Daily Cosmetic Research Analysis
Three studies stand out today: a human exposure experiment with machine-learning analysis shows personal care products can significantly increase dermal uptake and predicted serum levels of environmental SVOCs; a proof-of-concept diagnostic study demonstrates multispectral optoacoustic tomography with automated segmentation accurately maps pigmented basal cell carcinoma; and an in vitro high-throughput study reveals chlorhexidine and triclosan can drive azole resistance in Nakaseomyces glabratus
Summary
Three studies stand out today: a human exposure experiment with machine-learning analysis shows personal care products can significantly increase dermal uptake and predicted serum levels of environmental SVOCs; a proof-of-concept diagnostic study demonstrates multispectral optoacoustic tomography with automated segmentation accurately maps pigmented basal cell carcinoma; and an in vitro high-throughput study reveals chlorhexidine and triclosan can drive azole resistance in Nakaseomyces glabratus via specific mutations.
Research Themes
- Cosmetic product safety and environmental exposure
- Non-invasive dermatologic imaging and surgical planning
- Antimicrobial resistance linked to consumer antiseptics
Selected Articles
1. Exposure experiments and machine learning revealed that personal care products can significantly increase transdermal exposure of SVOCs from the environment.
In volunteer exposure experiments, applying common personal care products increased dermal adsorption of multiple SVOC classes by roughly 1.6–2.0-fold, with tocopherol-containing formulations further enhancing uptake. Machine-learning predictions indicated significant increases in serum concentrations of 2–3 ring PAHs and TCEP after product use, highlighting ingredient-dependent risks.
Impact: This is the first study to demonstrate that personal care products can significantly amplify dermal uptake and predicted systemic exposure to environmental SVOCs. It has direct implications for cosmetic formulation, exposure assessment, and regulation.
Clinical Implications: Clinicians should counsel patients—especially children, pregnant individuals, and those with dermatologic conditions—about ingredient-driven exposure risks, and consider recommending formulations with lower SVOC absorption potential. Public health and regulatory bodies may need to revise testing paradigms to include co-exposure scenarios with PCPs.
Key Findings
- Application of lotion, baby oil, sunscreen, and blemish balm increased dermal SVOC adsorption by 1.63±0.62, 1.97±0.73, 1.91±0.48, and 2.03±0.59 times, respectively.
- Tocopherol as an ingredient increased dermal SVOC adsorption by 2.59±1.60 times.
- Blemish balm yielded the highest hazard quotient for certain SVOCs; TCEP had the highest hazard quotient among compounds.
- Machine-learning predictions indicated significant increases in serum levels of 2–3 ring PAHs and TCEP after PCP use.
Methodological Strengths
- Human volunteer exposure with multi-class SVOC assessment
- Integration of machine-learning predictions linking dermal uptake to serum concentrations and ingredient-level analysis
Limitations
- Sample size and participant characteristics were not specified in the abstract
- Short-term exposure; long-term health outcomes were not assessed; real-world co-exposures and usage patterns may vary
Future Directions: Quantify dose–response across defined populations, validate serum predictions with longitudinal biomonitoring, and test formulation strategies that minimize SVOC uptake while preserving cosmetic performance.
We investigated the impacts of personal care products (PCPs) on dermal exposure to semi-volatile organic compounds (SVOCs), including phthalates, organophosphate esters, polycyclic aromatic hydrocarbons (PAHs), ultraviolet filters, and p-phenylenediamines, through an experiment from volunteers, explored the impact mechanisms of PCP ingredients on dermal exposure, and predicted the PCP effects on SVOC concentrations in human serum using machine learning. After applying PCPs, namely lotion, baby oil, sunscreen, and blemish balm, the dermal adsorption of SVOCs increased significantly by 1.63 ± 0.62, 1.97 ± 0.73, 1.91 ± 0.48, and 2.03 ± 0.59 times, respectively, probably due to the absorption effects of PCP ingredients. Ingredient tocopherol can increase dermal adsorption of SVOCs by 2.59 ± 1.60 times. PCPs can either increase or decrease the SVOC transdermal exposure risks, depending on the properties of their ingredients. Blemish balm caused the highest hazard quotient for certain SVOCs, while tris(2-chloroethyl) phosphate (TCEP) exhibited the highest hazard quotient. We predicted the SVOC concentrations in serum before and after applying PCPs based on the PCP-increased skin permeation doses and machine learning. PCPs can significantly increase the serum concentrations of PAHs with 2-3 rings and TCEP. This study first revealed that PCPs can significantly increase the dermal exposure of SVOCs from the surroundings, resulting in potentially higher health risks.
2. A proof-of-concept study for precise mapping of pigmented basal cell carcinoma in asian skin using multispectral optoacoustic tomography imaging with level set segmentation.
In 30 subjects with pigmented BCC, MSOT combined with automated level set segmentation produced tumor width and depth measurements that correlated strongly with histology (r=0.84 and 0.81). The method enables non-invasive 3D mapping for preoperative planning, potentially reducing tissue sacrifice and improving cosmetic outcomes.
Impact: Introduces a practical, high-resolution imaging workflow for precise tumor mapping in BCC with quantitative validation versus histology, addressing a key bottleneck in dermatologic surgery.
Clinical Implications: MSOT-based preoperative mapping could reduce Mohs stages or re-excisions, shorten operative time, and preserve healthy tissue, especially in cosmetically sensitive areas.
