Daily Cosmetic Research Analysis
Three studies stand out today: a pediatric randomized trial identifies chlorhexidine as the most clinically successful irrigant for LSTR in primary molars, while sodium hypochlorite excels radiographically. An engineered E. coli multi-enzyme cascade boosts sustainable production of the cosmetic fragrance 2-phenylethanol. Nano silver fluoride dentifrices show strong anti-Streptococcus mutans activity but exhibit steep, dose-dependent cytotoxicity, underscoring the need for concentration optimizat
Summary
Three studies stand out today: a pediatric randomized trial identifies chlorhexidine as the most clinically successful irrigant for LSTR in primary molars, while sodium hypochlorite excels radiographically. An engineered E. coli multi-enzyme cascade boosts sustainable production of the cosmetic fragrance 2-phenylethanol. Nano silver fluoride dentifrices show strong anti-Streptococcus mutans activity but exhibit steep, dose-dependent cytotoxicity, underscoring the need for concentration optimization.
Research Themes
- Optimization of irrigants for pediatric LSTR (clinical efficacy vs. radiographic outcomes)
- Bio-based production platforms for cosmetic fragrance molecules
- Safety–efficacy trade-offs in nanomaterial-containing dentifrices
Selected Articles
1. Efficacy of different endodontic irrigants in the lesion sterilization and tissue repair technique in primary molars: A randomized controlled clinical trial.
In a randomized trial of 40 children undergoing LSTR for primary molars, chlorhexidine yielded the best clinical outcomes and the least root resorption, while sodium hypochlorite produced the greatest reduction in furcation radiolucency. All irrigants outperformed saline, supporting irrigant use prior to alternate 3-Mix placement.
Impact: Provides comparative clinical evidence guiding irrigant choice in pediatric LSTR with 18-month follow-up, potentially standardizing protocols.
Clinical Implications: For pediatric LSTR, chlorhexidine may be preferred for overall clinical success and minimal root resorption, while sodium hypochlorite may be selected when radiographic lesion size reduction is prioritized.
Key Findings
- All irrigant groups achieved clinical success compared with saline (P < 0.05).
- 2% chlorhexidine showed the best clinical outcomes and the least root resorption.
- 2% sodium hypochlorite produced the greatest reduction in furcation radiolucency.
- Follow-up extended to 18 months with consistent clinical and radiographic evaluation.
Methodological Strengths
- Randomized allocation across four groups with active comparators and control
- Longitudinal follow-up up to 18 months with both clinical and radiographic endpoints
Limitations
- Single-center study with a modest sample size (n=40)
- Blinding and allocation concealment procedures are not detailed
Future Directions: Conduct larger, multicenter RCTs with standardized outcome measures and microbiological endpoints, and extend follow-up to natural exfoliation.
BACKGROUND AND AIM: This study aims to evaluate the efficacy of different endodontic irrigants employed in the lesion sterilization and tissue repair (LSTR) technique. METHODS: Forty children aged 4-8 years having at least one primary molar with irreversible pulpitis/pulpal necrosis indicated for pulpectomy were included. Participants were randomly divided into three test groups (Group A, B, and C) and one control group (Group D). After caries excavation using a spoon excavator, superficial pulp was removed under topical anesthesia in all groups. Following this, pulpal floor was irrigated using different endodontic irrigants in each group: Group A - 20% propolis, Group B - 2% sodium hypochlorite, Group C - 2% chlorhexidine gluconate, and Group D (control) - saline. Alternate 3-Mix (triple antibiotic paste containing metronidazole, ciprofloxacin, and amoxicillin) was then placed over the pulpal floor and the teeth were restored with glass ionomer cement followed by stainless steel crown. Patients were recalled at follow-up periods up to 18 months for clinical and radiographic evaluation. Repeated-measures ANOVA test, Chi-square test, and independent t-test were used for statistical analysis. RESULTS: Clinical success was achieved in all treated teeth, with the results showing statistical significance (P < 0.05). In addition, Group C showed best clinical results. Statistically significant results (P < 0.05) were obtained in reduction in size of furcation radiolucency, with Group B showing the best results compared to other groups. Statistically significant results (P < 0.05) were obtained in terms of rate of root resorption in all teeth, with Group C showing least resorption compared to other groups. CONCLUSIONS: The use of endodontic irrigant before the placement of alternate 3-Mix is an effective step for the improved success of LSTR technique in primary teeth, with chlorhexidine showing the best success rate.
