Bone Hardness Research Articles

Response to letter to the editor regarding "increased advanced glycation endproducts, stiffness, and hardness in iliac crest bone from postmenopausal women with type 2 diabetes mellitus on insulin".

Response to letter to the editor regarding "increased advanced glycation endproducts, stiffness, and hardness in iliac crest bone from postmenopausal women with type 2 diabetes mellitus on insulin".

Sclerotic prostate cancer bone metastasis: woven bone lesions with a twist.

Bone metastases are the most severe and prevalent consequences of prostate cancer (PC), affecting more than 80% of patients with advanced PC. PCBMs generate pain, pathological fractures, and paralysis. As modern therapies increase survival, more patients are suffering from these catastrophic consequences. Radiographically, PCBMs are predominantly osteosclerotic, but the mechanisms of abnormal bone formation and how this pathological increase in bone density is related to fractures are unclear. In this study, we conducted a comprehensive analysis on a cohort of 76 cadaveric PCBM specimens and 12 cancer-free specimens as controls. We used micro-computed tomography to determine 3D organization and quantify bone characteristics, quantitative backscattering electron microscopy to characterize mineral content and details in bone structure, nanoindentation to determine mechanical properties, and histological and immunohistochemical analysis of bone structure and composition. We define 4 PCBM phenotypes: osteolytic, mixed lytic-sclerotic, and 2 subgroups of osteosclerotic lesions-those with residual trabeculae, and others without residual trabeculae. The osteosclerotic lesions are characterized by the presence of abnormal bone accumulated on trabeculae surfaces and within intertrabecular spaces. This abnormal bone is characterized by higher lacunae density, abnormal lacunae morphology, and irregular lacunae orientation. However, mineral content, hardness, and elastic modulus at micron-scale were indistinguishable between this irregular bone and residual trabeculae. The collagen matrix of this abnormal bone presents with irregular organization and a prominent collagen III composition. These characteristics suggest that osteosclerotic PCBMs initiate new bone deposition as woven bone; however, the lack of subsequent bone remodeling, absence of lamellar bone deposition on its surface, and presence of collagen III distinguish this pathologic matrix from conventional woven bone. Although the mineralized matrix retains normal bone hardness and stiffness properties, the lack of fibril anisotropy presents a compromised trabecular structure, which may have clinical implications.

Creation of a prototype simulator object for quality control of bone segmentation algorithms for use in tomographic post-processing software

Considering the growing influence of Artificial Intelligence (AI) in medicine, especially in radiology, and the advances in computational power and theoretical understanding of AI algorithms (MESKÓ; GÖRÖG, 2020), concerns about the reliability of these methods arise. This study developed a prototype simulator object for quality control of bone segmentation algorithms in computed tomography. To achieve this objective, a 3D simulator object was created using advanced printing techniques, with materials that faithfully replicate the density and hardness of human bones, such as RadioMatrix. The results indicated that bone segmentation in post-processing software is strongly influenced by tissue density and that currently available AI models lack explainability (EXAI). The analysis revealed the need for algorithms that consider not only density but also the specific shapes and characteristics of bones. It is concluded that the developed prototype is effective in the evaluation and quality control of bone segmentation algorithms, promoting greater safety in clinical application and better explainability of bone segmentation algorithms in post-processing software for computed tomography.

Melatonin's protective role against Bisphenol F and S-induced skeletal damage: A morphometric and histological study in rat

This study aimed to evaluate the potential effects of Bisphenol F and S exposure on the skeletal structures of Sprague-Dawley rats. Given the increasing concern about the potential endocrine-disrupting effects of Bisphenol analogs on bone health, this research sought to elucidate their impact in conjunction with Melatonin. Using 80 male Sprague Dawley rats, bones were subjected to a 3-point bending test to assess mechanical properties, and histopathological evaluation was conducted after fixation and decalcification. Statistical analysis was performed using SPSS. The results of the mechanical tests revealed significant differences in deformation and elastic modulus values between groups treated with Bisphenol F+Melatonin and Bisphenol S+Melatonin compared to the control groups. However, the histological images showed no significant differences between the groups. In the discussion, it was noted that the injection of Bisphenol F and Melatonin together increased bone hardness, suggesting that Bisphenol F and Bisphenol S may mitigate the negative effects of melatonin on bone. We attributed the absence of histological differences to the male gender of the studied rats and previous exposure considerations. This study shows that Melatonin can reduce Bisphenol F and Bisphenol S′ rapid adjustment effects and increase bone elasticity. The side effects of Bisphenol F and S, as well as the prophylactic effects of Melatonin, can be observed and improved by carefully adjusting the duration, dose, and gender selection.

