Enzymes in therapy of biofilm-related oral diseases

The efficacy and safety of an enzyme-containing lozenge for dental biofilm control-a randomized controlled pilot trial

OBJECTIVES

To evaluate the effect of daily use of a multiple-enzyme lozenge on de novo plaque formation, on gingivitis development, and on the oral microbiome composition.

METHODS

This trial with two parallel arms included 24 healthy adults allocated to the Active (n = 12) or Placebo (n = 12) group. Subjects consumed one lozenge three times daily for seven days, and no oral hygiene procedures were allowed. Differences in de novo plaque accumulation between a baseline period, and one and seven days of intervention were assessed by the Turesky-modification of the Quigley-and-Hein-Plaque-Index (TM-QHPI). The development of gingivitis after seven days of intervention was assessed by the Gingival Index (GI). Plaque and saliva samples were collected at baseline and after seven days of intervention, and evaluated by 16S rRNA gene sequencing.

RESULTS

All subjects completed the study, and no adverse events were reported. After one day, the average TM-QHPI was significantly lower in the Active than in the Placebo group, as compared to baseline (p = 0.012). After 7 days, average TM-QHPI values did not differ significantly between groups (p = 0.37). GI values did not increase during the intervention period, with no difference between groups (p = 0.62). Bacterial richness increased in both plaque and saliva samples over a seven-day oral hygiene-free period, with a statistically significant difference for the saliva samples (p = 0.0495) between groups.

CONCLUSIONS

A multiple-enzymes lozenge decreased the build-up of de novo plaque after one day and slowed down the process of species increment in saliva. The lozenge may be an adjunct to regular mechanical plaque removal.

CLINICAL SIGNIFICANCE

Dental plaque is the main cause of caries, gingivitis, and periodontitis. The search for therapeutic adjuncts to mechanical plaque removal that have no harmful effects on the oral microbiome is important. Treatment with multiple plaque-matrix degrading enzymes is a promising non-biocidal approach to plaque control.

Effect of mutanase and dextranase on biofilms of cariogenic bacteria: A systematic review of in vitro studies

Matrix-degrading enzymes are promising non-biocidal adjuncts to dental biofilm control and caries prevention. By disrupting the biofilm matrix structure, enzymes may prevent biofilm formation or disperse established biofilms without compromising the microbial homeostasis in the mouth. This study reviewed whether treatment with mutanase and/or dextranase inhibits cariogenic biofilm growth and/or removes cariogenic biofilms in vitro. An electronic search was conducted in PubMed, EMBASE, Scopus, Web of Science, Cochrane, and LIVIVO databases. Manual searches were performed to identify additional records. Studies that quantitatively measured the effect of mutanase and/or dextranase on the inhibition/removal of in vitro cariogenic biofilms were considered eligible for inclusion. Out of 809 screened records, 34 articles investigating the effect of dextranase (n = 23), mutanase (n = 10), and/or combined enzyme treatment (n = 7) were included in the review. The overall risk of bias of the included studies was moderate. Most investigations used simple biofilm models based on one or few bacterial species and employed treatment times ≥30 min. The current evidence suggests that mutanase and dextranase, applied as single or combined treatment, are able to both inhibit and remove in vitro cariogenic biofilms. The pooled data indicate that enzymes are more effective for biofilm inhibition than removal, and an overall higher effect of mutanase compared to dextranase was observed.

The potential use of nanozymes as an antibacterial agents in oral infection, periodontitis, and peri-implantitis

Several studies suggest that oral pathogenic biofilms cause persistent oral infections. Among these is periodontitis, a prevalent condition brought on by plaque biofilm. It can even result in tooth loss. Furthermore, the accumulation of germs around a dental implant may lead to peri-implantitis, which damages the surrounding bone and gum tissue. Furthermore, bacterial biofilm contamination on the implant causes soft tissue irritation and adjacent bone resorption, severely compromising dental health. On decontaminated implant surfaces, however, re-osseointegration cannot be induced by standard biofilm removal techniques such as mechanical cleaning and antiseptic treatment. A family of nanoparticles known as nanozymes (NZs) comprise highly catalytically active multivalent metal components. The most often employed NZs with antibacterial activity are those that have peroxidase (POD) activity, among other types of NZs. Since NZs are less expensive, more easily produced, and more stable than natural enzymes, they hold great promise for use in various applications, including treating microbial infections. NZs have significantly contributed to studying implant success rates and periodontal health maintenance in periodontics and implantology. An extensive analysis of the research on various NZs and their applications in managing oral health conditions, including dental caries, dental pulp disorders, oral ulcers, peri-implantitis, and bacterial infections of the mouth. To combat bacteria, this review concentrates on NZs that imitate the activity of enzymes in implantology and periodontology. With a view to the future, there are several ways that NZs might be used to treat dental disorders antibacterially.

