Osseointegration of Anodized vs. Sandblasted Implant Surfaces in a Guided Bone Regeneration Acute Dehiscence-Type Defect: An In Vivo Experimental Mandibular Minipig Model.

OBJECTIVES: This controlled preclinical study analyzed the effect of implant surface characteristics on osseointegration and crestal bone formation in a grafted dehiscence defect minipig model. MATERIAL AND METHODS: A standardized 3 mm × 3 mm acute-type buccal dehiscence minipig model grafted with deproteinized bovine bone mineral and covered with a porcine collagen membrane after 2 and 8 weeks of healing was utilized. Crestal bone formation was analyzed histologically and histomorphometrically to compare three implant groups: (1) a novel, commercially available, gradient anodized (NGA) implant, to two custom-made geometric replicas of implant "1," (2) a superhydrophilic micro-rough large-grit sandblasted and acid-etched surface, and (3) a relatively hydrophobic micro-rough large-grit sandblasted and acid-etched surface. RESULTS: At 2 and 8 weeks, there was no difference between the amount and height of newly formed bone (NBH, new bone height; BATA, bone area to total area) for any of the groups (p > 0.05). First bone-to-implant contact (fBIC) and vertical bone creep (VBC) at 2 and 8 weeks were significantly increased for Groups 2 and 3 compared to Group 1 (p < 0.05). At 8 weeks, osseointegration in the dehiscence (dehiscence bone-implant-contact; dBIC) was significantly higher for Groups 2 and 3 compared to Group 1 (p < 0.05). CONCLUSIONS: The amount of newly formed bone (BATA) and NBH was not influenced by surface type. However, moderately rough surfaces demonstrated significantly superior levels of osseointegration (dBIC) and coronal bone apposition (fBIC) in the dehiscence defect compared to the NGA surface at 2 and 8 weeks. TRIAL REGISTRATION: For this type of study, clinical trial registration is not required. This study was conducted at the Biomedical Department of Lund University (Lund, Sweden) and approved by the local Ethics Committee of the University (M-192-14).

Osteogenic effect of alogliptin in chemical-induced bone loss: a tri-modal in silico, in vitro, and in vivo analysis.

OBJECTIVE: To investigate the effects of Alogliptin in chemical-induced post-menopausal osteoporosis. METHODOLOGY: The binding affinity of alogliptin with osteogenic proteins was analysed in silico. The effect of alogliptin on osteogenic proteins and mineralization of osteoblastic cells was evaluated in UMR-106 cells. Further, in vivo anti-osteoporotic activity of alogliptin was evaluated in postmenopausal osteoporosis. Various bone turnover markers were assayed in serum. This followed the analysis of microarchitecture of bone, histology, and immunohistochemistry (IHC) of bone tissue. RESULTS: Docking scores showed that alogliptin has binding affinity for bone alkaline phosphatase (BALP), osteocalcin, and bone morphogenic protein (BMP-2). Alogliptin also enhanced mineralization of osteoblast cells, evidenced with increased ALP, osteocalcin, and BMP-2. Animal studies revealed significant elevation of bone formation markers, bone ALP, osteocalcin and BMP-2, and decreased bone resorption markers, receptor activator of NF-κß (RANKL), cathepsin K (CTSK), tartrate resistant acid phosphatase (TRAcP5b) in VCD-induced post-menopausal osteoporosis. Micro computed tomography (µCT) analysis and histology of femur bone and lumbar vertebrae demonstrated decrease in trabecular separation and improved bone density. IHC of femur showed reduced DPP4 enzyme. CONCLUSIONS: Alogliptin increased mineralization in osteoblast cells. It had beneficial effects also altered bone turnover markers, repaired the trabecular microstructure, improved bone mineral density, and exhibited bone forming capacity targeting DPP-4 enzyme in postmenopausal osteoporosis.

Effects of Simvastatin-Loaded Nanomicelles on the Early Preservation of Tooth Extraction Sites.