Investigating the Underlying Molecular Mechanisms of Yunke on Bone Metastases from Prostate Cancer.

To explore analgesic effect and bone repair mechanism of non-radioactive technetium-99 conjugated with methylene diphosphonate (99Tc-MDP, brand name, Yunke) on bone metastases (BM). In vivo experiment, mouse BM models of prostate cancer RM-1 cell were constructed and divided into Control, Yunke, 99Tc+SnCl2 and MDP groups based on medicine composition. Tumor specimens were inspected for size, X-ray, microCT and histopathology. In vitro experiment, with Cell Counting Kit-8 (CCK8), scratch, clone, apoptosis, Polymerase Chain Reaction (PCR) and Western Blot experiments, effects of Yunke on RM-1 cells and osteoclast-related cells were observed. In vivo experiment, there was no difference in tumor size between Yunke and control group. Contrasted with control group, in Yunke group, trabecular spacing (Tb.Sp) of tumor bone was lower, bone volume/total volume (BV/TV) on marrow cavity and bone cortex were higher. Tunnel staining showed that positive rate of apoptosis in Yunke group was higher than that in control group. Ki67 staining showed that Yunke could not inhibit proliferation of tumor cells. In vitro experiment, CCK8 and scratch experiments showed that Yunke neither can inhibit proliferation nor can inhibit migration of RM-1 cells. High concentration of Yunke promoted late apoptosis of RM-1 cells. Yunke could inhibit BMM cell proliferation, differentiation of osteoclasts, and osteoclast-related transcription factors. Yunke displayed different degrees of inhibitory effects on MAPKs signaling pathway during osteoclast differentiation. It had obvious inhibitory effects on osteoclast-related transcription factors, such as cFOS, NFATC1, ACP-5, CTSK, D2 and MMP-9, the strongest inhibitory effects were observed with ACP-5, CTSK and D2. Yunke also displayed different degrees of inhibitory effects on protein activities of JNK, pERK, ERK and pP38. Yunke cannot inhibit the proliferation and migration of RM-1 cells, so we think it is not recommended for the treatment of primary tumors and prevention of occurrence of tumors metastatic to bones. The mechanism of therapeutic effect of Yunke on BM by inhibiting proliferation of BMM, inhibiting MAPKs signal transduction and activation of transcription factors during differentiation process of BMM-derived osteoclasts, inhibiting number and size of osteoclasts, inhibiting bone resorption and protecting bone destruction through enhancing bone hardness and bone mass. Thereby, we believe that Yunke is more suitable for promoting the repair induced by BMs, delaying its progression and reducing the occurrence of SREs.

Supplemental effect of Pediococcus acidilactici CNCM I-4622 probiotic on the laying characteristics and calcium and phosphorus metabolism in laying hens

