Delivery of MiR335‐5p‐Pendant Tetrahedron DNA Nanostructures Using an Injectable Heparin Lithium Hydrogel for Challenging Bone Defects in Steroid‐Associated Osteonecrosis

Abstract

Corticosteroids-induced Dickkopf-1 (DKK1) upregulation and Wnt signaling inhibition result in bone metabolism disorder and steroid-associated osteonecrosis (SAON). Implanting biomaterials to regulate the Wnt pathway is a promising method to repair challenging bone defects associated with SAON. Here, tetrahedral DNA nanostructures (TDNs) are fabricated as gene carriers to deliver MiR335-5p, which targets DKK1 translation. Heparin lithium hydrogel (Li-hep-gel) is synthesized to act as a lithium and MiR@TDNs delivery agent. Finally, the repair effects on challenging bone defect in SAON using a MiR@TDNs/Li-hep-gel composite are assessed in vivo. The results reveal that MiR@TDNs are absorbed by bone mesenchymal stem cells (BMSCs) and increase cell viability and reduce apoptosis. Moreover, MiR@TDNs promote alkaline phosphatase expression and calcium nodular deposition, decrease lipid droplet expression of BMSCs, and improve vascular endothelial growth factor secretion and vascular-like structure formation in vitro. After MiR@TDNs/Li-hep-gel is implanted into the SAON model, the internal bone defect of osteonecrosis is repaired with a large area of new bone accompanied with neovascularization and reduced empty lacunae. In conclusion, MiR@TDNs/Li-hep-gel can provide dual delivery of lithium and MiR@TDNs, which synergistically upregulate the Wnt signaling pathway, enhancing bone regeneration in challenging bone defects, and can be potentially used in SAON repair.

Copper-Lithium-Doped Nanohydroxyapatite Modulates Mesenchymal Stem Cells Homing to Treat Glucocorticoids-Related Osteonecrosis of the Femoral Head

“…Thirty New Zealand white rabbits (male, aged 28–32 weeks, weight 2.5–3.2 kg, one per cage) were housed at the animal center of our institution and maintained on a standard laboratory diet and water. The rabbit model of ONFH was established by intramuscular injection of lipopolysaccharide (10 μg/kg, Sigma, United States) combined with intramuscular injection of methylprednisolone (20 mg/kg, Sigma, United States) for the following 3 days ( Li et al, 2022 ).…”

Applications of Nonviral Biomaterials for microRNA Transfection in Bone Tissue Engineering

“…Lipofectamine 2000 was obviously toxic to BMSCs when carrying 500 nm miR, while stFNA changed cell viability only when carrying 4 times the amount of miR carried by Lipofectamine 2000 . However, the transfection efficiency of nucleic acid transporters may be lower than that of other types of vectors (Li et al, 2022).…”

“…When the complex enters the BMSCs through the cell membrane, RNase H cuts the complex to unload miRNA (Figure 5). Li et al used tetrahedral DNA nanostructures (TDNs) to carry miR-335-5p (Li et al, 2022). TDNs have been demonstrated to have high mechanical stiffness, high stability and rich functional modification sites as well as to be able to carry siRNA, CGP, and miRNA (Zhang et al, 2018;Li et al, 2022).…”

The Auxiliary Role of Heparin in Bone Regeneration and its Application in Bone Substitute Materials

“…In addition, magnetostrictive nanoparticles and biomimetic heparin coatings can change their shape according to the properties of the external magnetic field to better adapt to changes in the environment of bone regeneration ( Guillot-Ferriols, et al, 2020 ). Nanosilver, antibiotics, or specific genes can cooperate with heparin composite nanomaterials and have excellent antibacterial and anti-inflammatory effects, or can enhance osteogenic signaling activation ( Li et al, 2021 ; Coelho et al, 2015 ; Xie C. M et al, 2014 ). Different bonding modes between heparin and nanomaterials (e.g., nanocrystalline hydroxyapatite) produced different heparin chain conformations, which will affect the stability of heparin on nanomaterials and subsequent release of GFs ( Konar et al, 2019 ).…”