Artificial Bone Research Articles

Prediction of bone formation rate of bioceramics using machine learning and image analysis

To practically utilize artificial bones, scanning electron microscope (SEM) images of artificial bones are used to analyze their properties and extract important features for predicting bone formation rate, including grain size and contour.

Developments in Biomedical Materials: From Conventional Implantation to State-of-the-Art Pharmaceutical Uses

In order to improve and restore the functions of biological tissues and organs as well as for the identification and treatment of diseases, biomedical materials a developing subject of materials science are indispensable. Materials like these are frequently employed in many different medical equipment employed in clinical settings, such as scaffolding, sutures, substitute teeth, artificial bones, and even heart replacements. Innovative methods for identifying, treating, and regaining physiological functions have been made possible by biomedical materials, which have completely changed the healthcare industry. The development, categorization, and therapeutic uses of biomedical materials are examined in this study, with a focus on metallic biomaterials, synthetic polymers, and bio ceramics in addition to their biologically derived counterparts, such as collagen, silk, chitosan, and alginate. The functionality of medical devices has been significantly advanced by bioengineering improvements, that have produced healing implants and progressive diagnostic imaging that improve patient effects. This evaluation explores the capacity of nanomaterials in biomedicine, current wound dressings, and antimicrobial methods, highlighting the limitations and destiny opportunities inside the creation of extra powerful therapy and minimally harmful diagnostic tools.

Validation of an established TW3 artificial intelligence bone age assessment system: a prospective, multicenter, confirmatory study.

In 2020, our center established a Tanner-Whitehouse 3 (TW3) artificial intelligence (AI) system using a convolutional neural network (CNN), which was built upon 9059 radiographs. However, the system, upon which our study is based, lacked a gold standard for comparison and had not undergone thorough evaluation in different working environments. To further verify the applicability of the AI system in clinical bone age assessment (BAA) and to enhance the accuracy and homogeneity of BAA, a prospective multi-center validation was conducted. This study utilized 744 left-hand radiographs of patients, ranging from 1 to 20 years of age, with 378 boys and 366 girls. These radiographs were obtained from nine different children's hospitals between August and December 2020. The BAAs were performed using the TW3 AI system and were also reviewed by experienced reviewers. Bone age accuracy within 1 year, root mean square error (RMSE), and mean absolute error (MAE) were statistically calculated to evaluate the accuracy. Kappa test and Bland-Altman (B-A) plot were conducted to measure the diagnostic consistency. The system exhibited a high level of performance, producing results that closely aligned with those of the reviewers. It achieved a RMSE of 0.52 years and an accuracy of 94.55% for the radius, ulna, and short bones series. When assessing the carpal series of bones, the system achieved a RMSE of 0.85 years and an accuracy of 80.38%. Overall, the system displayed satisfactory accuracy and RMSE, particularly in patients over 7 years old. The system excelled in evaluating the carpal bone age of patients aged 1-6. Both the Kappa test and B-A plot demonstrated substantial consistency between the system and the reviewers, although the model encountered challenges in consistently distinguishing specific bones, such as the capitate. Furthermore, the system's performance proved acceptable across different genders and age groups, as well as radiography instruments. In this multi-center validation, the system showcased its potential to enhance the efficiency and consistency of healthy delivery, ultimately resulting in improved patient outcomes and reduced healthcare costs.

A coaxial electrospun mat coupled with piezoelectric stimulation and atorvastatin for rapid vascularized bone regeneration.

