Bone Restoration Research Articles

Preparation and characterization of mesoporous core-shell bioactive glass-based cements for direct pulp capping.

Direct pulp capping is crucial for maintaining dental pulp vitality. The materials employed for this purpose should possess properties such as easy-handling, excellent biocompatibility, infection resistance, and the ability to stimulate the formation of reparative dentin. Mineral trioxide aggregate (MTA) is commonly used for pulp capping. However, certain limitations, including its long setting time, insufficient anti-washout ability, high initial curing pH, and handling difficulties, restrict MTA from meeting a broader range of clinical demands. Bioactive glass (BG) is known for its osteo-inductive and bone restoration properties. This study aims to develop a novel bioactive glass-based cement (BG-x/SA) for pulp capping applications, using BG microspheres (BG-x) as the solid phase and sodium alginate solution (SA) as the liquid phase. The solid phase has core-shell microspheres made by in-situ transformation, with BG in the core and hydroxyapatite (HA) in the shell. The study focuses on how the in-situ synthesis reaction parameters affect the cement's properties. Ultimately, BG-6/SA cement was identified as the optimal formulation, and a comparison with MTA shows BG-6/SA cement has a short setting time, good anti-washout performance, can adjust pH to mildly alkaline, promotes dentin formation, and has antibacterial effects. Thus, BG-6/SA cement has significant research value and good prospects as a new pulp-capping material.

Exosomes in Oral Diseases: Mechanisms and Therapeutic Applications.

Exosomes, small extracellular vesicles secreted by various cells, play crucial roles in the pathogenesis and treatment of oral diseases. Recent studies have highlighted their involvement in orthodontics, periodontitis, oral squamous cell carcinoma (OSCC), and hand, foot, and mouth disease (HFMD). Exosomes have a positive effect on the inflammatory environment of the oral cavity, remodeling and regeneration of oral tissues, and offer promising therapeutic options for bone and periodontal tissue restoration. In OSCC tumor-derived exosomes promote cancer progression through cell proliferation, migration, invasion, and angiogenesis, and serve as potential biomarkers for early diagnosis and prognosis. Additionally, engineered exosomes constructed specifically based on exosome properties hold great promise for targeted drug delivery and regenerative therapies such as bone regeneration in orthodontics and periodontal healing. With continued research, exosomes hold great potential for improving diagnosis and treatment in oral diseases, advancing personalized and regenerative therapies.

Controllable design and evaluation of Voronoi-based irregular porous scaffolds for bone restoration

The Voronoi-based irregular porous scaffolds (VIPS) for bone restoration often suffer from uncontrollable structural characteristics and mechanical properties. In this study, a method using spherical spaces to control the randomness of the seed points distribution was proposed to achieve controllable design of the VIPS. The irregularity ε, porosity P and average pore size D̅ of the VIPS were calculated by parametric design software Grasshopper, and the apparent elastic modulus E, equivalent compressive strength S of the VIPS were obtained by quasi-static compressive test. The functional relationships between the design parameters (spherical radius to lattice spacing ratio R/a, seed points number N and pore size coefficient K) and ε, P, D̅, E, S were established through statistical analyses. The results indicated that the VIPS designed based on the spherical space method had high controllability. Design parameters in the range of R/a∈0,0.5, N∈64,1000, and K∈0.4,0.9 allow control over the irregularity, porosity, average pore size, elastic modulus, and compressive strength of VIPS in the range of 0–0.32, 37%–96%, 200–1200 μm, 0.8–5.4GPa, 15–240MPa, respectively, and all of which could meet the structural and mechanical requirements of the VIPS for bone restoration.