The effect of bovine trypsin on dental biofilm dispersion: an in vitro study

To investigate the degradation effect of bovine trypsin on multispecies biofilm of caries-related bacteria and provide an experimental foundation for the prevention of dental caries. Standard strains of S. mutans, S. sanguis, S. gordonii, and L. acidophilus were co-cultured to form 24 h, 48 h, and 72 h biofilms. The experimental groups were treated with bovine trypsin for 30 s, 1 min, and 3 min. Morphological observation and quantitative analysis of extracellular polymeric substances (EPS), live bacteria, and dead bacteria were conducted using the confocal laser scanning microscope (CLSM). The morphological changes of EPS and bacteria were also observed using a scanning electron microscope (SEM). When biofilm was treated for 1 min, the minimal inhibitory concentration (MIC) of bovine trypsin to reduce EPS was 0.5 mg/mL in 24 h and 48 h biofilms, and the MIC of bovine trypsin was 2.5 mg/mL in 72 h biofilms (P < 0.05). When biofilm was treated for 3 min, the MIC of bovine trypsin to reduce EPS was 0.25 mg/mL in 24 h and 48 h biofilms, the MIC of bovine trypsin was 1 mg/mL in 72 h biofilm (P < 0.05). The ratio of live-to-dead bacteria in the treatment group was significantly lower than blank group in 24 h, 48 h, and 72 h multispecies biofilms (P < 0.05). Bovine trypsin can destroy multispecies biofilm structure, disperse biofilm and bacteria flora, and reduce the EPS and bacterial biomass in vitro, which are positively correlated with the application time and concentration.

The Effect of Enzymatic Treatment with Mutanase, Beta-Glucanase, and DNase on a Saliva-Derived Biofilm Model

INTRODUCTION

The dental biofilm matrix is an important determinant of virulence for caries development and comprises a variety of extracellular polymeric substances that contribute to biofilm stability. Enzymes that break down matrix components may be a promising approach to caries control, and in light of the compositional complexity of the dental biofilm matrix, treatment with multiple enzymes may enhance the reduction of biofilm formation compared to single enzyme therapy. The present study investigated the effect of the three matrix-degrading enzymes mutanase, beta-glucanase, and DNase, applied separately or in combinations, on biofilm prevention and removal in a saliva-derived in vitro-grown model.

METHODS

Biofilms were treated during growth to assess biofilm prevention or after 24 h of growth to assess biofilm removal by the enzymes. Biofilms were quantified by crystal violet staining and impedance-based real-time cell analysis, and the biofilm structure was visualized by confocal microscopy and staining of extracellular DNA (eDNA) and polysaccharides.

RESULTS

The in vitro model was dominated by Streptococcus spp., as determined by 16S rRNA gene amplicon sequencing. All tested enzymes and combinations had a significant effect on biofilm prevention, with reductions of >90% for mutanase and all combinations including mutanase. Combined application of DNase and beta-glucanase resulted in an additive effect (81.0% ± 1.3% SD vs. 36.9% ± 21.9% SD and 48.2% ± 14.9% SD). For biofilm removal, significant reductions of up to 73.2% ± 5.5% SD were achieved for combinations including mutanase, whereas treatment with DNase had no effect. Glucans, but not eDNA decreased in abundance upon treatment with all three enzymes.

CONCLUSION

Multi-enzyme treatment is a promising approach to dental biofilm control that needs to be validated in more diverse biofilms.

Influence of Gallic Acid-Containing Mouth Spray on Dental Health and Oral Microbiota of Healthy Dogs: A Pilot Study

The pilot study aimed to investigate the effects of GAMS on oral microbiota in healthy dog subjects. Thirty-eight dogs were recruited and randomly allocated to the placebo (n = 19) and treatment groups (n = 19). The dogs were treated with mouth spray once daily for 42 days. The changes in the gingival index (GI), plaque index (PI), and calculus index (CI) were measured at baseline (day 0) and end of the study (42nd day). The changes in the oral microbial composition of representative dogs (placebo, n = 7; and treatment, n = 7) were also evaluated at baseline and end of the study. Oral microbial composition was assessed by sequencing. The sequences were annotated using the QIIME 2.0^TM. The GI, PI, and CI indexes were reduced after the GAMS usage. The abundance of the commensal bacterial phylum Actinobacteria and Chloroflexi, genera Frederiksenia, and Bergeyella was improved after six weeks of GAMS usage. GAMS reduced the pathogenic bacterial species, including Neisseria sp., Desulfobulbus sp., Capnocytophaga canis, and Corynebacterium mustelae. Moreover, some pathogenic bacterial abundances were increased at the end of the study. All the microbial variations were observed within the group. The inter-group analysis revealed that the changes were unrelated to GAMS usage. Further studies need to be carried out using more experimental subjects to confirm the effectiveness of GAMS. More metagenomic data are required to evidence the GMAS impact on the oral microbiome of healthy dogs.

