Promote Bone Growth Research Articles

A brief study of electrical and biological properties of BNT6BT/ZnO-HA Composite

The discovery of the piezoelectric properties of natural bone and their influence on bone growth within scaffolds has spurred researchers to investigate a range of bio-piezoelectric composite materials. By exploring these materials, researchers aim to better understand how piezoelectricity can be harnessed to promote bone growth and tissue regeneration, potentially leading to new breakthroughs in the field of regenerative medicine. In this study, the piezoelectric material, Bi0.5Na0.5TiO3-0.6BaTiO3/nano ZnO (BNT6BT/ZnO) and the biological hydroxyapatite (HA) were separately synthesized using the sol-gel method. The composite samples consisting of BNT6BT/ZnO and HA were fabricated using isostatic cold pressing. The composition and phase structure were studied using the X-ray diffraction (XRD) analysis, and the scanning electron microscopy (SEM) was used to study the microstructure and morphology. The presence of different phases and the distribution of elements were examined using EDAX elemental analysis and its corresponding maps. Among the composite samples the one containing 10 wt% HA (BNT6BT/ZnO-10HA) possessed the best dielectric properties. The Vickers hardness measurements showed that the addition of HA to the piezoelectric phase BNT6BT/ZnO results in higher hardness values, which expects to increase the fracture toughness of HA due to the higher elastic modulus to hardness ratio (E/H) of composite samples compared to pure HA. The in vitro bioactivity of the samples was tested in simulated body fluid (SBF) solution and the cell culture analysis was performed to examine the biocompatibility of the samples. Accordingly, apatite was deposited on the surface of the samples and all of the composite samples were bioactive. Furthermore, the BNT6BT/ZnO-10HA sample containing the largest amount of deposit showed the highest optical density (OD) in the MTT test.

FROM NOVEL COATING STRATEGY ON BIODEGRADABLE MG-BASED ORTHOPAEDIC IMPLANT MATERIAL TOWARDS CLINICAL TRIAL

Device-associated bacterial infections are a major and costly clinical challenge. This project aimed to develop a smart new biomaterial for implants that helps to protect against infection and inflammation, promote bone growth, and is biodegradable. Gallium (Ga) doped strontium-phosphate was coated on pure Magnesium (Mg) through a chemical conversion process. Mg was distributed in a graduated manner throughout the strontium-phosphate coating GaSrPO4, with a compact structure and a Ga-rich surface. We tested this sample for its biocompatibility, effects on bone remodeling and antibacterial activities including Staphylococcus aureus, S. epidermidis and E. coli - key strains causing infection and early failure of the surgical implantations in orthopaedics and trauma.Ga was distributed in a gradient way throughout the entire strontium-phosphate coating with a compact structure and a gallium-rich surface. The GaSrPO4 coating protected the underlying Mg from substantial degradation in minimal essential media at physiological conditions over 9 days. The liberated Ga ions from the coatings upon Mg specimens inhibited the growth of bacterial tested. The Ga dopants showed minimal interferences with the SrPO4 based coating, which boosted osteoblasts and undermined osteoclasts in in vitro co-cultures model.The results evidenced this new material may be further translated to preclinical trial in large animal model and towards clinical trial.Acknowledgements: Authors are grateful to the financial support from the Australian Research Council through the Linkage Scheme (ARC LP150100343). The authors acknowledge the facilities, and the scientific and technical assistance of the RMIT University and John Curtin School of Medical Research, Australian National University.

A zirconia/tantalum biocermet: in vitro and in vivo evaluation for biomedical implant applications.

A biocermet made of zirconia/20 vol% tantalum (3Y-TZP/Ta) is a new composite with exceptional capabilities due to a combination of properties that are rarely achieved in conventional materials (high strength and toughness, cyclic fatigue resistance and flaw tolerance, wear resistance, corrosion resistance, electrical conductivity, etc.). In this study, for the first time, the biomedical performance of a 3Y-TZP/Ta biocermet was evaluated in detail. Its in vitro biocompatibility was assessed using mesenchymal stem cell culture. The effectiveness of in vivo osteointegration of the biocermet was confirmed 6 months after implantation into the proximal tibiae of New Zealand white rabbits. In addition, the possibility of using magnetic resonance imaging (MRI) for medical analysis of the considered biocermet material was studied. The 3Y-TZP/Ta composite showed no injurious effect on cell morphology, extracellular matrix production or cell proliferation. Moreover, the implanted biocermet appeared to be capable of promoting bone growth without adverse reactions. On the other hand, this biocermet demonstrates artefact-free performance in MRI biomedical image analysis studies, making it more suitable for implant applications. These findings open up possibilities for a wide range of applications of these materials in orthopedics, dentistry and other areas such as replacement of hard tissues.

