Sakata Ryosuke, McNary Sean M, Miyatake Kazumasa, Lee Cassandra A, Van den Bogaerde James M, Marder Richard A, Reddi A Hari
Center for Tissue Regeneration and Repair, Department of Orthopaedic Surgery, School of Medicine, University of California, Davis, Sacramento, California, USA.
Center for Tissue Regeneration and Repair, Department of Orthopaedic Surgery, School of Medicine, University of California, Davis, Sacramento, California, USA
Am J Sports Med. 2015 Jun;43(6):1467-73. doi: 10.1177/0363546515575023. Epub 2015 Mar 26.
Platelet-rich plasma (PRP) contains high concentrations of autologous growth factors that originate from platelets. Intra-articular injections of PRP have the potential to ameliorate the symptoms of osteoarthritis in the knee. Superficial zone protein (SZP) is a boundary lubricant in articular cartilage and plays an important role in reducing friction and wear and therefore is critical in cartilage homeostasis.
To determine if PRP influences the production of SZP from human joint-derived cells and to evaluate the lubricating properties of PRP on normal bovine articular cartilage.
Controlled laboratory study.
Cells were isolated from articular cartilage, synovium, and the anterior cruciate ligament (ACL) from 12 patients undergoing ACL reconstruction. The concentrations of SZP in PRP and culture media were measured by enzyme-linked immunosorbent assay. Cellular proliferation was quantified by determination of cell numbers. The lubrication properties of PRP from healthy volunteers on bovine articular cartilage were investigated using a pin-on-disk tribometer.
In general, PRP stimulated proliferation in cells derived from articular cartilage, synovium, and ACL. It also significantly enhanced SZP secretion from synovium- and cartilage-derived cells. An unexpected finding was the presence of SZP in PRP (2.89 ± 1.23 μg/mL before activation and 3.02 ± 1.32 μg/mL after activation). In addition, under boundary mode conditions consisting of high loads and low sliding speeds, nonactivated and thrombin-activated PRP decreased the friction coefficient (μ = 0.012 and μ = 0.015, respectively) compared with saline (μ = 0.047, P < .004) and high molecular weight hyaluronan (μ = 0.080, P < .006). The friction coefficient of the cartilage with PRP was on par with that of synovial fluid.
PRP significantly stimulates cell proliferation and SZP secretion by articular cartilage and synovium of the human knee joint. Furthermore, PRP contains endogenous SZP and, in a functional bioassay, lubricates bovine articular cartilage explants.
These findings provide evidence to explain the biochemical and biomechanical mechanisms underlying the efficacy of PRP treatment for osteoarthritis or damage in the knee joint.
富含血小板血浆（PRP）含有高浓度源自血小板的自体生长因子。关节腔内注射PRP有改善膝关节骨关节炎症状的潜力。表面区蛋白（SZP）是关节软骨中的一种边界润滑剂，在减少摩擦和磨损方面起重要作用，因此对软骨内环境稳定至关重要。
确定PRP是否影响人关节来源细胞中SZP的产生，并评估PRP对正常牛关节软骨的润滑特性。
对照实验室研究。
从12例接受前交叉韧带（ACL）重建手术的患者的关节软骨、滑膜和前交叉韧带中分离细胞。通过酶联免疫吸附测定法测量PRP和培养基中SZP的浓度。通过测定细胞数量来量化细胞增殖。使用销盘摩擦计研究健康志愿者的PRP对牛关节软骨的润滑特性。
总体而言，PRP刺激关节软骨、滑膜和ACL来源细胞的增殖。它还显著增强滑膜和软骨来源细胞的SZP分泌。一个意外发现是PRP中存在SZP（激活前为2.89±1.23μg/mL，激活后为3.02±1.32μg/mL）。此外，在由高负荷和低滑动速度组成的边界模式条件下，与盐水（μ=0.047，P<.004）和高分子量透明质酸（μ=0.080，P<.006）相比，未激活和凝血酶激活的PRP降低了摩擦系数（分别为μ=0.012和μ=0.015）。含有PRP的软骨的摩擦系数与滑液的摩擦系数相当。
PRP显著刺激人膝关节的关节软骨和滑膜的细胞增殖和SZP分泌。此外，PRP含有内源性SZP，并且在功能生物测定中，可润滑牛关节软骨外植体。
这些发现为解释PRP治疗膝关节骨关节炎或损伤疗效的生化和生物力学机制提供了证据。
