Synthesis of Ce/Gd@HA/PLGA Scaffolds Contributing to Bone Repair and MRI Enhancement

Abstract

It is important for future clinical applications to design and synthesize multipurpose scaffolding materials for bone tissue engineering with high osteogenic induction and MRI capability. In the present study, we synthesized Ce/Gd@HA by co-doping Ce3+ and Gd3+ into hydroxyapatite (HA) using a hydrothermal synthesis method, and then Ce/Gd@HA composites were synthesized by combining Ce/Gd@HA nanoparticles with polylactic-co-glycolic acid (PLGA) to investigate whether implanted Ce/Gd@HA/PLGA composites could promote osteoblast viability, leading to tibia repair of the rats and enhance MRI. The measurement results contain X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and environmental scanning electron microscopy (ESEM) showing that HA doped with Ce3+ and Gd3+ was still a hexagonal crystal with high crystallinity. The synthesized Ce/Gd@HA/PLGA composites have a structure and obvious magnetic resonance imaging (MRI) capability. The in vitro experimental results indicated that Ce/Gd@HA/PLGA composites significantly promoted the performance of MC3T3-E1 cells, containing proliferation, adhesion, and osteogenic differentiation capacities. These include the improvement of alkaline phosphatase activity, enhancement of mineral deposition, and upregulation of OCN and COL-1 gene expression. The in vivo experimental results demonstrated that the Ce/Gd@HA/PLGA composites significantly improved the healing rate of rat bone defects. The MRI images indicated that the Ga-doped composites were observed in the MRI T1 sequence in rats. The aforementioned results suggested that Ce/Gd@HA/PLGA composites not only effectively promoted bone formation but also enhanced MRI capability. The composites synthesized in this study have great potential in bone regeneration with an extensive application in bone tissue engineering.

Cu/Gd co-doped hydroxyapatite/PLGA composites enhance MRI imaging and bone defect regeneration

“…The positions of these functional groups were consistent with the infrared absorption peak wavelengths of HA reported in the literature, and no other miscellaneous peaks were present, indicating that the main groups in the product were hydroxyl and phosphate root groups, which is in line with the HA infrared absorption spectrum results. (2,4) To further analyze the morphology of the product, SEM analysis of the nanoparticles was performed. Figure 1C shows the SEM images of the products obtained via hydrothermal reaction at 180℃ for 12 h at different doping ratios.…”

pH-Sensitive Hybrid System Based on Eu3+/Gd3+ Co-Doped Hydroxyapatite and Mesoporous Silica Designed for Theranostic Applications

“…Furthermore, the addition of rare earths elements into the hydroxyapatite structure resulted in reduced mean grain size about 20% ( Table 1 ). This may occur due to the decreasing of Ca-O distances and smaller ionic radius presented for rare earth elements, and the higher electronegativity of rare earth elements (RE 3+ ) ions, resulting in a reduction of cell parameters as shown in Table 1 [ 33 , 34 , 35 ].…”

Safe magnetic resonance imaging on biocompatible nanoformulations

“…HA-based NPs have been extensively used as in vivo MRI CAs including HA-IONPs, 72 HA-Fe 3 O 4 NPs, 73 FPPBH NPs, 74 HA-MnO 2 NPs, 75 HA-GdIO NPs, 76 Gd-HA NPs, 77 and Ce/Gd@HA/PLGA. 78…”

“…HA-based NPs have been extensively used as in vivo MRI CAs including HA–IONPs, 72 HA-Fe 3 O 4 NPs, 73 FPPBH NPs, 74 HA-MnO 2 NPs, 75 HA-GdIO NPs, 76 Gd-HA NPs, 77 and Ce/Gd@HA/PLGA. 78 Based on the advantages of HA, Wu et al fabricated hyaluronic acid-functionalized gadolinium oxide nanoparticles (HA-Gd 2 O 3 NPs) for MRI imaging and radio sensitization of tumors. As shown in Fig.…”