The repair of critical bone defects caused by various clinical conditions needs to be addressed urgently, and the regeneration of large bone defects depends on early vascularization. Therefore, enhanced vascularization of artificial bone grafts may be a promising strategy for the regeneration of critical-sized bone defects. Taking into account the importance of rapid angiogenesis during bone repair and the potential of piezoelectric stimulation in promoting bone regeneration, novel coaxial electrospun mats coupled with piezoelectric materials and angiogenic drugs were fabricated in this study using coaxial electrospinning technology, with a shell layer loaded with atorvastatin (AVT) and a core layer loaded with zinc oxide (ZnO). AVT was used as an angiogenesis inducer, and piezoelectric stimulation generated by the zinc oxide was used as an osteogenesis enhancer. The multifunctional mats were characterized in terms of morphology, core-shell structure, piezoelectric properties, drug release, and mechanical properties, and their osteogenic and angiogenic capabilities were validated in vivo and ex vivo. The results revealed that the coaxial electrospun mats exhibit a porous surface morphology and nanofibers with a core-shell structure, and the piezoelectricity of the mats improved with increasing ZnO content. Excellent biocompatibility, hydrophilicity and cell adhesion were observed in the multifunctional mats. Early and rapid release of AVT in the fibrous shell layer of the mat promoted angiogenesis in human umbilical vascular endothelial cells (HUVECs), whereas ZnO in the fibrous core layer harvested bioenergy and converted it into electrical energy to enhance osteogenic differentiation of rat bone mesenchymal stem cells (BMSCs), and both modalities synergistically promoted osteogenesis and angiogenesis. Furthermore, optimal bone regeneration was achieved in a model of critical bone defects in the rat mandible. This osteogenesis-promoting effect was induced by electrical stimulation via activation of the calcium signaling pathway. This multifunctional mat coupling piezoelectric stimulation and atorvastatin promotes angiogenesis and bone regeneration, and shows great potential in the treatment of large bone defects.

Tactile Perception-Based Depth and Angle Control During Robot-Assisted Bent Bone Grinding

During bent bone grinding, the robot often needs to adjust its grinding depth and angle in real-time to ensure surgical quality. Optical- or vision-based navigation methods are no longer applicable due to the interference caused by splashing cooling water in the operating field. Inspired by orthopedic surgeons, this manuscript presents a tactile perception-based method to solve this problem. The effect of grinding parameters on the cutter's current and vibration is analyzed, and current and vibration signals are further processed to predict depth and angle. Depth and angle estimation models were calibrated on homogeneous artificial bone. Grinding control experiments were carried out on femur models, and the statistical mean and standard deviation results of the measured depth show that the accuracy of depth control can be further improved by adding angle estimation and proper adjustment when depth is indirectly estimated based on sensing signals. The proposed approach relies solely on the estimation of the relative position and posture between the tool and the bone surface and is expected to improve the safety of automatic grinding with orthopedic robots.

Insertion torque, flexural strength and surface alterations of stainless steel and titanium alloy orthodontic mini-implants: an in vitro study.

This study aimed to compare the insertion torque (IT), flexural strength (FS) and surface alterations between stainless steel (SS-MIs) and titanium alloy (Ti-MIs) orthodontic mini-implants. Twenty-four MIs (2 x 10 mm; SS-MIs, n = 12; Ti-MIs, n = 12) were inserted on artificial bone blocks of 20 lb/ft3 (20 PCF) and 40 lb/ft3 (40 PCF) density. The maximum IT was recorded using a digital torque meter. FS was evaluated at 2, 3 and 4 mm-deflection. Surface topography and chemical composition of MIs were assessed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). General linear and mixed models were used to assess the effect of the MI type, bone density and deflection on the evaluated outcomes. The IT of Ti-MIs was 1.1 Ncm greater than that obtained for the SS-MIs (p= 0.018). The IT for MIs inserted in 40 PCF test blocks was 5.4 Ncm greater than that for those inserted in 20 PCF test blocks (p < 0.001). SS-MIs inserted in higher density bone (40 PCF) had significantly higher flexural strength than the other groups, at 2 mm (98.7 ± 5.1 Ncm), 3 mm (112.0 ± 3.9 Ncm) and 4 mm (120.0 ± 3.4 Ncm) of deflection (p< 0.001). SEM evidenced fractures in the Ti-MIs. EDS revealed incorporation of 18% of C and 2.06% of O in the loaded SS-MIs, and 3.91% of C in the loaded Ti-MIs. Based on the findings of this in vitro study, it seems that SS-MIs offer sufficient stability and exhibit greater mechanical strength, compared to Ti-MIs when inserted into higher density bone.