Europium-tannic acid nanocomplexes devised for bone regeneration under oxidative or inflammatory environments.

Europium ions (Eu3+) are gaining attention in the field of regenerative medicine due to increasing evidence of their osteogenic properties. However, inflammatory and oxidative environments present in many bone diseases, such as osteoporosis or rheumatoid arthritis, are known to hinder this regenerative process. Herein, we describe a straightforward synthetic procedure to prepare Eu3+-tannic acid nanocomplexes (EuTA NCs) with modulable physicochemical characteristics, as well as antioxidant, anti-inflammatory, and osteogenic properties. EuTA NCs were rationally synthesized to present different contents of Eu3+ on their structure to evaluate the effect of the cation on the biological properties of the formulations. In all the cases, EuTA NCs were stable in distilled water at physiological pH, had a highly negative surface charge (ζ ≈ -25.4 mV), and controllable size (80 < Dh < 160 nm). In vitro antioxidant tests revealed that Eu3+ complexation did not significantly alter the total radical scavenging activity (RSA) of TA but enhanced its ability to scavenge H2O2 and ferrous ions, thus improving its overall antioxidant potential. At the cellular level, EuTA NCs reduced the instantaneous toxicity of high concentrations of free TA, resulting in better antioxidant (13.3% increase of RSA vs. TA) and anti-inflammatory responses (17.6% reduction of nitric oxide production vs. TA) on cultures of H2O2- and LPS-stimulated macrophages, respectively. Furthermore, the short-term treatment of osteoblasts with EuTA NCs was found to increase their alkaline phosphatase activity and their matrix mineralization capacity. Overall, this simple and tunable platform is a potential candidate to promote bone growth in complex environments by simultaneously targeting multiple pathophysiological mechanisms of disease.

Collagen membrane functionalized with magnesium oxide via room-temperature atomic layer deposition promotes osteopromotive and antimicrobial properties.

Artificial bone grafting materials such as collagen are gaining interest due to the ease of production and implantation. However, collagen must be supplemented with additional coating materials for improved osteointegration. Here, we report room-temperature atomic layer deposition (ALD) of MgO, a novel method to coat collagen membranes with MgO. Characterization techniques such as X-ray photoelectron spectroscopy, Raman spectroscopy, and electron beam dispersion mapping confirm the chemical nature of the film. Scanning electron and atomic force microscopies show the surface topography and morphology of the collagen fibers were not altered during the ALD of MgO. Slow release of magnesium ions promotes bone growth, and we show the deposited MgO film leaches trace amounts of Mg when incubated in phosphate-buffered saline at 37°C. The coated collagen membrane had a superhydrophilic surface immediately after the deposition of MgO. The film was not toxic to human cells and demonstrated antibacterial properties against bacterial biofilms. Furthermore, in vivo studies performed on calvaria rats showed MgO-coated membranes (200 and 500 ALD) elicit a higher inflammatory response, leading to an increase in angiogenesis and a greater bone formation, mainly for Col-MgO500, compared to uncoated collagen. Based on the characterization of the MgO film and in vitro and in vivo data, the MgO-coated collagen membranes are excellent candidates for guided bone regeneration.