Object: The present study intended to evaluate the effect of simvastatin-loaded nanomicelles (SVNs) on promoting new bone formation and reducing alveolar ridge resorption at the tooth extraction sites at the early healing of the extraction sockets. Methods: SVNs were synthesized using a dialysis method. The rabbit tooth extraction model was established, SVNs and simvastatin (SV) were loaded on gelatin sponge and inserted into the extraction socket. CBCT scans were performed at 0, 2, and 4 weeks postoperatively to evaluate bone formation and alveolar ridge absorption in the extraction sockets. And all the animals were sacrificed and the mandibles were harvested. And HE staining and Masson staining were used for histological evaluation of the bone formation in the extraction sockets. Results: Radiographic evaluation showed that compared with the blank control group, at 2 and 4 weeks after extraction, SVNs increased the new bone density in the extraction sockets by 75.7% and 96.5%, and reduced the absorption rate of alveolar ridge length at the extraction sites by 60.8% and 49.1%, respectively. Histological evaluation showed that SVNs significantly improved the maturation of new bone tissue in the extraction sockets. Conclusion: SVNs can significantly accelerate healing and effectively reduce the absorption of alveolar ridge at the extraction sites in the early stage of tooth extraction socket healing.

HyperAttention and Linformer-Based ß-catenin Sequence Prediction For Bone Formation.

Introduction Beta (ß)-catenin, a pivotal protein in bone development and homeostasis, is implicated in various bone disorders. Peptide-based therapeutics offer a promising approach due to their specificity and potential for reduced side effects. Attention networks are widely used for peptide sequence prediction, specifically sequence-to-sequence models. Hence, the current study aims to develop a HyperAttention and informatics-based ß-catenin sequence prediction for bone formation. Methods ß-catenin protein sequences were downloaded and quality-checked using UniProt and FASTA sequences using DeepBio (Deep Bio Inc., Seoul, South Korea) for predictive analysis. Data was analyzed for duplicates, outliers, and missing values. The data was then split into training and testing sets, with 80% of the data used for training and 20% for testing, and peptide sequences were encoded and subjected to algorithms. Results The HyperAttention and Linformer models perform well in predictive sequence, with HyperAttention correctly predicting 87% of instances and Linformer predicting 89%. Both models have higher sensitivity and specificity, with Linformer showing better identification of 91% of negative instances and slightly better sensitivity. Conclusion The HyperAttention and Linformer models effectively predict peptide sequences with high specificity and sensitivity. Further optimization and development are needed for optimal application and balance between positive and negative instances.

Bone augmentation using bioresorbable mesh domes containing bone graft granules.

Bone graft granules are valuable tools for ridge area bone grafting owing to their ease of manipulation and interconnected porous structure. Guided bone regeneration (GBR) using barrier membranes is commonly used for alveolar ridge augmentation; however, the surgical procedures are technically complicated. In this study, we fabricated bioresorbable mesh domes (BMDs) using two types of Vicryl mesh (woven and knitted types) containing carbonate apatite granules. BMD samples were prepared in three groups: upper sides made from the woven type (UW) and lower sides made from the woven type (LW) (the UW/LW group), upper sides made from the woven type (UW) and lower sides made from the knitted type (LK) (the UW/LK group), and upper sides made from the knitted type (UK) and lower sides made from the knitted type (LK) (the UK/LK group). The samples were subsequently implanted into rabbit calvaria, and radiomorphometric and histological analyses were conducted. The UK/LK group exhibited enhanced appositional bone formation because the knitted mesh on the skin side prevented the infiltration of a substantial amount of fibrous tissue. This increase in bone formation could be attributed to the interaction between granules and osteoprogenitors that pass through the mesh from the host bone. Conversely, the UW/LW and UW/LK groups presented limited appositional bone formation. Compared with knitted mesh, woven mesh might tend to be absorbed over a short span, allowing fibrous tissue invasion and inhibiting new bone formation. Additionally, BMDs could retain granules in a targeted location and avoid displacement of the granules to unintended locations.

The short-chain fatty acid receptors Gpr41/43 regulate bone mass by promoting adipogenic differentiation of mesenchymal stem cells.

