The bioengineering theory of the key modes of action of a cyanoacrylate liquid skin protectant

Abstract

The objective of this article is to formulate a new bioengineering theoretical framework for modelling the biomechanical efficacy of cyanoacrylate skin protectants, with specific focus on the Marathon technology (Medline Industries, Inc., Northfield, Illinois) and its modes of action. This work details the bioengineering and mathematical formulations of the theory, which is based on the classic engineering theories of flexural stiffness of coated elements and deformation friction. Based on the relevant skin anatomy and physiology, this paper demonstrates: (a) the contribution of the polymerised cyanoacrylate coating to flexural skin stiffness, which facilitates protection from non‐axial (eg, compressive) localised mechanical forces; and (b) the contribution of the aforementioned coating to reduction in frictional forces and surface shear stresses applied by contacting objects such as medical devices. The present theoretical framework establishes that application of the cyanoacrylate coating provides considerable biomechanical protection to skin and subdermally, by shielding skin from both compressive and frictional (shearing) forces. Moreover, these analyses indicate that the prophylactic effects of the studied cyanoacrylate coating become particularly strong where the skin is thin or fragile (typically less than ~0.7 mm thick), which is characteristic to old age, post‐neural injuries, neuromuscular diseases, and in disuse‐induced tissue atrophy conditions.

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“…4 The majority of PI prevention research has targeted pressure force reduction through offloading, but there is growing awareness of friction and shear importance to PI development leading to more studies on how to address these barriers. 3,15,16,18 The complexities of skin aging with the interactions of these forces make the older population at more risk for PIs. This highlights the need for skin protection during patient care and repositioning, which warrants the inclusion of older adults in future studies on this topic.…”

“…13 Shear is a mechanical force that acts internally on the skin tissue in a direction parallel to the body's surface. [13][14][15][16] Shearing forces occur between the internal body structures and skin tissues typically moving in opposite directions and may lead to deep tissue injury. 14,16 Friction and shear have a direct relationship so if friction increases, then shear likely increases.…”

“…26 Protective products such as cyanoacrylate topical skin protectants increase skin surface stiffness and can reduce the effects of friction forces on thin elderly skin. 15 Protective dressings may also be used over bony prominences during movement to help prevent skin damage during patient transfers. 11 The roughness of surfaces underneath patients is also a main contributor to friction and shear especially among older adults with decreased skin elasticity.…”

“…29 Few examples of SPHM devices include friction-reducing transfer sheets, air transfer devices, transfer boards, and overhead lifting devices. 15,26,30 Friction-reducing sheets as opposed to standard cotton sheets when used during lateral patient transfers may help reduce skin drag. 30 Other devices like transfer boards and slings may increase friction along the skin so proper selection of equipment based on patient size, needs, and skin features are imperative.…”

A review of the bio-tribology of medical devices

“…For example, foam alternatives were found to be more effective than the standard foam mattress in reducing the incidence of pressure ulcers [78]. Synthetic fibers were found to be effective in reducing friction coefficient [79].…”