A study of titanium porous intervertebral body fusion cage for adjusting mechanical properties of porous structure and promoting bone growth

A study of titanium porous intervertebral body fusion cage for adjusting mechanical properties of porous structure and promoting bone growth

BONE REMODELLING PREDICTION FOR IMPROVED POROUS IMPLANT DESIGN

AbstractObjectivesYoung patients receiving metallic bone implants after surgical resection of bone cancer require implants that last into adulthood, and ideally life-long. Porous implants with similar stiffness to bone can promote bone ingrowth and thus beneficial clinical outcomes. A mechanical remodelling stimulus, strain energy density (SED), is thought to be the primary control variable of the process of bone growth into porous implants. The sequential process of bone growth needs to be taken into account to develop an accurate and validated bone remodelling algorithm, which can be employed to improve porous implant design and achieve better clinical outcomes.MethodsA bone remodelling algorithm was developed, incorporating the concept of bone connectivity (sequential growth of bone from existing bone) to make the algorithm more physiologically relevant. The algorithm includes adaptive elastic modulus based on apparent bone density, using a node-based model to simulate local remodelling variations while alleviating numerical checkerboard problems. Strain energy density (SED) incorporating stress and strain effects in all directions was used as the primary stimulus for bone remodelling. The simulations were developed to run in MATLAB interfacing with the commercial FEA software ABAQUS and Python. The algorithm was applied to predict bone ingrowth into a porous implant for comparison against data from a sheep model.ResultsThe accuracy of the predicted bone remodelling was verified for standard loading cases (bending, torsion) against analytical calculations. Good convergence was achieved. The algorithm predicted good bone remodelling and growth into the investigated porous implant. Using the standard algorithm without connectivity, bone started to remodel at locations unconnected to any bone, which is physiologically implausible. The implementation of bone connectivity ensures the gradual process of bone growth into the implant pores from the sides. The bone connectivity algorithm predicted that the full remodelling required more time (approximately 50% longer), which should be considered when developing post-surgical rehabilitation strategies for patients. Both algorithms with and without bone connectivity implementation converged to same final stiffness (less than 0.01% difference). Almost all nodes reached the same density value, with only a limited number of nodes (less than 1%) in transition areas with a strong density gradient having noticeable differences.ConclusionsAn improved bone remodelling algorithm based on strain energy density that modelled the sequential process of bone growth has been developed and tested. For a porous metallic bone implant the same final bone density distribution as for the original adaptive elasticity theory was predicted, with a slower and more fidelic process of growth from existing surrounding bone into the porous implant.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Structural and biological analysis of Zn–Cu based biodegradable alloys for orthopedic application

This study focuses on the structural and biological analysis of Zn–Cu based biodegradable alloys for orthopedic applications. Five samples of Zn–Cu based alloys were prepared using a solid-state method at a temperature of 750 °C. X-ray diffraction (XRD) analysis revealed that all samples predominantly exhibited the single phase of Cu5Zn8 with minor peaks of Zn,Fe and Mg.SEM/EDX results shows the coral-like structure with grain size of 160 nm in all samples. The electrical conductivity of the alloys was evaluated through a four-probe analysis, and ZnCu0.5Fe0.4 exhibited the highest electric stimulation (1.5 × 108 S/m) can promote bone growth and aid in the healing process. Optical studies of the Zn–Cu based alloys showed absorption peaks in the range of (335–525) nm, with ZnCu0.5Fe0.4 exhibiting the lowest band gap energy (5.25 eV). The biocompatibility of the alloys was assessed through a simulated body fluid (SBF) immersion test, which indicated that all samples demonstrated biocompatible behavior. ZnCu0.5Mg0.4 exhibited the lowest corrosion rate (0.09 mm/year). Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of the Cu5Zn8 phase and the formation of hydroxyapatite after in vivo testing in all samples. The electrochemical analysis demonstrated the degradation behavior of all samples, with ZnCu0.5Mg0.4 exhibiting the highest corrosion potential (−0.28 V) and improved corrosion resistance compared to the other alloys.

Anti-resorption role of low-intensity pulsed ultrasound (LIPUS) during large-scale bone reconstruction using porous titanium alloy scaffolds through inhibiting osteoclast differentiation

BackgroundTi6Al4V biomaterials combine with low-intensity pulsed ultrasound (LIPUS) has been reported with great bone regeneration capacity. It is important to better understand how LIPUS benefits bone microenvironment to seek for target of therapeutic medicine. Osteoclast differentiation plays a crucial role in bone resorption. Recent advances in molecular biology have revealed that N6-methyladenosine (m6A) RNA modifications can modulate biological processes, but their role in bone biology, particularly in osteoclast differentiation, remains unclear. We aim to understand how LIPUS regulates bone microenvironment especially osteoclast formation during bone regeneration to provide new therapeutic options for preventing and delaying bone resorption, thus with better bone regeneration efficiency. Results1. LIPUS promoted bone ingrowth and bone maturity while inhibiting osteoclast formation within Ti6Al4V scaffolds in large-scale bone defect model. 2. LIPUS was found to inhibit osteoclast differentiation by decreasing the overall expression of osteoclast markers in vitro. 3. LIPUS decreases RNA m6A-modification level through upregulating FTO expression during osteoclast differentiation during. 4. Inhibiting FTO expression and function leads to less inhibition during osteoclast differentiation. ConclusionLIPUS suppresses osteoclast differentiation during bone regeneration through reducing m6A modification of osteoclastic RNAs by up regulating FTO expression.

