A pre-experimental, observational study was conducted to evaluate the clinical performance and safety of Dermomina^® clay as a topical adjunct in the management of infected and non-infected diabetic foot ulcers (DFUs). Patients were treated at the wound care units of Elio Fiallo Provincial Hospital (Pedernales, Dominican Republic) and the National Institute for Research on Infectious Diseases (INIEICONT) between March 2022 and October 2024.

A total of 24 patients were recruited using convenience sampling. Eligible participants were adults with a diagnosis of diabetic foot ulcer classified as Wagner grade 1 to 3 who provided written informed consent. Exclusion criteria included incomplete treatment or follow-up, prior systemic antibiotic use before baseline evaluation, Wagner grade 4 or 5 ulcers, referral or admission to tertiary care hospitals, or death during the study period.

Ulcer infection was defined as a pathological condition caused by the invasion and multiplication of microorganisms within host tissue, accompanied by tissue destruction and/or a host inflammatory response, in accordance with current international guidelines (14).

Clinical and microbiological criteria were jointly applied to classify ulcers as infected or non-infected using the International Working Group on the Diabetic Foot (IWGDF)/Infectious Diseases Society of America (IDSA) foot infection classification system. Baseline wound cultures were obtained in patients with clinically infected ulcers.

Patients classified as having infected ulcers received systemic antibiotic therapy according to institutional protocols, in combination with autolytic medical debridement, before and during topical Dermomina^® treatment.

Lower-limb vascular perfusion was assessed using arterial and venous Doppler ultrasound to identify peripheral arterial disease and venous abnormalities. Neurological function was evaluated through standardized clinical examination performed by the neurology service, including assessment of protective sensation.

Brown Dermomina^® clay was used throughout the study. Additional materials included sterile saline solution, potable water, a 1-L Pyrex glass container, a wooden spatula, sterile gauze, disposable gloves, elastic bandages, adhesive tape, disposable examination sheets, and a flexible measuring tape for wound assessment. Pain intensity was assessed using the Visual Analog Scale (VAS). The clay deposit from which Dermomina^® is sourced contains approximately two billion metric tons of material, with an estimated 23% clay content and a homogeneous mineral composition.

Raw Dermomina^® clay underwent physical purification before clinical use. Coarse particulate matter and sand were removed by repeated decantation using natural spring water, allowing separation of the fine clay fraction based on sedimentation principles. The purified clay was stored at room temperature in plastic or glass containers, retaining its natural moisture content until application.

Chemical characterization of the purified clay was performed using X-ray fluorescence (XRF) analysis, as provided in the supplier’s Certificate of Analysis. XRF enables quantitative determination of major, minor, and trace elemental oxides in mineral materials.

As summarized in Table 1, Dermomina^® clay is predominantly composed of silica (SiO₂) and alumina (Al₂₃), consistent with an aluminosilicate mineral matrix. Minor oxides, including iron(III) oxide, sodium oxide, potassium oxide, magnesium oxide, and calcium oxide, were present at low concentrations, while trace elements were detected at minimal levels. Loss on ignition reflected structural water and volatile components, and total organic carbon and sulfur contents were negligible. This compositional profile confirms the mineral purity and chemical stability of the clay used in the study.

Pain intensity was assessed using a 10-point Visual Analog Scale (0 = no pain; 10 = worst pain imaginable). Clinical data were collected using an 83-item validated questionnaire.

The Dermomina^® application protocol followed a standardized procedure:

Primary outcomes included time to granulation tissue formation, time to epithelialization, time to complete ulcer closure, weekly wound size reduction rate, and the proportion of ulcers achieving complete closure by week 20.

Ulcer size was assessed using a flexible measuring tape to measure the maximum diameter of the lesion at each evaluation. This method was applied consistently throughout follow-up to allow standardized longitudinal comparison of wound dimensions. Secondary outcomes included adverse events, microbiological findings in infected ulcers, and identification of independent predictors of wound closure. Healing progression was documented through clinical evaluation and serial photographic records.