Clinical Trial Data on the Mechanical Removal of 14-Day-Old Dental Plaque Using Accelerated Micro-Droplets of Air and Water (Airfloss)

Novel strategies to combat dental biofilms aim at reducing biofilm stability with the ultimate goal of facilitating mechanical cleaning. To test the stability of dental biofilms, they need to be subjected to a defined mechanical stress. Here, we employed an oral care device (Airfloss) that emits microbursts of compressed air and water to apply a defined mechanical shear to 14-day-old dental plaque in 20 healthy participants with no signs of oral diseases (clinical trial no. NCT05082103). Exclusion criteria included pregnant or nursing women, users of oral prostheses, retainers or orthodontic appliances, and recent antimicrobial or anti-inflammatory therapy. Plaque accumulation, before and after treatment, was assessed using fluorescence images of disclosed dental plaque on the central incisor, first premolar, and first molar in the third quadrant (120 images). For each tooth, the pre- and post-treatment plaque percentage index (PPI) and Turesky modification of the Quigley-Hein plaque index (TM-QHPI) were recorded. The mean TM-QHPI significantly decreased after treatment (p = 0.03; one-sample sign test), but no significant difference between the mean pre- and post-treatment PPI was observed (p = 0.09; one-sample t-test). These data are of value for researchers that seek to apply a defined mechanical shear to remove and/or disrupt dental biofilms.

Revisiting Periodontal Disease in Dogs: How to Manage This New Old Problem?

Periodontal disease (PD) is one of the most prevalent oral inflammatory diseases in dogs. PD onset begins with the formation of a polymicrobial biofilm (dental plaque) on the surface of the teeth, followed by a local host inflammatory response. To manage this disease, several procedures focusing on the prevention and control of dental plaque establishment, as well as on the prevention of local and systemic PD-related consequences, are essential. The removal of dental plaque and the inhibition of its formation can be achieved by a combination of dental hygiene homecare procedures including tooth brushing, the application of different oral products and the use of specific diet and chew toys, and regular professional periodontal procedures. Additionally, in some cases, periodontal surgery may be required to reduce PD progression. Associated with these measures, host modulation therapy, antimicrobial therapy, and other innovative therapeutic options may be useful in PD management. Moreover, PD high prevalence and its relation with potential local and systemic consequences reinforce the need for investment in the development of new preventive measures, treatments, and oral procedures to improve the control of this disease in dogs. Knowledge on the specific guidelines and diversity of the available products and procedures are fundamental to apply the most adequate treatment to each dog with PD.

Purification and characterization of cold-adapted and salt-tolerant dextranase from Cellulosimicrobium sp. THN1 and its potential application for treatment of dental plaque

The cold-adapted and/or salt-tolerant enzymes from marine microorganisms were confirmed to be meritorious tools to enhance the efficiency of biocatalysis in industrial biotechnology. We purified and characterized a dextranase CeDex from the marine bacterium Cellulosimicrobium sp. THN1. CeDex acted in alkaline pHs (7.5-8.5) and a broad temperature range (10-50°C) with sufficient pH stability and thermostability. Remarkably, CeDex retained approximately 40% of its maximal activities at 4°C and increased its activity to 150% in 4 M NaCl, displaying prominently cold adaptation and salt tolerance. Moreover, CeDex was greatly stimulated by Mg2+, Na+, Ba2+, Ca2+ and Sr2+, and sugarcane juice always contains K+, Ca2+, Mg2+ and Na+, so CeDex will be suitable for removing dextran in the sugar industry. The main hydrolysate of CeDex was isomaltotriose, accompanied by isomaltotetraose, long-chain IOMs, and a small amount of isomaltose. The amino acid sequence of CeDex was identified from the THN1 genomic sequence by Nano LC-MS/MS and classified into the GH49 family. Notably, CeDex could prevent the formation of Streptococcus mutans biofilm and disassemble existing biofilms at 10 U/ml concentration and would have great potential to defeat biofilm-related dental caries.

Effect of an enzyme-containing mouthwash on the dental biofilm and salivary microbiome in patients with fixed orthodontic appliances: a randomized placebo-controlled pilot trial

BACKGROUND

Mouthwashes containing oral antiseptics or enzymes are suggested suitable for controlling biofilm accumulation in patients with fixed appliances and thereby limiting unwanted side effects during the orthodontic treatment.

OBJECTIVES

To evaluate the effect of an enzyme-based mouthwash on the amount of dental biofilm and the composition of the salivary microbiome in patients undergoing treatment with fixed orthodontic appliances.

TRIAL DESIGN

Randomized double-blind placebo-controlled trial.

MATERIAL AND METHODS

In total, 35 young adolescents (14-18 years) under treatment with fixed appliances were consecutively enrolled and randomly allocated to an experimental or a placebo group by opening a computer-generated numbered envelope. The subjects were instructed to rinse twice daily during an intervention period of 8 days with experimental mouthwash or placebo without active enzymes. Unstimulated whole saliva samples were collected at baseline and after 8 days. The participants and examiner were blinded for the allocation. The primary outcome was the Orthodontic Plaque Index (OPI) and the secondary was the composition of the salivary microbiome.

RESULTS

In total, 28 adolescents (21 females and 7 males) completed the trial and there were no differences in age, clinical, or microbial findings between the test (n = 14) and the placebo group (n = 14) at baseline. We found a decreased OPI in the test group after 8 days and the difference was statistically significant compared with the placebo group (P < 0.05). There were no significant treatment effects on the richness and global composition of the salivary microbiome.

HARMS

In total, one participant in the test group claimed nausea and abandoned the project. In total, two participants did not like the taste of the mouthwash but used it as instructed. No other adverse events or side effects were reported.

LIMITATIONS

Short-term pilot trials may by nature be sensitive for selection and performance biases and are not designed to unveil persisting effects.

