Enhanced bone regeneration and visual monitoring via superparamagnetic iron oxide nanoparticle scaffold in rats

Abstract

A main challenge for use of scaffolds in bone engineering involves non-invasive monitoring in vivo and enhanced bone regeneration. The tissue repair effect of superparamagnetic iron oxide nanoparticles (SPIONs) was demonstrated previously by our group. However, testing in vivo is needed to confirm in vitro results. Here, SPIONs loaded gelatin sponge (GS) was used as a scaffold (SPIONs-GS) and implanted in the incisor sockets of Sprague-Dawley rats. Incisor sockets filled with nothing and filled with GS served as controls. Rats were sacrificed at 2 and 4 weeks. A significant decrease in the signal intensity of T2-weighted magnetic resonance imaging (MRI) in the SPIONs-GS group was noted. Changes in image intensity of scaffolds (indicating scaffold degradation and interaction with host tissues) could be visually monitored over time. Microcomputed tomography showed that the SPIONs-GS group had more newly formed bone (64.44 ± 10.92 vs. 28.1 ± 4.49, p < .0001) and a better preserved alveolar ridge than blank control group at 4 weeks (0.962 ± 0.01 vs. 0.92 ± 0.01, p < .0001). Histology confirmed imaging results, showing good consistency in new bone formation and scaffold degradation. The number of SPIONs decreased rapidly with time due to quick degradation of GS, whereas the number of endocytic SPIONs in cells increased with time. These residual SPIONs, together with newly formed bone, could be detected by MRI at 4 weeks. Therefore, it was clear that SPIONs induced active osteogenesis. In conclusion, good visibility on MRI and enhanced regeneration of bone can be obtained by implanting SPIONs-GS in vivo without using an external magnetic field.

Bone tissue regeneration: biology, strategies and interface studies

“…SPIONs/nHA and PLA nanofibrous scaffold was implanted in the lumbar transverse defects in rabbit model and then SMF were applied. The MNP scaffold with application of an SMF persuaded more osteogenesis, new bone formation and remodeling in the rabbit defects (Hu et al 2018). Along with stem cells and scaffolds, growth factors delivering are a vital method in bone tissue regeneration.…”

Cerium- and Iron-Oxide-Based Nanozymes in Tissue Engineering and Regenerative Medicine

“…Components of the ECM such as collagen or gelatin were also employed to construct IO-NP-containing scaffolds [143,144]. To improve the mechanical strength of collagen scaffolds, a common approach is to apply plastic compression [145,146].…”

<p>Enhanced osteoinduction of electrospun scaffolds with assemblies of hematite nanoparticles as a bioactive interface</p>

“…57,58 However, there are only several published papers concerning the application of αFeNPs in bone tissue engineering, 33,43 let alone its effects on cell adhesion and proliferation, because the focus of the research is on their counterpart, superparamagnetic iron oxide nanoparticles (mainly γFe 2 O 3 and Fe 3 O 4 ). [26][27][28]43 Therefore, the current study represents a new way to apply nanomaterials in bone tissue engineering. Determining the detailed molecular pathways and in vivo animal testing are needed for further verification before this method can be applied clinically.…”

“…Recently, LbL was reported to be applied in scaffold modification for bone tissue engineering. 25 Among the many types of nanomaterials used for biomedical applications, iron oxide nanoparticles (IONPs) are promising to enhance the osteogenic differentiation of stem cells, [26][27][28] and can provide transduction of dynamic mechanical stimulation, which is required for bone formation. 29 IONPs have been used with various polymers in the electrospinning process.…”