The close link between intestinal microbiota and bone health (‘gut-bone’ axis) has recently been revealed: the modulation of the amount and nature of bacteria present in the intestinal tract has an impact on bone health and calcium (Ca) metabolism. Probiotics are known to favorably impact the intestinal microbiota. The objective of this study was to investigate the effect of Pediococcus acidilactici CNCM I-4622 (PA) on laying performance, egg/eggshell quality, Ca metabolism and bone mineralization and resistance in relatively old layers (50 wks old at the beginning of the experiment) during 14 weeks. 480 Hy Line brown layers were divided into 2 groups (CON and PA: 3 layers/rep, 80 rep/group) and fed with a diet formulated to be suboptimal in calcium (Ca) and phosphorus (P) (− 10% of the requirements). The total egg weight was improved by 1.1% overall with PA, related to an improvement of the weight of marketable eggs (+ 0.9%). PA induced a decreased % of downgraded eggs, mainly broken eggs (− 0.4 pts) and FCR improvement (− 0.8% for all eggs, − 0.9% for marketable eggs). PA also led to higher Haugh units (HU: + 7.4%). PA tended to decrease crypt depth after the 14 weeks of supplementation period in the jejunum (− 25.2%) and ileum (− 17.6%). As a consequence, the VH/CD ratio appeared increased by PA at the end of the trial in the jejunum (+ 63.0%) and ileum (+ 48.0%). Ca and P retention were increased by 4 pts following PA supplementation, translating into increased bone hardness (+ 19%), bone cohesiveness (+ 43%) and bone Ca & P (+ 1 pt) for PA-supplemented layers. Blood Ca and P were respectively improved by 5% and 12% with PA. In addition, blood calcitriol and osteocalcin concentrations were respectively improved by + 83% and + 3% in PA group at the end of the trial, compared to CON group. There was no difference between the 2 groups for ALP (alkaline phosphatase) and PTH (parathyroid hormone). PA significantly decreased the expression of the following genes: occludin in the small intestine, calbindin 1 in the ovarian tissue and actin B in the bone. PA therefore improved zootechnical performance of these relatively old layers, and egg quality. The parallel increase in Ca and P in the blood and in the bone following PA supplementation suggests an improvement of the mineral supply for eggshell formation without impacting bone integrity, and even increasing bone resistance.

Micro-CT, Mechanical, and Histological Examination of the Effect of Local Adjuvants on Porcine Cortical Bone Following Intralesional Curettage of Bone Tumors

Background and ObjectivesCurettage is the removal of a tumor from the bone while preserving the surrounding healthy cortical bone, and is associated with higher rates of local recurrence. To lower these rates, curettage should be combined with local adjuvants, although their use is associated with damage to nearby healthy bone.ObjectiveThe purpose of this analysis is to determine the effect of local adjuvants on cortical porcine bone by using micro-computed tomography (micro-CT) along with histological and mechanical examination.MethodsLocal adjuvants were applied to porcine specimens under defined conditions. To assess changes in bone mineral density (BMD), a micro-CT scan was used. The pixel gray values of the volume of interest (VOI) were evaluated per specimen and converted to BMD values. The Vickers hardness test was employed to assess bone hardness (HV). The depth of necrosis was measured histologically using hematoxylin and eosin-stained tissue sections.ResultsA noticeable change in BMD was observed on the argon beam coagulation (ABC) sample. Comparable hardness values were measured on samples following electrocautery and ABC, and lowering of bone hardness was obtained in the case of liquid nitrogen. Extensive induced depth of necrosis was registered in the specimen treated with liquid nitrogen.ConclusionThis study determined the effect of local adjuvants on cortical bone by using micro-CT along with histological and mechanical examination. Phenolization and liquid nitrogen application caused a decrease in bone hardness. The bone density was affected in the range of single-digit percentage values. Liquid nitrogen induced extensive depth of necrosis with a wide variance of values.

Bone quality in zebrafish vertebrae improves after alendronate administration in a glucocorticoid-induced osteoporosis model

Glucocorticoid-induced osteoporosis (GIOP) changes the microarchitecture of bones and often leads to the reduction of bone-mineral density (BMD) and increased fracture rates. Zebrafish has been used as an alternative model for GIOP, however, the interaction of GIOP, and its treatment, with zebrafish bone morphometrics and mechanical properties, remains a challenge. Thus, this study aimed to evaluate the effects of prednisolone and alendronate on the properties of zebrafish vertebrae. Adult 7-month-old zebrafish were distributed into four groups: control (CTRL), prednisolone-only (PN), alendronate-only (ALN), and the sequential use of both medicines (PN + ALN). Fish skeletons were scanned via micro-tomography (n = 3) to obtain vertebra morphometrics (e.g., BMD). Bone morphology was assessed using scanning electron microscopy (n = 4) and the biomechanical behaviour with nanoindentation technique (n = 3). The BMD decreased in PN (426.08 ± 18.58 mg/cm3) and ALN (398.23 ± 10.20 mg/cm3) groups compared to the CTRL (490.43 ± 41.96 mg/cm3) (p < 0.001); however, administering the medicines in sequence recovered the values to healthy levels (495.43 ± 22.06 mg/cm3) (p > 0.05). The bone layered structures remain preserved in all groups. The vertebrae of the groups that received ALN and PN + ALN, displayed higher modulus of elasticity (27.27 ± 1.59 GPa and 25.68 ± 2.07 GPa, respectively) than the CTRL (22.74 ± 1.60 GP) (p < 0.001). ALN alone increased the hardness of zebrafish vertebrae to the highest value among the treatments (1.32 ± 0.13 GPa) (p < 0.001). Conversely, PN + ALN (1.25 ± 0.11 GPa) showed unaltered hardness from the CTRL (1.18 ± 0.13 GPa), but significantly higher than the PN group (1.08 ± 0.12 GPa) (p < 0.001). ALN administered after GIOP development, rescued osteoporotic condition by recovering the BMD and bone hardness in zebrafish vertebrae.

