Icariin-Loaded TiO₂ Nanotubes for Regulation of the Bioactivity of Bone Marrow Cells

Abstract

To explore the effects of icariin on the biocompatibility of dental implants, icariin-(ICA-) loaded TiO 2 nanotubes were fabricated on Ti substrates via anodic oxidation and physical absorption. The surface characteristics of the specimens were monitored by field emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), contact angle measurements (CA), and highpressure liquid chromatography. Additionally, the activities of bone marrow cells, such as cytoskeletal, proliferative activities, mineralization, and osteogenesis-related gene expression on the substrates were investigated in detail. The characterization results demonstrated that ICA-loaded TiO 2 nanotubes were successfully fabricated and the hydrophilicity of these TiO 2 nanotubes was significantly higher than that of the pure Ti groups. The results also showed that ICA-loaded TiO 2 nanotubes might not have enhanced effects on cell proliferation and ALP expression. However, it seemed to significantly promote differentiation of bone marrow cells, demonstrated by enhancing the formation of mineralized nodule and the upregulation of the gene expression such as OC, BSP, OPN, and COL-1. The results indicated that ICA-loaded TiO 2 nanotubes can modulate bioactivity of bone marrow cells, which is promising for potential applications in the orthopedics field.

TiO2 Nanotubes Functionalized with Icariin for an Attenuated In Vitro Immune Response and Improved In Vivo Osseointegration

“…Rupp et al [ 68 ] demonstrated that the wettability of various Ti surfaces could be greatly influenced by its roughness and morphology, while Takebe et al [ 69 ] highlighted that the hydrophilic character of TNT structures could be slightly increased due to the easy infiltration of water into the TiO 2 porous network, causing a decrease of contact angle value. In our study, the contact angles of the bare TNT and Ica-loaded substrates were significantly lower in comparison to that of flat Ti, in compliance with previously reported data [ 43 ]. As a means to load the biologically active molecules and drugs onto the surface of implants, the physical adsorption method has been widely applied in previous studies [ 40 , 70 , 71 ], due to its main advantage of ensuring the chemical structure and biological characteristics of the loaded molecules [ 43 ].…”

“…In our study, the contact angles of the bare TNT and Ica-loaded substrates were significantly lower in comparison to that of flat Ti, in compliance with previously reported data [ 43 ]. As a means to load the biologically active molecules and drugs onto the surface of implants, the physical adsorption method has been widely applied in previous studies [ 40 , 70 , 71 ], due to its main advantage of ensuring the chemical structure and biological characteristics of the loaded molecules [ 43 ]. Our results indicate that Ica was released from the TNT-DP substrate in a sustained manner, therefore indicating that Ica was loaded successfully onto the TNT-DP surface and that its biological activity was preserved.…”

“…Very recently Ica has been also used to modify PLLA/chitosan composite fibrous membranes exhibiting favourable osteogenic activity and superior angiogenic activity [ 42 ]. However, only a few studies have used the incorporation of Ica into Ti implants [ 43 , 44 , 45 ]. Overall, the results reported in the literature underline the favourable outcome of Ica as a surface functionalization agent in terms of bone regeneration.…”

Bench-to-bedside: Feasibility of nano-engineered and drug-delivery biomaterials for bone-anchored implants and periodontal applications

“…The experimental results in vitro and in vivo showed better bone responses when compared to smooth surfaces without nanotubes, suggesting the significance of having specific sites for maintaining the compounds on the surface [ 37 ]. Icariin (ICA) was shown to be a promising osteoinductive compound for bone regeneration studies; some authors reported the application of ICA by simple physical absorption into TiO 2 nanotube surfaces [ 38 ]. Releasing ICA improved the spreading, mineralization and expression of some bone-associated markers of bone marrow cells, suggesting a promising option for new implant surfaces [ 38 ].…”

“…Icariin (ICA) was shown to be a promising osteoinductive compound for bone regeneration studies; some authors reported the application of ICA by simple physical absorption into TiO 2 nanotube surfaces [ 38 ]. Releasing ICA improved the spreading, mineralization and expression of some bone-associated markers of bone marrow cells, suggesting a promising option for new implant surfaces [ 38 ].…”