Electrospun sandwich mesh structures loaded with naringenin and vitamin K2 polycaprolactone/gelatin nanofibers synergistically promote bone regeneration

Osteoblasts and osteoclasts play a crucial role in the dynamically coupled balance during bone regeneration and remodeling. They complement and restrict each other in the human body. Decreased osteoblasts lead to insufficient bone formation or excessive formation of osteoclasts, leading to increased bone resorption, which will destroy the structure of the bone tissue. This will greatly increase the risk of diseases such as osteoporosis and nonunions caused by bone defects.Herein, gelatin and polycaprolactone were used as substrates, and biomaterial membranes with mesh and sandwich structures were constructed using the electrospinning technology. Naringenin was loaded into the shell, and vitamin K2 was loaded into the core layer of the nanofibrous membrane. The biocompatibility and osteogenic capacity of the membranes were assessed in vitro using mouse bone marrow mesenchymal stem cells (BMSCs). During osteoclast induction, the receptor activator of nuclear factor kappa-Β ligand (RANKL) was used to coculture RAW264.7 cells with various materials. The regulatory effect of various membranes on osteoclast growth was evaluated by detecting the expression levels of osteoclast-related genes and proteins in the cells.Subsequently, we constructed a model of a rat skull defect and implanted different membranes into the defect. Then, we evaluated the new bone formation in the defect using histological staining and micro-computed tomography after 4 and 8 weeks. The results of in vitro experiments confirmed that the incorporation of naringenin and vitamin K2 stimulated the expression of osteogenesis-related genes and the secretion of osteogenesis-related proteins. Simultaneously, the results showed that naringenin and vitamin K2 inhibited the formation and growth of osteoclasts. Therefore, naringenin and vitamin K2 have a synergistic effect in promoting bone growth and regulating osteoclast growth.

Atomically Resolved Interfacial Analysis of Bone‐Like Hydroxyapatite Nanoparticles on Titanium

Titanium is commonly used for medical devices, including osseointegrating implants, owing to its biocompatibility and mechanical properties. Nanostructuring titanium implants is known to enhance the healing process by promoting bone growth on the implant surface. Hydroxyapatite nanoparticles, resembling natural bone mineral, have been used to further improve osseointegration. While previous studies have investigated the osseointegration of titanium implants using atom probe tomography, limited research has focused on the attachment of synthetic hydroxyapatite to titanium. Herein, electron microscopy and atom probe tomography are used to reveal the assembly of synthetic hydroxyapatite nanoparticles in the titanium oxide surface. By sputter coating with chromium, a suitable matrix is formed for detailed interfacial analysis. The results demonstrate the diffusion of calcium, phosphorus, and carbon from hydroxyapatite nanoparticles into the titanium oxide surface.

Role and molecular mechanism of ghrelin in degenerative musculoskeletal disorders.

Ghrelin is a brain-gut peptide, and the first 28-peptide that was found in the gastric mucosa. It has a growth hormone (GH)-releasing hormone-like effect and can potently promote the release of GH from pituitary GH cells; however, it is unable to stimulate GH synthesis. Therefore, ghrelin is believed to play a role in promoting bone growth and development. The correlation between ghrelin and some degenerative diseases of the musculoskeletal system has been reported recently, and ghrelin may be one of the factors influencing degenerative pathologies, such as osteoporosis, osteoarthritis, sarcopenia and intervertebral disc degeneration. With population ageing, the risk of health problems caused by degenerative diseases of the musculoskeletal system gradually increases. In this article, the roles of ghrelin in musculoskeletal disorders are summarized to reveal the potential effects of ghrelin as a key target in the treatment of related bone and muscle diseases and the need for further research.