2. Biosynthesis of 2-phenylethanol from styrene using engineered Escherichia coli whole cells.
An engineered E. coli multi-enzyme cascade converted styrene to 2-phenylethanol, improving yield from 6.28 mM to 10.28 mM via copy-number balancing and reaching 48.17 mM within 10 hours under optimized conditions (pH 7.5, 35°C). The platform advances sustainable bioproduction of a key cosmetic fragrance molecule.
Impact: Demonstrates an efficient whole-cell cascade for 2-phenylethanol production, relevant to cosmetics, with clear quantitative gains and process optimization.
Clinical Implications: While not clinical, this work supports sustainable manufacturing of fragrance ingredients, potentially reducing reliance on petrochemical routes and enabling greener cosmetic supply chains.
Key Findings
- Initial production of 2-phenylethanol at 6.28 mM using engineered E. coli expressing styA/styB, SOI, yahK, and gdh.
- Plasmid copy-number balancing increased yield to 10.28 mM (63.7% increase).
- Optimized whole-cell conditions (pH 7.5, 35°C) enabled 48.17 mM production within 10 hours.
Methodological Strengths
- Rational pathway design with enzyme expression balancing via plasmid copy-number tuning
- Systematic optimization of bioprocess conditions (pH and temperature)
Limitations
- Use of styrene as substrate poses toxicity and safety considerations for scale-up
- Titers and productivity require further improvement for industrial deployment
Future Directions: Engineer host metabolism for alternative, safer substrates (e.g., glucose to styrene in situ), improve tolerance and cofactor balance, and integrate in situ product removal for higher titers.
2-Phenylethanol, an aromatic alcohol with a rose scent, is widely used in the cosmetics, food, and pharmaceutical industries. We designed an efficient multi-enzyme cascade pathway for production of 2-phenylethanol from styrene as the substrate. Initially, 2-phenylethanol was produced by overexpression of styrene monooxygenase A (styA), styrene monooxygenase B (styB), styrene oxide isomerase (SOI), alcohol dehydrogenase (yahK), and glucose dehydrogenase (gdh) in Escherichia coli to give 6.28 mM 2-phenylethanol. Subsequently, plasmids with different copy numbers were employed to balance the expression of pathway enzymes to produce 10.28 mM 2-phenylethanol, resulting in a 63.7 % increase in the final yield. Furthermore, the pH and temperature of the whole-cell conversion reaction were optimized, the optimum pH and temperature are 7.5 and 35℃, respectively. Finally, whole-cell conversion experiment was conducted, and the production of 2-phenylethanol reached 48.17 mM within 10 h. This study provides a theoretical and practical foundation for production of 2-phenylethanol.
3. Formulation of different concentrations of nanosilver fluoride incorporated dentifrices, evaluation of its cytotoxicity and antimicrobial effect on Streptococcus mutans.
NSF-containing dentifrices suppressed S. mutans growth in a dose-dependent manner, but higher NSF concentrations markedly reduced RAW 264.7 cell viability (from 86.67% at 0.156% to 0.68% at 10%). These results highlight the need to balance antimicrobial potency with biocompatibility in product formulation.
Impact: Provides quantitative efficacy–toxicity data for NSF, informing safe concentration ranges for consumer dentifrices and pediatric applications.
