Effect of Local Rosuvastatin Administration on Calvarial Bone Defects

Magnesium-oxide-enhanced bone regeneration: 3D-printing of gelatin-coated composite scaffolds with sustained Rosuvastatin release

Critical-size bone defects are one of the main challenges in bone tissue regeneration that determines the need to use angiogenic and osteogenic agents. Rosuvastatin (RSV) is a class of cholesterol-lowering drugs with osteogenic potential. Magnesium oxide (MgO) is an angiogenesis component affecting apatite formation. This study aims to evaluate 3D-printed Polycaprolactone/β-tricalcium phosphate/nano-hydroxyapatite/ MgO (PCL/β-TCP/nHA/MgO) scaffolds as a carrier for MgO and RSV in bone regeneration. For this purpose, PCL/β-TCP/nHA/MgO scaffolds were fabricated with a 3D-printing method and coated with gelatin and RSV. The biocompatibility and osteogenicity of scaffolds were examined with MTT, ALP, and Alizarin red staining. Finally, the scaffolds were implanted in a bone defect of rat's calvaria, and tissue regeneration was investigated after 3 months. Our results showed that the simultaneous presence of RSV and MgO improved biocompatibility, wettability, degradation rate, and ALP activity but decreased mechanical strength. PCL/β-TCP/nHA/MgO/gelatin-RSV scaffolds produced sustained release of MgO and RSV within 30 days. CT images showed that PCL/β-TCP/nHA/MgO/gelatin-RSV scaffolds filled approximately 86.83 + 4.9 % of the defects within 3 months and improved angiogenesis, woven bone, and osteogenic genes expression. These results indicate the potential of PCL/β-TCP/nHA/MgO/gelatin-RSV scaffolds as a promising tool for bone regeneration and clinical trials.

Development of a thermosensitive statin loaded chitosan-based hydrogel promoting bone healing

Statins have been proposed as potential adjuvant to periodontal treatment due to their pleiotropic properties. A new thermosensitive chitosan hydrogel loaded with statins (atorvastatin and lovastatin) nanoemulsions was synthesized to allow a spatially controlled local administration of active compounds at lesion site. Spontaneous nano-emulsification method was used to synthesize statins loaded nanoemulsions. In vitro, atorvastatin and lovastatin loaded nanoemulsions were cytocompatible and were able to be uptake by oral epithelial cells. Treatment of Porphyromonas gingivalis infected oral epithelial cells and gingival fibroblasts with atorvastatin and lovastatin loaded nanoemulsions decreased significantly pro-inflammatory markers expression (TNF-α and IL-1β) and pro-osteoclastic RANKL. Nevertheless, such treatment induced the expression of Bone sialoprotein 2 (BSP2) in osteoblast emphasizing the pro-healing properties of atorvastatin and lovastatin nanoemulsions. In vivo, in a calvarial bone defect model (2 mm), treatment with the hydrogel loaded with atorvastatin and lovastatin nanoemulsions induced a significant increase of the neobone formation in comparison with systemic administration of statins. This study demonstrates the potential of this statins loaded hydrogel to improve bone regeneration and to decrease soft tissue inflammation. Its use in the specific context of periodontitis management could be considered in the future with a reduced risk of side effects.

Effects of Different Tissue Adhesives in Treating Calvarial Bone Defects

The purpose of this study is to investigate the potential of the 2 different tissue adhesive materials as a barrier for guided bone regeneration and to compare them with resorbable collogen membrane on autogenous grafted critical-sized cortical bone defects. Twenty-four rats were divided into 3 groups: Group M, Group G, and Group B. A 5-mm diameter critical-size defect was created in the calvarium of each animal. All defects were filled by autogenous graft harvested from tibia. In group M, resorbable collogen membrane was applied to defect area. In groups G and B, defects were closed by Glubran2 and Bioglue. All animals were euthanized at 28 days postoperative. Stereologic analyses were performed. New bone area and connective tissue volumes were measured. Mean new bone volumes were 0.97 ± 0.28, 0.59 ± 0.2, and 0.8 ± 0.32 mm in groups M, G, and B, respectively. The differences between groups were not statistically significant (P > 0.05). In group M, mean connective tissue volumes were 4.25 ± 0.7 mm, in groups G and B, 2.9 ± 1.82 and 4.54 ± 0.64 mm. Connective tissue volume differences were not statistically significant between groups. Glubran2 and Bioglue may play a role as a barrier for guided bone regeneration in treatment of critical size defects.