Endosseous implant optimization:from implant surface modifications to bone regeneration

Replacing one or several missing teeth, whether for reasons of pathology or trauma, has become very common. A system of artificial roots are inserted and integrated in the mandible or the maxilla to support fixed or removable restorations. The implant has to be mechanically stable, and integrated into the bone in order to mediate and distribute, as physiologically as possible, the biomechanical stresses applied to the system tooth-bone, a phenomenon called osseointegration. The success of a good osseointegration is multifactorial, including the materials properties (chemical, physical mechanical and structural), the implant design, the surgical techniques, the pathophysiological context and the bone health and quality. During our research, we focused on two particular issues: 1- The materials “ surface characteristics », and more specifically the surface chemistry of endosseous implants on which we applied various thin metallic coatings. 2- The « health and bone quality » by developping innovative materials for bone regeneration. We demonstrated that TiNxOy coatings may be applied to various metallic substrates to improve their osseointegration, allowing the use of materials more efficient mechanically, beyond their native biocompatibility. On the other hand, we also developed an innovative bone substitute by using 3D-printing processes. This material, structurally highly organized, may lead to an osseoconduction rate (i.e. the capacity for a structure to conduct bone cells migration and growth) that is largely superior to actual standards. This material is also resorbable, and may support the development of a mature bone tissue. These works open a broad range of perspectives both in the basic science and in the applied science, including, as for example, a better understanding of the molecular mechanisms of osseointegration, or the development of hybrid materials combining cells, bioceramics and hydrogels in a prevasscularized osseoconductive structure

Le titane : son potentiel allergique est-il lié à sa corrosion ?

Since decades, implantology is predominantly dominated by titanium thanks to its mechanical and biological properties. However, questions related to its ageing and its resistance to corrosion have rarely been asked. A phenomenon named tribocorrosion was reported in the recent literature resulting in the release of titanium particles into the soft tissues and the bone. The scientific evidence has shown particles could interact with osteoclasts, affect the cellular homeostasis of fibroblasts and promote inflammatory reactions. Regarding any allergic reactions to titanium, data remained limited and subject to controversy in their interpretation. Nowadays, titanium dioxide is commonly used by the food, cosmetic and pharmaceutic industry

L'ostéoblaste, tout ce que vous avez toujours voulu savoir sans jamais oser le demander

International audienc

Expression du peptide en feuille de trèfle 3 (TFF3) au cours de la différenciation des cellules à mucus et de processus inflammatoires (étude à partir de lignées cellulaires intestinales)

L'expression de TFF3, peptide protecteur et réparateur de l'épithélium intestinal contenu dans les cellules à mucus, est étudiée au cours de la différenciation cellulaire et lors de pathologies inflammatoires caractérisées par une hyperplasie/hypertrophie des cellules à mucus. Nous montrons d'une part que l'inhibition de la Phosphatidylinositol3-Kinase au cours de la différenciation de lignées mucoïdes diminue l'expression de TFF3 et MUC2, d'autre part que les interleukines-4/-13 stimulent les cellules à mucus, entraînant une sur-expression de TFF3 dépendante du facteur de transcription STAT6 via une synthèse protéique intermédiaire. Ces résultats soulignent l'implication de la Phosphatidylinositol3-Kinase dans l'acquisition des stigmates de différenciation des cellules à mucus alors que lors d'un processus inflammatoire de type 2, l'activité transcriptionnelle de ces cellules dépend de STAT6.LYON1-BU.Sciences (692662101) / SudocSudocFranceF

Alveolar ridge augmentation with 3D‐printed synthetic bone blocks: A clinical case series

Abstract This report documents the clinical and histological outcome of 3D‐printed calcium phosphate blocks placed in two‐stage procedures to successfully rehabilitate atrophic alveolar ridges. This approach yielded a functionally favorable result. Histological evaluations were performed after healing periods of 6 months and showed ongoing bone regeneration and sprouting capillaries

Delivery of microRNA-302a-3p by APTES modified hydroxyapatite nanoparticles to promote osteogenic differentiation in vitro

To demonstrate the miRNA delivery by hydroxyapatite nanoparticles modified with APTES (HA-NPs-APTES) and promote osteogenic gene expression. Materials and methods Osteosarcoma cells (HOS, MG-63) and primary human mandibular osteoblasts (HmOBs) were co-cultured with HA-NPs-APTES conjugated with miRNA-302a-3p. Resazurin reduction assay was performed to evaluate HA-NPs-APTES biocompatibility. Intracellular uptake was demonstrated by confocal fluorescent and scanning electron microscopy. The miRNA-302a-3p and its mRNA targets expression levels including COUP-TFII and other osteogenic genes were assessed by qPCR on day1 or day5 post-delivery. Calcium deposition induced by the osteogenic gene upregulation was shown by alizarin red staining on day7 and 14 post-delivery. Results Proliferation of HOS cells treated with HA-NPs-APTES was similar to that of untreated cells. HA-NPs-APTES was visualized in cell cytoplasm within 24 hours. MiRNA-302a-3p level was upregulated in HOS, MG-63 and HmOBs as compared to untreated cells. As a result, COUP-TFII mRNA expression was reduced, followed by an increase of RUNX2 and other osteogenic genes mRNA expression. Calcium deposition induced by HA-NPs-APTES-miR-302a-3p in HmOBs was significantly higher than in untreated cells. Conclusion HA-NPs-APTES may support the delivery of miRNA-302a-3p into bone cells, as assessed by osteogenic gene expression and differentiation improvement once this combination is used on osteoblast cultures.</p