Middle East Technical University (METU), Department of Biological Sciences, Ankara, Turkey.
Biomed Mater. 2018 Jul 27;13(5):055010. doi: 10.1088/1748-605X/aad139.
A bone tissue replacement with relevant anatomical size requires the production of 3D scaffolds, which in turn limits the mass transport of nutrients and oxygen to sustain cell survival. A viable vascular network is required to overcome this problem. However, this cannot be established immediately after the implantation of a scaffold. The aim of this study was to develop a 3D wet-spun bone tissue engineering scaffold, coated with an elastin-like recombinamer (ELR) peptide with an endothelial cell-attracting REDV sequence to promote early vascularization. Scaffolds were produced using biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and an ELR was immobilized onto it after oxygen plasma treatment (PHBV-O-ELR-REDV). O plasma treatment and ELR modification of the PHBV changed the wettability, topography, and composition of the surface. A moderately hydrophilic surface was obtained after oxygen plasma treatment and ELR-REDV coating with a contact angle of 66.63 ± 0.77°. The surface roughness decreased after plasma treatment from 343.4 to 160.0 nm and increased to 280.3 nm after ELR-REDV coating. FTIR-ATR showed amide I and amide II bonds after ELR-REDV coating showing that the coating was successful. Scaffolds were tested in vitro with rabbit bone marrow mesenchymal cells. ELR modification did not cause a significant difference in adhesion or proliferation compared to unmodified controls. On the other hand, ELR-modified scaffolds attracted a higher number of human umbilical vein endothelial cells (HUVECs) due to the REDV sequence. The Alamar Blue test and confocal laser scanning microscopy micrographs showed that HUVEC migration and attachment on PHBV-O-ELR-REDV scaffolds was around 2.5-fold higher than untreated PHBV scaffolds after 14 d. Plasma-treated scaffolds (PHBV-O) showed an increase in the number of adhered HUVECs due to increased surface wettability. It can, therefore, be suggested that PHBV-O-ELR-REDV scaffolds have significant potential to induce early vascularization due to increased attractiveness for endothelial cells. This could alleviate the vascularization problem of 3D implants for bone tissue engineering.
一种具有相关解剖尺寸的骨组织替代物需要生产 3D 支架，而这反过来又限制了营养物质和氧气的质量传递，从而维持细胞的存活。需要建立一个可行的血管网络来克服这个问题。然而，这不能在支架植入后立即建立。本研究的目的是开发一种 3D 湿法纺丝的骨组织工程支架，该支架涂有弹性蛋白样重组体（ELR）肽，其中含有内皮细胞吸引肽 REDV 序列，以促进早期血管化。支架采用可生物降解的聚（3-羟基丁酸-co-3-羟基戊酸）（PHBV）制成，并在氧等离子体处理后将 ELR 固定在其上（PHBV-O-ELR-REDV）。O 等离子体处理和 PHBV 的 ELR 修饰改变了表面的润湿性、形貌和组成。经过氧等离子体处理和 ELR-REDV 涂层处理后，表面获得了中等亲水性，接触角为 66.63±0.77°。等离子体处理后表面粗糙度从 343.4 降低到 160.0nm，而 ELR-REDV 涂层后增加到 280.3nm。FTIR-ATR 显示 ELR-REDV 涂层后出现酰胺 I 和酰胺 II 键，表明涂层成功。将支架与兔骨髓间充质细胞在体外进行测试。与未修饰的对照相比，ELR 修饰对粘附或增殖没有显著影响。另一方面，由于 REDV 序列，ELR 修饰的支架吸引了更多的人脐静脉内皮细胞（HUVECs）。Alamar Blue 测试和共聚焦激光扫描显微镜照片显示，在 14 天后，PHBV-O-ELR-REDV 支架上 HUVEC 的迁移和附着比未经处理的 PHBV 支架高约 2.5 倍。经过等离子体处理的支架（PHBV-O）由于表面润湿性增加，附着的 HUVEC 数量增加。因此，可以认为 PHBV-O-ELR-REDV 支架由于对内皮细胞的吸引力增加，具有诱导早期血管化的巨大潜力。这可以缓解 3D 植入物用于骨组织工程的血管化问题。