Bone is a dynamic tissue that is constantly remodeled throughout adult life. Recently, it has been shown that bone turnover decreases shortly after food consumption. This process has been linked to the fermentation of non-digestible food ingredients such as inulin by gut microbes, which results in the production of the short-chain fatty acids (SCFAs) acetate, propionate and butyrate. SCFAs exert various metabolic functions, which in part can be explained by activation of G protein-coupled receptors (Gpr) 41 and 43. However, the potential relevance of a SCFA-Gpr41/43 signaling axis for bone metabolism has not been established. The aim of our study is to investigate the role of Gpr41/43 in bone metabolism and osteogenic differentiation of mesenchymal stem cells. For this purpose, we analyzed the skeletal phenotype of wild type controls (WT) and Gpr41/43 double knockout (Gpr41/43 dKO) mice fed either a chow or an inulin-enriched diet. In addition, we isolated bone marrow derived mesenchymal stem cells from WT and Gpr41/43 dKO mice and differentiated them into osteoblasts in the absence or presence of acetate. MicroCT scanning of femoral bones of Gpr41/43 dKO mice revealed a significant increase of trabecular bone volume and trabecular compared to WT controls. Treatment of WT bone marrow-derived osteoblasts with acetate resulted in decreased mineralization and substantial downregulation of bone formation markers such as Phex, Ptgs2 and Col1a1. Notably, this effect was strongly attenuated in differentiated osteoblasts lacking Gpr41/43. Inversely, acetate supplementation resulted in higher levels of adipocyte marker genes including Pparg, Lpl and Adipoq in bone marrow-derived cells from WT mice, an effect blunted in differentiated cells isolated from Gpr41/43 dKO mice. Overall, these data indicate that acetate regulates bone architecture via SCFA-Gpr41/43 signaling by modulating the osteogenic versus adipogenic differentiation of mesenchymal stem cells.

The Effects of the AGE Inhibitor Pyridoxamine on Bone in Older Women with Type 2 Diabetes: a Randomized Clinical Trial.

CONTEXT: Type 2 diabetes (T2D) patients have reduced bone turnover and increased fractures. Advanced glycation endproducts (AGEs) impair osteoblasts and are implicated in diabetic fractures. Pyridoxamine (PM) is a vitamin B6 metabolite which inhibits formation of AGEs. OBJECTIVE: We hypothesized that PM treatment in older T2D patients, by inhibiting AGEs, would increase bone formation. DESIGN: Double-blind RCT. SETTING: Academic center. PARTICIPANTS: Older T2D women (n=55). INTERVENTION: Oral PM 200 mg twice daily for one year. MAIN OUTCOMES: The primary outcome was the change in the bone formation marker P1NP. Other outcomes were changes in bone resorption, bone mineral density (BMD), HbA1c and skin autofluorescence (SAF), and in a bone biopsy sub-group, the correlation between bone fluorescent AGEs (fAGEs) and SAF. RESULTS: P1NP increased 23.0% with PM (95% CI: 9, 37; within-group p=0.028) vs. 4.1% with placebo (-9, 17; within-group p=0.576; between-groups p=0.056). BMD increased at the femoral neck (PM: 2.6±5% vs. placebo: -0.9±4%; between-groups p=0.007). Bone resorption markers and SAF did not change. HbA1c decreased (PM: -0.38 ± 0.7% vs. placebo: 0.05 ± 1.7%; between-groups p =0.04). Within the PM group, the HbA1c change correlated inversely with the % P1NP change (r =-0.50, p=0.034). Cortical bone biopsy fAGEs correlated with SAF (r=0.86, p=0.001). Adverse events were similar between groups. CONCLUSION: PM tended to increase P1NP in older T2D women, as well as increasing bone density and reducing HbA1c. Further studies are needed to investigate the potential of PM as a disease mechanism-directed approach to reduce fractures in T2D.

Inflammatory priming of human mesenchymal stem cells induces osteogenic differentiation via the early response gene IER3.

