Improve the Strength of PLA/HA Composite Through the Use of Surface Initiated Polymerization and Phosphonic Acid Coupling Agent.
Improve the Strength of PLA/HA Composite Through the Use of Surface Initiated Polymerization and Phosphonic Acid Coupling Agent.
复制标题
DOI：
10.6028/jres.116.021
复制
发表时间：
2011-09
影响因子：
1.5
通讯作者：
Mitchell JW
中科院分区：
文献类型：
--
作者：
Wang T;Chow LC;Frukhtbeyn SA;Ting AH;Dong Q;Yang M;Mitchell JW
由可降解聚合物制成的生物可吸收复合材料，聚乳酸（PLA）和生物活性磷酸钙，例如，羟基磷灰石（HA）在临床上是骨固定、修复和组织工程所需的，因为它们在骨愈合后不需要通过手术去除。然而，从未改性的HA制备PLA/HA复合材料通常会导致由于PLA和HA之间的弱界面而导致机械强度降低。在这项研究中，开发了钙-磷酸盐/膦酸盐混合壳，以在HA颗粒上引入更大量的反应性羟基。然后，通过表面羟基的非离子性，将PLA成功地接枝到HA表面。热重分析表明，PLA在HA上的接枝量可达7%，比文献报道的高出约50%。PLA接枝的HA显示出与未涂覆的HA显著不同的pH依赖性微生物电位和粒度分布。将膦酸偶联剂与表面引发聚合相结合，可使PLA与HA以共价键的形式直接连接，从而显著改善PLA/HA复合材料的界面相互作用。PLA接枝HA制备的PLA/HA复合材料的径向拉伸强度是未改性HA制备的复合材料的两倍以上。而且，改进后的复合材料的拉伸强度比单独的PLA提高了23%。通过改变额外的变量，这种方法有可能产生具有改善的机械性能的生物可吸收的复合材料，这些性能在天然骨的范围内，并且可以广泛应用于承重区域的骨固定和修复。
Bioresorbable composite made from degradable polymers, e.g., polylactide (PLA), and bioactive calcium phosphates, e.g., hydroxyapatite (HA), are clinically desirable for bone fixation, repair and tissue engineering because they do not need to be removed by surgery after the bone heals. However, preparation of PLA/HA composite from non-modified HA usually results in mechanical strength reductions due to a weak interface between PLA and HA. In this study, a calcium-phosphate/phosphonate hybrid shell was developed to introduce a greater amount of reactive hydroxyl groups onto the HA particles. Then, PLA was successfully grafted on HA by surface-initiated polymerization through the non-ionic surface hydroxyl groups. Thermogravimetric analysis indiated that the amount of grafted PLA on HA can be up to 7 %, which is about 50 % greater than that from the literature. PLA grafted HA shows significantly different pH dependent ζ-potential and particle size profiles from those of uncoated HA. By combining the phosphonic acid coupling agent and surface initiated polymerization, PLA could directly link to HA through covalent bond so that the interfacial interaction in the PLA/HA composite can be significantly improved. The diametral tensile strength of PLA/HA composite prepared from PLA-grafted HA was found to be over twice that of the composite prepared from the non-modified HA. Moreover, the tensile strength of the improved composite was 23 % higher than that of PLA alone. By varying additional variables, this approach has the potential to produce bioresorbable composites with improved mechanical properties that are in the range of natural bones, and can have wide applications for bone fixation and repair in load-bearing areas.
登录
查看更多内容
DOI：
10.6028/jres.109.042
发表时间：
2004-11
影响因子：
1.5
作者：
Markovic M;Fowler BO;Tung MS
通讯作者：
Tung MS
DOI：
10.1002/jbm.10044
发表时间：
2002-03-15
期刊：
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH
影响因子：
--
作者：
Gibson, IR;Bonfield, W
通讯作者：
Bonfield, W
影响因子：
14
作者：
Shikinami, Y;Okuno, M
通讯作者：
Okuno, M
影响因子：
3.9
作者：
Haque, Saba;Rehman, Ihtesham;Darr, Jawwad A.
通讯作者：
Darr, Jawwad A.
影响因子：
56.9
作者：
Munch, E.;Launey, M. E.;Ritchie, R. O.
通讯作者：
Ritchie, R. O.