Weiner Ashley A, Shuck Danielle M, Bush Jordan R, Prasad Shastri V
Department of Biomedical Engineering, Vanderbilt University, Station B Box 351631, 5824 Stevenson Center, Nashville, TN 37235, USA.
Biomaterials. 2007 Dec;28(35):5259-70. doi: 10.1016/j.biomaterials.2007.08.022. Epub 2007 Sep 7.
In the past decade, injectable biomaterials that are capable of in situ formation have garnered increased interest for use in restorative orthopedic procedures. In this study, the in vitro degradation of photocrosslinked polyanhydride matrices, derived from methacrylic anhydrides of 1,6-bis(p-carboxyphenoxy)hexane (MCPH) and sebacic acid (MSA) were evaluated over a 6-week period under physiological conditions. These matrices were augmented with two additives--the reactive diluent poly(ethylene glycol) diacrylate (PEGDA) and the buffering agent calcium carbonate (CaCO3). Disk shaped specimens were produced by crosslinking the components using both chemical and photoinitiators and exposure to visible light. The experimental variables studied included: MCPH:MSA ratio, PEGDA molecular weight and weight fraction, and incorporation of CaCO3. The effects of these variables on local pH, water uptake, mass loss, and mechanical properties were explored. Increasing the MCPH:MSA ratio decreased the mass loss and water uptake at predetermined endpoints, and decreased buffer acidity during degradation. Both PEGDA and CaCO3 were found to decrease acidity and to reduce water uptake during degradation. Incorporation of CaCO3 enabled maintenance of compressive modulus during degradation. These results demonstrate that incorporation of reactive diluents and nonreactive additives into networks of photocrosslinked anhydrides can improve system properties as a material for bone replacement.
在过去十年中，能够原位形成的可注射生物材料在修复性骨科手术中的应用引起了越来越多的关注。在本研究中，对由1,6-双（对羧基苯氧基）己烷（MCPH）和癸二酸（MSA）的甲基丙烯酸酐衍生而来的光交联聚酸酐基质在生理条件下6周内的体外降解情况进行了评估。这些基质添加了两种添加剂——反应性稀释剂聚（乙二醇）二丙烯酸酯（PEGDA）和缓冲剂碳酸钙（CaCO3）。通过使用化学引发剂和光引发剂交联各组分并暴露于可见光来制备圆盘状标本。所研究的实验变量包括：MCPH:MSA比例、PEGDA分子量和重量分数以及CaCO3的掺入情况。探讨了这些变量对局部pH值、吸水率、质量损失和力学性能的影响。增加MCPH:MSA比例可降低预定终点时的质量损失和吸水率，并降低降解过程中的缓冲酸度。发现PEGDA和CaCO3均可降低酸度并减少降解过程中的吸水率。掺入CaCO3可在降解过程中维持压缩模量。这些结果表明，将反应性稀释剂和非反应性添加剂掺入光交联酸酐网络中可改善作为骨替代材料的系统性能。