CONCLUSION

Daily use of enzyme-containing mouthwash reduced the amount of dental biofilm in adolescents under treatment with the fixed orthodontic appliances, without affecting the composition of the salivary microbiota.

ETHICAL APPROVAL

Approved by the Regional Ethical Board, Lund, Sweden (Dnr 2020-05221).

CLINICAL TRIAL REGISTRATION

NCT05033015.

Recent Advances in the Control of Clinically Important Biofilms

Biofilms are complex structures formed by bacteria, fungi, or even viruses on biotic and abiotic surfaces, and they can be found in almost any part of the human body. The prevalence of biofilm-associated diseases has increased in recent years, mainly because of the frequent use of indwelling medical devices that create opportunities for clinically important bacteria and fungi to form biofilms either on the device or on the neighboring tissues. As a result of their resistance to antibiotics and host immunity factors, biofilms have been associated with the development or persistence of several clinically important diseases. The inability to completely eradicate biofilms drastically increases the burden of disease on both the patient and the healthcare system. Therefore, it is crucial to develop innovative ways to tackle the growth and development of biofilms. This review focuses on dental- and implant-associated biofilm infections, their prevalence in humans, and potential therapeutic intervention strategies, including the recent advances in pharmacology and biomedical engineering. It lists current strategies used to control the formation of clinically important biofilms, including novel antibiotics and their carriers, antiseptics and disinfectants, small molecule anti-biofilm agents, surface treatment strategies, and nanostructure functionalization, as well as multifunctional coatings particularly suitable for providing antibacterial effects to the surface of implants, to treat either dental- or implant-related bacterial infections.

Innovations in Chewable Formulations: The Novelty and Applications of 3D Printing in Drug Product Design

Since their introduction, chewable dosage forms have gained traction due to their ability to facilitate swallowing, especially in paediatric, geriatric and dysphagia patients. Their benefits stretch beyond human use to also include veterinary applications, improving administration and palatability in different animal species. Despite their advantages, current chewable formulations do not account for individualised dosing and palatability preferences. In light of this, three-dimensional (3D) printing, and in particular the semi-solid extrusion technology, has been suggested as a novel manufacturing method for producing customised chewable dosage forms. This advanced approach offers flexibility for selecting patient-specific doses, excipients, and organoleptic properties, which are critical for ensuring efficacy, safety and adherence to the treatment. This review provides an overview of the latest advancements in chewable dosage forms for human and veterinary use, highlighting the motivations behind their use and covering formulation considerations, as well as regulatory aspects.

Inhibitory effect of ficin on Candida albicans biofilm formation and pre-formed biofilms

BACKGROUND

To investigate the effect of ficin, a type of proteases, on Candida albicans (C. albicans) biofilm, including forming and pre-formed biofilms.

METHODS

Crystal violet tests together with colony forming unit (CFU) counts were used to detect fungal biofilm biomass. Live/dead staining of biofilms observed by confocal laser scanning microscopy was used to monitor fungal activity. Finally, gene expression of C. albicans within biofilms was assessed by qRT-PCR.

RESULTS

According to our results, biofilm biomass was dramatically reduced by ficin in both biofilm formation and pre-formed biofilms, as revealed by the crystal violet assay and CFU count (p < 0.05). Fungal activity in biofilm formation and pre-formed biofilms was not significantly influenced by ficin according to live/dead staining. Fungal polymorphism and biofilm associated gene expression were influenced by ficin, especially in groups with prominent antibiofilm effects.

CONCLUSIONS

In summary, ficin effectively inhibited C. albicans biofilm formation and detached its preformed biofilm, and it might be used to treat C. albicans biofilm associated problems.

Oral Dysbiosis and Neurodegenerative Diseases: Correlations and Potential Causations

Biofilms are a heterogenous complex community of vegetative cells and extracellular polymeric substances that can adhere to various surfaces and are responsible for a variety of chronic and acute diseases. The impact of bacterial biofilms on oral and intestinal health is well studied, but the correlation and causations of biofilms and neurodegenerative diseases are still in their infancy. However, the correlations between biofilms and diseases such as Alzheimer’s Disease, Multiple Sclerosis, and even Parkinson’s Disease are starting to demonstrate the role bacterial biofilms have in promoting and exasperating various illnesses. The review article provides insight into the role bacterial biofilms may have on the development and progression of various neurodegenerative diseases and hopefully shine a light on this very important area of research.

