A Biomimetic Coating to Enhance Cell Adhesion at the Skin-Implant Interface of Percutaneous Osseointegrated Prosthetic (POP) Devices
Abstract
Limb loss affects thousands of people and can be devastating, especially for normally-active amputees. Studies have shown that the best way to attach a prosthetic to the residual limb is via a metal implant that anchors in the bone and passes through the skin, providing a post to which the artificial limb can attach, rather than a conventional socket system. Direct attachment to bone results in better walking and running, sensation of the ground, comfort, and overall satisfaction of the user. However, these same clinical studies have identified a specific problem that has kept this technology from being available outside of clinical trials, the area where the implant passes through the skin, is rejected by the body, and detaches and becomes infected, ultimately requiring removal of the implant. Our work has focused on developing a coating that impersonates the human fingernail, “tricking” the skin into growing into intimate contact with the implant surface, thereby forming a strong bond that does not detach or become infected, similar to a healthy skin-fingernail interface. This technology is made possible by synthesizing the same proteins as those found in human fingernail, keratins, and using them to coat metal implants. Our team has already shown in bench and animal tests that preliminary coatings using human keratins isolated from tissues can suppress implant rejection. We now propose to execute a plan to manufacture the keratin under standards required by the Food and Drug Administration and show success in an animal model that replicates human use. This work addresses the FY 2019 PRORP Topic Area of Skin-Implant Interface, as POP devices are designed to provide maximum human performance for amputees and have been shown to deliver superior biomechanics, balance, proprioception, and overall quality of life. If successful, the implant coating technology will give military amputees the option of an alternative prosthetic attachment system that will allow them to maintain an active life, compared to the socket system, which comes with significant limitations. The technology could also benefit civilian amputees that seek a more advanced attachment system and greater functionality from an artificial limb. In the future, the technology may enable successful deployment of prosthetics that are also connected directly to the nervous system, allowing control through thought, similar to a natural limb. The biomimetic coating may be applicable to other tissues and different devices and may make it possible to integrate medical devices more effectively. A broader application of the technology may be helpful for products as simple as catheters to complex devices such as a bioartificial pancreas. Ultimately, many patients that receive implantable medical devices, a population that grows by more than 6.7 million per year, may experience better performance by making devices that are more compatible with the human body. A benefit of the proposed project is that our team recently finished a government-funded study that has already shown the feasibility of our approach. With follow-on funding from the PRORP, we can accelerate our efforts toward clinical implementation. Part of our strategy is to take advantage of the expertise of collaborators who have recent finished a clinical study of uncoated implants. This will allow us to transition to human clinical trials more efficiently. Additional clinical trials will most certainly be necessary, with a product approval attainable within 10 years. The experiments proposed herein are among the first required steps prior to human testing. The data generated in this study will be used to design more extensive preclinical experiments that will support a transition to human clinical trials. If these early experiments are successful and show promise in our clinically relevant models, a significant and long-standing problem with direct attachment of prosthetics to the musculoskel
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010233
Entities
People
- Mark Van Dyke
Organizations
- Arizona Board of Regents
- United States Army