A skin-interfaced, miniaturized platform for triggered induction, capture and colorimetric multicomponent analysis of microliter volumes of sweat

Eccrine sweat can serve as a source of biomarkers for assessing physiological health and nutritional balance, for tracking loss of essential species from the body and for evaluating exposure to hazardous substances. The growing interest in this relatively underexplored class of biofluid arises in part from its non-invasive ability for capture and analysis. The simplest devices, and the only ones that are commercially available, exploit soft microfluidic constructs and colorimetric assays with purely passive modes of operation. The most sophisticated platforms exploit batteries, electronic components and radio hardware for inducing sweat, for electrochemical evaluation of its content and for wireless transmission of this information. The work reported here introduces a technology that combines the advantages of these two different approaches, in the form of a cost-effective, easy-to-use device that supports on-demand evaluation of multiple biomarkers in sweat. This flexible, skin-interfaced, miniaturized system incorporates a hydrogel that contains an approved drug to activate eccrine sweat glands, electrodes and a simple circuit and battery to delivery this drug by iontophoresis through the surface of the skin, microfluidic channels and microreservoirs to capture the induced sweat, and multiple colorimetric assays to evaluate the concentrations of chloride, zinc, and iron. As demonstrated in healthy human participants monitored before and after a meal, such devices yield results that match those of traditional laboratory analysis techniques. Clinical studies that involve cystic fibrosis pediatric patients illustrate the use of this technology as a simple, painless, and reliable alternative to traditional hospital systems for measurements of sweat chloride.

Perceptions of safety monitoring in CF clinical studies and potential impact on future study participation

BACKGROUND

Individuals with CF and their parents cite safety concerns as barriers to participating in clinical studies. We assessed whether a brochure/infographic describing patient safety monitoring processes could reduce knowledge and attitude barriers regarding safety monitoring. We also identified factors associated with likely participation in future CF studies.

METHODS

Respondents from three CF centers in the U.S. were randomly assigned to receive the safety monitoring brochure/infographic or an unrelated brochure. Fifty parents of children with CF <16, 50 adolescents with CF 16-21, and 50 adults with CF ≥22 years old were recruited to complete the study survey. Factors associated with survey responses and with reported likelihood of participating in future studies were assessed.

RESULTS

Overall the safety monitoring brochure/infographic was associated with increased likelihood of future participation in non-drug studies (aOR 2.30, CI₉₅ 1.01-5.28), but not in drug studies. Non-Hispanic respondents reported greater likelihood of participating in a future drug study than Hispanic respondents (aOR 3.18, CI₉₅ 1.30-7.74). Adults with CF (aOR 2.62, CI₉₅ 1.05-6.51) and parents (aOR 4.49, CI₉₅ 1.66-12.15) were more likely than adolescents to report they would ask their care team about clinical trials. Confidence in safety monitoring was associated with reported likelihood of future participation in drug studies.

CONCLUSIONS

Potential future participation in CF drug and/or non-drug studies was associated with respondent age and ethnicity, receiving the safety monitoring brochure/infographic, and confidence in safety monitoring. Our findings underscore the need for education about safety monitoring, with targeted approaches for the Hispanic CF population and adolescents.