In situ construction of flower-like nanostructured calcium silicate bioceramics for enhancing bone regeneration mediated via FAK/p38 signaling pathway.

BACKGROUND: The repair of tissue defects has attracted considerable attention and remained a substantial challenge. Calcium silicate (CaSiO3, CS) bioceramics have attracted the interest of researchers due to their excellent biodegradability. Recent studies have demonstrated that nanoscale-modified bioactive materials with favorable biodegradability could promote bone tissue regeneration, providing an alternative approach for the repair of bone defects. However, the direct construction of biodegradable nanostructures in situ on CS bioceramics was still difficult. RESULTS: In this study, flower-like nanostructures were flexibly prepared in situ on biodegradable CS bioceramics via hydrothermal treatment. The flower-like nanostructure surfaces exhibited better hydrophilicity and more significantly stimulated cell adhesion, alkaline phosphatase (ALP) activity, and osteogenic differentiation. Furthermore, the CS bioceramics with flower-like nanostructures effectively promoted bone regeneration and were gradually replaced with newly formed bone due to the favorable biodegradability of these CS bioceramics. Importantly, we revealed an osteogenesis-related mechanism by which the FAK/p38 signaling pathway could be involved in the regulation of bone mesenchymal stem cell (BMSC) osteogenesis by the flower-like nanostructure surfaces. CONCLUSIONS: Flower-like nanostructure surfaces on CS bioceramics exerted a strong effect on promoting bone repair and regeneration, suggesting their excellent potential as bone implant candidates for improving bone regeneration.

Combined Surgical-Orthodontic Treatment of Patients With Severe Parry-Romberg Syndrome.

ABSTRACT: Parry-Romberg syndrome (PRS) refers to a relatively rare dysfunction disease that is characterized by chronic progressive maxillofacial atrophy, especially one side of facial skin, subcutaneous tissue, muscle, and bone. According to the atrophy degree of skin, subcutaneous tissue, and skeleton in the area innervated by the trigeminal nerve, PRS can be classified into mild, moderate, and severe. In general, cases with different severity have specific treatment regimens. For mild and moderate cases, soft tissue augmentation techniques are the optimal strategy for aesthetic reconstruction. In this study, the authors report a 19-year-old female with severe PRS. Considering the severity of the case, a combined surgical and orthodontic treatment was performed, which was involved in alveolar bone augmentation, preoperative and postoperative orthodontic treatment in combination with orthognathic surgery, medpor filling of zygomatic and maxillary complex, free fat grafting, as well as angulus oris and lip trimming. Comprehensive treatment is recommended for severe cases with extensive atrophy of soft tissue and craniofacial bone, obvious deviation of the chin and occlusal plane.

Hemifacial microsomia treated with a hybrid technique combining distraction osteogenesis and a mandible-guided functional appliance: Pilot study.

INTRODUCTION: The purpose of this study was to evaluate the therapeutic effect of a hybrid treatment for hemifacial microsomia that combines distraction osteogenesis and a mandible-guided functional appliance to correct mandibular asymmetry. METHODS: This was a retrospective analysis of 10 patients with unilateral hemifacial microsomia who underwent mandibular ramus distraction osteogenesis in our hospital from February 2013 to July 2015. The cases were classified into 2 comparison groups: 5 patients were in the MG-DO group (distraction osteogenesis combined with an mandible-guided functional appliance) and 5 in the control group (distraction osteogenesis only). Anteroposterior cephalometric analyses were conducted before and after treatment. Soft tissue symmetry and the occlusal relationship were observed from facial and intraoral photographs. Statistical analyses were performed to determine changes between before and after treatment as well as intergroup differences. RESULTS: The MG-DO group showed greater vertical elongation of the mandibular ramus and less overcorrection and mandibular deviation than the control group. Occlusal reconstruction was enabled by the mandible-guided functional appliance owing to a decrease in lateral shifting. The symmetry of both skeletal and soft tissues was significantly improved in the MG-DO group. CONCLUSIONS: The hybrid technique combining distraction osteogenesis and the mandible-guided functional appliance proved to be effective in correcting canting and deviation during mandibular elongation, which improved facial symmetry and occlusal balance in patients with hemifacial microsomia.