DYNAMICS OF MINERAL ELEMENT CONTENT IN MANDIBULAR BONE TISSUE OF EXPERIMENTAL ANIMALS DURING THE HEALING OF AN ARTIFICIAL DEFECT FILLED WITH OCTACALCIUM PHOSPHATE

Introduction: The problem of bone trauma and restoration of bone integrity with defects of various localization, shape and size is particularly relevant today. Objective: To determine the features of post-traumatic dynamics of the mineral elements content in the bone tissue of the mandible using octacalciumphosphate. Materials and Methods: The study was conducted on 65 sexually mature male rabbits weighing 2.5-3.0 kg, aged 6-7 months which were divided into 3 groups (20 rabbits each): Group I - control - the bone tissue defect healed under a blood clot; Group II - the defect was filled with native octacalciumphosphate (OCP-N); Group III - the defect was filled with octacalciumphosphate with chitosan and ampicillin (OCP-N-Chitosan-Ampicillin). Five intact animals were used to study the normal mineral composition of the rabbit mandibular bone tissue (MBT). The content of five mineral elements was determined using atomic absorption and emission spectral analysis. Data was carried out after 7, 14, 21, 28, 35, 56, and 84 days. Results: It was established that the calcium and phosphorus content in the MBT were lower than in the control, but higher than normal. Magnesium and sodium levels with OCP-N were similar to controls, while with OCP-N-Chitosan-Ampicillin, they returned to normal. Sodium levels were higher than controls. Sodium levels were higher than the first control group data. Magnesium levels, while using OCP-N were higher than the parameters for intact animals and first control group throughout the entire experiment. While using the OCP-N-Chitosan-Ampicillin material they were higher than the first control group. The potassium content throughout the experiment in both experimental groups was lower than data of first control group. However, when using OCP-N material on day 84, the studied parameter remains significantly lower than in intact animals; with OCP-N-Chitosan-Ampicillin it returns to normal values. Conclusions: The mineral composition of bone tissue undergoes significant changes following a bone-destructive injury, characterized by a substantial increase in calcium, phosphorus, and magnesium levels. The dynamics of sodium and potassium content are less pronounced. When the bone defect is filled with the osteoconductive material OCP-N-Chitosan-Ampicillin, the levels of calcium, phosphorus, magnesium, sodium, and potassium return to normal values by the 84th day after injury

3D‐Printed Dual‐Bionic Scaffolds to Promote Osteoconductivity and Angiogenesis for Large Segment Bone Restoration

AbstractLarge segment bone defects pose a significant challenge in the field of orthopedic surgery, requiring effective and innovative approaches for restoration. However, many existing scaffolds are bioinert and do not support crucial processes such as cell adhesion, proliferation, and vascularization. In this study, a dual‐bionic 3D printing bredigite scaffold is developed, featuring a combination of physical structure and bioactive functions. Specifically, the structure‐mimetic scaffold has an isotropic single‐cell structure suitable for defects with varying load‐bearing requirements and allowing the ingrowth of vessels and bone. Meanwhile, an extracellular matrix peptide‐mimetic β‐amino acid polymer DM50CO50 and deferoxamine are modified onto the scaffold simultaneously to promote the adhesion of bone marrow mesenchymal stem cells and vascularization. The dual‐bionic scaffolds demonstrate outstanding osteogenic and angiogenic properties in a rat model with large segment bone defects to promote bone restoration, implying a promising strategy in designing scaffolds to promote osteoconductivity and angiogenesis for large segment bone restoration.

