Boffito Monica, Servello Lucia, Arango-Ospina Marcela, Miglietta Serena, Tortorici Martina, Sartori Susanna, Ciardelli Gianluca, Boccaccini Aldo R
Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
Institute of Biomaterials, University of Erlangen-Nuremberg, Cauerstr. 6, 91058 Erlangen, Germany.
Polymers (Basel). 2021 Dec 31;14(1):151. doi: 10.3390/polym14010151.
The replication method is a widely used technique to produce bioactive glass (BG) scaffolds mimicking trabecular bone. However, these scaffolds usually exhibit poor mechanical reliability and fast degradation, which can be improved by coating them with a polymer. In this work, we proposed the use of custom-made poly(urethane)s (PURs) as coating materials for 45S5 Bioglass-based scaffolds. In detail, BG scaffolds were dip-coated with two PURs differing in their soft segment (poly(ε-caprolactone) or poly(ε-caprolactone)/poly(ethylene glycol) 70/30 /) (PCL-PUR and PCL/PEG-PUR) or PCL (control). PUR-coated scaffolds exhibited biocompatibility, high porosity (ca. 91%), and improved mechanical properties compared to BG scaffolds (2-3 fold higher compressive strength). Interestingly, in the case of PCL-PUR, compressive strength significantly increased by coating BG scaffolds with an amount of polymer approx. 40% lower compared to PCL/PEG-PUR- and PCL-coated scaffolds. On the other hand, PEG presence within PCL/PEG-PUR resulted in a fast decrease in mechanical reliability in an aqueous environment. PURs represent promising coating materials for BG scaffolds, with the additional pros of being customized in their physico-chemical properties. Moreover, PUR-based coatings exhibited high adherence to the BG surface, probably because of the formation of hydrogen bonds between PUR N-H groups and BG surface functionalities, which were not formed when PCL was used.
复制法是一种广泛应用的技术，用于制备模仿松质骨的生物活性玻璃（BG）支架。然而，这些支架通常表现出较差的机械可靠性和快速降解性，通过用聚合物涂层可以改善这些问题。在这项工作中，我们提出使用定制的聚（聚氨酯）（PURs）作为基于45S5生物玻璃的支架的涂层材料。具体而言，BG支架用两种软段不同的PURs（聚（ε-己内酯）或聚（ε-己内酯）/聚（乙二醇）70/30 /）（PCL-PUR和PCL/PEG-PUR）或PCL（对照）进行浸涂。与BG支架相比，PUR涂层支架表现出生物相容性、高孔隙率（约91%）和改善的机械性能（抗压强度高2-3倍）。有趣的是，在PCL-PUR的情况下，与PCL/PEG-PUR和PCL涂层支架相比，用约40% 低含量的聚合物涂覆BG支架可使抗压强度显著提高。另一方面，PCL/PEG-PUR中PEG的存在导致在水性环境中机械可靠性快速下降。PURs是BG支架有前景的涂层材料，还有可定制其物理化学性质的额外优点。此外，基于PUR的涂层对BG表面表现出高附着力，这可能是由于PUR的N-H基团与BG表面官能团之间形成了氢键，而使用PCL时不会形成这种氢键。