Evaluation of antibiofilm potential of four-domain α-amylase from Streptomyces griseus against exopolysaccharides (EPS) of bacterial pathogens using Danio rerio

Biofilm formation is a major issue in healthcare settings as 75% of nosocomial infection arises due to biofilm residing bacteria. Exopolysaccharides (EPS), a key component of the biofilm matrix, contribute to the persistence of cells in a complex milieu and defends greatly from exogenous stress and demolition. It has been shown to be vital for biofilm scaffold and pathogenic features. The present study was aimed to investigate the effectiveness of four domain-containing α-amylase from Streptomyces griseus (SGAmy) in disrupting the EPS of multidrug-resistant bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. In vitro analysis of preformed biofilm unveiled the antibiofilm efficacy of SGAmy against MRSA (85%, p < 0.05) and P. aeruginosa (82%, p < 0.05). The total carbohydrate content in the EPS matrix of MRSA and P. aeruginosa was significantly reduced to 71.75% (p < 0.01) and 74.09% (p < 0.01), respectively. The findings inferred from in vitro analysis were further corroborated through in vivo studies using an experimental model organism, Danio rerio. Remarkably, the survival rate was extended to 88.8% (p < 0.05) and 74.2% (p < 0.05) in MRSA and P. aeruginosa infected fishes, respectively. An examination of gills, kidneys, and intestines of D. rerio organs depicted the reduced level of microbial colonization in SGAmy-treated cohorts and these findings were congruent with bacterial enumeration results.

Serum proteases prevent bacterial biofilm formation: role of kallikrein and plasmin

Biofilm formation is a general strategy for bacterial pathogens to withstand host defense mechanisms. In this study, we found that serum proteases inhibit biofilm formation by Neisseria meningitidis, Neisseria gonorrhoeae, Haemophilus influenzae, and Bordetella pertussis. Confocal laser-scanning microscopy analysis revealed that these proteins reduce the biomass and alter the architecture of meningococcal biofilms. To understand the underlying mechanism, the serum was fractionated through size-exclusion chromatography and anion-exchange chromatography, and the composition of the fractions that retained anti-biofilm activity against N. meningitidis was analyzed by intensity-based absolute quantification mass spectrometry. Among the identified serum proteins, plasma kallikrein (PKLK), FXIIa, and plasmin were found to cleave neisserial heparin-binding antigen and the α-peptide of IgA protease on the meningococcal cell surface, resulting in the release of positively charged polypeptides implicated in biofilm formation by binding extracellular DNA. Further experiments also revealed that plasmin and PKLK inhibited biofilm formation of B. pertussis by cleaving filamentous hemagglutinin. We conclude that the proteolytic activity of serum proteases toward bacterial adhesins involved in biofilm formation could constitute a defense mechanism for the clearance of pathogens.

Evaluation of the time-dependent efficacy of commercial denture or orthodontic appliance cleansers: An in vitro study

The aim of this study was to evaluate the antimicrobial, stain and protein removal efficacy of denture or orthodontic appliance cleansers using in vitro test methods. Experimental cleansers were applied for experimental time in each evaluation method. To evaluate the microorganism removal efficacy, C. albicans and S. mutans removal rate was calculated from the specimen surface. Stain and protein removal rate was calculated using the spectrophotometer. Experimental cleansers significantly affected the microorganism removal rate for both C. albicans and S. mutans, as well as the stain and protein removal rates, at each experimental time (p<0.05). As the application time increased, the stain and protein removal rates of all experimental cleansers significantly increased (p<0.05). The present study provided in vitro evaluation methods to assess the efficacy of denture or orthodontic appliance cleansers. Also, manufacturers and researchers can predict clinical outcomes and ensure proper hygiene management of dentures or orthodontic appliances.

Inhibition of Streptococcus mutans biofilm formation by strategies targeting the metabolism of exopolysaccharides

Dental caries is one of the most prevalent and costly biofilm-associated infectious diseases affecting most of the world's population. In particular, dental caries is driven by dysbiosis of the dental biofilm adherent to the enamel surface. Specific types of acid-producing bacteria, especially Streptococcus mutans, colonize the dental surface and cause damage to the hard tooth structure in the presence of fermentable carbohydrates. Streptococcus mutans has been established as the major cariogenic pathogen responsible for human dental caries, with a high ability to form biofilms. The exopolysaccharide (EPS) matrix, mainly contributed by S. mutans, has been considered as a virulence determinant of cariogenic biofilm. As EPS is an important virulence factor, targeting EPS metabolism could be useful in preventing cariogenic biofilm formation. This review summarizes plausible strategies targeting S. mutans biofilms by degrading EPS structure, inhibiting EPS production, and disturbing the EPS metabolism-related gene expression and regulatory systems.

The Inhibitory Effects of Ficin on Streptococcus mutans Biofilm Formation

To investigate the effects of ficin on biofilm formation of conditionally cariogenic Streptococcus mutans (S. mutans). Biomass and metabolic activity of biofilm were assessed using crystal violet assay, colony-forming unit (CFU) counting, and MTT assay. Extracellular polysaccharide (EPS) synthesis was displayed by SEM imaging, bacteria/EPS staining, and anthrone method while acid production was revealed by lactic acid assay. Growth curve and live/dead bacterial staining were conducted to monitor bacterial growth state in both planktonic and biofilm form. Total protein and extracellular proteins of S. mutans biofilm were analyzed by protein/bacterial staining and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), severally. qRT-PCR was conducted to detect acid production, acid tolerance, and biofilm formation associated genes. Crystal violet assay, CFU counting, and MTT assay showed that the suppression effect of ficin on S. mutans biofilm formation was concentration dependent. 4 mg/mL ficin had significant inhibitory effect on S. mutans biofilm formation including biomass, metabolic activity, EPS synthesis, and lactic acid production (p < 0.05). The growth curves from 0 mg/mL to 4 mg/mL ficin were aligned with each other. There was no significant difference among different ficin groups in terms of live/dead bacterial staining result (p > 0.05). Protein/bacterial staining outcome indicated that ficin inhibit both total protein and biofilm formation during the biofilm development. There were more relatively small molecular weight protein bands in extracellular proteins of 4 mg/mL ficin group when compared with the control. Generally, ficin could inhibit biofilm formation and reduce cariogenic virulence of S. mutans effectively in vitro; thus, it could be a potential anticaries agent.