SCOPE OF DENTAL IMPLANTS IN PEDIATRIC DENTISTRY

Introduction: Dental implants in pediatric patients represent a relatively new approach in dental care. However, the application of implants in children, or in individuals whose growth is not yet complete, remains a subject of debate. Since their introduction, dental implants have provided a reliable, long-lasting, and easy-to-maintain solution for replacing missing teeth in adults. They are known to help preserve the alveolar bone and offer highly aesthetic outcomes. Methods: Before placing a dental implant, it is crucial to consider the growth and development of the patient, particularly in the context of a growing individual. The biological environment of a developing patient must be understood, as it can influence the implants stability and success. Additionally, there are distinct differences in facial growth patterns between the maxilla and mandible, which can affect the timing and positioning of implants in these areas. Result: The use of dental implants has been shown to be effective in children who have undergone bone removal in the maxillary and mandibular regions due to tumors, as well as in long-term bone restoration in cases of palatal clefts. Implant-based treatments have also proven beneficial for addressing dental issues related to congenital conditions, including ectodermal dysplasia, Williams-Beuren syndrome, dental agenesis, and hemifacial microsomia. Conclusion: Although there is limited published research on the use of dental implants in young patients, long-term clinical studies are needed to draw definitive conclusions. Therefore, the potential benefits of implants should always be carefully weighed against the associated risks and complications. While the scarcity of long-term data should not deter clinicians from utilizing implant-assisted prostheses in pediatric patients, it is particularly important in cases such as children with ectodermal dysplasia (ED), where implants can be a viable and beneficial treatment option.

Comprehensive rehabilitation of patients after injuries of the facial region: interaction of dentists and surgeons

This work highlights in detail modern approaches to the comprehensive rehabilitation of patients who have suffered injuries to the maxillofacial region, which can significantly affect the quality of life, causing functional disorders such as problems with chewing, speech and breathing, as well as significant aesthetic defects. Injuries in this area require the participation of specialists from different fields, and in this context, special attention is paid to the interaction of dentists and maxillofacial surgeons. Comprehensive rehabilitation includes several key stages: surgical treatment, restoration of bone and soft tissue structures, orthopedic and orthodontic treatment, as well as aesthetic correction. The need for close cooperation between the surgeon and the dentist is emphasized at all stages of treatment, from the initial diagnosis of injuries and treatment planning to surgical interventions and subsequent dental rehabilitation. Modern methods of surgical correction, such as osteosynthesis, reconstruction of bone defects using bone grafts and implants, as well as the use of new biomaterials, are discussed. Dental rehabilitation includes occlusion restoration, dental prosthetics and bite correction, which requires careful planning and consideration of surgical aspects. The issues of functional rehabilitation of patients, such as restoration of chewing function, proper articulation and facial aesthetics, are also considered. Special attention is paid to new technologies and innovative approaches, such as 3D modeling, digital surgery planning and the use of dental implants, which allow achieving high results in restoring both functionality and appearance of the patient. The article focuses on the importance of coordinated work of an interdisciplinary team to achieve the best results in the rehabilitation of patients after maxillofacial injuries. The authors emphasize that an integrated approach, including the interaction of specialists of different profiles, provides a more effective restoration of functions and aesthetics, which significantly improves the quality of life of patients.

Selective Pyk2 inhibition enhances bone restoration through SCARA5-mediated bone marrow remodeling in ovariectomized mice

Understanding the intricate cellular interactions involved in bone restoration is crucial for developing effective strategies to promote bone healing and mitigate conditions such as osteoporosis and fractures. Here, we provide compelling evidence supporting the anabolic effects of a pharmacological Pyk2 inhibitor (Pyk2-Inh) in promoting bone restoration. In vitro, Pyk2 signaling inhibition markedly enhances alkaline phosphatase (ALP) activity, a hallmark of osteoblast differentiation, through activation of canonical Wnt/β-catenin signaling. Notably, analysis of human mesenchymal stem cells through RNA-seq revealed a novel candidate, SCARA5, identified through Pyk2-Inh treatment. We demonstrate that Scara5 plays a crucial role in suppressing the differentiation from stromal cells into adipocytes, and accelerates lineage commitment to osteoblasts, establishing Scara5 as a negative regulator of bone formation. Additionally, Pyk2 inhibition significantly impedes osteoclast differentiation and bone resorption. In a co-culture system comprising osteoblasts and osteoclasts, Pyk2-Inh effectively suppressed osteoclast differentiation, accompanied by a substantial increase in the transcriptional expression of Tnfrsf11b and Csf1 in osteoblasts, highlighting a dual regulatory role in osteoblast-osteoclast crosstalk. In an ovariectomized mouse model of osteoporosis, oral administration of Pyk2-Inh significantly increased bone mass by simultaneously reducing bone resorption, promoting bone formation and decreasing bone marrow fat. These results suggest Pyk2 as a potential therapeutic target for both adipogenesis and osteogenesis in bone marrow. Our findings underscore the importance of Pyk2 signaling inhibition as a key regulator of bone remodeling, offering promising prospects for the development of novel osteoporosis therapies.