Hydrogel-Based Systems in Neuro-Vascularized Bone Regeneration: A Promising Therapeutic Strategy.

Blood vessels and nerve fibers are distributed throughout the skeletal tissue, which enhance the development and function of each other and have an irreplaceable role in bone formation and remodeling. Despite significant progress in bone tissue engineering, the inadequacy of nerve-vascular network reconstruction remains a major limitation. This is partly due to the difficulty of integrating and regulating multiple tissue types with artificial materials. Thus, understanding the anatomy and underlying coupling mechanisms of blood vessels and nerve fibers within bone to further develop neuro-vascularized bone implant biomaterials is an extremely critical aspect in the field of bone regeneration. Hydrogels have good biocompatibility, controllable mechanical characteristics, and osteoconductive and osteoinductive properties, making them important candidates for research related to neuro-vascularized bone regeneration. This review reports the classification and physicochemical properties of hydrogels, with a focus on the application advantages and status of hydrogels for bone regeneration. The authors also highlight the effect of neurovascular coupling on bone repair and regeneration and the necessity of achieving neuro-vascularized bone regeneration. Finally, the recent progress and design strategies of hydrogel-based biomaterials for neuro-vascularized bone regeneration are discussed.

Engineering mesoporous bioactive glasses for emerging stimuli-responsive drug delivery and theranostic applications.

Mesoporous bioactive glasses (MBGs), which belong to the category of modern porous nanomaterials, have garnered significant attention due to their impressive biological activities, appealing physicochemical properties, and desirable morphological features. They hold immense potential for utilization in diverse fields, including adsorption, separation, catalysis, bioengineering, and medicine. Despite possessing interior porous structures, excellent morphological characteristics, and superior biocompatibility, primitive MBGs face challenges related to weak encapsulation efficiency, drug loading, and mechanical strength when applied in biomedical fields. It is important to note that the advantageous attributes of MBGs can be effectively preserved by incorporating supramolecular assemblies, miscellaneous metal species, and their conjugates into the material surfaces or intrinsic mesoporous networks. The innovative advancements in these modified colloidal inorganic nanocarriers inspire researchers to explore novel applications, such as stimuli-responsive drug delivery, with exceptional in-vivo performances. In view of the above, we outline the fabrication process of calcium-silicon-phosphorus based MBGs, followed by discussions on their significant progress in various engineered strategies involving surface functionalization, nanostructures, and network modification. Furthermore, we emphasize the recent advancements in the textural and physicochemical properties of MBGs, along with their theranostic potentials in multiple cancerous and non-cancerous diseases. Lastly, we recapitulate compelling viewpoints, with specific considerations given from bench to bedside.

ZIF-8-based Nanoparticles for Inflammation Treatment and Oxidative Stress Reduction in Periodontitis.

Periodontitis, an inflammatory bone resorption disease associated with dental plaque, poses significant challenges for effective treatment. In this study, we developed Mino@ZIF-8 nanoparticles inspired by the periodontal microenvironment and the unique properties of zeolitic imidazolate framework 8, aiming to address the complex pathogenesis of periodontitis. Transcriptome analysis revealed the active engagement of Mino@ZIF-8 nanoparticles in innate and adaptive inflammatory host defense and cellular metabolic remodeling. Through sustained release of the anti-inflammatory and antibacterial agent minocycline hydrochloride (Mino) and the generation of Zn2+ with pro-antioxidant effects during degradation, Mino@ZIF-8 nanoparticles synergistically alleviate inflammation and oxidative damage. Notably, our study focuses on the pivotal role of zinc ions in mitochondrial oxidation protection. Under lipopolysaccharide (LPS) stimulation, periodontal ligament cells undergo a metabolic shift from oxidative phosphorylation (OXPHOS) to glycolysis, leading to reduced ATP production and increased reactive oxygen species levels. However, Zn2+ effectively rebalances the glycolysis-OXPHOS imbalance, restoring cellular bioenergetics, mitigating oxidative damage, rescuing impaired mitochondria, and suppressing inflammatory cytokine production through modulation of the AKT/GSK3ß/NRF2 pathway. This research not only presents a promising approach for periodontitis treatment but also offers novel therapeutic opportunities for zinc-containing materials, providing valuable insights into the design of biomaterials targeting cellular energy metabolism regulation.

