Foster William J, Meen James K, Fox Donald A
Department of Physics, The University of Houston, Houston, TX, USA.
Cutan Ocul Toxicol. 2013 Mar;32(1):18-22. doi: 10.3109/15569527.2012.694090. Epub 2012 Jun 15.
Perovskite compounds, including lead-lanthanum-zirconium titanate (PLZT), have wide technological application because of their unique physical properties. The use of PLZT in neuro-prosthetic systems, such as retinal implants, has been discussed in a number of publications. Since inorganic lead is a retinotoxic compound that produces retinal degeneration, the long-term stability of PLZT in aqueous biological solutions must be determined.
We evaluated the stability and effects of prolonged immersion of a PLZT-coated crystal in a buffered balanced salt solution.
Scanning Electron Microscopy and Electron Dispersive Spectroscopy (EDS) using a JEOL JSM 5410 microscope equipped with EDS were utilized to evaluate the samples before and after prolonged immersion.
We found that lead and other constituents of PLZT leached into the surrounding aqueous medium.
By comparing the unit cell of PLZT with that of CaTiO(3), which has been found to react with aqueous fluids, Lead is in the same site in PLZT as Ca is in CaTiO(3). It is thus reasonable that PLZT will react with aqueous solutions.
The results suggest that PLZT must either be coated with a protective layer or is not appropriate for long-term in vivo or in vitro biological applications.
钙钛矿化合物，包括铅镧锆钛酸盐（PLZT），因其独特的物理性质而具有广泛的技术应用。许多出版物都讨论了PLZT在神经假体系统中的应用，如视网膜植入物。由于无机铅是一种会导致视网膜变性的视网膜毒性化合物，因此必须确定PLZT在水性生物溶液中的长期稳定性。
我们评估了PLZT涂层晶体在缓冲平衡盐溶液中长时间浸泡的稳定性和影响。
使用配备能谱仪的JEOL JSM 5410显微镜进行扫描电子显微镜和能谱分析（EDS），以评估长时间浸泡前后的样品。
我们发现PLZT中的铅和其他成分会渗入周围的水性介质中。
通过将PLZT的晶胞与已发现会与水性流体发生反应的CaTiO₃的晶胞进行比较，发现PLZT中铅的位置与CaTiO₃中钙的位置相同。因此，PLZT与水溶液发生反应是合理的。
结果表明，PLZT要么必须涂有保护层，要么不适合长期体内或体外生物应用。