Development of paste-like organic/inorganic artificial bones compatible with bone remodeling cycles, consisting of β-tricalcium phosphate, calcium sulfate hemihydrate, and poly(lactic-co-glycolic acid) particles

Schematic illustration of organic/inorganic hybrid cement with the simultaneous addition of CSH and PLGA particles.

Anti-inflammatory loading of cinnamaldehyde on artificial bone scaffolds against the process of bone regeneration

Anti-inflammatory loading of cinnamaldehyde on artificial bone scaffolds against the process of bone regeneration

Stabilization of Traumatic Iliosacral Instability Using Innovative Implants: A Biomechanical Comparison.

(1) Background: Demographic changes over the past decade have had a significant impact on pelvic ring fractures. They have increased dramatically in the orthogeriatric population. Surgeons are faced with implant fixation issues in the treatment of these fragility fractures. This study compares two innovative implants for stabilizing the iliosacral joint in a biomechanical setting. (2) Methods: An iliosacral screw with a preassembled plate allowing the placement of an additional short, angular stable screw in the ilium and a triangular fixation system consisting of a fenestrated ilium screw and an iliosacral screw quasi-statically inserted through the "fenestra" were instrumented in osteoporotic artificial bone models with a simulated Denis zone 1 fracture. Biomechanical testing was performed on a servo-hydraulic testing machine using increasing, synchronous axial and torsional sinusoidal cyclic loading to failure. (3) Results: The SI-Plate and TriFix showed comparable stiffness values. The values for fracture gap angle and screw tip cutout were significantly lower for the TriFix compared to the SI-Plate. In addition, the number of cycles to failure was significantly higher for the TriFix. (4) Conclusions: Implant anchorage and primary stability can be improved in iliosacral instability using the triangular stabilization system.

Fixation strength of swelling copolymeric anchors in artificial bone.

Fixation with suture anchors and metallic hardware for osteosynthesis is common in orthopedic surgeries. Most metallic commercial bone anchors achieve their fixation to bone through shear of the bone located between the threads. They have several deficiencies, including stress-shielding due to mechanical properties mismatch, generation of acidic by-products, poor osteointegration, low mechanical strength and catastrophic failure often associated with large bone defects that may be difficult to repair. To overcome these deficiencies, a swelling porous copolymeric material, to be used as bone anchors with osteointegration potential, was introduced. The purpose of this study was to investigate the fixation strength of these porous, swelling copolymeric bone anchors in artificial bone of various densities. The pull-out and subsidence studies indicate an effective fixation mechanism based on friction including re-fixation capabilities, and minimization of damage following complete failure. The study suggests that this swelling porous structure may provide an effective alternative to conventional bone anchors, particularly in low-density bone.

The influence of truncated-conical implant length on primary stability in maxillary and mandibular regions: an in vitro study using polyurethane blocks.

This in vitro study is aimed at assessing whether implant primary stability is influenced by implant length in artificial bone with varying densities. A total of 120 truncated-conical implants (60 long-length: 3p L, 3.8 × 14 mm; 60 short-length: 3p S, 3.8 × 8 mm) were inserted into 20, 30, and 40 pounds per cubic foot (PCF) density polyurethane blocks. The insertion torque (IT), removal torque (RT), and resonance frequency analysis (RFA) values were recorded for each experimental condition. In 30 and 40 PCF blocks, 3p S implants exhibited significantly higher IT values (90 and 80 Ncm, respectively) than 3p L (85 and 50 Ncm, respectively). Similarly, RT was significantly higher for 3p S implants in 30 and 40 PCF blocks (57 and 90 Ncm, respectively). However, there were no significant differences in RFA values, except for the 20 PCF block, where 3pS implants showed significantly lower values (63 ISQ) than 3p L implants (67 ISQ) in both the distal and mesial directions. These results demonstrated that the implant's length mainly influences the IT and RT values in the polyurethane blocks that mimic the mandibular region of the bone, resulting in higher values for the 3p S implants, while the RFA values remained unaffected. However, in the lowest density block simulating the maxillary bone, 3p L implants exhibited significantly higher ISQ values. Therefore, our data offer valuable insights into the biomechanical behavior of these implants, which could be clinically beneficial for enhancing surgical planning.