Temporomandibular joint changes after activator appliance therapy: a prospective magnetic resonance imaging study.

The aim of this prospective clinical and magnetic resonance imaging study was to analyze the effect of 1-year Activator (Yi-fan Dental Co., Shanghai, China) treatment in internal anatomical relationships of the temporomandibular joint (TMJ) complex, including the condyle-disc relationship, condyle-fossa relationship, condylar height change, disc length change, and morphologic change of the glenoid fossa. The study was composed of patients with class II division 1 malocclusion (11 girls and 13 boys) who underwent 1-year Activator treatment. All the patients were in the acceleration or peak phase of the pubertal growth spurt. Magnetic resonance imaging in closed-mouth position and lateral cephalometric radiographs before and after 1 year of Activator treatment were analyzed metrically. Overall, condylar height showed a significant increase (P < 0.001), and the eminence angle decreased (P = 0.037). TMJ disc length has no statistically significant change before and after treatment. A slight advancement (P = 0.041) was found in the sagittal condylar position. A significant backward movement (P = 0.04) was shown in the sagittal disc position. Our results showed that the disc is not impaired by Activator therapy; it seems possible that adaptive remodeling, including a shallower glenoid fossa and increased condylar height, was seen after treatment.

Three-dimensional analysis of soft tissue changes in full-face view after surgical correction of skeletal class III malocclusion.

OBJECTIVE: The objective of this study was to evaluate changes in soft tissue in full-face view because of surgical correction of skeletal Class III malocclusion, using 3-dimensional (3D) laser scanning. METHODS: Twenty-seven subjects with skeletal Class III malocclusion [11 males; mean age (SD), 24.0 (5.7) years] underwent bilateral sagittal split ramus osteotomy for mandibular setback combined with Lefort I osteotomy with/without maxillary advancement. Twelve patients (group 1) had mandibular setback surgery, and the other 15 (group 2) had combination surgery. Lateral cephalograms and 3D facial scan images were assessed preoperatively and postoperatively. The facial widths upon superimposition of 3D facial images were measured in the same coordinates using a Rapidform 2006 system. Paired and independent t tests were done for statistical analysis. RESULTS: The midface soft tissue broadened significantly above the cheilion plane postoperatively (P < 0.05). A larger change was observed nearer to subnasale plane, and a similar trend was seen among the horizontal planes in 1- or 2-jaw surgery groups. The widths from the exocanthion plane to the subnasale plane increased more in group 2 [mean (SD), 4.45 (2.45) mm, 8.71 (2.92) mm, and 7.62 (3.13) mm] than those in group 1 [mean (SD), 1.26 (0.97) mm, 1.84 (1.06) mm, and 1.35 (0.65) mm], and this difference was significant (P < 0.05). There was a decrease below the cheilion plane with mandibular setback between groups, but this difference was not significant. CONCLUSIONS: The measurement method used here for the shape outline of the lateral parts of the face could provide quantitative data for the clinical evaluation and objective analysis of the human face in full-face view. The midface soft tissue in subjects with skeletal Class III malocclusion exhibited a greater increase in width after bimaxillary surgery procedures than mandibular setback-only surgery.

Bone grafting, corticotomy, and orthodontics: treatment of cleft alveolus in a chinese cohort.

Objective : A multimodal therapy was applied to solve a set of related problems including collapse of the posterior segment, high level gingival margin of canine, and resorption of grafted bone in a cohort of Chinese youngsters with cleft lip and palate. This study aimed to evaluate the benefits of this treatment procedure. Methods : Thirty patients with unilateral cleft lip and palate were included in this prospective study. All patients had previously undergone only cleft lip and palate repair and presented with alveolar cleft and an obvious step in the gingival margin between the canine tooth and the teeth beside it. A multimodal therapy that included bone grafting, corticotomy, and orthodontics was applied to solve these problems. Grafted bone volume, parallelism of the roots, root resorption, gingival margin, and mobility of the canine on the cleft side were established before surgery, 1 week after surgery, and after straightening of the canine. Results : Less than 25% of the grafted bone was reabsorbed in 25 of the 30 patients, while less than 50% was resorbed in the remaining five. The roots of the canines on the cleft side were mostly parallel to the adjacent teeth. Root resorption and mobility of the canines were slight. The difference in the gingival margin between the canines on the cleft side and the other side was small. Conclusions : Canines moved into the grafted bone safely and effectively, thus achieving a normal gingival margin and retaining grafted bone volume in one operation.