Patients were actively monitored for adverse effects potentially associated with Dermomina^® application, including local irritation, inflammation, allergic reactions, or signs of systemic hypersensitivity. Adverse events were classified according to severity, duration, and requirement for treatment discontinuation.

Data were entered into Microsoft Excel (version 8.0) and analyzed using Epi Info version 7 (Centers for Disease Control and Prevention, Atlanta, GA, USA). Data quality control included error correction and variable recoding before analysis. Continuous variables were summarized as mean ± standard deviation or median (range), as appropriate. Categorical variables were expressed as frequencies and percentages with 95% confidence intervals.

Normality of continuous variables was assessed using the Shapiro–Wilk test. Between-group comparisons were performed using the Mann–Whitney U test for continuous variables and chi-square or Fisher’s exact test for categorical variables. Multivariate logistic regression analysis was conducted to identify independent predictors of complete wound closure. Statistical significance was defined as p < 0.05.

The study was conducted in accordance with the Declaration of Helsinki and was approved by the INIEICONT Ethics Committee. Written informed consent was obtained from all participants before study inclusion. Participants in the study gave their consent for the use of images and personal data as necessary.

The chemical composition of Dermomina^® clay used in this study is presented in Table 1. X-ray fluorescence analysis demonstrated that the material was predominantly composed of silica (SiO₂, 50.60 wt%) and alumina (Al₂₃, 30.85 wt%), consistent with an aluminosilicate mineral matrix. Minor oxides, including iron(III) oxide, sodium oxide, potassium oxide, magnesium oxide, and calcium oxide, were present at low concentrations. Loss on ignition was 11.54 wt%, reflecting structural water and volatile components. Total organic carbon and sulfur content were negligible (<0.1 wt%), confirming the mineral purity and compositional stability of the clay applied during treatment.

Normality of continuous variables was assessed using the Shapiro–Wilk test (Table 2). All variables demonstrated distributions consistent with normality (p > 0.05). Nevertheless, given the small sample size (n = 24) and the presence of unequal baseline characteristics between groups, non-parametric statistical methods (Mann–Whitney U test) were used for between-group comparisons as a conservative analytical approach.

A total of 24 patients with chronic diabetic foot ulcers were included in the analysis. At baseline, 14 patients (58.3%, 95% CI: 36.6%–77.9%) presented without clinical signs of infection, whereas 10 patients (41.7%, 95% CI: 22.1%–63.4%) had clinically infected ulcers (Table 3).

Baseline demographic and clinical characteristics are summarized in Table 3. Patients with infected ulcers were older than those without infection (mean age 62.4 vs. 53.8 years, p = 0.042) and had significantly larger baseline wound areas (median 28.6 cm² vs. 15.4 cm², p = 0.003). Glycemic control, body mass index, diabetes duration, sex distribution, peripheral neuropathy prevalence, and peripheral arterial disease prevalence did not differ significantly between groups.

Ulcer severity at baseline, assessed using the Wagner classification, differed significantly between groups (Table 4). Infected ulcers were more frequently classified as higher Wagner grades compared with non-infected ulcers (p = 0.015). Grade 3 ulcers accounted for 20.0% of infected wounds versus 7.1% of non-infected wounds, while Grade 1–2 ulcers predominated in both groups.

Time-to-event healing outcomes are reported in Table 5. Non-infected ulcers demonstrated significantly shorter times to initial size reduction, granulation tissue formation, epithelialization, and complete closure compared with infected ulcers (all p < 0.001). By week 20, complete ulcer closure was achieved in 92.9% of non-infected ulcers compared with 40.0% of infected ulcers (p = 0.009).

Surface area reduction at week 20 was significantly greater in the non-infected group (mean 94.8% vs. 52.6%, p < 0.001). Confidence intervals were narrower among non-infected ulcers, indicating less variability in healing trajectories.

Detailed wound healing kinetics are presented in Table 6. The weekly wound size reduction rate was significantly higher in non-infected ulcers than in infected ulcers (12.2% vs. 6.5%, p < 0.001). Non-infected ulcers also exhibited significantly shorter times to granulation tissue formation, resolution of inflammation, and complete epithelialization (all p < 0.001).