The Intervention of Anchovy (Stokphorus commrsouli) Calcium Extract Could Elevate Calcium Levels during Pregnancy and Give Birth and Promote Bone Development: An in vivo Study

Background: During pregnancy, calcium deficiency has become a frequent phenomenon. Calcium intake is essential for supporting maternal and fetal health to maintain calcium homeostasis and promotes bone formation. Anchovy is a high calcium source from marine. The anchovy diet impact on fetal development during pregnancy is inconclusive. Therefore, Anchovy Calcium Extract (ACE) effect on calcium homeostasis and bone formation was studied. Methods: Female Sprague Dawley rats were grouped into three: without ACE administration, with ACE administration prior to mating until two weeks post-labor and with ACE administration after pregnancy confirmation until two weeks post-labor. Blood calcium levels and bone hardness were measured. Result: ACE improved maternal’s and offspring’s calcium levels. ACE also provided adequate blood calcium levels during pregnancy, labor and breastfeeding. In addition, ACE improve maternal bone firmness but has no significant effect on its offspring. In conclusion, ACE has excellent potential as a dietary supplement to promote adequate calcium requirements for maternal and infant health.

Characteristics of Soft Bone Milkfish (Chanos chanos) with Different Boiling Times

Soft bone milkfish is a modification technique by softening the fish bone using high temperature. The advantage of this method is lower the risk of bone chocking while consuming the milkfish. The purpose of this study was to determine the effect of boiling time on the characteristics of soft durian milkfish and the best boiling time favored by the community. The processing method begins with weeding the raw materials and washing them clean, arranging them in a bamboo basket covered with floating bamboo leaves. Boiling is done in a large cauldron with wood fuel and filled with water one third of the height of the casserole with ground spices. Conventional cooking is done for 8 hours. The research design used was a pressure cooker for 2 hours (control), conventional cooking for 6 hours, 7 hours and 8 hours. Cooking time did not affect protein content and moisture content, but did affect the levels of amino acid profiles, bone hardness and hedonic parameters of appearance, smell, taste and texture. The results showed that the best treatment was conventional cooking for 7 hours which had an appearance value of 8.57 ± 0.50, odor 8.67 ± 0.48, taste 8.47 ± 0.51, texture 8.53 ± 0.51, protein content 31.12 ± 0.84%, moisture content 64.48 ± 2.39%, essential amino acid profile content 135.521 mg/1000g, profile content non-essential amino acids 132.785 mg/1000g, bone hardness 44.12 ± 14.11N.

Effect of nickel – Graphene addition on the 3D printed 17-4 PH stainless steel

In this work, 3D printing method was used to prepare 17-4 PH SS/additives samples, these additives represented by nickel (Ni), graphene (G) and nickel-graphene (Ni – G) with the volume ratios of 2.5 %, 5 % and 5 % respectively. The printed samples were characterized using XRD, SEM with EDS and optical microscope. These characterization methods showed the good incorporation between the base material (17-4 PH SS) and additive materials (Ni, G and Ni – G) through the new peaks appeared in XRD analysis, the homogenous distribution of particles in SEM images and elemental analysis in EDS for 3D printed samples.The measured properties indicated the variation in density with different additives to get lowest density for 17-4 PH SS/Ni – G coated sample (7.2516 g cm−3) confirming the good incorporation among the components of this sample after 3D printing process that can be candidate for bioapplication. Rockwell hardness also measured to give the lowest hardness for 17-4 PH SS/Ni – G coated sample that equal to 46.36 which is closed for the hardness of human bone that ranged from 33.30 HV for the head to 43.82 HV for the diaphysis. Some cracks that observed in optical microscopy of 17-4 PH SS/Ni – G coated sample can be share in osseointegration inside human body to get biocompatibility.