Melatonin Engineering M2 Macrophage-Derived Exosomes Mediate Endoplasmic Reticulum Stress and Immune Reprogramming for Periodontitis Therapy.

Periodontitis is a chronic infectious disease caused by bacterial irritation. As an essential component of the host immunity, macrophages are highly plastic and play a crucial role in inflammatory response. An appropriate and timely transition from proinflammatory (M1) to anti-inflammatory (M2) macrophages is indispensable for treating periodontitis. As M2 macrophage-derived exosomes (M2-exos) can actively target inflammatory sites and modulate immune microenvironments, M2-exos can effectively treat periodontitis. Excessive endoplasmic reticulum stress (ER stress) and unfolded protein response (UPR) are highly destructive pathological characteristics during inflammatory periodontal bone loss. Although melatonin has antioxidant and anti-inflammatory effects, studies focusing on melatonin ER stress modulation remain limited. This study fabricates engineered M2-exos loading with melatonin (Mel@M2-exos) for treating periodontitis. As a result, M2-exos drive an appropriate and timely macrophage reprogramming from M1 to M2 type, which resolves chronic inflammation and accelerated periodontal healing. Melatonin released from Mel@M2-exos rescues the osteogenic and cementogenic differentiation capacity in inflammatory human periodontal ligament cells (hPDLCs) by reducing excessive ER stress and UPR. Injectable gelatin methacryloyl (GelMA) hydrogels with sustained-release Mel@M2-exos accelerate periodontal bone regeneration in rats with ligation-induced periodontitis. Taken together, melatonin engineering M2 macrophage-derived exosomes are promising candidates for inflammatory periodontal tissue regeneration.

Oral delivery of bi-autoantigens by bacterium-like particles (BLPs) against autoimmune diabetes in NOD mice.

Induction of oral tolerance by vaccination with type 1 diabetes mellitus (T1DM)-associated autoantigens exhibits great potential in preventing and treating this autoimmune disease. However, antigen degradation in the gastrointestinal tract (GIT) limits the delivery efficiency of oral antigens. Previously, bacterium-like particles (BLPs) have been used to deliver a single-chain insulin (SCI-59) analog (BLPs-SCI-59) or the intracellular domain of insulinoma-associated protein 2 (IA-2ic) (BLPs-IA-2ic). Both monovalent BLPs vaccines can suppress T1DM in NOD mice by stimulating the corresponding antigen-specific oral tolerance, respectively. Here, we constructed two bivalent BLPs vaccines which simultaneously deliver SCI-59 and IA-2ic (Bivalent vaccine-mix or Bivalent vaccine-SA), and evaluated whether there is an additive beneficial effect on tolerance induction and suppression of T1DM by treatment with BLPs-delivered bi-autoantigens. Compared to the monovalent BLPs vaccines, oral administration of the Bivalent vaccine-mix could significantly reduce morbidity and mortality in T1DM. Treatment with the bivalent BLPs vaccines (especially Bivalent vaccine-mix) endowed the mice with a stronger ability to regulate blood glucose and protect the integrity and function of pancreatic islets than the monovalent BLPs vaccines treatment. This additive effect of BLPs-delivered bi-autoantigens on T1DM prevention may be related to that SCI-59- and IA-2-specific Th2-like immune responses could be induced, which was more beneficial for the correction of Th1/Th2 imbalance. In addition, more CD4+CD25+Foxp3+ regulatory T cells (Tregs) were induced by treatment with the bivalent BLPs vaccines than did the monovalent BLPs vaccines. Therefore, multiple autoantigens delivered by BLPs maybe a promising strategy to prevent T1DM by efficiently inducing antigen-specific immune tolerance.

miR-150-5p in neutrophil-derived extracellular vesicles associated with sepsis-induced cardiomyopathy in septic patients.