Calcium sulfate-based load-bearing bone grafts with patient-specific geometry

The treatment of bone defects with complex three-dimensional geometry presents challenges in terms of bone grafting and restoration. In this paper, we propose a rapid and effective method that uses 3D printing, ceramic casting, and the incorporation of mesh reinforcement to create load-bearing bone grafts with patient-specific three-dimensional geometry. Using two types of facial bones as examples, we show that this fabrication method has a high degree of geometrical fidelity. We also experimentally study the fracture behavior of six different architectures designed for the treatment of mandibular defects, one of the principal load-bearing facial bones. These design configurations include un-reinforced calcium sulfate samples, and samples reinforced with one or two layers of stainless steel, poly (lactic acid), and poly (L-lactic acid). The results suggested a trade-off between energy dissipation and maximum load based on the position of the metal mesh in the sample. Samples reinforced with one layer of metallic mesh at their lowermost margin exhibited a 17% higher stiffness and a 21.3% higher peak load, while samples with a layer of metal mesh embedded within dissipated 16% more energy. Samples with two layers of metallic mesh demonstrated the highest improvements among all samples, dissipating 5767.85% more energy and exhibiting a peak load 145.6% higher compared to plain CS. The improvements in stiffness for SD, SL, and S2 were 3%, 21.3%, and 21.9% respectively compared to the plain ceramic. In contrast, PLA mesh improved energy dissipation by 96.71% but reduced the peak load by 29.18%, while PLLA mesh decreased both the peak load and the dissipated energy by 13.05% and 35.31%, respectively. While PLA mesh reduced stiffness by 11% compared to plain CS, PLLA mesh-reinforced samples were slightly stiffer than pure CS by 1.6%.

Histopathological characterization of mandibular condyles in four temporomandibular joint osteoarthritis mouse models

ObjectiveTemporomandibular joint osteoarthritis (TMJOA) has been modeled in different ways with a lack of uniformity. We aimed to investigate four TMJOA mouse models and assess histopathological changes in condyles, which could assist in the selection of animal models in further TMJOA-related studies. DesignFour TMJOA mouse models were established, including unilateral hyperocclusion, discectomy, monosodium iodoacetate injection and aged model. Bilateral condyles were collected at different time points. The condylar alterations were analyzed by Micro-CT, Hematoxylin and eosin staining, Toluidine blue staining, Safranin O staining, Trap staining, immunofluorescence staining, immunohistochemistry staining and quantitative polymerase chain reaction. ResultsRadiographic and histopathological analysis indicated that all four methods could cause condylar degeneration successfully. Differences in morphologic and histologic changes were found among four models. The hyperocclusion model was time-dependent and the lesions got worse over time. Discectomy model presented obvious damage of cartilage and subchondral bone. Injected model showed severe inflammation and chondrocyte hypertrophy. The aged model was characterized by decreased of proteoglycan and osteolysis. ConclusionsThe four methods had different characteristics and applicability. The harvest time affected the degree of cartilage degradation. Hyperocclusion was suited to explore the early-stage of TMJOA. Discectomy present advantages in investigating the long-term restoration of cartilage and subchondral bone. Monosodium iodoacetate-injection was appropriate for screening the agents for inflammatory relief. The aged model more naturally facilitated discovering underlying mechanisms in primary TMJOA. Unilateral modeling methods could initiate contralateral condylar alterations. The TMJOA models should be selected based on experimental requirements and applicability of each model.

