacin was observed over 4 weeks, but not for minocycline. Confocal laser scanning microscopy demonstrated complete elimination of all viable bacteria exposed to the TAP solution. Meanwhile, TAP-mimic scaffolds led to a significant (P < .05) reduction in the percentage of viable bacteria compared with the negative control and PDS. Conclusions Our findings suggest that TAP-mimic scaffolds hold significant potential in the eradication/elimination of bacterial biofilm, a critical step in regenerative endodontics.

Antibacterial TAP-mimic electrospun polymer scaffold: effects on P. gingivalis-infected dentin biofilm

“…In brief, violet-colored PDS sutures were cut (ca. 2-3 cm) and incubated in dichloromethane (Sigma-Aldrich, St. Louis, MO, USA) at room temperature (RT) for 2 days to remove the dye [15-19]. Next, clear PDS pieces were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFP, Sigma-Aldrich).…”

“…During electrospinning, electrical voltage between 15-19 kV was applied to the needle using a high voltage power supply (ES50P-10W/DAM, Gamma High-Voltage Research, Inc., Ormond Beach, FL, USA). After electrospinning, the scaffolds were removed from the mandrel and placed under vacuum at RT for 48 h to ensure complete elimination of any residual solvent prior to storage at 4°C [15-19]. …”

“…Twenty-four recently extracted, caries-free, non-restored human canine teeth were cleansed and stored in 0.1% thymol until used [18,19]. The crowns were sectioned using a diamond disc.…”

“…The crowns were sectioned using a diamond disc. Next, the teeth were cut along the bucco-lingual plane to obtain two halves for dentin specimen (4×4×1 mm 3 ) preparation [19]. The cementum was removed and the specimens were wet-finished with SiC papers (600-1200-grit).…”

“…Moreover, it has enabled the synthesis of bioactive ( i.e. , therapeutic drugs and growth factors) polymer-based nanofibrous scaffolds [11, 15-19]. Thus, the purpose of this in-vitro study was to investigate the effects of a recently developed antibiotic-containing TAP-mimic scaffold against an established P. gingivalis -infected dentin biofilm.…”