INTRODUCTION: Early diagnosis and potential therapeutic targets of sepsis-induced cardiomyopathy (SIC) remain challenges clinically. Circulating extracellular vesicles from immune cells carrying crucial injurious mediators, including miRNAs in sepsis. However, the impacts of neutrophil-derived extracellular vesicles and their miRNAs in the SIC development are unknown. OBJECTIVES: The present study focused on the in-depth miRNA expression profiles of neutrophil-derived extracellular vesicles and explored the potential molecular biomarkers during the process of SIC. METHODS: Neutrophil-derived extracellular vesicles were isolated from the blood samples in three sepsis patients with or without cardiomyopathy on day 1 and day 3 after ICU admission in comparison with three healthy controls. miRNAs were determined by RNA sequencing. The closely related differentially expressed miRNAs with SIC were further validated through qRT-PCR in the other cohorts of sepsis patients with (30 patients) or without cardiomyopathy (20 patients) and the association between miRNAs and the occurrence or disease severity of septic cardiomyopathy were stratified with logistic regression analysis. RESULTS: Sixty-eight miRNAs from neutrophil-derived extracellular vesicles were changed significantly between healthy controls and without septic cardiomyopathy patients (61 miRNAs upregulated and seven downregulated). Thirty-eight miRNAs were differentially expressed in the septic cardiomyopathy patients. 27 common differentially expressed miRNAs were found in both groups with similar kinetics (23 miRNAs upregulated and four downregulated). The enriched cellular signaling pathway mediated by miRNAs from sepsis to septic cardiomyopathy was the HIF-1 signaling system modulated septic inflammation. Using multivariate logistic regression analysis, miR-150-5p coupled with NT-pro BNP, LVEF, and SOFA score (AUC = 0.941) were found to be the independent predictors of septic cardiomyopathy. CONCLUSION: miRNAs derived from neutrophil-derived extracellular vesicles play an important role in septic disease severity development towards cardiomyopathy. miR-150-5p may be a predictor of sepsis severity development but warrants further study.

Treatment of severe skeletal open bite deformity in patients with Möbius syndrome: a report of 3 cases.

PURPOSE: To investigate the treatment of severe skeletal open bite deformities in Möbius syndrome patients. MATERIALS AND METHODS: Three patients aged 17 to 24 years (2 male patients and 1 female patient) with Möbius syndrome were evaluated and treated with preoperative orthodontics, orthognathic surgery, and postoperative orthodontic management. One patient was treated by bilateral V osteotomies of the mandibular body and one patient with bilateral V osteotomies of the mandibular body plus a Le Fort I osteotomy. The third patient had bilateral mandibular ramus sagittal split osteotomies in combination with maxillary osteotomies. Two of the patients had preoperative electromyographic studies on the temporalis and masseter muscles. RESULTS: Postoperative and post-orthodontic stability was good in 2 cases, whereas a 5-mm anterior open bite developed after treatment in 1 case and additional orthodontic management was required to re-establish good occlusion. Potential to redevelop anterior open bites may likely be related to the functional deficiencies of the muscles of mastication and facial paralysis. Two patients who had electromyographic studies to evaluate muscle function showed lower-than-normal function of the temporalis and masseter muscles. Lower lip ptosis remained a significant esthetic issue in 2 of 3 patients. CONCLUSIONS: Patients with Möbius syndrome with severe skeletal open bite deformities can be treated with combined orthodontic and orthognathic surgery; however, there is a tendency for redevelopment of an anterior open bite with the surgical and orthodontic techniques used in these cases.

Novel insights into nanomaterials for immunomodulatory bone regeneration.

Bone defect repair caused by trauma, congenital malformation, tumors, infection or systemic diseases remains the focus of attention in regeneration medicine. Recent advances in osteoimmunology indicate that immune cells and correlative cytokines modulate the delicate balance between osteoblasts and osteoclasts and induce a favorable microenvironment for bone regeneration. With superior attributes that imitate the three-dimensional architecture of natural bone, excellent fabricability, mechanical and biological properties, nanomaterials (NMs) are becoming attractive in the field of bone tissue engineering. Particularly, it could be an effective strategy for immunomodulatory bone regeneration by engineering NMs involved in composition nature, nanoarchitectural morphology, surface chemistry, topography and biological molecules, whose mechanisms potentially refer to regulating the phenotype of high-plastic immune cells and inducing cytokine secretion to accelerate osteogenesis. Despite these prominent achievements, the employment of NMs is poorly translated into clinical trials due to the lack of knowledge about the interaction between NMs and the immune system. For this reason, we sketch out the hierarchical structure of bone and its natural healing process, followed by discussion about the effects of immune cells on bone regeneration. Novel horizons focusing on recent progressions in the architectural and physicochemical performances of NMs and their impacts on the body defence mechanism are also emphasized, hoping to provide novel insights for the fabrication of bone graft materials in tissue engineering.