Mesenchymal stem cells (MSCs) have gained tremendous interest due to their overall potent pro-regenerative and immunomodulatory properties. In recent years, various in vitro and preclinical studies have investigated different priming ("licensing") approaches to enhance MSC functions for specific therapeutic purposes. In this study, we primed bone marrow-derived human MSCs (hMSCs) with an inflammation cocktail designed to mimic the elevated levels of inflammatory mediators found in serum of patients with severe injuries, such as bone fractures. We observed a significantly enhanced osteogenic differentiation potential of primed hMSCs compared to untreated controls. By RNA-sequencing analysis, we identified the immediate early response 3 (IER3) gene as one of the top-regulated genes upon inflammatory priming. Small interfering RNA knockdown experiments established IER3 as a novel positive regulator of osteogenic differentiation. Mechanistic analysis further revealed that IER3 deletion significantly downregulated bone marrow stromal cell antigen 2 (BST2) expression and extracellular signal-related kinase 1/2 (ERK1/2) phosphorylation in hMSCs, suggesting that IER3 regulates osteogenic differentiation through BST2 and ERK1/2 signaling pathway activation. On the basis of these findings, we propose IER3 as a novel therapeutic target to promote hMSC osteoblastogenesis, which might be of high clinical relevance, for example, in patients with osteoporosis or compromised fracture healing.

Effects of total flavonoids of Rhizoma Drynariae on biochemical indicators of bone metabolism: a systematic review and meta-analysis.

Background: Evidence shows that the total flavonoids of Rhizoma Drynariae (TFRD) can improve bone mineral density (BMD). However, there is no evidence to summarize the improvement of biochemical indicators of bone metabolism (BIBM). Methods: The PubMed, Web of Science, Cochrane Library, Embase, Chinese National Knowledge Infrastructure (CNKI), Wanfang Database, Chongqing VIP Information Database (VIP) and SinoMed were searched from inception to 6 May 2024. The final included studies performed meta-analyses using RevMan 5.3. Results: Nine randomized controlled trials (RCTs) were ultimately included. The TFRD group had higher bone gla protein (BGP) and type I procollagen-N-propeptide (PINP) compared to the Other therapies (WMD: 5.11; 95% CI: 3.37, 6.84; p < 0.00001; WMD: 13.89; 95% CI: 11.81, 15.97; p < 0.00001). The tartrate-resistant acid phosphatase (TRACP) decreased significantly (WMD: -1.34; 95% CI: -1.62, -1.06; p < 0.00001). The alkaline phosphatase (ALP) increased significantly (WMD: 7.47; 95% CI: 6.29, 8.66; p < 0.00001). There were no significant differences in serum calcium (SC) or serum phosphorus (SP) levels between the TFRD and control groups (WMD: 0.08; 95% CI: -0.04, 0.20; p = 0.17; WMD: 0.02; 95% CI: -0.02, 0.05; p = 0.36). Conclusion: TFRD can stimulate bone formation and prevent bone resorption in osteoporosis (OP) patients, but it has no effect on SC and SP. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/.

O-GlcNAcylation mediates Wnt-stimulated bone formation by rewiring aerobic glycolysis.

Wnt signaling is an important target for anabolic therapies in osteoporosis. A sclerostin-neutralizing antibody (Scl-Ab), that blocks the Wnt signaling inhibitor (sclerostin), has been shown to promote bone mass in animal models and clinical studies. However, the cellular mechanisms by which Wnt signaling promotes osteogenesis remain to be further investigated. O-GlcNAcylation, a dynamic post-translational modification of proteins, controls multiple critical biological processes including transcription, translation, and cell fate determination. Here, we report that Wnt3a either induces O-GlcNAcylation rapidly via the Ca2+-PKA-Gfat1 axis, or increases it in a Wnt-ß-catenin-dependent manner following prolonged stimulation. Importantly, we find O-GlcNAcylation indispensable for osteoblastogenesis both in vivo and in vitro. Genetic ablation of O-GlcNAcylation in the osteoblast-lineage diminishes bone formation and delays bone fracture healing in response to Wnt stimulation in vivo. Mechanistically, Wnt3a induces O-GlcNAcylation at Serine 174 of PDK1 to stabilize the protein, resulting in increased glycolysis and osteogenesis. These findings highlight O-GlcNAcylation as an important mechanism regulating Wnt-induced glucose metabolism and bone anabolism.