Degradation of Staphylococcus aureus Biofilm Using Hydrolytic Enzymes Produced by Amazonian Endophytic Fungi

Microbial biofilms can cause serious health problems, since, due to their persistent character, they often function as spreaders of contaminants. Hydrolytic enzymes have a number of industrial applications and have been indicated as an alternative to the traditional chemical methods that are used to eradicate microbial biofilms. In this study, we evaluated the ability of enzymatic extracts produced by endophytic fungi isolated from the Amazonian species Myrcia guianensis to remove Staphylococcus aureus biofilms. After culture in liquid medium, the fungal hydrolytic extracts showed amylase (3.77 U/mL), lipase (3.84 U/mL), protease (3.63 U/mL), and xylanase (2.91 U/mL) activity. A 24 h mature S. aureus ATCC6538 biofilm was exposed to each enzyme extract with standardized enzyme activities for 10, 30, and 60 min. The optical density at 630 nm was used to calculate the growth rate (GR%) and the residual biofilm rate (RBR%). The most promising solutions were used in combination, based on a 2⁴ factorial design for 0, 10, 20, and 30 min of exposure. Lipase and protease solutions, when applied separately, were the most effective, and promoted the complete removal of S. aureus biofilms in t₁₀ (lipase) and t₃₀ and t₆₀ (lipase and protease). Of the combined treatments using 1.0 U/mL protease and 0.4 U/mL lipase, total biofilm degradation was observed for all exposure times. Thus, the hydrolases produced by the Amazonian endophytic fungi evaluated here are highlighted as an interesting tool in the fight against microbial biofilms.

A visual evaluation of oral plaque removal utilizing an adjunct enzyme pre-rinse in orthodontic subjects

OBJECTIVE

To determine if an adjunct proteolytic pre-rinse along with contemporary methods of dental cleaning may more effectively remove visual plaque in subjects with fixed orthodontic appliances.

MATERIALS AND METHODS

Forty-three orthodontic subjects, ages 10 to 25, completed this single site, double-blind, crossover clinical trial. Subjects randomly received bromelain enzyme or a powdered-sugar placebo pre-rinse, followed by manual tooth brushing and use of a Waterpik. Subjects received the alternate pre-rinse during the subsequent visit. Baseline and residual plaque accumulation were recorded via disclosing tablet and digital photography. A single, blinded examiner scored visual plaque scores from randomized photographs. Treatment effects on composite plaque score were evaluated using repeated-measures analysis of variance. A 5% significance level was used for all tests.

RESULTS

No significant differences in plaque scores were noted at baseline or post-rinse between the enzyme and placebo. The changes from baseline to post-rinse (P = .190), post-brushing (P = .764), and post-Waterpik (P = .882) were not significantly different between interventions. Significant reduction in plaque scores were observed in both arms of the study after brushing (P < .01) and waterjet use (P < .01). Neither age (P = .220) nor gender (P = .449) impacted plaque scores.

CONCLUSIONS

Use of a bromelain enzyme pre-rinse alone did not significantly enhance plaque removal. A significant reduction in retained plaque was observed with the application of brushing and or Waterpik.

Understanding the Role of Shape and Composition of Star-Shaped Polymers and their Ability to Both Bind and Prevent Bacteria Attachment on Oral Relevant Surfaces

In this study, we have prepared a series of 4- and 6-arm star-shaped polymers with varying molecular weight and hydrophobicity in order to provide insight into the role and relationship that shape and composition have on the binding and protecting of oral relevant surfaces (hydroxyapatite, HAP) from bacteria colonization. Star-shaped acrylic acid polymers were prepared by free-radical polymerization in the presence of chain transfer agents with thiol groups, and their binding to the HAP surfaces and subsequent bacteria repulsion was measured. We observed that binding was dependent on both polymer shape and hydrophobicity (star vs. linear), but their relative efficacy to reduce oral bacteria attachment from surfaces was dependent on their hydrophobicity only. We further measured the macroscopic effects of these materials to modify the mucin-coated HAP surfaces through contact angle experiments; the degree of angle change was dependent on the relative hydrophobicity of the materials suggesting future in vivo efficacy. The results from this study highlight that star-shaped polymers represent a new material platform for the development of dental applications to control bacterial adhesion which can lead to tooth decay, with various compositional and structural aspects of materials being vital to effectively design oral care products.