[Cone-beam CT measurement of morphological changes of the root and alveolar bone of the central incisor during orthodontic treatment with extraction].

PURPOSE: To study the effect of orthodontic treatment with extraction on root resorption and alveolar bone morphology of the central incisor in adult patients. METHODS: Eleven adult patients receiving orthodontic treatment were enrolled, and asked to take cone-beam CT(CBCT) scanning before and after treatment. Root resorption of the upper and lower central incisors after treatment, changes in alveolar bone thickness and height of alveolar bone were measured and compared. Statistical analysis was performed using SPSS 23.0 software package. RESULTS: The length of the tooth and root was reduced to a certain degree. The change in root length of the maxillary incisor was larger than that of the mandibular incisor. The alveolar bone width of the lingual and palatal neck of the central incisor showed some reduction, and alveolar bone width of the palatal neck of the upper central incisor and the middle lingual side of the mandibular central incisor changed to a certain extent. The width of the alveolar bone in the middle labial side of the mandibular central incisor increased, but the alveolar bone on the lingual and palatal side increased after orthodontic treatment, which was more obvious than that of the maxillary central incisor. CONCLUSIONS: Orthodontic treatment with tooth extraction is accompanied by a certain degree of root resorption of the central incisor and alveolar bone on the lingual and palatal side. However it is also accompanied by an increase in the amount of alveolar bone on the labial side. More fenestration and dehiscence are observed in the mandible.

Calcium silicate bioactive ceramics induce osteogenesis through oncostatin M.

Immune reactions are a key factor in determining the destiny of bone substitute materials after implantation. Macrophages, the most vital factor in the immune response affecting implants, are critical in bone formation, as well as bone biomaterial-mediated bone repair. Therefore, it is critical to design materials with osteoimmunomodulatory properties to reduce host-to-material inflammatory responses by inducing macrophage polarization. Our previous study showed that calcium silicate (CS) bioceramics could significantly promote osteogenesis. Herein, we further investigated the effects of CS on the behavior of macrophages and how macrophages regulated osteogenesis. Under CS extract stimulation, the macrophage phenotype was converted to the M2 extreme. Stimulation by a macrophage-conditioned medium that was pretreated by CS extracts resulted in a significant enhancement of osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), indicating the important role of macrophage polarization in biomaterial-induced osteogenesis. Mechanistically, oncostatin M (OSM) in the macrophage-conditioned medium promoted osteogenic differentiation of BMSCs through the ERK1/2 and JAK3 pathways. This in vivo study further demonstrated that CS bioceramics could stimulate osteogenesis better than ß-TCP implants by accelerating new bone formation at defective sites in the femur. These findings improve our understanding of immune modulation of CS bioactive ceramics and facilitate strategies to improve the in vitro osteogenesis capability of bone substitute materials.

The synergistic effects of Sr and Si bioactive ions on osteogenesis, osteoclastogenesis and angiogenesis for osteoporotic bone regeneration.