Engineering 3D Printed Bioceramic Scaffolds to Reconstruct Critical-Sized Calvaria Defects in a Skeletally Immature Pig Model.

Three-dimensional printed bioceramic scaffolds composed of 100% β-tricalcium phosphate augmented with dipyridamole (3DPBC-DIPY) can regenerate bone across critically sized defects in skeletally mature and immature animal models. Before human application, safe and effective bone formation should be demonstrated in a large translational animal model. This study evaluated the ability of 3DPBC-DIPY scaffolds to restore critically sized calvarial defects in a skeletally immature, growing minipig. Unilateral calvarial defects (~1.4 cm) were created in 6-week-old Göttingen minipigs ( n = 12). Four defects were filled with a 1000 μm 3DPBC-DIPY scaffold with a cap (a solid barrier on the ectocortical side of the scaffold to prevent soft-tissue infiltration), four defects were filled with a 1000 μm 3DPBC-DIPY scaffold without a cap, and four defects served as negative controls (no scaffold). Animals were euthanized 12 weeks postoperatively. Calvariae were subjected to micro-computed tomography, 3D reconstruction with volumetric analysis, qualitative histologic analysis, and nanoindentation. Scaffold-induced bone growth was statistically greater than in negative controls ( P ≤ 0.001), and the scaffolds with caps produced significantly more bone generation compared with the scaffolds without caps ( P ≤ 0.001). Histologic analysis revealed woven and lamellar bone with haversian canals throughout the regenerated bone. Cranial sutures were observed to be patent, and there was no evidence of ectopic bone formation or excess inflammatory response. Reduced elastic modulus and hardness of scaffold-regenerated bone were found to be statistically equivalent to native bone ( P = 0.148 for reduced elastic modulus of scaffolds with and without caps and P = 0.228 and P = 0.902 for hardness of scaffolds with and without caps, respectively). 3DPBC-DIPY scaffolds have the capacity to regenerate bone across critically sized calvarial defects in a skeletally immature translational pig model. This study assessed the bone generative capacity of 3D-printed bioceramic scaffolds composed of 100% β-tricalcium phosphate and augmented with dipyridamole placed within critical-sized calvarial defects in a growing porcine model.

Repair of Cranial Defects in Rabbits with 3D-Printed Hydroxyapatite/Polylactic Acid Composites.

The safety and efficacy of three-dimensional- (3D-) printed hydroxyapatite/polylactic acid (HA-PLA) composites in repairing cranial defects were evaluated in a rabbit experimental model. Twelve New Zealand rabbits were selected as experimental subjects. Two holes (A and B), each with a diameter of approximately 1 cm, were made in the cranium of each rabbit. Hole A served as the experimental manipulation, and hole B served as the control manipulation. A 3D-printed HA-PLA composite was used for placement onto hole A, whereas autologous bone powder was used for placement onto hole B. Samples from the experimental holes and the control holes were collected at 30 and 90 days after surgery. The obtained materials were examined in terms of their morphologies and histopathologies and were also subjected to simultaneous hardness tests. Both the 3D-printed HA-PLA composite and autologous bone powder were able to repair and fill the cranial defects at 30 days and 90 days after surgery. At 30 days after surgery, the microhardness of the area repaired by the HA-PLA composite was lower than that of the area repaired by autogenous bone powder (p < 0.01), but neither of these treatments reached the hardness of normal bone at this time (p < 0.01). At 90 days after surgery, there was no statistically significant difference in the microhardness of the repaired area from the 3D-printed HA-PLA composite compared with that of the repaired area from autologous bone powder (p > 0.05), and there was no statistically significant difference in the hardness of the two repaired areas compared with that of the normal bone (p > 0.05). Hematoxylin-eosin staining showed that bone cells in the HA-PLA material in the experimental group grew and were arranged in an orderly manner. Bone trabeculae and marrow cavities were formed on the pore surface and inside of the HA-PLA scaffold, and the arrangement of bone trabeculae was regular. 3D-printed HA-PLA composites can induce bone regeneration, are biocompatible, have the same strength as autologous bone powder, are able to degrade, and are ultimately safe and effective for repairing cranial defects in rabbits. However, further research is needed to determine the feasibility of 3D-printed HA-PLA composites in human cranioplasty.