Wnt family members regulating osteogenesis and their origins.

Wnt signaling plays an important role in the regulation of bone metabolism. Wnt activates the ß-catenin-mediated canonical pathway and ß-catenin-independent non-canonical pathway. When Wnt ligands bind to the co-receptors low density lipoprotein receptor-related protein (Lrp)5 or Lrp6, and a seven-transmembrane receptor frizzled, the canonical pathway is activated. On the other hand, when Wnt ligands bind to the receptor complex consisting of the co-receptor receptor tyrosine kinase-like orphan receptor (Ror)1 and Ror2 or Ryk and frizzled, the non-canonical pathway is activated. An analysis of loss-of-function and gain-of-function mutations in molecules involved in Wnt signaling (ligands, receptors, and inhibitors) has revealed the mechanisms by which Wnt signaling regulates bone metabolism. In this review, based on transcriptome analyses of Wnt expression in bone tissues including single cell RNA sequence analysis and previous literatures, we herein introduce and discussed the latest findings on the mechanisms by which Wnt ligand mutations impair bone metabolism, especially bone formation.

Sodium butyrate protect bone mass in lipopolysaccharide-treated rats by reducing oxidative stress and inflammatory.

OBJECTIVE: The study will be to observe the effect of Sodium butyrate (NaB) on bone loss in lipopolysaccharide (LPS)-treated rats. METHODS: In the rat model, we observed that changes in the expression of oxidative stress regulators, inflammatory markers and target genes were measured by immunofluorescence and RT-PCR after treatment. Changes in viability and osteogenesis of MC3T3-E1, osteoclast differentiation in RAW264.7 cells in the presence of LPS were evaluated using CCK-8, ALP staining, RES staining, and TRAP staining. RESULTS: In vitro experiments have shown that LPS-induced inhibition of JC-1, SIRT1, GPX1 and SOD2 is associated with increased levels of inflammation and oxidative stress. In addition, NaB has been found to suppress oxidative stress, inflammation and Mito SOX, promote osteogenic differentiation, and inhibit osteoclast differentiation. In addition, NaB significantly promoted SITR1 expression, repaired impaired bone metabolism, and improved bone strength and bone mineral density. CONCLUSION: Given all this experimental evidence, the results strongly suggest that NaB can restore osteogenic activity in the presence of LPS by reducing intracellular ROS, inhibiting osteoclast differentiation and reducing bone loss in LPS-treated rat models.

Extracellular Vesicles Derived from Ligament Tissue Transport Interleukin-17A to Mediate Ligament-To-Bone Crosstalk in Ankylosing Spondylitis.

Pathological new bone formation is a critical feature of the progression of ankylosing spondylitis (AS), and spine ankylosis is a distinctive feature of this condition. Ligaments are the primary regions of pathological new bone formation in AS. Here, it is demonstrated that ligament tissue-derived extracellular vesicles (EVs) and their interleukin-17A (IL-17A) cargo mediate the communication between the tissue and other cells. The investigation revealed that IL-17A in EVs can activate the JAK-STAT3 pathway, thereby stimulating the expression of MMP14 in AS ligament. Overexpression of MMP14 can lead to changes in the cytoskeleton and mechanical signaling of mesenchymal stem cells and other cells. These alterations in cellular cytoskeleton and mechanical signaling at ligament sites in patients with AS or in stem cells treated with EVs can result in pathological new bone formation. Finally, inhibiting IL-17A activity and EV endocytosis effectively controlled inflammation and pathological new bone formation. Overall, these data suggest that ligament-derived EVs and the enclosed IL-17A have a potential role in driving pathological new bone formation in AS, and targeting EVs may therefore emerge as a novel approach to delaying ectopic ossification in AS.

Effects of Glucagon-Like Peptide-1 Receptor Agonist on Bone Mineral Density and Bone Turnover Markers: A Meta-Analysis.