Bioactive ions released from bioceramics play important roles in bone regeneration; however, it is unclear how each ionic composition in complex bioceramics exerts its specific effect on bone regeneration. The aim of this study is to elucidate the functional effects of Sr and Si ions in bioceramics on the regeneration of osteoporotic bone. A model bioceramic with Sr- and Si-containing components (SMS) was successfully fabricated and the effects of ionic products from SMS bioceramics on the osteogenic, osteoclastic and angiogenic differentiation of rBMSCs-OVX and RANKL-induced osteoclasts were investigated. The results showed that SMS bioceramics could enhance ALP activity and expression of Col 1, OCN, Runx2, and angiogenic factors including VEGF and Ang-1. SMS bioceramics not only rebalanced the OPG/RANKL ratio of rBMSCs-OVX at early stage, but also repressed RANKL-induced osteoclast formation and expression of TRAP, DC-STAMP, V-ATPase a3, and NFATc1. The synergistic effects of Sr and Si ions were further investigated as compared with those of similar concentrations of Sr and Si ions alone. Sr and Si ions possessed synergistic effects on osteogenesis, osteoclastogenesis, and angiogenesis, attributed to the dominant effects of Sr ions on enhancing angiogenesis and repressing osteoclastogenesis, and the dominant effects of Si ions on stimulating osteogenesis. The in vivo study using critical-size mandibular defects of OVX rat models showed that SMS bioceramics could significantly enhance bone formation and mineralization compared with ß-TCP bioceramics. Our results are the first to elucidate the specific effect of each ion from bioceramics on osteogenesis, osteoclastogenesis and angiogenesis for osteoporotic bone regeneration, paving the way for the design of functional biomaterials with complex compositions for tissue engineering and regenerative medicine. STATEMENT OF SIGNIFICANCE: Bioactive ions released from bioceramics play important roles for bone regeneration; however, it is unclear how each of ionic compositions in complex bioceramics exerts its specific effect on bone regeneration. The aim of present study is to elucidate the functional effects of Sr and Si ions in complex bioceramics on the regeneration of osteoporotic bone. A model bioceramic with Sr and Si-containing components (SMS) was successfully fabricated and the effects of ionic products from SMS bioceramics on the osteogenic, osteoclastic and angiogenic differentiation of rBMSCs-OVX and RANKL-induced osteoclasts were investigated. The results showed that SMS bioceramics could enhance ALP activity and expression of Col 1, OCN, Runx2 and angiogenic factors including VEGF and Ang-1. SMS bioceramics not only rebalanced the ratio of OPG/RANKL of OVX-BMSCs at early stage, but also repressed RANKL-induced osteoclast formation and expression of TRAP, DC-STAMP, V-ATPase a3, and NFATc1. The synergistic effects of Sr and Si ions were further investigated as compared with the similar concentration of Sr and Si ions alone. It was found that Sr and Si ions possessed synergistic effects on osteogenesis, osteoclastogenesis and angiogenesis, attributed to the dominant effects of Sr ions on enhancing angiogenesis and repressing osteoclastogenesis, and the dominant effects of Si ions on stimulating osteogenesis. The in vivo study using critical-size mandibular defects of OVX rat models showed that SMS bioceramics could significantly enhance bone formation and mineralization as compared with ß-TCP bioceramics. It is suggested that SMS bioceramics may be a promising biomaterial for osteoporotic bone regeneration. To our knowledge, this is the first time to elucidate the specific effect of each ion from bioceramics on osteogenesis, osteoclastogenesis and angiogenesis for osteoporotic bone regeneration, paving the way to design functional biomaterials with complex compositions for tissue engineering and regenerative medicine.

AGEs Induce Apoptosis in Rat Osteoblast Cells by Activating the Caspase-3 Signaling Pathway Under a High-Glucose Environment In Vitro.

Advanced glycation end products (AGEs) accumulate under high-glucose conditions and affect the healing of bone damage through various pathways; however, the detail mechanisms underlying these changes are unknown. In this study, we investigated the effects of AGEs on the apoptosis of in vitro-cultured rat osteoblasts under high-glucose conditions and explored the underlying mechanisms of these effects. First, we cultured rat osteoblasts and determined the accumulation of AGEs in the culture medium under high-glucose conditions. Then, we cultured rat osteoblasts under a high glucose concentration (35 mM), a normal glucose concentration (5.5 mM), and a normal glucose concentration (5.5 mM) in the presence of AGEs. We examined the effects of high glucose and AGEs on the apoptosis of rat osteoblasts at different time points and further analyzed the activity and changes in the levels of procaspase-3, caspase-3, and the caspase-3 substrate poly ADP-ribose polymerase (PARP). Finally, we added sRAGE (soluble RAGE) (an AGE inhibitor) or DEVD (a caspase-3 inhibitor) to each culture group and examined apoptosis under each culture condition and the changes in the levels of procaspase-3, caspase-3, and its substrate PARP. The results showed that the high-glucose condition and the addition of AGEs increased the apoptosis of rat osteoblast cells and simultaneously increased the activity and quantity of caspase-3. These increases could be inhibited by the AGE inhibitor sRAGE or the caspase-3 inhibitor DEVD. The above results demonstrate that high-glucose conditions lead to the accumulation of AGEs and activation of the caspase-3 signaling pathway, resulting in the increased apoptosis of cultured rat osteoblast cells.

