Synergistic effect of strontium, bioactive glass and nano‐hydroxyapatite promotes bone regeneration of critical‐sized radial bone defects

Abstract

Critical-sized bone defects constitute a major health issue in orthopedics and usually cause mal-unions due to an inadequate number of migrated progenitor cells into the defect site or their incomplete differentiation into osteogenic precursor cells. The current study aimed to develop an optimized osteoinductive and angiogenic scaffold by incorporation of strontium (Sr) and bioglass (BG) into gelatin/nano-hydroxyapatite (G/nHAp) seeded with bone marrow mesenchymal stem cells to enhance bone regeneration. The scaffolds were fabricated by a freeze-drying technique and characterized in terms of morphology, structure, porosity and degradation rate. The effect of fabricated scaffolds on cell viability, attachment and differentiation into osteoblastic lineages was evaluated under in vitro condition. Micro computed tomography scan, histological and histomorphometric analysis were performed after implantation of scaffolds into the radial bone defects in rat. RT-PCR analysis showed that G/nHAp/BG/Sr scaffold significantly increased the expression level of osteogenic and angiogenic markers in comparison to other groups (P < 0.05). Moreover, the defects treated with the BMSCs-seeded scaffolds showed superior bone formation and mechanical properties compared to the cell-free scaffolds 4 and 12 weeks post-implantation. Finally, the BMSCs-seeded G/nHAp/BG/Sr scaffold showed the greatest bone regenerative capacity which was more similar to autograft. It is concluded that combination of Sr, BG, and nHAp can synergistically enhance the bone regeneration process. In addition, our results demonstrated that the BMSCs have the potential to considerably increase the bone regeneration ability of osteoinductive scaffolds. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018.

Octacalcium phosphate collagen composite stimulates the expression and activity of osteogenic factors to promote bone regeneration

“…To detect the bone matrix distribution, angiogenesis, and osteoclasts and osteoblasts in the new bone, we analyzed the expression of cell‐specific biomarkers in these tissues. OPN, OCN, RUNX2, and TRAP positivity were evaluated based on the number of cells exhibiting strong immunolabeling of the cell membrane and/or cytoplasm according to the previous studies (Hawthorne et al, ; Karsenty, Kronenberg, & Settembre, ; Kern, Shen, Starbuck, & Karsenty, ; Komori et al, ; Oryan et al, ; Pereira et al, ; Wang et al, ). VEGF expression was assessed based on the number of cells bordering new vessels as previously described (Soini et al, ).…”

Development of polypyrrole/collagen/nano-strontium substituted bioactive glass composite for boost sciatic nerve rejuvenation in vivo

“…The normal mats breadths of PPY/Coll and PPY/Coll/n-Sr@BG were in the scope of 276 ± 25 and 241 ± 17 nm separately. It has been accounted for that the distance across of the electrospun nanofibers diminished by diminishing the thickness and expanding the conductivity of dope arrangement [32,34]. The exceptional peak of Ca, Sr, P, O and Si affirms the statement of PPY/Coll/ n-Sr@BG.…”

“…As can be seen, the PPY/Coll composite display wide planes at two-theta ¼ 24, which might be because of the undefined idea of collagen particles [19]. Similarly, the PPY/Coll/n-Sr@BG (demonstrates a wide planes at two-theta ¼ 24) [32]. It might be because of the formless idea of PPy and the dissipating from PPy chains at the interplanar dividing [33].…”

In vitro and in vivo assessment of glucose cross‐linked gelatin/zein nanofibrous scaffolds for cranial bone defects regeneration

“…The cells grown on TCP were round shaped, while the cells on the nanofibrous scaffolds were spindle shaped and stretched across the randomly interconnected structures. At higher magnification (Figure S3), pseudopodia were clearly observed, indicating that the cells could firmly connect with the nanofibers (Oryan et al, ). Figure c showed the CLSM images of the cells seeded on the scaffolds and TCPs after 1 and 3 days, respectively.…”