Kapusetti Govinda, Misra Nira, Singh Vakil, Srivastava Swati, Roy Partha, Dana Kausik, Maiti Pralay
School of Biomedical Engineering, Indian Institute of Technology, (Banaras Hindu University), Varanasi 221 005, India.
J Mater Chem B. 2014 Jul 7;2(25):3984-3997. doi: 10.1039/c4tb00501e. Epub 2014 May 21.
A novel nanohybrid based on bone cement has been developed which is capable of healing fractured bone in 30 days, one-third of the time required for the natural healing process. Nanohybrids of bone cement based on poly(methyl methacrylate) (PMMA), currently used as a grouting material in joint replacement surgery, were prepared by simple mixing with organically modified layered silicates of varying chemical compositions. The temperature arising from exothermic polymerization in one of the nanohybrids is 12 °C lower than that in pure bone cement, thus circumventing the reported cell necrosis that occurs during implantation with pure bone cement. The thermal stability and mechanical superiority of this nanohybrid were verified in terms of its higher degradation temperature, better stiffness, superior toughness, and significantly higher fatigue resistance compared with pure bone cement; these properties make it appropriate for use as an implant material. The biocompatibility and bioactivity of the nanohybrid were confirmed using cell adhesion, cell viability, and fluorescence imaging studies. Osteoconductivity and bone bonding properties were monitored in vivo in rabbits through radiographic imaging and histopathological studies of growing bone and muscle near the surgery site. The observed dissimilarity of the properties of two different nanoclays used as fillers were visualized through interactions measured using spectroscopic techniques. Studies of the influence of different elements on bioactivity showed a higher efficiency for the nanoclay containing greater amounts of iron.
一种基于骨水泥的新型纳米复合材料已被研发出来,它能够在30天内治愈骨折,这仅为自然愈合过程所需时间的三分之一。以聚甲基丙烯酸甲酯(PMMA)为基础的骨水泥纳米复合材料目前用作关节置换手术中的灌浆材料,通过与不同化学组成的有机改性层状硅酸盐简单混合制备而成。其中一种纳米复合材料中由放热聚合产生的温度比纯骨水泥中的低12℃,从而避免了报道中纯骨水泥植入过程中发生的细胞坏死。与纯骨水泥相比,这种纳米复合材料具有更高的降解温度、更好的硬度、更优越的韧性以及显著更高的抗疲劳性,其热稳定性和机械优越性得到了验证;这些特性使其适合用作植入材料。通过细胞黏附、细胞活力和荧光成像研究证实了该纳米复合材料的生物相容性和生物活性。通过对手术部位附近生长的骨骼和肌肉进行影像学成像和组织病理学研究,在兔体内监测了骨传导性和骨结合特性。通过光谱技术测量的相互作用,直观地观察到用作填料的两种不同纳米黏土在性能上的差异。对不同元素对生物活性影响的研究表明,含铁量较高的纳米黏土具有更高的效率。