The Photomodulation Activity of Metformin Against Oral Microbiome

Periodontitis is one of the most common inflammatory diseases of the periodontium, which results in the inflammatory destruction of supporting structures around teeth and is closely associated with the development of systemic disease. Due to a wide variety of antibiotic resistance periodontopathic bacteria, photodynamic therapy (PDT) is a non-invasive adjunctive therapeutic modality that is capable of destroying the whole range of microbes. Metformin (Metf) is an antidiabetic drug, and recent studies suggest that cancer patients who receive Metf and are exposed to radiotherapy and chemotherapy show better outcomes. Our surveys in this review introduce Metf as a potent stimulus in increasing the efficacy of PDT in the induction of destruction in microbial cells.

Effectiveness of Enzyme Dentifrices on Oral Health in Orthodontic Patients: A Randomized Controlled Trial

Plaque accumulation and white spot lesions are common adverse effects of fixed orthodontic appliance use. This study compared the effects between enzyme-containing and conventional dentifrices on orthodontic patients. This double-blind randomized controlled trial included 42 orthodontic patients (25 women and 17 men: 22.7 ± 4.2 years) from Taipei Medical University Hospital between 2017 and 2018. The patients were randomly divided into three groups and assigned to dentifrice use during the first 3 months of the orthodontic treatment: group 1 used dentifrices containing enzymes including amyloglucosidase and glucose oxidase, group 2 used dentifrices containing 1450 ppm fluoride, and group 3 used natural dentifrices containing no chemical agent. White spot lesion index (WSL), gingival bleeding index (GBI), and visible plaque index (VPI) were recorded and analyzed. WSL, GBI, and VPI values exhibited no significant difference among the three groups. WSL increased significantly in group 3, GBI decreased significantly in all groups, and VPI decreased significantly in groups 1 and 2. No significant difference was observed between the use of enzyme-containing and conventional dentifrices after fixed orthodontic appliance placement.

Dextran-Coated Zinc-Doped Hydroxyapatite for Biomedical Applications

Dextran-coated zinc-doped hydroxyapatite (ZnHApD) was synthesized by an adapted sol-gel method. The stability of ZnHApD nanoparticles in an aqueous solution was analyzed using ultrasonic measurements. The analysis of the evolution in time of the attenuation for each of the frequencies was performed. The X-ray diffraction (XRD) investigations exhibited that no impurity was found. The morphology, size and size distribution of the ZnHApD sample was investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The TEM and SEM results showed that the ZnHApD particles have an ellipsoidal shape and a narrow distribution of sizes. The cell growth and toxicity of HEK-293 cells were investigated on the ZnHApD solution for four different concentrations and analyzed after 24 and 48 h. The ZnHApD solution presented a non-toxic activity against HEK-293 cells for all analyzed concentrations. The antibacterial assay revealed that all the tested microorganisms were inhibited by the ZnHApD dispersion after 24 and 48 h of incubation. It was observed that the effect of the ZnHApD solution on bacteria growth depended on the bacterial strain. The Porphyromonas gingivalis ATCC 33277 bacterial strain was the most sensitive, as a growth inhibition in the presence of 0.075 μg/mL ZnHApD in the culture medium was observed.

Recent Progress of Basic Studies of Natural Products and Their Dental Application

The present article reviews the research progress of three major polyphenols (tannins, flavonoids and lignin carbohydrate complexes), chromone (backbone structure of flavonoids) and herbal extracts. Chemical modified chromone derivatives showed highly specific toxicity against human oral squamous cell carcinoma cell lines, with much lower toxicity against human oral keratinocytes, as compared with various anticancer drugs. QSAR analysis suggests the possible correlation between their tumor-specificity and three-dimensional molecular shape. Condensed tannins in the tea extracts inactivated the glucosyltransferase enzymes, involved in the biofilm formation. Lignin-carbohydrate complexes (prepared by alkaline extraction and acid-precipitation) and crude alkaline extract of the leaves of Sasa species (SE, available as an over-the-counter drug) showed much higher anti-HIV activity, than tannins, flavonoids and Japanese traditional medicine (Kampo). Long-term treatment with SE and several Kampo medicines showed an anti-inflammatory and anti-oxidant effects in small size of clinical trials. Although the anti-periodontitis activity of synthetic angiotensin II blockers has been suggested in many papers, natural angiotensin II blockers has not yet been tested for their possible anti-periodontitis activity. There should be still many unknown substances that are useful for treating the oral diseases in the natural kingdom.

Purification and characterization of cysteine protease from miswak Salvadora persica

Background

Generally, proteases in medicinal plants had different therapeutic effects such as anti-inflammatory effect; modulate the immune response and inhibitory effect toward tumor growth. In this study, protease was purified and characterized from miswak roots, as medicinal plant and natural toothbrush.

Results

Physical and chemical characterization of cysteine protease P1 were studied such as pH optimum (6.5), optimum temperature (50 °C), thermal stability (50 °C) and Km (3.3 mg azocasein/ml). The enzyme digested some proteins in the order of caseine > haemoglobin > egg albumin >gelatin > bovine serum albumin. Hg²⁺ had strong inhibitory effect on enzyme activity compared with other metal ions. Kinetic of inhibition for determination the type of protease was studied. Iodoactamide and p-Hydroximercuribenzaoic acid (p-HMB) caused strong inhibitory effect on enzyme activity indicating the enzyme is cysteine protease.

Conclusions

The biochemical characterization of this enzyme will be display the suitable conditions for using of this enzyme in toothpaste in the future and the enzyme may be used in other applications.