The temporal evolution of wound healing outcomes is shown in Table 7. At week 4, partial or complete healing was observed in 85.7% of non-infected ulcers compared with 50.0% of infected ulcers. By week 8, complete closure occurred in 57.1% of non-infected ulcers and 20.0% of infected ulcers (p = 0.015). At week 20, complete closure was achieved in 92.9% of non-infected ulcers versus 40.0% of infected ulcers (p < 0.001).

Results of the multivariate logistic regression analysis are summarized in Table 8. Independent predictors of reduced odds of complete ulcer closure included higher Wagner grade, larger initial wound size (>20 cm²), presence of infection, HbA1c > 7%, age > 60 years, and peripheral arterial disease (all p < 0.05). Wagner Grade 3 demonstrated the strongest negative association with closure (adjusted OR = 0.15, 95% CI: 0.06–0.38).

Safety outcomes are presented in Table 9. Two mild adverse events were reported, yielding an overall incidence of 8.3% (95% CI: 1.0%–27.0%). These events consisted of transient local discomfort or mild skin irritation and resolved within approximately two days. No serious adverse events, treatment discontinuations, amputations, or deaths were observed during follow-up.

Microbiological findings from first wound cultures are summarized in Table 10. Pseudomonas aeruginosa was the most frequently isolated pathogen (25.6%), followed by Staphylococcus aureus and Escherichia coli. Other Gram-negative organisms, including extended-spectrum β-lactamase–producing E. coli and Stenotrophomonas maltophilia, were identified at lower frequencies.

A consistent and robust finding across analyses was the markedly superior healing trajectory observed in non-infected ulcers compared with infected ulcers. Non-infected wounds demonstrated significantly shorter times to initial size reduction, granulation tissue formation, epithelialization, and complete closure (Tables 5, 6), with these differences remaining evident throughout follow-up (Table 7). These findings are visually reinforced by the divergence in healing curves shown in Figure 1, where non-infected ulcers exhibited faster progression to closure, and by Figure 2, which illustrates parallel acceleration across multiple wound healing domains.

This pattern aligns with established pathophysiological understanding that infection and bacterial burden disrupt wound healing through sustained inflammation, protease activity, and impaired angiogenesis. Importantly, while the present study does not permit causal inference, the association between non-infected status and improved outcomes remained statistically significant after adjustment for relevant clinical covariates in multivariate analysis (Table 8).

The observed differences in weekly wound size reduction rate—nearly double in non-infected ulcers compared with infected ulcers (Table 6)—suggest that Dermomina^® application was associated with more favorable local wound dynamics in the absence of active infection. Earlier granulation and faster resolution of inflammation further support a potential role of the clay environment in promoting conditions conducive to tissue repair.

The chemical characterization of Dermomina^® (Table 1) confirms a predominantly aluminosilicate composition with minimal organic content, supporting hypotheses related to moisture regulation, adsorption of exudate, and modulation of the wound microenvironment. While mechanistic pathways were not directly assessed in this study, the convergence of faster granulation and epithelialization observed in Figures 1 and 2 suggests a biologically plausible interaction between wound status and topical clay application.

Baseline characteristics significantly influenced healing outcomes. Larger initial wound size (>20 cm²), higher Wagner grade, presence of infection, suboptimal glycemic control (HbA1c >7%), advanced age, and peripheral arterial disease were all independently associated with reduced odds of complete closure (Table 8). Among these, wound severity emerged as the strongest predictor, with Wagner Grade 3 ulcers exhibiting substantially lower closure probability.

These findings underscore the importance of early intervention. Smaller, less severe ulcers demonstrated more consistent and rapid healing trajectories, suggesting that Dermomina^® may be most effective when applied before advanced tissue damage and infection are established. This has direct clinical implications for endocrinology practice, where early identification and intervention in DFUs are critical to preventing progression, hospitalization, and amputation.

The serial clinical images (Figures 3–11) provide qualitative corroboration of the quantitative findings and highlight the heterogeneity of wound presentations and responses. Notably, meaningful healing responses were observed across a range of ulcer types, including infected ulcers, vascular ulcers, surgical bed abscesses, and complex anatomical locations.

