Properties of pressure-sensitive adhesive tapes with soft adhesives to human skin and their mechanism

The Science of Skin: Measuring Damage and Assessing Risk

Significance: Healthy skin provides a barrier to contaminants. Breaches in skin integrity are often encountered in the patient health care journey, owing to intrinsic health issues or to various procedures and medical devices used. The time has come to move clinical practice beyond mere awareness of medical adhesive-related skin injury and toward improved care and outcomes. Recent Advances: Methods developed in research settings allow quantitative assessments of skin damage based on the measurement of baseline skin properties. These properties become altered by stress and over time. Assessment methods typically used by the cosmetic industry to compare product performance could offer new possibilities to improve clinical practice by providing better information on the status of patient skin. This review summarizes available skin assessment methods as well as specific patient risks for skin damage. Critical Issues: Patients in health care settings may be at risk for skin damage owing to predisposing medical conditions, health status, medications taken, and procedures or devices used in their treatment. Skin injuries come as an additional burden to these medical circumstances and could be prevented. Technology should be leveraged to improve care, help maintain patient skin health, and better characterize functional wound closure. Future Directions: Skin testing methods developed to evaluate cosmetic products or assess damage caused by occupational exposure can provide detailed, quantitative information on the integrity of skin. Such methods have the potential to guide prevention and treatment efforts to improve the care of patients suffering from skin integrity issues while in the health care system.

Carboxymethylated starch and cellulose derivatives-based film as human skin equivalent for adhesive properties testing

The films based on carboxymethyl derivatives of starch (CMS) and cellulose (CMC) were proposed as a novel human skin equivalent. The physicochemical properties (moisture absorption, solubility in water, mechanical properties) of CMS/CMC films were evaluated. Additionally, some properties were compared to the human skin ones (surface roughness, tribology). The system based on CMS/CMC 25/75 wt. % was selected for testing the adhesive properties of pressure-sensitive adhesives commonly used for medical purposes (acrylic, silicone and polyisobutylene). Similar tests were performed for human skin. The peel adhesion values for CMS/CMC film and human skin were similar for all adhesives types tested. Applying such a skin equivalent allows to evaluate the functional properties of medical pressure-sensitive adhesives without the ethical and economic issues.

Novel instrumentation to determine peel force in vivo and preliminary studies with adhesive skin barriers

BACKGROUND/PURPOSE

Adhesive barriers secure medical devices to skin. Laboratory adhesion models are not predictive of in vivo performance. The objectives of these studies were to validate a novel peel force device, and to investigate relationships between barrier formulations, barrier width, subjective discomfort during barrier removal, and substrates.

METHODS

Three hydrocolloid barrier formulations in three widths were adhered to ethylene/methyl acrylate film (EMA), VITRO-SKIN(®) and human abdominal skin. Peel force was measured using a MTS Insight™ and a cyberDERM Inc. Mini Peel Tester (CMPT). Subjects reported their discomfort.

RESULTS

Peel forces were highly correlated between devices and highly dependent on substrate. Data suggested a weak direct association between peel force in vivo and discomfort. The 0.5″-wide barriers had the most precise peel forces measurements in vivo. A weak negative relationship between normalized peel force and barrier width on human skin was found. There was a strong positive relationship between peel force in vivo and on EMA, whereas no correlation was observed with VITRO-SKIN(®).

CONCLUSION

The CMPT correlates with a standard instrument and can advantageously investigate adhesion in vivo. Barrier width and substrate impact the reliability and predictability of peel force measurements.

Quick-release medical tape

Medical tape that provides secure fixation of life-sustaining and -monitoring devices with quick, easy, damage-free removal represents a longstanding unmet medical need in neonatal care. During removal of current medical tapes, crack propagation occurs at the adhesive-skin interface, which is also the interface responsible for device fixation. By designing quick-release medical tape to undergo crack propagation between the backing and adhesive layers, we decouple removal and device fixation, enabling dual functionality. We created an ordered adhesive/antiadhesive composite intermediary layer between the medical tape backing and adhesive for which we achieve tunable peel removal force, while maintaining high shear adhesion to secure medical devices. We elucidate the relationship between the spatial ordering of adhesive and antiadhesive regions to create a fully tunable system that achieves strong device fixation and quick, easy, damage-free device removal. We also described ways of neutralizing the residual adhesive on the skin and have observed that thick continuous films of adhesive are easier to remove than the thin islands associated with residual adhesive left by current medical tapes.