The application of 3D-printed auto-stable artificial vertebral body in en bloc resection and reconstruction of thoracolumbar metastases

BackgroundNerve compression symptoms and spinal instability, resulting from spinal metastases, significantly impact the quality of life for patients. A 3D-printed vertebral body is considered an effective approach to reconstruct bone defects following en bloc resection of spinal tumors. The advantage of this method lies in its customized shape and innermost porous structure, which promotes bone ingrowth and leads to reduced postoperative complications.ObjectiveThe purpose of this study is to assess the effectiveness of 3D-printed auto-stable artificial vertebrae in the en bloc resection and reconstruction of thoracolumbar metastases.MethodsThis study included patients who underwent en bloc resection of thoracolumbar metastases based on the Weinstein-Boriani-Biagini surgical staging system, between January 2019 and April 2021. The patients were divided into two groups: the observation group, which was reconstructed using 3D-printed auto-stable vertebral bodies, and the control group, treated with titanium cages and allograft bone. Evaluation criteria for the patients included assessment of implant subsidence, instrumentation-related complications, VAS score, and Frankel grading of spinal cord injury.ResultsThe median follow-up period was 21.8 months (range 12–38 months). Among the patients, 10 received a customized 3D-printed artificial vertebral body, while the remaining 10 received a titanium cage. The observation group showed significantly lower operation time, intraoperative blood loss, and postoperative drainage compared to the control group (P < 0.05). At the final follow-up, the average implant subsidence was 1.8 ± 2.1 mm for the observation group and 5.2 ± 5.1 mm for the control group (P < 0.05). The visual analog scale (VAS) scores were not statistically different between the two groups at preoperative, 24 h, 3 months, and 1 year after the operation (P < 0.05). There were no statistically significant differences in the improvements of spinal cord functions between the two groups.ConclusionThe utilization of a 3D-printed auto-stable artificial vertebra for reconstruction following en bloc resection of thoracolumbar metastases appears to be a viable and dependable choice. The low occurrence of prosthesis subsidence with 3D-printed prostheses can offer immediate and robust stability.

Novel Electroactive Mineralized Polyacrylonitrile/PEDOT:PSS Electrospun Nanofibers for Bone Repair Applications.

Bone defect repair remains a critical challenge in current orthopedic clinical practice, as the available therapeutic strategies only offer suboptimal outcomes. Therefore, bone tissue engineering (BTE) approaches, involving the development of biomimetic implantable scaffolds combined with osteoprogenitor cells and native-like physical stimuli, are gaining widespread interest. Electrical stimulation (ES)-based therapies have been found to actively promote bone growth and osteogenesis in both in vivo and in vitro settings. Thus, the combination of electroactive scaffolds comprising conductive biomaterials and ES holds significant promise in improving the effectiveness of BTE for clinical applications. The aim of this study was to develop electroconductive polyacrylonitrile/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PAN/PEDOT:PSS) nanofibers via electrospinning, which are capable of emulating the native tissue's fibrous extracellular matrix (ECM) and providing a platform for the delivery of exogenous ES. The resulting nanofibers were successfully functionalized with apatite-like structures to mimic the inorganic phase of the bone ECM. The conductive electrospun scaffolds presented nanoscale fiber diameters akin to those of collagen fibrils and displayed bone-like conductivity. PEDOT:PSS incorporation was shown to significantly promote scaffold mineralization in vitro. The mineralized electroconductive nanofibers demonstrated improved biological performance as observed by the significantly enhanced proliferation of both human osteoblast-like MG-63 cells and human bone marrow-derived mesenchymal stem/stromal cells (hBM-MSCs). Moreover, mineralized PAN/PEDOT:PSS nanofibers up-regulated bone marker genes expression levels of hBM-MSCs undergoing osteogenic differentiation, highlighting their potential as electroactive biomimetic BTE scaffolds for innovative bone defect repair strategies.