An MRI-Derived Formula for Estimating the Native Joint Line Position in the Presence of Distal Femoral Bone Loss.

Background In the presence of distal femoral condyle bone loss, estimation and restoration of the joint line (JL) position can be guided by extraarticular bony landmarks with the aid of mathematical formulas that rely on the innate correlations between periarticular measurements. To prevent JL elevation, the formula should incorporate the thickness of distal femoral articular cartilage. The aim of this study was to derive a formula to estimate native JL position. Methods One hundred and fifty knee magnetic resonance imaging (MRI) studies belonging to 150 patients were chosen from a database of scans. Multiple periarticular measurements were taken. Based on the strongest correlation between measurements, linear regression analysis was used to derive a regression equation to estimate the JL position. This formula was then tested to determine its accuracy and reliability in estimating the JL. Results Using the Pearson correlation test, the strongest correlation was identified to be between adductor tubercle to joint line distance (ATJL) and transepicondylar width (TEW) with r = 0.723, p <.001. Using linear regression analysis, the following regression equation was obtained: ATJL in millimetres = 0.53 (TEW in millimetres) + 2.4mm. This formula estimated the JL within 4 mm of the native JL in 86% of measured knees and within 8 mm in 100% of measured knees. The mean difference between calculated ATJL and measured ATJL was 2.43 mm with a standard deviation of 1.94 mm. Conclusion The current formula (ATJL = 0.53(TEW) + 2.4mm) reliably estimates native JL distance from the adductor tubercle (AT) to within a clinically significant range, using femoral TEW.

Inorganic-Based Nanoparticles and Biomaterials as Biocompatible Scaffolds for Regenerative Medicine and Tissue Engineering: Current Advances and Trends of Development

Regenerative medicine amalgamates stem cell technology and tissue engineering strategies to replace tissues and organs damaged by injury, aging, ailment, and/or chronic conditions by leveraging the innate self-healing mechanism of the body. The term ‘regenerative medicine’ was coined by William A. Haseltine during a 1999 conference on Lake Como. Since its inception in 1968, the field has offered clinical benefits for the regeneration, repair, and restoration of bones, skin, cartilage, neural tissue, and the heart, as well as scaffold fabrication. The field of tissue engineering and regenerative medicine can vastly benefit from advancements in nanoscience and technology, particularly in the fabrication and application of inorganic-based nanoparticles and bionanomaterials. Due to the tunable intrinsic properties, i.e., size, topography, surface charge, and chemical stability, inorganic-based nanoparticles and biomaterials have surpassed traditional synthetic materials. Given the wide gamut of near-future applications of inorganic nanoparticles and biomaterials, this article gives an overview of the emerging roles in stem cell regenerative research, tissue engineering, artificial skin and cartilage regeneration, neural nerve injuries, 3D bioprinting, and development of new inorganic bio-scaffolds. The review also addresses the challenges related to the clinical application and tissue compatibility of inorganic nanoparticles and biomaterials, utilizing current state-of-the-art techniques.

Structure of Medication Therapy in Patients with Complex Hand Bone Fractures in Kyrgyz Republic

This article analyzes the structure of medication therapy in patients with complex hand bone fractures in the Kyrgyz Republic. Complex hand fractures are common injuries requiring a multi-stage treatment approach, including surgery, immobilization, and adequate medication therapy. The article examines various therapeutic regimens used at different stages of treatment: the first-line therapy includes analgesics and anti-inflammatory drugs, the second-line therapy adds hormonal medications and tissue regeneration stimulants, and alternative methods incorporate biologically active agents and physiotherapy. Effectiveness was evaluated based on clinical indicators such as pain level, bone healing rate, complication frequency, and restoration of hand function. The article also discusses gender-specific differences in therapeutic approaches, necessitating the consideration of pharmacokinetics and pharmacodynamics in men and women. This study highlights the need for the development of standardized treatment protocols adapted to local healthcare conditions to improve treatment efficacy and reduce complications.

