Influence of nano‐hydroxyapatite coating implants on gene expression of osteogenic markers and micro‐CT parameters. An in vivo study in diabetic rats

This study evaluated the response of a nano‐hydroxyapatite coating implant through gene expression analysis (runt‐related transcription factor 2 (Runx2), alkaline phosphatase (Alp), osteopontin (Opn), osteocalcin (Oc), receptor activator of nuclear factor‐kappa B (Rank), receptor activator of nuclear factor‐kappa B ligand (Rank‐L), and osteoprotegerin (Opg)). Three‐dimensional evaluation (percent bone volume (BV/TV); percent intersection surface (BIC); bone surface/volume ratio (BS/BV); and total porosity (To.Po)) were also analyzed. Mini implants were surgically placed in tibias of both healthy and diabetic rats. The animals were euthanized at 7 and 30 days. Evaluating all factors the relative expression of Rank showed that NANO surface presented the best results at 7 days (diabetic rats). Furthermore the levels of Runx2, Alp, Oc, and Opn suggest an increase in osteoblasts proliferation, especially in early stages of osseointegration. %BIC in healthy and diabetic (7 days) depicted statistically significant differences for NANO group. BV/TV, BS/BV and To.Po demonstrated higher values for NANO group in all evaluated time point and irrespective of systemic condition, but BS/BV 30 days (healthy rat) and 7 and 30 days (diabetic rat). Microtomographic and gene expression analyses have shown the benefits of nano‐hydroxyapatite coated implants in promoting new bone formation in diabetic rats.