Khandaker Morshed, Vaughan Melville B, Morris Tracy L, White Jeremiah J, Meng Zhaotong
Department of Engineering and Physics, University of Central Oklahoma, Edmond, OK, USA.
Department of Biology, University of Central Oklahoma, Edmond, OK, USA.
Int J Nanomedicine. 2014 May 27;9:2699-712. doi: 10.2147/IJN.S61964. eCollection 2014.
The most common bone cement material used clinically today for orthopedic surgery is poly(methyl methacrylate) (PMMA). Conventional PMMA bone cement has several mechanical, thermal, and biological disadvantages. To overcome these problems, researchers have investigated combinations of PMMA bone cement and several bioactive particles (micrometers to nanometers in size), such as magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica. A study comparing the effect of these individual additives on the mechanical, thermal, and cell functional properties of PMMA would be important to enable selection of suitable additives and design improved PMMA cement for orthopedic applications. Therefore, the goal of this study was to determine the effect of inclusion of magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica additives in PMMA on the mechanical, thermal, and cell functional performance of PMMA. American Society for Testing and Materials standard three-point bend flexural and fracture tests were conducted to determine the flexural strength, flexural modulus, and fracture toughness of the different PMMA samples. A custom-made temperature measurement system was used to determine maximum curing temperature and the time needed for each PMMA sample to reach its maximum curing temperature. Osteoblast adhesion and proliferation experiments were performed to determine cell viability using the different PMMA cements. We found that flexural strength and fracture toughness were significantly greater for PMMA specimens that incorporated silica than for the other specimens. All additives prolonged the time taken to reach maximum curing temperature and significantly improved cell adhesion of the PMMA samples. The results of this study could be useful for improving the union of implant-PMMA or bone-PMMA interfaces by incorporating nanoparticles into PMMA cement for orthopedic and orthodontic applications.
当今临床上用于骨科手术最常用的骨水泥材料是聚甲基丙烯酸甲酯（PMMA）。传统的PMMA骨水泥存在一些机械、热学和生物学方面的缺点。为克服这些问题，研究人员研究了PMMA骨水泥与几种生物活性颗粒（尺寸从微米到纳米）的组合，如氧化镁、羟基磷灰石、壳聚糖、硫酸钡和二氧化硅。一项比较这些单一添加剂对PMMA的机械、热学和细胞功能特性影响的研究，对于选择合适的添加剂以及设计用于骨科应用的改良PMMA骨水泥至关重要。因此，本研究的目的是确定在PMMA中加入氧化镁、羟基磷灰石、壳聚糖、硫酸钡和二氧化硅添加剂对PMMA的机械、热学和细胞功能性能的影响。进行了美国材料与试验协会标准的三点弯曲挠曲和断裂试验，以确定不同PMMA样品的挠曲强度、挠曲模量和断裂韧性。使用定制的温度测量系统来确定最高固化温度以及每个PMMA样品达到其最高固化温度所需的时间。进行成骨细胞粘附和增殖实验，以使用不同的PMMA骨水泥确定细胞活力。我们发现，加入二氧化硅的PMMA试样的挠曲强度和断裂韧性明显高于其他试样。所有添加剂都延长了达到最高固化温度所需的时间，并显著改善了PMMA样品的细胞粘附。本研究结果对于通过在用于骨科和正畸应用的PMMA骨水泥中加入纳米颗粒来改善植入物-PMMA或骨-PMMA界面的结合可能是有用的。