Platelet-Rich Fibrin (PRF) Analyzed for Cytokine Profiles - A Misguided Hope for Osteogenesis in Jawbone Defects? Research and Clinical Observational Study.

Platelet-rich fibrin (PRF) blood concentrates are used in oral implantology and defect surgery to promote osteoneogenesis in Bone Marrow Defects in Jawbone (BMDJ), according to the morphology of fatty-degenerative osteonecrosis also called FDOJ. Can the benefit of PRF on alveolar osteoneogenesis be confirmed by cytokine analysis?. The cytokine expressions of the PRF samples in 26 patients undergoing BMDJ/FDOJ surgery in the same session were analysed for seven cytokines (RANTES/CCL5; FGF-2; IL-1RA; Il-6; IL-8; MCP-1; TNF-a) by multiplex (Luminex). The FDOJ samples of these 26 BMDJ/FDOJ patients were analysed for the RANTES/CCL5 expression only. Cytokine expression in PRF is compared to reference values for healthy medullary bone of the jaw and BMDJ/FDOJ and shows that the cytokine expressions of the PRF samples do not compensate or counteract prima vista for the cytokine dysregulations present in the BMDJ/FDOJ areas. To define the aid of cytokines studied in PRF in the restoration of the immunological dysregulation in areas of BMDJ/FDOJ, literature is reviewed comparing RANTES/CCL5, IL-1ra, TNF-α and MCP-1/CCL2 expression in PRF and BMDJ/FDOJ. Immunoregulatory properties of PRF in alveolar bone restoration are evaluated. PRF was mistakenly thought to be a cure for bone healing, which is here shown to be incorrect. Enoral Ultrasound Sonography of bone density is available for the clinical measurement of individually developed osteoneogenesis by PRF. The multiplex analysis of PRF shows a dynamic and cytokine-based interaction with osteoneogenesis that is not yet fully clarified.

Evaluation of stiffness-matched, 3D-printed, NiTi mandibular graft fixation in an ovine model

BackgroundManually bent, standard-of-care, Ti–6Al–4V, mandibular graft fixation devices are associated with a significant post-operative failure rate. These failures require the patient to endure stressful and expensive re-operation. The approach recommended in this report demonstrates the optimization of graft fixation device mechanical properties via “stiffness-matching” by varying the fixation device’s location, shape, and material composition through simulation of the device’s post-operative performance. This provides information during pre-operative planning that may avoid future device failure. Optimized performance may combine translation of all loading into compression of the bone graft with the adjacent bone segments and elimination or minimization of post-healing interruption of normal stress–strain (loading) trajectories.ResultsThis study reports a sheep mandibular graft model where four animals received virtually optimized, experimental nickel–titanium (NiTi) fixation plates fabricated using laser beam powder bed fusion (LPBF) additive manufacturing (AM). The last animal, our control, received a standard-of-care, manually bent, Ti–6Al–4V (aka Ti64) fixation plate. A 17.5-mm mandibular graft healed completely in all four animals receiving the experimental device. Experimental NiTi-implanted sheep experienced mandibular bone healing and restoration. The Ti64 plate, in the control animal, fractured and dislocated shortly after being implanted.ConclusionThe use of stiffness-matched implants, by means of plate material (NiTi) and geometry (porosity) enhanced bone healing and promoted better load transfer to the healed bone when compared to the bulk Ti64 found in the fixation plate that the Control animal received. The design technique and screw orientation and depth planning improved throughout the study leading to more rapid healing. The large animal model reported here provides data useful for a follow-on clinical trial.Graphical

Distinct role of Klotho in long bone and craniofacial bone: skeletal development, repair and regeneration.

