Department of Biomedical Engineering, Orthopaedic Biomechanics, Eindhoven University of Technology, Eindhoven, The Netherlands.
Department of Biomedical Engineering, University Medical Center Groningen, Groningen, The Netherlands.
J Biomed Mater Res B Appl Biomater. 2023 Aug;111(8):1523-1532. doi: 10.1002/jbm.b.35251. Epub 2023 Mar 23.
Frictional properties of cartilage resurfacing implants should be sufficiently low to limit damaging of the opposing cartilage during articulation. The present study determines if native lubricious molecule proteoglycan 4 (PRG4) can adsorb onto a layer-by-layer bioinspired coating composed of poly-l-lysine (PLL) and dopamine modified hyaluronic acid (HADN) and thereby can reduce the friction between implant and articular cartilage. An ELISA was developed to quantify the amount of immobilized human recombinant (rh)PRG4 after exposure to the PLL-HADN coating. The effect on lubrication was evaluated by comparing the coefficient of friction (CoF) of bare polycaprolactone (PCL) disks to that of PLL-HADN coated PCL disks while articulated against cartilage using a ring-on-disk geometry and a lubricant solution consisting of native synovial fluid components including rhPRG4. The PLL-HADN coating effectively immobilized rhPRG4. The surface roughness of PCL disks significantly increased while the water contact angle significantly decreased after application of the coating. The average CoF measured during the first minute of bare PCL against cartilage exceeded twice the CoF of the PLL-HADN coated PCL against cartilage. After 60 min, the CoF reached equilibrium values which were still significantly higher for bare PCL compared to coated PCL. The present study demonstrated that PCL can effectively be coated with PLL-HADN. Additionally, this coating reduces the friction between PCL and cartilage when a PRG4-rich lubricant is used, similar to the lubricating surface of native cartilage. This makes PLL-HADN coating a promising application to improve the clinical success of PCL-based cartilage resurfacing implants.
软骨表面置换植入物的摩擦性能应足够低，以限制在关节运动过程中对 opposing cartilage 的损伤。本研究旨在确定天然润滑分子蛋白聚糖 4（PRG4）是否可以吸附到由聚-l-赖氨酸（PLL）和多巴胺修饰透明质酸（HADN）组成的层层仿生涂层上，从而降低植入物与关节软骨之间的摩擦。开发了一种 ELISA 来定量分析暴露于 PLL-HADN 涂层后固定化的人重组（rh）PRG4 的量。通过比较裸聚己内酯（PCL）盘与 PLL-HADN 涂层的 PCL 盘在关节软骨上的摩擦系数（CoF），同时在包含 rhPRG4 的天然滑液成分的润滑剂溶液中使用环盘几何形状，评估了润滑效果。PLL-HADN 涂层有效地固定化 rhPRG4。PCL 盘的表面粗糙度显著增加，而水接触角在涂层应用后显著降低。在与软骨接触的裸 PCL 最初一分钟内测量的平均 CoF 超过 PLL-HADN 涂层的 PCL 与软骨接触的 CoF 的两倍。60 分钟后，CoF 达到平衡值，但与涂层 PCL 相比，裸 PCL 的 CoF 仍然明显更高。本研究表明，PLL-HADN 可以有效地涂覆 PCL。此外，当使用富含 PRG4 的润滑剂时，这种涂层可降低 PCL 与软骨之间的摩擦，类似于天然软骨的润滑表面。这使得 PLL-HADN 涂层成为改善基于 PCL 的软骨表面置换植入物临床成功率的有前途的应用。