AIMS: Glucagon-like peptide-1 receptor agonist (GLP-1RA) may promote bone formation, but conversely, they could also weaken bones due to the reduction in mechanical load associated with weight loss. However, the clinical effects in humans have not been clearly demonstrated. This meta-analysis aimed to evaluate whether GLP-1RAs affect BMD and bone turnover markers. MATERIAL AND METHODS: PubMed, Embase, and Scopus were searched on June 13, 2024. The eligibility criteria were: (1) human studies, (2) receiving a GLP-1RA for more than 4 weeks, (3) an untreated control group or a placebo group, (4) reporting of at least one BMD or bone turnover marker, and (5) an RCT design. The risk of bias was assessed using the Cochrane risk of bias 2 tool. Fixed- or random-effects meta-analysis was performed according to heterogeneity. RESULTS: Seven studies were included in the meta-analysis. GLP-1RAs did not significantly change BMD in the femoral neck (mean difference [MD], 0.01 g/cm2; 95% CI, -0.01-0.04 g/cm2), in the total hip (MD, -0.01 g/cm2; 95% CI, -0.02-0.01 g/cm2), and in the lumbar spine (MD, 0 g/cm2; 95% CI, -0.02-0.02 g/cm2). C-terminal telopeptide of type 1 collagen (CTX), a bone resorption marker, significantly increased after GLP-1RA treatment (MD, 0.04 µg/L; 95% CI, 0.01-0.07 µg/L). GLP-1RAs did not significantly change bone formation markers such as procollagen type 1 N-terminal propeptide, bone-specific alkaline phosphatase, osteocalcin. CONCLUSIONS: GLP-1RA did not affect BMD and bone formation markers. However, GLP-1RAs led to a significant increase in CTX.

Induced pluripotent stem cell-derived neural stem cells promote bone formation in mice with calvarial defects.

Nerve-derived factors have attracted attention in bone regeneration therapy due to their ability to promote bone regeneration and nerve innervation. Mesenchymal stem cells transported to target sites promote osteogenesis. However, there are few reports on the effects of neural stem cells on bone regeneration. Therefore, the aim of this study was to investigate the role of neural stem cells in osteogenesis. Here, embryoid bodies (EB) or primary neurospheres (1NS) were generated using mouse induced pluripotent stem cells (iPS cells), which were then seeded onto gelatin (Gel) sponges. The seeded Gel sponges were then transplanted into mouse calvarial bone defects. We noted that 1NS-seeded Gel promoted bone regeneration and the presence of tartrate-resistant acid phosphatase (TRAP)-positive cells, whereas the EB-seeded Gel did not. RNA-sequencing of the 1NS-seeded and EB seeded Gels showed an upregulation of the transforming growth factor (TGF)-ß signaling pathway in the 1NS-seeded Gel group. Immunostaining confirmed the presence of Id3 positive cells in mice with bone defects treated with the 1NS-seeded Gel. These findings suggest that the transplantation of neural stem cells may contribute to the promotion of bone regeneration. STATEMENT OF SIGNIFICANCE: This study aimed to investigate whether neural stem cells, when seeded in Gel sponges, promoted bone regeneration. It has been well documented that bone is tightly linked with the nervous systems. Bioscaffolds comprising factors that promote innervation and bone regeneration have been investigated for use in bone therapy. However, there is limited research on the use of neural stem cells for promoting bone formation. To assess this relationship, we conducted both in vivo and in vitro assays to determine whether neural stem cells promoted bone formation. We noted that 1NS-seeded Gel sponges promoted bone formation significantly in mice with calvarial defects after 4 weeks. This study provides a novel approach of neural stem cells for bone therapy.

Mussel-inspired bifunctional coating for long-term stability of oral implants.