Clinical Implications: Formulators should target lower NSF concentrations that retain antimicrobial effects while minimizing cytotoxicity; clinical trials are needed to validate safety and efficacy in vivo.
Key Findings
- NSF dentifrices showed dose-dependent inhibition of S. mutans by agar well diffusion.
- Significant differences across concentrations were confirmed by one-way ANOVA and Bonferroni post hoc tests.
- Cytotoxicity increased with concentration: cell viability was 86.67% at 0.156% NSF and 0.68% at 10% NSF.
- TEM confirmed nanosilver particle sizes of 40–50 nm produced by chemical reduction.
Methodological Strengths
- Parallel evaluation of antimicrobial activity and mammalian cell cytotoxicity across graded concentrations
- Use of standardized assays (agar diffusion, MTT) with statistical comparisons
Limitations
- In vitro assays may not translate directly to clinical efficacy and safety
- No assessment of long-term ion release or in situ biofilm models
Future Directions: Define therapeutic windows via in situ biofilm and enamel/dentin models, conduct in vivo safety studies (oral mucosa, microbiome), and evaluate clinical caries outcomes.
BACKGROUND: Dental caries is a prevalent oral health issue primarily caused by Streptococcus mutans, a bacterium that contributes to tooth decay. Antimicrobial agents in dentifrices are often utilized to target these pathogens. Nano silver fluoride (NSF) has emerged as a potential antimicrobial agent due to its ability to inhibit bacterial growth. This study aims to investigate the antimicrobial efficacy and cytotoxicity of dentifrices containing varying concentrations of NSF against Streptococcus mutans. AIM: The primary aim of this study was to evaluate the antimicrobial effectiveness of Nano silver fluoride-incorporated dentifrices against Streptococcus mutans and assess their cytotoxic effects on mammalian cells. OBJECTIVES: To synthesize and characterize nano silver particles using transmission electron microscopy (TEM).To determine the antimicrobial activity of NSF dentifrices at different concentrations using the agar well diffusion method. To assess the cytotoxicity of NSF dentifrices on RAW 264.7 mouse macrophage cells using the MTT assay. MATERIAL AND METHOD: Synthesis and Characterization: Nano silver particles were synthesized through a chemical reduction process, resulting in particles with sizes ranging between 40-50 nm, confirmed via TEM analysis. Preparation of Dentifrice: Various concentrations of Nano silver fluoride (0%, 0.65%, 1.25%, 2.5%, and 5%) were incorporated into a dentifrice base. Antimicrobial Testing: The antimicrobial efficacy of the NSF dentifrices was assessed using the agar well diffusion method, where the zone of inhibition around each well was measured to evaluate bacterial growth suppression. Cytotoxicity Assessment: Cytotoxicity was analyzed using the MTT assay on RAW 264.7 mouse macrophage cells, with NSF concentrations ranging from 0.156% to 10% to determine their impact on cell viability. RESULTS: The study demonstrated that dentifrices containing NSF showed significant antimicrobial activity against Streptococcus mutans, with a dose-dependent increase in the zone of inhibition. Higher concentrations of NSF were associated with larger zones of bacterial inhibition. A one-way ANOVA revealed statistically significant differences between various concentrations, with post hoc Bonferroni tests confirming significant differences between specific pairs. In terms of cytotoxicity, a dose-dependent decrease in cell viability was observed with increasing concentrations of NSF. The lowest concentration (0.156% NSF) had the highest cell viability (86.67%), while the highest concentration tested (10% NSF) resulted in minimal cell viability (0.68%). CONCLUSION: The study concludes that NSF-incorporated dentifrices exhibit promising antimicrobial efficacy against Streptococcus mutans in a concentration-dependent manner. However, increasing concentrations of NSF also correlated with higher cytotoxicity levels in mammalian cells. Therefore, optimizing the concentration of NSF in dentifrices is crucial to balance antimicrobial benefits with biocompatibility.