Introduction
Bone delay union is mostly caused by lack of blood supply. Although autografts, allografts and artificial bone have been widely used to treat bone delay union, the bone regeneration fails in the ischemic site accompanied by the bone donor site complications and disease transmission. Recently, there is a growing recognition of the importance of hydrogel scaffolds which are regarded as an eligible engineer tissue for bone repair. However, hydrogel is still limited in improving neovascularization.
Methods
In this work, black phosphorus nanosheet and deferoxamine (BPN-DFO) were loaded in the gelatin hydrogel to overcome the high risk of bone delay union and systemically investigated the regeneration capability of BPN-DFO hydrogel in vitro and vivo.
Results
The resulting BPN-DFO hydrogel scaffold showed superior swollen, degradation and release rate, as well as satisfied biocompatibility. BPN-DFO hydrogel shown the significant up-expression of mRNA related to bone regeneration and cell proliferation. In vivo, the proposed BPN-DFO hydrogel significantly improved osteogenesis and neovascularization in the ischemic tibial bone site of SD rats with acute femoral artery occlusion. Both macroscopic and histological evaluation of new regenerated bone showed newly formed blood vessel and collagen using BPN-DFO hydrogel. The immunohistochemistry and RT-PCR revealed that the bone regeneration could be improved via BMP/Runx2 pathway.
Conclusion
The BPN-DFO hydrogel possesses potential tissue engineer material for ischemic bone defect treatment. However, furthermore studies are needed to testify the safety and efficacy of BPN-DFO hydrogel.
Beta‐tricalcium phosphate (β‐TCP) is considered as one of the most promising biomaterials for bone reconstruction. This study generated a functional molybdenum disulfide (MoS2)/polydopamine (PDA)/−bone morphogenetic protein 2 (BMP2)‐insulin‐like growth factor‐1 (IGF‐1) coating on the β‐TCP scaffold and analyzed the outcomes. The MoS2/PDA‐BMP2‐IGF‐1@β‐TCP (MPBI@β‐TCP) scaffold was prepared by 3D printing and physical adsorption, followed by characterization to validate its successful construction. The in vitro osteogenic effect of the MPBI@β‐TCP scaffold was evaluated. It was found that MPBI@β‐TCP augmented the adhesion, diffusion and proliferation of mesenchymal stem cells (MSCs). The alkaline phosphatase (ALP) activity, collagen secretion and extracellular matrix (ECM) mineralization along with the expression of Runx2, ALP and OCN were also enhanced in the presence of MPBI@β‐TCP. Additionally, MPBI@β‐TCP stimulated endothelial cells to secrete VEGF and promoted capillary‐like tubule formation. We then confirmed the biocompatibility of MPBI@β‐TCP to macrophages and its anti‐inflammatory effects. Furthermore, under near‐infrared (NIR) laser irradiation, MPBI@β‐TCP produced photothermal effect to not only kill MG‐63 osteosarcoma cells, but also enhance bone regeneration in vivo with biosafety. Overall, this work demonstrates that 3D‐printed MPBI@β‐TCP with enhanced osteogenic activity under NIR laser irradiation has a vast potential in the field of tissue defects.
Background: Anterior occipital condyle screw (AOCS) could be a feasible technique apply to the reconstruction of craniovertebral junction. This study was to analyze the feasibility of AOCS.Method: The craniovertebral junction computed tomography (CT) scans of 40 adults were enrolled and imported into Mimics software. Then the three-dimensional reconstruction digital model of craniovertebral junction were established to determine entry point, insertion angle and screw’s trajectory. After AOCS inserted into ten human cadaver spine specimens, CT scans were performed to verify the location between screws and important structures. Result: The optimal entry point is located caudally and medial to the ventral of occipital condyle. The optimal trajectory is in inclination angle (5.9°±3.4°) in the sagittal plane and diverge angle (26.7°±6.0°) in the axial plane with the screw length around 21.6±1.2mm. There were no screws invaded into hypoglossal canal and vertebral artery in all specimens.Conclusion: AOCS fixation is a feasible novel technique for anterior craniovertebral junction reconstruction, and it could be an effective alternative operation for anterior reconstruction with titanium mesh cage.
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