Department of Regenerative Biomaterials , Radboud University Medical Center , 6525 EX Nijmegen , The Netherlands.
Department of Systems Chemistry , Radboud University , 6525 AJ Nijmegen , The Netherlands.
ACS Appl Mater Interfaces. 2019 Jul 31;11(30):26690-26703. doi: 10.1021/acsami.9b08311. Epub 2019 Jul 16.
Calcium phosphate ceramics are frequently applied to stimulate regeneration of bone in view of their excellent biological compatibility with bone tissue. Unfortunately, these bioceramics are also highly brittle. To improve their toughness, fibers can be incorporated as the reinforcing component for the calcium phosphate cements. Herein, we functionalize the surface of poly(vinyl alcohol) fibers with thermoresponsive poly(-isopropylacrylamide) brushes of tunable thickness to improve simultaneously fiber dispersion and fiber-matrix affinity. These brushes shift from hydrophilic to hydrophobic behavior at temperatures above their lower critical solution temperature of 32 °C. This dual thermoresponsive shift favors fiber dispersion throughout the hydrophilic calcium phosphate cements (at 21 °C) and toughens these cements when reaching their hydrophobic state (at 37 °C). The reinforcement efficacy of these surface-modified fibers was almost double at 37 versus 21 °C, which confirms the strong potential of thermoresponsive fibers for reinforcement of calcium phosphate cements.
磷酸钙陶瓷因其与骨组织具有极好的生物相容性，常被应用于刺激骨再生。然而，这些生物陶瓷的韧性也很差。为了提高它们的韧性，可以将纤维作为增强相加入到磷酸钙水泥中。在此，我们通过在聚乙烯醇纤维表面接枝温敏性聚（N-异丙基丙烯酰胺）刷，来改善纤维的分散性和纤维与基体的亲和性。这些刷层在高于其低临界溶解温度（LCST）32°C 时，从亲水转变为疏水。这种双重温敏转变有利于纤维在亲水性磷酸钙水泥（21°C）中的分散，并在达到疏水性状态（37°C）时使这些水泥增韧。在 37°C 时，与 21°C 相比，这些经过表面改性的纤维的增强效果几乎增加了一倍，这证实了温敏纤维在增强磷酸钙水泥方面的巨大潜力。