Influence of 60-day administration of tartrazine and infliction of a defect in the tibia on the histological structure and morphometric parameters of the rat’s thyroid gland

Aim: to study the histological structure and histomorphometric parameters of the thyroid gland in rats in the period after the completion of the 60-day administration of tartrazine and the creation of a through defect in the tibiae.Material and methods. One hundred and fifty white male rats were divided into five groups: groups T1 and T2 - 60 days of exposure to tartrazine at a dosage of 750 and 1500 mg/kg; group K+D – 60-day administration of saline solution and infliction of a defect in the tibiae; groups T1+D and T2+D – 60-day exposure to tartrazine at a dosage of 750 and 1500 mg/kg and causing a defect in the tibia. The histological structure and histomorphometric parameters of the thyroid gland were studied on days 3, 10, 15, 24 and 45.Results. In the T1+D and T2+D groups, mainly small follicles, lined with cuboidal shaped cells, and in some of them - a flat or columnar shaped cells were detected in the center of the gland from days 3 to 15. Many thyrocytes had a vacuolated cytoplasm and an intensely stained nucleus. The heterogeneous colloid partially filled or was practically absent in the follicles cavity, anemia of the capillaries between them was determined. Singly areas of the organ parenchyma with a significant accumulation of lymphocytes were detected. Histomorphometric study showed a decrease in the internal diameter of the follicles, lumen-epithelial index and nucleo-cytoplasmic ratio and the raise in the height of the follicular epithelium and the area of the cytoplasm of follicular cells.Conclusion. Sixty-day administration of tartrazine to rats and artificial traumatic bone injury leads, in comparison with the data of control groups, to a more pronounced change in the histological picture and morphometric data of the thyroid gland. The intensity and duration of changes are dosedependent: in the T1+D group, most of the qualitative and quantitative changes are smoothed out by 45 days, and in the T2+D group, many of them remain, and the body does not adapt to them.

Bone Regeneration Potential of Periodontal Ligament Stem Cells in Combination with Cold Atmospheric Plasma-Pretreated Beta-Tricalcium Phosphate: An In Vivo Assessment

In regenerative bone tissue medicine, combining artificial bone substitutes with progenitor cells is a prospective approach. Surface modification via cold atmospheric plasma (CAP) enhances biomaterial–cell interactions, which are crucial for successful bone regeneration. Using a rabbit calvarial critical-size defect model, we assessed the use of CAP-pretreated beta-tricalcium phosphate (β-TCP), alone or with periodontal ligament stem cells (PDLSCs), for bone regeneration. Histological and histomorphometric analyses at two and four weeks revealed significantly improved bone regeneration and reduced inflammation in the CAP-treated β-TCP with PDLSCs compared to β-TCP alone. Immunohistochemical analysis also showed an increase in the bone healing markers, including bone morphogenic proteins 2 and 4, runt-related transcription factor 2, collagen-1, and osteonectin, after two and four weeks in the CAP-treated β-TCP implants with PDLSC. This in vivo study demonstrates for the first time the superior bone regenerative capacity of CAP-pretreated β-TCP seeded with PDLSCs, highlighting the therapeutic potential of this combined approach in osteoregeneration.

Comparative Mechanical Testing for Digitally Produced Provisional Fixed Partial Dentures vs the Conventional Method: An In Vitro Study

To examine and compare the fracture strength of implant-cemented fixed partial denture (FPD) prostheses fabricated with digital vs conventional chairside methods. Three groups of seven specimens each were produced: group A (3D printing); group B (milling); and group C (conventional chairside manufacturing), which served as a control. All groups were cemented to standard implant abutments placed in artificial bone blocks. Fracture strength testing was performed using a universal testing machine. Statistical analysis of the resultant maximum forces was performed using SPSS version 25 software (Mann- Whitney U test, P < .05). The mean fracture load value of the group A FPDs was 260.14 N ± 28.88, for group B was 663.57 N ± 140.55, and for group C was 266.65 N ± 63.66. Milled provisional FPDs showed a higher fracture resistance compared to 3D-printed and control groups. However, no such difference could be detected between the 3D-printed and control groups.