Several cases illustrate substantial epithelialization or granulation despite advanced age, vascular disease, or infection (e.g., Figures 7-10), reinforcing that while baseline factors modulate the probability of closure, clinically relevant improvement may still occur. These images also reflect the real-world variability inherent to DFU management and support the external validity of the findings.

Microbiological analysis identified Pseudomonas aeruginosa as the most frequently isolated pathogen, followed by Staphylococcus aureus and Escherichia coli (Table 10). The predominance of Gram-negative organisms, including non-fermenters, is consistent with chronic DFU microbiology and may partially explain the attenuated healing observed in infected ulcers. Importantly, no microbiological worsening or superinfection attributable to Dermomina^® application was observed.

Dermomina^® demonstrated a favorable safety profile. Only two mild, transient adverse events were reported, both resolving without treatment discontinuation (Table 9). Similar to the study by Rosario Arias (9) no serious adverse events, amputations, or deaths occurred. These findings support the local tolerability of the intervention and are particularly relevant given the vulnerability of patients with diabetes-related wounds.

The strengths of this study include comprehensive outcome assessment, multivariate adjustment for key confounders, microbiological characterization, and longitudinal visual documentation. However, several limitations must be acknowledged. The study’s observational, pre-experimental design and small sample size limit causal inference and generalizability. The absence of a randomized control group precludes definitive attribution of outcomes to Dermomina^® alone, and unmeasured confounders cannot be excluded. Nevertheless, within these constraints, the consistency of findings across tables, figures, and clinical images strengthens confidence in the observed associations and supports further investigation.

Taken together, the findings suggest that Dermomina^® may represent a safe and potentially useful adjunct in the management of chronic DFUs, particularly in non-infected, early-to-moderate wounds with favorable baseline characteristics. The results also highlight the critical role of infection control and metabolic optimization in maximizing therapeutic response.

Future randomized controlled trials with larger sample sizes, standardized comparator treatments, and mechanistic endpoints are warranted to confirm efficacy, define optimal patient selection, and clarify biological mechanisms.

As a pre experimental observational cohort without randomization or a control group, this study cannot establish causality or directly compare the effectiveness of Dermomina with standard wound care. The concurrent use of nutritional supplementation, including ABINTRA, limits the ability to attribute observed healing exclusively to clay therapy. In addition, the single center design and convenience sampling from wound care clinics in the Dominican Republic restrict the generalizability of the findings to similar clinical and resource settings.

Baseline imbalances between infected and non infected groups were observed, including differences in age, glycemic control, and baseline wound size. These imbalances were addressed through multivariate adjustment; however, residual confounding cannot be excluded.

The modest sample size of twenty four participants limits statistical power and increases uncertainty around effect estimates. More importantly, the multivariate regression model included a limited number of outcome events per variable, increasing the risk of model overfitting. Consequently, adjusted associations should be interpreted as descriptive within this cohort rather than as precise population estimates or predictive tools. The multivariate analysis was intended to identify candidate variables for future hypothesis testing rather than to confirm independent causal effects.

By contrast, univariate findings describing healing kinetics and closure proportions are less vulnerable to overfitting and provide more robust descriptive information regarding treatment response patterns in this population.

Clinical outcome assessment was not blinded and relied on pragmatic bedside measurements rather than objective planimetric or digital imaging techniques, introducing potential measurement bias. Furthermore, the absence of a parallel control or standard of care comparison group limits the ability to contextualize observed healing rates relative to expected outcomes with conventional topical therapies.

Despite these limitations, the study achieves its primary objective of establishing an initial safety and feasibility profile for Dermomina in diabetic foot ulcers. The low incidence of adverse events, all of which were mild and transient, supports local tolerability. Additionally, the detailed characterization of healing trajectories across infection status and ulcer severity provides essential descriptive data to inform the design of adequately powered randomized studies. Identification of infection status and Wagner grade as key determinants of outcome offers clinically relevant stratification variables for future trials.