Peri-implantitis and osseointegration failure present considerable challenges to the prolonged stability of oral implants. To address these issues, there is an escalating demand for a resilient implant surface coating that seamlessly integrates antimicrobial features to combat bacteria-induced peri­implantitis, and osteogenic properties to promote bone formation. In the present study, a bio-inspired poly(amidoamine) dendrimer (DA-PAMAM-NH2) is synthesized by utilizing a mussel protein (DA) known for its strong adherence to various materials. Conjugating DA with PAMAM-NH2, inherently endowed with antibacterial and osteogenic properties, results in a robust and multifunctional coating. Robust adhesion between DA-PAMAM-NH2 and the titanium alloy surface is identified using confocal laser scanning microscopy (CLSM) and attenuated total reflectance-infrared (ATR-IR) spectroscopy. Following a four-week immersion of the coated titanium alloy surface in simulated body fluid (SBF), the antimicrobial activity and superior osteogenesis of the DA-PAMAM-NH2-coated surface remain stable. In contrast, the bifunctional effects of the PAMAM-NH2-coated surface diminish after the same immersion period. In vivo animal experiments validate the enduring antimicrobial and osteogenic properties of DA-PAMAM-NH2-coated titanium alloy implants, significantly enhancing the long-term stability of the implants. This innovative coating holds promise for addressing the multifaceted challenges associated with peri­implantitis and osseointegration failure in titanium-based implants. STATEMENT OF SIGNIFICANCE: Prolonged stability of oral implants remains a clinically-significant challenge. Peri-implantitis and osseointegration failure are two important contributors to the poor stability of oral implants. The present study developed a mussel-bioinspired poly(amidoamine) dendrimer (DA-PAMAM-NH2) for a resilient implant surface coating that seamlessly integrates antimicrobial features to combat bacteria-induced peri­implantitis, and osteogenic properties to promote bone formation to extend the longevity of oral implants.

Inositol Hexaphosphate in Bone Health and Disease.

Dietary phytic acid/phytate/myo-inositol hexaphosphate (IP6), a phosphate reservoir in plants, was viewed as antinutrient, caused by an influence on the bioavailability of minerals through its chelating activity. However, there is a growing body of evidence indicating that IP6 has beneficial (e.g., antiinflammatory, antibacterial, and anticancer) effects on multiple biological processes. Also, IP6 and its metabolites are known to exist in mammalian cells, including human cells, and the role of IP6 as a functional molecule is attracting attention. IP6 can bind to the growth sites of hydroxy-apatite (HA) and calcium oxalate crystals to prevent their growth and hence inhibit pathological calcification. SNF472, hexasodium IP6, is currently being evaluated in clinical studies as a treatment for vascular calcification and calciphylaxis. However, since HA crystal growth within bone matrix is an essential process in bone formation, it is possible that IP6 intake may inhibit physiological mineralization and bone formation, although currently more published studies suggest that IP6 may contribute to bone health rather than inhibit bone formation. Given that IP6 and its metabolites are thought to have diverse activities and many health benefits, it remains important to consider the range of effects of IP6 on bone.

Gradient Boosting Prediction of Overlapping Genes From Weighted Co-expression and Differential Gene Expression Analysis of Wnt Pathway: An Artificial Intelligence-Based Bioinformatics Study.

Introduction The Wnt (wingless-related integration site) signalling pathway is crucial for bone formation and remodelling, regulating the commitment of mesenchymal stem cells (MSCs) to the osteoblastic lineage. It triggers the transcriptional activation of Wnt target genes and promotes osteoblast proliferation and survival. Weighted co-expression network analysis (WGCNA) and differential gene expression analysis help researchers understand gene roles. Gradient boosting, a machine learning technique, enhances understanding of genetic and molecular mechanisms contributing to overlap genes, improving gene regulation and functional genomics. The aim is to predict overlapping genes in the Wnt signalling pathway. Methods Differential gene expression analysis was performed using the National Center for Biotechnology Information (NCBI) geo dataset-GSE251951, focusing on the effect of Wnt signaling on treatment. The WGCNA module was analyzed using the iDEP tool to identify interconnected gene clusters. Hub genes were identified by calculating module eigengenes, correlated with external traits, and ranked based on module membership values. The study utilized gradient boosting, an ensemble learning method, to predict models, evaluate their performance using metrics like accuracy, precision, recall, and F1 score, and adjust predictions based on gradient and learning rate. Results The dendrogram uses the "Dynamic TreeCut" algorithm to analyze gene clusters, aiding researchers in understanding gene modules and biological processes, identifying co-expressed genes, and discovering new pathways. The confusion matrix displays 88 actual and predicted cases. The gradient boosting model achieves 78.9% accuracy in predicting Wnt pathway overlapping genes, with a respectable area under the curve (AUC) and classification accuracy values. It accurately predicts 73.9% of samples, with a high precision ratio and low recall. Conclusion Future research should enhance differential expression analysis and WGCNA to identify key Wnt pathway genes, improve sensitivity, specificity, hyperparameter tuning, and validation experiments, and use larger datasets.