Effect of radiation-induced damage of trabecular bone tissue evaluated using indentation and digital volume correlation

Exposure to X-ray radiation for an extended amount of time can cause damage to the bone tissue and therefore affect its mechanical properties. Specifically, high-resolution X-ray Computed Tomography (XCT), in both synchrotron and lab-based systems, has been employed extensively for evaluating bone micro-to-nano architecture. However, to date, it is still unclear how long exposures to X-ray radiation affect the mechanical properties of trabecular bone, particularly in relation to lab-XCT systems. Indentation has been widely used to identify local mechanical properties such as hardness and elastic modulus of bone and other biological tissues. The purpose of this study is therefore, to use indentation and XCT-based investigative tools such as digital volume correlation (DVC) to assess the microdamage induced by long exposure of trabecular bone tissue to X-ray radiation and how this affects its local mechanical properties. Trabecular bone specimens were indented before and after X-ray exposures of 33 and 66 h, where variation of elastic modulus was evaluated at every stage. The resulting elastic modulus was decreased, and micro-cracks appeared in the specimens after the first long X-ray exposure and crack formation increased after the second exposure. High strain concentration around the damaged tissue exceeding 1% was also observed from DVC analysis. The outcomes of this study show the importance of designing appropriate XCT-based experiments in lab systems to avoid degradation of the bone tissue mechanical properties due to radiation and these results will help to inform future studies that require long X-ray exposure for in situ experiments or generation of reliable subject-specific computational models.

Invention of an Online Interactive Virtual Neurosurgery Simulator With Audiovisual Capture for Tactile Feedback.

Present neurosurgical simulators are not portable. To maximize portability of a virtual surgical simulator by providing online learning and to validate a unique psychometric method ("audiovisual capture") to provide tactile information without force feedback probes. An online interactive neurosurgical simulator of a posterior petrosectomy was developed. The difference in the hardness of compact vs cancellous bone was presented with audiovisual effects as inclinations of the drilling speed and sound based on engineering perspectives. Three training methods (the developed simulator, lectures and review of slides, and dissection of a 3-dimensional printed temporal bone model [D3DPM]) were evaluated by 10 neurosurgical residents. They all first attended a lecture and were randomly allocated to 2 groups by the training D3DPM (A: simulator; B: review of slides, no simulator). In D3DPM, objective measures (required time, quality of completion, injury scores of important structures, and the number of instructions provided) were compared between groups. Finally, the residents answered questionnaires. The objective measures were not significantly different between groups despite a younger tendency in group A (graduate year -2.4 years, 95% confidence interval -5.3 to 0.5, P = .081). The mean perceived hardness of cancellous bone on the simulator was 70% of that of compact bone, matching the intended profile. The simulator was superior to lectures and review of slides in feedback and repeated practices and to D3DPM in adaptability to multiple learning environments. A novel online interactive neurosurgical simulator was developed, and satisfactory validity was shown. Audiovisual capture successfully transmitted the tactile information.