Porous Si3N4 ceramics with surface roughness for bone repair

The repair and functional reconstruction of bone defects had become an urgent need and an important research topic. To repair bone defects, artificial bone materials must have an interconnected microporous structure to match the defect site with sufficient mechanical strength and good biocompatibility. To fulfill these requirements, a continuous porous Si3N4 ceramic with high strength and toughness, low friction and good biological properties was prepared. The particle-stabilized foam provided a controlled hierarchical porous structure, whereas the in situ growth of β-Si3N4 grains during sintering not only enhanced mechanical strength to meet practical applications in tissue engineering scaffolds but also changed the surface chemistry of pores to improve biocompatibility. These attractive properties promoted porous Si3N4 ceramics with advanced applications in bone defect repair.

Ginger extract loaded Fe2O3/MgO-doped hydroxyapatite: Evaluation of biological properties for bone-tissue engineering.

Since antiquity, the medicinal properties of naturally sourced biomolecules such as ginger (Zingiber officinale) extract are documented in the traditional Indian and Chinese medical systems. However, limited work is performed to assess the potential of ginger extracts for bone-tissue engineering. Our work demonstrates the direct incorporation of ginger extract on iron oxide-magnesium oxide (Fe2O3 and MgO) co-doped hydroxyapatite (HA) for enhancement in the biological properties. The addition of Fe2O3 and MgO co-doping system and ginger extract with HA increases the osteoblast viability up to ~ 1.4 times at day 11. The presence of ginger extract leads to up to ~ 9 times MG-63 cell viability reduction. The co-doping does not adversely affect the release of ginger extract from the graft surface in the biological medium at pH 7.4 for up to 28 days. Assessment of antibacterial efficacy according to the modified ISO 22196: 2011 standard method indicates that the combined effects of Fe2O3, MgO, and ginger extract lead to ~ 82 % more bacterial cell reduction, compared to the control HA against S. aureus. These ginger extract-loaded artificial bone grafts with enhanced biological properties may be utilized as a localized site-specific delivery vehicle for various bone tissue engineering applications.

Biomimetic vascularized adipose-derived mesenchymal stem cells bone-periosteum graft enhances angiogenesis and osteogenesis in a male rabbit spine fusion model.

Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration. A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials - acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC - were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses. At 12 weeks, the VBPC group significantly increased new bone formation volume compared with the other groups. Biomechanical testing demonstrated higher torque strength in the VBPC group. Notably, the haematoxylin and eosin, Masson's trichrome, and immunohistochemistry-stained histological results revealed that VBPC promoted neovascularization and new bone formation in the spine fusion areas. The tissue-engineered VBPC showed great capability in promoting angiogenesis and osteogenesis in vivo. It may provide a novel approach to create a superior blood supply and nutritional environment to overcome the deficits of current artificial bone graft substitutes.

Effect of changing the acquisition trajectory of the 3D C-arm (CBCT) on image quality in spine surgery: experimental study using an artificial bone model

