Department of Materials Science and Engineering, Virginia Tech, Blacksburg, VA, 24061, United States.
Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, 24061, United States.
Colloids Surf B Biointerfaces. 2019 Oct 1;182:110351. doi: 10.1016/j.colsurfb.2019.110351. Epub 2019 Jul 8.
Percutaneous osseointegrated prosthetics (POP), which consist of a metallic post attached to the bone that extends outward through the skin to connect to an external prosthesis, have become a clinically relevant option to replace the typical socket-residual limb connection. POP devices offer several advantages such as mechanical off-loading of soft tissues, direct force transfer to the musculoskeletal system, greater proprioception, and overall improvement in limb kinesis compared to a socket system. However, POP devices create several challenges including epidermal downgrowth, increased infection risk, and mechanical tearing at the skin-implant interface. To address these issues, biomimetic surfaces and coatings have been developed in an attempt to create an infection-free and cohesive interface between POP devices and skin. The fingernail is a prime example of a natural system with a skin interface that is both mechanically and biologically stable. Exploiting keratins' previously demonstrated tissue compatibility and creating a biomimetic coating for POP devices that can imitate the human fingernail, and demonstrating its ability to promote a stable interface with skin tissue is the goal of this work. Silane coupling aided in producing a coating on titanium substrates consisting of human keratin proteins. Several combinations of silane and keratin derivatives were investigated, and in general showed a nano-scale coating thickness that supported skin cell (i.e. fibroblast and keratinocyte) adhesion. Initial enzyme-mediated degradation resistance was also demonstrated, but the coatings appeared to degrade at long time periods. Importantly, keratinocytes showed a stable phenotype with no indication of wound healing-like activity. These data provide justification to further explore keratin biomaterials for POP coatings that may stabilize the implant-skin interface.
经皮骨整合假体（POP）由附着在骨骼上的金属柱组成，该金属柱向外延伸穿过皮肤与外部假体相连，已经成为替代典型套接残肢连接的一种具有临床相关性的选择。POP 装置具有许多优点，例如软组织的机械卸载、直接将力传递到肌肉骨骼系统、更好的本体感觉以及与套接系统相比肢体运动学的整体改善。然而，POP 装置会带来一些挑战，包括表皮向下生长、感染风险增加以及皮肤-植入物界面的机械撕裂。为了解决这些问题，已经开发出仿生表面和涂层，试图在 POP 装置和皮肤之间创造一个无感染和有凝聚力的界面。指甲是一个很好的例子，它具有机械和生物稳定的皮肤界面。利用角蛋白已被证明的组织相容性，并为 POP 装置创建一种仿生涂层，以模仿人类指甲，并证明其促进与皮肤组织稳定界面的能力，是这项工作的目标。硅烷偶联剂有助于在钛基底上生成由人类角蛋白蛋白组成的涂层。研究了几种硅烷和角蛋白衍生物的组合，一般来说，显示出支持皮肤细胞（即成纤维细胞和角质形成细胞）黏附的纳米级涂层厚度。还初步证明了酶介导的抗降解能力，但涂层似乎在长时间内降解。重要的是，角质形成细胞表现出稳定的表型，没有伤口愈合样活性的迹象。这些数据为进一步探索角蛋白生物材料用于 POP 涂层提供了依据，这可能稳定植入物-皮肤界面。