Key Findings
- Automated level set segmentation on MSOT enabled precise delineation of pigmented BCC and measurement of width, depth, and volume.
- MSOT-derived width and depth correlated strongly with histology (r=0.84 and r=0.81).
- High isotropic resolution (80 μm) and enhanced penetration allowed contrast-rich 3D mapping suitable for surgical planning.
Methodological Strengths
- Prospective proof-of-concept with histologic validation of imaging-derived metrics
- Novel integration of automated level set segmentation to enhance boundary precision
Limitations
- Small sample size (n=30) and single proof-of-concept setting
- Focused on pigmented BCC and Asian skin; generalizability to other subtypes and populations requires study
Future Directions: Conduct larger, multicenter diagnostic accuracy studies and evaluate clinical utility endpoints (e.g., reduced Mohs stages, operative time, margin status) and cost-effectiveness.
PURPOSE: Basal Cell Carcinoma (BCC), the most common subtype of non-melanoma skin cancers (NMSC), is prevalent worldwide and poses significant challenges due to their increasing incidence and complex treatment considerations. Existing clinical approaches, such as Mohs micrographic surgery, are time-consuming and labour-intensive, requiring meticulous layer-by-layer excision and examination, which can significantly extend the duration of the procedure. Current optical imaging solutions also lack the necessary spatial resolution, penetration depth, and contrast for effective clinical use. METHODS: Here, we introduce photoacoustic imaging, also known as optoacoustic imaging, based Multispectral Optoacoustic Tomography (MSOT) as a promising solution for non-invasive, high-resolution imaging in dermatology, which also measures hemodynamic changes. MSOT offers high isotropic resolution (80 μm), increased tissue penetration, and contrast-enhanced 3D spatial imaging map. For the first time, we integrated an automated level set image segmentation methodology on optoacoustic images to further enhance the precision in delineating tumor boundaries. Through this proof-of-concept study in 30 subjects, we demonstrate that this segmentation allows for precise measurement of tumor width, depth, and volume, aiding in preoperative tumor mapping and surgical planning. RESULTS: The MSOT measurements, validated against histology, achieved a correlation coefficient of 0.84 and 0.81 for width and depth respectively, ensuring reliable tumor metrics with a low margin of error. CONCLUSION: Clinicians can use these tumor metrics to optimize treatment efficacy, while preserving healthy tissue and cosmetic outcomes. This advancement has the potential to revolutionize diagnostics and treatment, significantly improving the patient outcomes in managing NMSC.
3. In vitro long-term exposure to chlorhexidine or triclosan induces cross-resistance against azoles in Nakaseomyces glabratus.
A high-throughput in vitro exposure platform showed that long-term chlorhexidine or triclosan exposure led to azole resistance in 50 N. glabratus isolates, associated with PDR1 and PMA1 mutations, while octenidine did not induce cross-resistance. Resistance to the antiseptics themselves did not become stable.
Impact: Reveals a previously undescribed pathway to azole resistance in yeasts driven by widely used antiseptics, informing stewardship of oral care and cosmetic antiseptics and antifungal resistance surveillance.
Clinical Implications: Consider limiting routine use of chlorhexidine and triclosan where alternatives (e.g., octenidine) are feasible, and strengthen surveillance for azole resistance in Candida/Nakaseomyces species, especially in high-exposure settings.
Key Findings
- Long-term exposure to chlorhexidine or triclosan induced azole resistance in 50 N. glabratus isolates, with mutations identified in PDR1 and PMA1.
- Stable resistance to the antiseptics themselves did not develop after prolonged exposure.
- Octenidine did not promote cross-resistance to azoles under the same conditions.
Methodological Strengths
- High-throughput parallel exposure of multiple clinical and reference isolates with stepwise concentration increases
- Whole-genome sequencing linking phenotype to specific resistance mutations
Limitations
- In vitro-only findings; clinical translatability and exposure conditions in vivo remain to be established
- Species-specific results; effects on other Candida species are not detailed in the abstract
Future Directions: Validate findings in clinical cohorts with antiseptic exposure histories, assess fitness costs and reversibility, and evaluate stewardship interventions substituting octenidine in high-use settings.
BACKGROUND: Topical antiseptics are crucial for preventing infections and reducing transmission of pathogens. However, commonly used antiseptic agents have been reported to cause cross-resistance to other antimicrobials in bacteria, which has not yet been described in yeasts. This study aims to assess the in vitro efficacy of antiseptics against clinical and reference isolates of Candida albicans and Nakaseomyces glabratus, and whether prolonged exposure to antiseptics promotes the development of antifungal (cross)resistance. METHODS: A high-throughput approach for in vitro resistance development was established to simultaneously expose 96 C. albicans and N. glabratus isolates to increasing concentrations of a given antiseptic - chlorhexidine, triclosan or octenidine. Susceptibility testing and whole genome sequencing of yeast isolates pre- and post-exposure were performed. RESULTS: Long-term exposure to antiseptics does not result in the development of stable resistance to the antiseptics themselves. However, 50 N. glabratus isolates acquired resistance to azole antifungals after long-term exposure to triclosan or chlorhexidine, revealing newly acquired mutations in the PDR1 and PMA1 genes. CONCLUSIONS: Chlorhexidine as well as triclosan, but not octenidine, were able to introduce selective pressure promoting resistance to azole antifungals. Although we assessed this phenomenon only in vitro, these findings warrant critical monitoring in clinical settings.