BackgroundIntraoperative 3D imaging using cone-beam CT (CBCT) provides improved assessment of implant position and reduction in spine surgery, is used for navigated surgical techniques, and therefore leads to improved quality of care. However, in some cases the image quality is not sufficient to correctly assess pedicle screw position and reduction, especially due to metal artifacts. The aim of this study was to investigate whether changing the acquisition trajectory of the CBCT in relation to the pedicle screw position during dorsal instrumentation of the spine can reduce metal artifacts and consequently improve image quality as well as clinical assessability on the artificial bone model.MethodsAn artificial bone model was instrumented with pedicle screws in the thoracic and lumbar spine region (Th10 to L5). Then, the acquisition trajectory of the CBCT (Cios Spin, Siemens, Germany) to the pedicle screws was systematically changed in 5° steps in angulation (− 30° to + 30°) and swivel (− 30° to + 30°). Subsequently, radiological evaluation was performed by three blinded, qualified raters on image quality using 9 questions (including anatomical structures, implant position, appearance of artifacts) with a score (1–5 points). For statistical evaluation, the image quality of the different acquisition trajectories was compared to the standard acquisition trajectory and checked for significant differences.ResultsThe angulated acquisition trajectory increased the score for subjective image quality (p < 0.001) as well as the clinical assessability of pedicle screw position (p < 0.001) highly significant with particularly strong effects on subjective image quality in the vertebral pedicle region (d = 1.06). Swivel of the acquisition trajectory significantly improved all queried domains of subjective image quality (p < 0.001) as well as clinical assessability of pedicle screw position (p < 0.001). The data show that maximizing the angulation or swivel angle toward 30° provides the best tested subjective image quality.SummaryAngulation and swivel of the acquisition trajectory result in a clinically relevant improvement in image quality in intraoperative 3D imaging (CBCT) during dorsal instrumentation of the spine.

Expanding the mechanical and mass-transport combination for bone scaffolds: Through stretched structure

Optimizing the mechanical and mass-transport properties of porous biomaterials simultaneously can be challenging, as they often correspond one-to-one through structure. For instance, increasing permeability by reducing relative density frequently leads to lower mechanical properties. In this study, we introduced a stretched structure to optimize the two properties simultaneously. Initially, the stretched scaffolds were evaluated at the same porosity, revealing that the elastic modulus and permeability of the stretched scaffold are approximately twice that of the original type. Subsequently, the orientation dependence of these properties was investigated. The results suggest that the stiffness of the stretched structure in the width direction is compromised, aligning with the mechanical properties of cortical bone in shaft bones. The permeability of the stretched structure exhibits significant anisotropy, with values much higher than those of original structure. Moreover, our biological experiments demonstrate that extremely stretched structures exhibit low and uneven curvature, potentially impeding cell growth. Hence, striking a balance between curvature and the stretching method employed is crucial. The stretching method can also be applied to other strut-based structures, enabling greater design flexibility in achieving a desirable mechanical and mass-transport combination, providing a foundation for high-performance artificial bone prostheses.

Development of artificial bone graft via in vitro endochondral ossification (ECO) strategy for bone repair

Endochondral ossification (ECO) is a form of bone formation whereby the newly deposited bone replaces the cartilage template. A decellularized artificial cartilage graft (dLhCG), which is composed of hyaline cartilage matrixes, has been developed in our previous study. Herein, the osteogenesis of bone marrow-derived MSCs in the dLhCG through chondrogenic differentiation, chondrocyte hypertrophy, and subsequent transdifferentiation induction has been investigated by simulating the physiological processes of ECO for repairing critical-sized bone defects. The MSCs were recellularized into dLhCGs and subsequently allowed to undergo a 14-day proliferation period (mrLhCG). Following this, the mrLhCG constructs were subjected to two distinct differentiation induction protocols to achieve osteogenic differentiation: chondrogenic medium followed by chondrocytes culture medium with a high concentration of fetal bovine serum (CGCC group) and canonical osteogenesis inducing medium (OI group). The formation of a newly developed artificial bone graft, ossified dLhCG (OsLhCG), as well as its capability of aiding bone defect reconstruction were characterized by in vitro and in vivo trials, such as mRNA sequencing, quantitative real-time PCR (qPCR), immunohistochemistry, the greater omentum implantation in nude mice, and repair for the critical-sized femoral defects in rats. The results reveal that the differentiation induction of MSCs in the CGCC group can realize in vitro ECO through chondrogenic differentiation, hypertrophy, and transdifferentiation, while the MSCs in the OI group, as expected, realize ossification through direct osteogenic differentiation. The angiogenesis and osteogenesis of OsLhCG were proved by being implanted into the greater omentum of nude mice. Besides, the OsLhCG exhibits the capability to achieve the repair of critical-size femoral defects.