Bone defects are highly prevalent diseases caused by trauma, tumors, inflammation, congenital malformations and endocrine abnormalities. Ideally effective and side effect free approach to dealing with bone defects remains a clinical conundrum. Klotho is an important protein, which plays an essential role in regulating aging and mineral ion homeostasis. More recently, research revealed the function of Klotho in regulating skeleton development and regeneration. Klotho has been identified in mesenchymal stem cells, osteoblasts, osteocytes and osteoclasts in different skeleton regions. The specific function and regulatory mechanisms of Klotho in long bone and craniofacial bone vary due to their different embryonic development, ossification and cell types, which remain unclear and without conclusion. Moreover, studies have confirmed that Klotho is a multifunctional protein that can inhibit inflammation, resist cancer and regulate the endocrine system, which may further accentuate the potential of Klotho to be the ideal molecule in inducing bone restoration clinically. Besides, as an endogenous protein, Klotho has a promising potential for clinical therapy without side effects. In the current review, we summarized the specific function of Klotho in long bone and craniofacial skeleton from phenotype to cellular alternation and signaling pathway. Moreover, we illustrated the possible future clinical application for Klotho. Further research on Klotho might help to solve the existing clinical difficulties in bone healing and increase the life quality of patients with bone injury and the elderly.

Fumarate Restrains Alveolar Bone Restoration via Regulating H3K9 Methylation

Nonresolving inflammation causes irreversible damage to periodontal ligament stem cells (PDLSCs) and impedes alveolar bone restoration. The impaired tissue regeneration ability of stem cells is associated with abnormal mitochondrial metabolism. However, the impact of specific metabolic alterations on the differentiation process of PDLSCs remains to be understood. In this study, we found that inflammation altered the metabolic flux of the tricarboxylic acid cycle and induced the accumulation of fumarate through metabolic testing and metabolic flux analysis. Transcriptome sequencing revealed the potential of fumarate in modulating epigenetics. Specifically, histone methylation typically suppresses the expression of genes related to osteogenesis. Fumarate was found to impede the osteogenic differentiation of PDLSCs that exhibited high levels of H3K9me3. Various techniques, including assay for transposase-accessible chromatin with high-throughput sequencing, chromatin immunoprecipitation sequencing, and RNA sequencing, were used to identify the target genes regulated by H3K9me3. Mechanistically, accumulated fumarate inhibited lysine-specific demethylase 4B (KDM4B) activity and increased H3K9 methylation, thus silencing asporin gene transcription. Preventing fumarate from binding to the histone demethylase KDM4B with α-ketoglutarate effectively restored the impaired osteogenic capacity of PDLSCs and improved alveolar bone recovery. Collectively, our research has revealed the significant impact of accumulated fumarate on the regulation of osteogenesis in stem cells, suggesting that inhibiting fumarate production could be a viable therapeutic approach for treating periodontal diseases.

Osteochondral Repair with Autologous Cartilage Transplantation with or without Bone Grafting: A Short Pilot Study in Mini-Pigs

Category: Basic Sciences/Biologics; Other Introduction/Purpose: Treatment strategies for osteochondral defects, for which particulated autologous cartilage transplantation (PACT) is an emerging treatment strategy, aim to restore the structure and function of the hyaline cartilage. Herein, we compared the efficacy of PACT with control or human transforming growth factor-β (rhTGF-β), and clarified the necessity of bone graft (BG) with PACT to treat shallow osteochondral defects in a porcine model. Methods: Two skeletally mature male micropigs received 4 osteochondral defects in each knee. The 16 defects were randomized to (1) empty control, (2) PACT, (3) PACT with BG, or (4) rhTGF-β. Animals were euthanized after 2 months and histomorphometry, immunofluorescence analysis, semiquantitative evaluation (O’Driscoll score), and magnetic resonance observation of cartilage repair tissue (MOCART) score were performed. Results: Hyaline cartilages, glycosaminoglycan synthesis, and collagen type II staining were more abundant in the PACT than in the control and rhTGF-β groups. The O’Driscoll score was significantly different between groups (P &lt; 0.001), with both PACT groups showing superiority (P = 0.002). PACT had the highest score (P = 0.002), with improved restoration of subchondral bone compared with PACT with BG. The MOCART score showed significant differences between groups (P = 0.021); MOCART and O’Driscoll scores showed high correlation (r = 0.847, P &lt; 0.001). Conclusion: Treatment of osteochondral defects with PACT improved tissue quality compared with that with control or rhTGF-β in a porcine model. BG, in addition to PACT, may be unnecessary for shallow osteochondral defects. Clinical Relevance. BG may not be necessary while performing PACT.