Therapeutic effect of recombinant human growth hormone on children with growth hormone deficiency and different pituitary developmental conditions: a prospective study

To investigate the therapeutic effect of recombinant human growth hormone (rhGH) on children with growth hormone deficiency (GHD) and different pituitary developmental conditions. A prospective study was performed on 90 children with GHD who were admitted to Xuchang Maternity and Child Health Hospital from June 2020 to December 2021. According to pituitary height on the median sagittal plane, they were divided into three groups: pituitary dysplasia group (n=45), normal pituitary group (n=31), and enlarged pituitary growth group (n=14). The changes in body height, growth velocity, height standard deviation score and serum levels of insulin-like growth factor binding protein-3 (IGFBP-3) and insulin-like growth factor-1 (IGF-1) were examined after treatment in the above three groups, and the differences of the above indices before and after treatment were compared among the three groups. After treatment, all three groups had significant increases in body height, growth velocity, height standard deviation score, and the serum levels of IGFBP-3 and IGF-1 (P<0.05). Compared with the normal pituitary group, the pituitary dysplasia group and the enlarged pituitary growth group had significantly higher values in terms of the differences in body height, growth velocity, height standard deviation score, IGF-1, and IGFBP-3 before and after treatment (P<0.05). There was no significant difference in the incidence rate of adverse reactions among the three groups (P>0.05). In GHD children with different pituitary developmental conditions, rhGH can promote bone growth and increase body height, especially in children with pituitary dysplasia and pituitary hyperplasia, with good safety.

Design of customized implants and 3D printing of symmetric and asymmetric cranial cavities

A methodology has been developed in this work to design customized cranial implants from computed tomography (CT) scan images for symmetric as well as asymmetric defects. The two-dimensional CT scan images were converted into three-dimensional geometric models using software packages. Two cases of cranial cavities at different locations were considered for implant design using two different approaches. Case 1 is having a symmetric cranial cavity while Case 2 has an asymmetric frontal cranial cavity. The craniums with defects were 3D reconstructed. Customized cranial implants were made for the two cases. In Case 1, symmetry was used to design the cranial implant. Symmetry cannot be used in Case 2. In Case 2, the implant was designed by blending from the surface available adjacent to the missing portion of the cranium. 3D reconstructed bone models and customized implants were 3D printed in poly-lactic acid (PLA) using a fused deposition modeling process for form and fit evaluation. Finite element analysis was performed to compare the mechanical behavior of bone, and the two biomaterials – polyether ether ketone (PEEK), and Ti6Al4V. Static structural finite element analysis was performed to simulate the impact of falling off a bicycle with an impact on the cranial implants in the two cases. The load was modeled as a normal force acting on the surface of the implant. It was found that the stresses in the titanium alloy are comparable to those of PEEK for both the cases. However, the strains and deformation were found to be much smaller compared to those in PEEK. Therefore, the titanium alloy is the material of choice for both the cases among the materials under consideration. The designed implants are solid hence may face the challenge in bone ingrowth. In future studies, the implant can be made porous by incorporating a lattice structure to enhance osseointegration and promote bone ingrowth. Implants for both symmetric and asymmetric defect cases in cranium were successfully designed.

Fabrication of Ti-6Al-4v cellular lattice structure using selective laser melting for orthopedic use: A review

Additive Manufacturing (AM) plays a vital role in the field of biomedical applications, particularly in the production of implants for bone repair. These implants possess an internal cellular structure that promotes bone ingrowth and is crucial for their successful integration in the human body. To meet the requirements of biomedical implants, the material used should be biodegradable, non-toxic, possess similar biomechanical properties to natural bone, and exhibit porosity. consequently, the precise design and production of implants hold great significance.This review focuses on the fabrication of Ti-6Al-4 V cellular lattice structures using selective laser melting (SLM) for orthopedic applications. It discusses the structure of bone, its characteristics, and the mechanism of bone healing, emphasizing the importance of understanding bone biology for effective implant design. The suitability of the bio-compatible Ti-6Al-4 V alloy for orthopedic use is explored, highlighting its biocompatibility, mechanical properties, and corrosion resistance and also delves into the design considerations for cellular lattice structures, including pore size, shape, and interconnectivity. These design features aim to promote bone ingrowth, enhance mechanical properties, and facilitate tissue regeneration.The review emphasizes the significance of these structures in orthopedic applications, with their combination of biocompatibility, mechanical strength, and tailored design features for bone repair and tissue engineering. It also anticipates further advancements in SLM technology and material research to enhance clinical outcomes of orthopedic implants.

