Dermal Integration Sleeve to Reduce Exit Site Infections.

DESCRIPTION (provided by applicant): The longer-term objective of this project is to develop cuffs that will greatly improve tissue integration and sealing to percutaneous devices at their skin exit sites. Improved sealing restores the natural skin barrier and can remove a major path for bacterial infection. In Phase I we intend to build from earlier work in a porcine model showing reduced inflammation and well-integrated dermal tissue with the engineered porous biomaterial central to this proposal and to develop more extensive and quantitative results in support of eventual clinical testing. Catheters and other percutaneous devices are used in multiple treatment situations, often over long time periods. Infections are an ever present issue; some hundreds of thousands occur each year with a mortality rate exceeding 30,000 patients in the US alone. A significant fraction of these infections occur via the skin barrier breach, providing a microbial migration path along the device outer surface. Present approaches to this issue rely on releasing antimicrobial agents from the device surface or from subcutaneously applied cuffs. These reduce short term infections but do not provide any seal to restore the natural skin barrier for longer term effectiveness. Concern over extended use of agents provoking superbug strains, rising pressure from Medicare and others to reduce nosocomial infections, and increasing device use, especially with older patients, make improved approaches essential. With an estimated cost per infection of 25 - 50k, the present situation represents a 6B annual cost to US healthcare. Sphere Templated Angiogenic Regeneration (STAR) 3D scaffolds are engineered biomaterials with tightly controlled pore sizing (~35 m). Previous work has shown that when formed and applied as exit site cuffs; these scaffolds strongly integrate with dermal tissue and control epidermal tongue permigration. The resulting interface forms a tight seal between the percutaneous device and the surrounding tissue and addresses the root causes of exit site vulnerability - marsupialization, permigration, and microtrauma. The STAR effects are primarily due to pore sizing and largely independent of material or surface chemistry. This allows recognized biocompatible substrate materials to be used, providing an easier commercialization path. PUBLIC HEALTH RELEVANCE: Use of percutaneous medical devices is associated with a significant risk of infection. A major pathway for bacteria is provided by non healing skin exit sites. Present approaches to this problem are only short term effective and do not address the root causes. New developments in porous biomaterials and methods of using these to form device cuffs that will integrate and seal the exit site offer potential for reduced infection rates.