Engineering Nitric Oxide-Releasing Antimicrobial Dental Coating for Targeted Gingival Therapy

Bacterial biofilms play a central role in the development and progression of periodontitis, a chronic inflammatory condition that affects the oral cavity. One solution to current treatment constraints is using nitric oxide (NO)─with inherent antimicrobial properties. In this study, an antimicrobial coating is developed from the NO donor S-nitroso-N-acetylpenicillamine (SNAP) embedded within polyethylene glycol (PEG) to prevent periodontitis. The SNAP-PEG coating design enabled a controlled NO release, achieving tunable NO levels for more than 24 h. Testing the SNAP-PEG composite on dental floss showed its effectiveness as a uniform and bioactive coating. The coating exhibited antibacterial properties against Streptococcus mutans and Escherichia coli, with inhibition zones measuring up to 7.50 ± 0.28 and 14.80 ± 0.46 mm2, respectively. Furthermore, SNAP-PEG coating materials were found to be stable when stored at room temperature, with 93.65% of SNAP remaining after 28 d. The coatings were biocompatible against HGF and hFOB 1.19 cells through a 24 h controlled release study. This study presents a facile method to utilize controlled NO release with dental antimicrobial coatings comprising SNAP-PEG. This coating can be easily applied to various substrates, providing a user-friendly approach for targeted self-care in managing gingival infections associated with periodontitis.

Genistein binding protein targets in dental pathogens

Oral pathogens have created a menace in recent years due to biofilm formation and antimicrobial drug resistance. The current treatment strategy works well with antibiotics. However, constant use of antibiotics creates a selective pressure, which increases adaptability of the pathogens. Therefore, it is of interest to analyze the potential targets of genistein in dental pathogens using computer aided prediction tools.

Lactobacillus plantarum Lipoteichoic Acids Possess Strain-Specific Regulatory Effects on the Biofilm Formation of Dental Pathogenic Bacteria

Bacterial biofilm residing in the oral cavity is closely related to the initiation and persistence of various dental diseases. Previously, we reported the anti-biofilm activity of Lactobacillus plantarum lipoteichoic acid (Lp.LTA) on a representative dental cariogenic pathogen, Streptococcus mutans. Since LTA structure varies in a bacterial strain-specific manner, LTAs from various L. plantarum strains may have differential anti-biofilm activity due to their distinct molecular structures. In the present study, we isolated Lp.LTAs from four different strains of L. plantarum (LRCC 5193, 5194, 5195, and 5310) and compared their anti-biofilm effects on the dental pathogens, including S. mutans, Enterococcus faecalis, and Streptococcus gordonii. All Lp.LTAs similarly inhibited E. faecalis biofilm formation in a dose-dependent manner. However, their effects on S. gordonii and S. mutans biofilm formation were different: LRCC 5310 Lp.LTA most effectively suppressed the biofilm formation of all strains of dental pathogens, while Lp.LTAs from LRCC 5193 and 5194 hardly inhibited or even enhanced the biofilm formation. Furthermore, LRCC 5310 Lp.LTA dramatically reduced the biofilm formation of the dental pathogens on the human dentin slice infection model. Collectively, these results suggest that Lp.LTAs have strain-specific regulatory effects on biofilm formation of dental pathogens and LRCC 5310 Lp.LTA can be used as an effective anti-biofilm agent for the prevention of dental infectious diseases.

Graphene Oxide Enables the Reosteogenesis of Previously Contaminated Titanium In Vitro

The main goal of peri-implantitis treatment is to control infection and arrest bone loss, which requires the removal of polymicrobial biofilms on the implant surface and the reduction of tissue invasion. Additionally, prognosis can be improved if reosseointegration occurs on previously contaminated implants. To evaluate whether graphene oxide (GO) can remove polymicrobial biofilms, biofilms were established on titanium surfaces in vitro and treated with different methods: group B, removed only with brushing; group G, treated with different GO concentrations (64, 128, 256, and 512 μg/mL); group GB, combined treatments of groups B and G; and group C, untreated. Subsequently, to evaluate reosteogenesis on previously contaminated titanium, 4 groups were used: groups C, B, GB-256, and GB-512 (treated with 256 and 512 μg/mL of GO, respectively). Intact clean titanium (IC) was used as a control. Additionally, cell behavior on IC treated with GB-256 (IGB-256) and GB-512 (IGB-512) was compared with that of the GB-256 and GB-512 groups, respectively. The results showed that at high concentrations (≥256 μg/mL), GO eliminated residual bacteria and inhibited biofilm reformation after brushing, whereas neither GO nor brushing alone could achieve this. Bone marrow-derived mesenchymal stem cell viability in groups GB-256 and IC was higher than that in groups GB-512, C, and B (P < 0.05). No significant difference was found between group GB-256 and group IC (P > 0.05). Osteogenic differentiation of bone marrow-derived mesenchymal stem cells in group GB-256 was higher than that in groups IC, GB-512, C, and B. No difference was found between groups IGB-256 and IGB-512 and groups GB-256 and GB-512, respectively (P > 0.05). In conclusion, 256 μg/mL of GO combined with brushing significantly removed polymicrobial biofilms that remained on the previously contaminated titanium surfaces. The bone marrow-derived mesenchymal stem cell osteogenic potential was regained or even enhanced on the titanium surfaces treated this way in vitro, which might provide a new idea for treating peri-implantitis.

Killing dental pathogens using antibacterial graphene oxide

Dental caries and periodontal diseases have a close relationship with microbes such as Streptococcus mutans, Porphyromonas gingivalis and Fusobacterium nucleatum. Graphene oxide (GO), as the derivative of graphene, plays an important role in many areas including biology and medicine. In particular, it has been known as a promising antimicrobial nanomaterial. In this study, we focused on the antimicrobial property of GO against dental pathogens. With the utilization of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduced test, colony forming units (CFU) counting, growth curve observation, live/dead fluorescent staining, and confocal laser scanning microscopy (CLSM), we found GO nanosheets were highly effective in inhibiting the growth of dental pathogens. Transmission electron microscopy (TEM) images revealed that the cell wall and membrane of bacteria lost their integrity and the intracellular contents leaked out after they were treated by GO. Therefore, GO nanosheets would be an effective antibacterial material against dental pathogens and the potential applications in dental care and therapy are promising.