Akermanite bioceramics promote osteogenesis, angiogenesis and suppress osteoclastogenesis for osteoporotic bone regeneration.

It is a big challenge for bone healing under osteoporotic pathological condition with impaired angiogenesis, osteogenesis and remodeling. In the present study, the effect of Ca, Mg, Si containing akermanite bioceramics (Ca2MgSi2O7) extract on cell proliferation, osteogenic differentiation and angiogenic factor expression of BMSCs derived from ovariectomized rats (BMSCs-OVX) as well as the expression of osteoclastogenic factors was evaluated. The results showed that akermanite could enhance cell proliferation, ALP activity, expression of Runx2, BMP-2, BSP, OPN, OCN, OPG and angiogenic factors including VEGF and ANG-1. Meanwhile, akermanite could repress expression of osteoclastogenic factors including RANKL and TNF-α. Moreover, akermanite could activate ERK, P38, AKT and STAT3 signaling pathways, while crosstalk among these signaling pathways was evident. More importantly, the effect of akermanite extract on RANKL-induced osteoclastogenesis was evaluated by TRAP staining and real-time PCR assay. The results showed that akermanite could suppress osteoclast formation and expression of TRAP, cathepsin K and NFATc1. The in vivo experiments revealed that akermanite bioceramics dramatically stimulated osteogenesis and angiogenesis in an OVX rat critical-sized calvarial defect model. All these results suggest that akermanite bioceramics with the effects of Mg and Si ions on osteogenesis, angiogenesis and osteoclastogenesis are promising biomaterials for osteoporotic bone regeneration.

Europium-Containing Mesoporous Bioactive Glass Scaffolds for Stimulating in Vitro and in Vivo Osteogenesis.

Bone tissue engineering offers a possible strategy for regenerating large bone defects, in which how to design beneficial scaffolds for accelerating bone formation remains significantly challenging. Europium, as an important rare earth element, has been used as a solid-state lighting material. However, there are few reports on whether Eu can be used for labeling bone tissue engineering scaffolds, and its biological effect on bone cells and bone tissue regeneration is unknown. In this study, we incorporated Eu into mesoporous bioactive glass (Eu-MBG) scaffolds by an in situ cotemplate method to achieve a bifunctional biomaterial with biolabeling and bone regeneration. The prepared Eu-MBG scaffolds have highly interconnective large pores (300-500 µm), a high specific surface area (140-290 m(2)/g), and well-ordered mesopores (5 nm) as well as uniformly distributed Eu. The incorporation of 2-5 mol % Eu into MBG scaffolds gives them a luminescent property. The in vitro degradation of Eu-MBG scaffolds has a functional effect on the change of the luminescence intensity. In addition, Eu-MBG can be used for labeling bone marrow stromal cells (BMSCs) in vitro and still presents a distinct luminescence signal in deep bone tissues in vivo to label new bone tissue via release of Eu ions. Furthermore, the incorporation of different contents of Eu (1, 2, and 5 mol %) into MBG scaffolds significantly enhances the osteogenic gene expression of BMSCs in the scaffolds. The Eu- and Si-containing ionic products released from Eu-MBG scaffolds distinctly promote the osteogenic differentiation of BMSCs. Critically sized femur defects in ovariectomized (OVX) rats are created to simulate an osteoporotic phenotype. The results show that Eu-MBG scaffolds significantly stimulate new bone formation in osteoporotic bone defects when compared to MBG scaffolds alone and Eu may be involved in the acceleration of bone regeneration in OVX rats. Our study for the first time reports that the incorporation of the rare earth element Eu into bioscaffolds has the ability to accelerate bone regeneration in vivo, and thus, the prepared Eu-MBG scaffolds possess bifunctional properties with biolabeling and bone regeneration.