Regeneration of amputated mice digit tips by including Wnt signaling pathway with CHIR99021 and IWP-2 chemicals in limb organ culture system.

Objectives: Mammals have limited limb regeneration compared to amphibians. The role of Wnt signaling pathways in limb regeneration has rarely been studied. So, this study aimed to investigate the effect of Wnt-signaling using chemicals CHIR99021 and IWP-2 on amputated mice digit tips regeneration in an in vitro organ culture system. Materials and Methods: The distal phalanx of paws from C57BL/6J mouse fetuses at E14.5, E16.5, and E18.5 was amputated. Then, the hands were cultured for 7 days. Subsequently, paws were treated with 1-50 µg/ml concentration of CHIR99021 and 5-10 µg/ml concentration of IWP-2. Finally, the new tissue regrowth was assessed by histological analysis, immunohistochemistry for BC, TCF1, CAN, K14, and P63 genes, and beta-catenin and Tcf1 genes were evaluated with RT-qPCR. Results: The paws of E14.5 and E16.5 days were shrinkaged and compressed after 7 days, so the paws of 18.5E that were alive were selected. As a result, newly-grown masses at digit tips were observed in 25 and 30 µl/ml concentrations of the CHR99021 group but not in the IWP2 treatment (*P<0.05; **P<0.01). qRT-PCR analysis confirmed the significant up-regulation of beta-catenin and Tcf1 genes in CHIR99021 group in comparison to the IWP-2 group (P<0.05). Moreover, Alcian-blue staining demonstrated the presence of cartilage-like tissue at regenerated mass in the CHIR group. In immunohistochemistry analysis beta-catenin, ACN, Keratin-14, and P63 protein expression were observed in digit tips in the CHIR-treated group. Conclusion: By activating the Wnt signaling pathway, cartilage-like tissue formed in the blastema-like mass in the mouse's amputated digit tips.

Higher solubility and lower onset temperature of protein denaturation increase the osteoconductive capacity of collagen membranes: A preclinical in vivo study.

OBJECTIVES: Collagen membranes are extensively used for guided bone regeneration procedures, primarily for horizontal bone augmentation. More recently, it has been demonstrated that collagen membranes promote bone regeneration. Present study aimed at assessing if structural modifications of collagen membranes may enhance their osteoconductive capacity. METHODS: Twenty-four adult Wistar rats were used. Bilateral calvaria defects with a diameter of 5 mm were prepared and covered with prototypes of collagen membranes (P1 or P2). The P1 membrane (positive control) presented a lower onset temperature of protein denaturation and a higher solubility than the P2 membrane (test). The contralateral defects were left uncovered (NC). After 1 and 4 weeks, the animals were euthanized. A microcomputed tomography analysis of the harvested samples was performed within and above the bony defect. Undecalcified ground sections were subjected to light microscopy and morphometric analysis. RESULTS: Bone formation was observed starting from the circumferential borders of the defects in all groups at 1-week of healing. The foci of ossification were observed at the periosteal and dura mater sites, with signs of collagen membrane mineralization. However, there was no statistically significant difference between the groups. At 4 weeks, remnants of the collagen fibers were embedded in the newly formed bone. In the P2 group, significantly more bone volume, more new bone, and marrow spaces compared to the NC group were observed. Furthermore, the P2 group showed more bone volume ectocranially then the P1 group. CONCLUSIONS: Bone formation subjacent to a P2 membrane was superior than subjacent to the P1 membrane and significantly better compared to the control. Modifications of the physico-chemical properties may enhance the osteoconductive competence of collagen membranes, supporting bone formation outside the bony defects.