Mechanotransduction and Biomechanical Properties of Bone Tissue as a Basis for the Use of Intraosseous Osteopathic Techniques

The development and maintenance of bone mass is critical to movement, health, and quality of life. Bone mass is regulated by various factors, activation of biologically active substances, enzymes, including changes in mechanical load. The osteocyte network provides a wide-ranging load monitoring "network" that penetrates every cubic millimeter of bone tissue. Deformities or trauma create a limitation that can cause asymmetric bone growth, such as plagiocephaly. A deep understanding of the cellular mechanisms responsible for bone remodeling as well as bone mechanotransduction is essential for the development of effective exercise, osteopathic techniques, and pharmaceutical strategies to increase and/or prevent bone loss. This review summarizes current data on the main molecular mechanisms involved in bone mechanotransduction, which provides insight into bone tissue, methods of working with it, and points of application for correcting various dysfunctions to promote bone growth in length. This process is carried out by increasing the proliferation of chondrocytes and the activity of growth plates. This contributes to the correction of such consequences of intraosseous dysfunctions as the development of anatomical differences in the size of the lower extremities in children.

Computational Fluid Dynamic Analysis of customised 3D-printed bone scaffolds with different architectures.

Through the recent years, tissue engineering has been proven as a solid substitute of autografts in the stimulation of bone tissue regeneration, through the development of three dimensional (3D) porous matrices, commonly known as scaffolds. In this work, we analysed two scaffold structures with 500μm pore size, by performing computational fluid dynamics simulations, to compare permeability, Wall Shear Stress (WSS), velocity and pressure distributions. Taking into account those parameters the geometry named as "PCL-50" was the best to anticipate showing a superior performance in supporting cell growth due to the improved flow characteristics in the scaffold.Clinical Relevance- Bone defects that require invasive surgical treatment with high risks in terms of success and effectiveness. Bone tissue engineering (BTE) in combination with the use of computational fluid dynamics (CFD) analysis tools aim to assist in designing optimal scaffolds that better promote bone growth and repair. The fluid dynamic characteristics of a porous scaffold plays a vital role in cell viability and cell growth, affecting the osteogenic performance of the scaffold.

Agglomeration effect on biomechanical performance of CNT-reinforced dental implant using micromechanics-based approach

Dental implants have long played an important role in restoring lost teeth, but there are still concerns about their durability and long-term success. Commercial dental implants have traditionally been made of metallic and ceramic materials like titanium and zirconia; however, each kind of material has restrictions regarding osseointegration and mechanical characteristics that differ between native bone and the implant material, limiting the implant's longevity and reliability. To address these concerns, this research explores the use of carbon nanotubes (CNTs) in restorative dentistry, their excellent properties make them an ideal candidate for promoting bone growth around implanted device and ensuring long-lasting success. The objective of this study was to understand how CNT properties when incorporated into the titanium matrix may be able to better adapt to the oral environment taking into consideration the CNT agglomeration effects when designing reinforced nanocomposite materials for dental implant. A mathematical formulation of the micromechanics model was developed and improved to extend its application for the case of CNT-based composite materials for dental implants. A three dimensional (3D) model of bone structure around the osseointegrated dental implant was established considering different compositions of implant material. Finite Element Analysis (FEA) were conducted to assess the aggregation effect of implant incorporating CNTs into the titanium matrix, considering CNTs with both spherical inclusions (CNT clusters), and randomly dispersive ones (CNTs) in the titanium matrix, on osseointegration and bone remodeling around the dental implant and supporting bone system over a period of 48 months. Firstly, the effects of CNT-Ti implantation on time-dependent performance are evaluated in a computational remodeling framework. Then, Von Mises equivalent stresses are investigated to evaluate the stress distributions and micromotions in jaw bones of loaded implant with different composition of prosthetic material. Three agglomeration patterns are considered, particularly without agglomeration (ζ = ξ), partial and complete agglomeration (ζ < ξ, ξ = 1). Further, the influence of CNTs volume fraction variation is taken into account to predict the mechanical response of the bony system after CNT-reinforced dental implantation. It can be inferred that the agglomeration of CNTs reduces the elastic stiffness of the matrix. This is due to the fact that when CNTs are agglomerated, the inter-tube contacts are reduced and the effective stiffness of the matrix is decreased.