An injectable supramolecular hydrogel hybridized with silver nanoparticles for antibacterial application

Silver nanoparticles (AgNPs) show long-lasting and broad-spectrum antibacterial activity. Herein, PEGylated AgNPs were prepared in situ by complexing AgNO₃ with the random copolymer of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and polyacrylic acid via electrostatic interaction followed by in situ reduction. AgNP hybrid supramolecular hydrogels were thus prepared through host-guest inclusion between PEGMA side chains and α-cyclodextrins in aqueous solution. The hydrogels were physically cross-linked by both pseudopolyrotaxane crystallization and AgNPs, which showed temperature responsiveness and self-healing properties. By hybridizing AgNPs, the hydrogels showed excellent antibacterial properties against S. aureus and E. coli bacteria as well as low cytotoxicity and have potential applications as injectable antibacterial materials.

Skin permeability enhancement by Bacillus subtilis alkaline protease: Application to transdermal drug delivery

Enzymes may offer great potentials in topical pharmaceutical applications provided that treatment conditions are controlled for efficacy and safety. In this study, the effect of alkaline protease produced by recombinant Bacillus subtilis cells on the ex-vivo permeability of rabbit ear skin was investigated under different conditions of enzyme activity (5-60 units) and exposure time (15-60min). Data for transepidermal water loss (TEWL) and permeation of a hydrophilic dye, rhodamine B (Rb), indicated biphasic activity-dependent and exposure time-dependent skin permeability. Maximum effects were obtained at 20 proteolytic units and 30min exposure. Findings proved consistent with histopathological changes indicating progressive stratum corneum (SC) loss and disruption of the dermo-epidermal junction at 20 units and up to 30min exposure time followed by dermal hyalinization at longer exposure. This was associated with progressive loss of skin hair. Applying the identified pretreatment conditions to transdermal delivery of vardenafil in a gel base across dorsal rat skin indicated a significant increase in plasma levels at 30 and 60min with minimal histopathological changes 5days post enzyme treatment. Accordingly, the recombinant B. subtilis alkaline protease offers promise as a pharmaceutical enzyme for transdermal drug delivery bioenhancement and dermatological applications.

(1→3)-α-d-Glucan from Fruiting Body and Mycelium ofCerrena unicolor(Bull.) Murrill: Structural Characterization and Use as a Novel Inducer of Mutanase

Water-insoluble, alkali-soluble polysaccharide (marked as ASP) was extracted from the vegetative mycelium and fruiting body ofCerrena unicolorstrain. Monosaccharide examination of ASP demonstrated that the isolated biopolymer was composed mainly of glucose, xylose, and mannose monomers. The methylation investigation of studied polymers indicated that (1→3)-linkedα-D-Glcpis the major chain constituent (92.2% for glucans isolated from fruiting body and 90.1% from mycelium).1H NMR, FT-IR, and immunofluorescent labelling determinations confirmed that the polysaccharides isolated from both fruiting body and mycelium ofC. unicolorare (1→3)-α-d-glucans. The obtained (1→3)-α-d-glucans showed differences in viscosity and similar characteristics in optical rotations. (1→3)-α-d-Glucans extracted from mycelium and fruiting body ofC. unicolorwere also used as potential and specific inducers of mutanase synthesis byTrichoderma harzianum. The highest mutanase activity (0.38 U/mL) was obtained after induction of enzyme by (1→3)-α-d-glucan isolated from the mycelium ofC. unicolor, and this biopolymer has been suggested as a new alternative to streptococcal mutan for the mutanase induction inT. harzianum. (1→3)-α-d-Glucan-induced mutanase showed high hydrolysis potential in reaction with dextranase-pretreated mutan, where maximal degree of saccharification and solubilization of this bacterial homoglucan (83.1% and 78.4%, resp.) was reached in 3 h at 45°C.

Klebsiella pneumoniae Planktonic and Biofilm Reduction by Different Plant Extracts: In Vitro Study

This study evaluated the action of Pfaffia paniculata K., Juglans regia L., and Rosmarius officinalis L. extracts against planktonic form and biofilm of Klebsiella pneumoniae (ATCC 4352). Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values were determined for each extract by microdilution broth method, according to Clinical and Laboratory Standards Institute. Next, antimicrobial activity of the extracts on biofilm was analyzed. For this, standardized suspension at 10⁷ UFC/mL of K. pneumoniae was distributed into 96-well microplates (n = 10) and after 48 h at 37°C and biofilm was subjected to treatment for 5 min with the extracts at a concentration of 200 mg/mL. ANOVA and Tukey tests (5%) were used to verify statistical significant reduction (p < 0.05) of planktonic form and biofilm. P paniculata K., R. officinalis L., and J. regia L. showed reductions in biomass of 55.6, 58.1, and 18.65% and cell viability reduction of 72.4, 65.1, and 31.5%, respectively. The reduction obtained with P. paniculata and R. officinalis extracts was similar to the reduction obtained with chlorhexidine digluconate 2%. In conclusion, all extracts have microbicidal action on the planktonic form but only P. paniculata K. and R. officinalis L. were effective against biofilm.