Controlling the pore size of carbonate apatite honeycomb scaffolds enhances orientation and strength of regenerated bone

To restore functions of long bones and avoid reconstruction failure, segmental defects should be quickly repaired using abundant amounts of regenerated bone with high mechanical strength and orientation along the bone axis. Although both bone volume and bone matrix orientation are important for faster restoration of long bones with segmental defects, researchers have primarily focused on the former. Artificial bone scaffolds with uniaxial channels, (e.g., honeycomb (HC) scaffolds), are considered adequate for regenerating bone oriented along the bone axis. The channel size may affect the orientation, amount, and strength of the regenerated bone. In this study, we investigated the effects of channel size in carbonate apatite HC scaffolds on the orientation of bones regenerated in segmental bone defects and determined the adequate channel size. Carbonate apatite HC scaffolds, with different channel sizes (350, 550, 730, and 890 μm in length on the side of the square aperture), were fabricated by extrusion molding of a mixture of calcium carbonate and organic binder, debinding, and subsequent phosphatization to convert the composition from calcium carbonate to carbonate apatite. No significant difference in the amounts of regenerated bones was observed for different channel sizes. However, bone along the bone axis was formed in the channels ≤550 μm in size but not in channels ≥730 μm. The HC scaffolds with a channel size of 350 μm regenerated bone with higher bending strength than those with a channel size of 890 μm. However, bone regenerated with the HC scaffolds having channel sizes of 350, 550, and 730 μm showed equal bending strength. Thus, the adequate channel size for fast regeneration of high-strength bone, oriented to the bone axis, is ≤730 μm. To the best of our knowledge, this is the first study to report the effect of channel size on bone orientation and strength. The findings of this study are relevant to the fast repair of segmental bone defects.

Zinc, Magnesium and Tantalum for biomedical applications: A comprehensive review

The historical development and biomedical applications of magnesium, tantalum, and zinc are examined in this integrated study. It traces the development of magnesium from its use in military applications through its integration into many businesses, with an emphasis on its use in orthopaedic implants. Along with early attempts and failures in orthopaedic implantation, the mechanical properties of magnesium alloys suitable for biodegradable osteosynthetic materials are investigated. Clinical cases highlighting the successes and difficulties of magnesium implants in bone restoration are presented. Magnesium alloys have recently played important roles in biomedicine, particularly in stents and scaffolds. This analysis highlights their biocompatibility and corrosion behaviour. The numerous biomedical applications of tantalum and zinc, such as those in implants, surgical equipment, and drug delivery, are then discussed. Tantalum's porosity, biocompatibility, and biomechanical qualities make it the ideal material for implants, producing positive results in bone, tissue, and dental applications. Zinc's robust antibacterial characteristics and promise in targeted drug release are highlighted. Innovative manufacturing techniques, composite optimisation, surface alterations, and thorough clinical assessments are among the future directions. Key areas of interest include standardised testing, tissue interactions, and regulatory frameworks. This paper highlights the crucial contributions of tantalum, magnesium, and zinc to the development of biomedical engineering and provides insights for improved patient care, innovation, and therapeutic efficacy.