Kefir peptides ameliorate osteoporosis in AKR1A1 knockout mice with vitamin C deficiency by promoting osteoblastogenesis and inhibiting osteoclastogenesis

The AKR1A1 protein is a member of the aldo-keto reductase superfamily that catalyzes the transformation of D-glucuronate to L-gulonate in the synthesis of L-ascorbic acid (vitamin C, Vit C). We previously demonstrated that AKR1A1 knockout mice (AKR1A1eGFP/eGFP) with Vit C deficiency exhibited aberrant bone formation and osteoporosis. In this study, we aimed to evaluate the osteoprotective effects of kefir peptides (KPs) in AKR1A1eGFP/eGFP mice and uncover the underlying mechanism of KPs in the modulation of bone remodeling. Six male CD-1 mice and 24 male AKR1A1eGFP/eGFP mice were used in this study, in which the AKR1A1eGFP/eGFP mice were randomly divided into four groups (n = 6). KPs treatment for 12 weeks exerted several effects in AKR1A1eGFP/eGFP mice including the reduction of serum proinflammatory cytokines (IL-1β, IL-6, TNF-α), bone resorption markers (CTX-1, RANKL), and the increase of serum bone formation markers (P1NP, OPG, OC). μ-CT analysis indicated that KPs prevented the bone loss in the femurs of AKR1A1eGFP/eGFP mice by significantly increasing the trabecular parameters of bone mineral density, bone volume and bone number. Nanoindentation analysis demonstrated that KPs enhanced the elasticity and hardness of femoral cortical bones in AKR1A1eGFP/eGFP mice. KPs promoted bone marrow mesenchymal stem cells (BMMSCs)-derived osteoblast differentiation and mineralization by upregulating positive regulators of osteoblastogenesis (Runx2, β-catenin, BMP-2, NFATc1). Conversely, KPs inhibited bone marrow macrophages (BMMs)-derived osteoclast differentiation and bone resorption, which was demonstrated by the facts that KPs suppressed RANKL-induced p38, NF-κB, Akt, PLCγ2 and CREB-1 phosphorylation, decreased the nuclear translocation of NFATc1 and c-Fos. Our findings demonstrate the efficacy of KPs in the prevention of osteoporosis in AKR1A1eGFP/eGFP mice and also unveil the dual effects of KPs in osteogenic promotion and osteoclastic inhibition. This study supports the use of KPs as nutritional supplements for the prevention of osteoporosis.

Assessing minipig compact jawbone quality at the microscale

Preclinical studies often require animal models for in vivo experiments. Particularly in dental research, pig species are extensively used due to their anatomical similarity to humans. However, there is a considerable knowledge gap on the multiscale morphological and mechanical properties of the miniature pigs' jawbones, which is crucial for implant studies and a direct comparison to human tissue. In the present work, we demonstrate a multimodal framework to assess the jawbone quantity and quality for a minipig animal model that could be further extended to humans.Three minipig genotypes, commonly used in dental research, were examined: Yucatan, Göttingen, and Sinclair. Three animals per genotype were tested. Cortical bone samples were extracted from the premolar region of the mandible, opposite to the teeth growth. Global morphological, compositional, and mechanical properties were assessed using micro-computed tomography (micro-CT) together with Raman spectroscopy and nanoindentation measurements, averaged over the sample area. Local mineral-mechanical relationships were investigated with the site-matched Raman spectroscopy and micropillar compression tests. For this, a novel femtosecond laser ablation protocol was developed, allowing high-throughput micropillar fabrication and testing without exposure to high vacuum.At the global averaged sample level, bone relative mineralization demonstrated a significant difference between the genotypes, which was not observed from the complementary micro-CT measurements. Moreover, bone hardness measured by nanoindentation showed a positive trend with the relative mineralization. For all genotypes, significant differences between the relative mineralization and elastic properties were more pronounced within the osteonal regions of cortical bone. Site-matched micropillar compression and Raman spectroscopy highlighted the differences between the genotypes' yield stress and mineral to matrix ratios.The methods used at the global level (averaged over sample area) could be potentially correlated to the medical tools used to assess jawbone toughness and morphology in clinics. On the other hand, the local analysis methods can be applied to quantify compressive bone mechanical properties and their relationship to bone mineralization.

Effect of Diabetes Mellitus on Implant Osseointegration of Titanium Screws: An Animal Experimental Study.

ObjectiveTo explore the effect of diabetes mellitus (DM) on implant osseointegration of titanium screws.MethodsSixty rats were randomly divided into a DM group and a control group (each group, n = 30). DM group rats were injected with 1% Streptozotocin solution at 65 mg/kg to establish a DM model. Titanium screws were implanted into the rats' distal femurs in both groups. The rats were sacrificed for micro‐CT scanning, micro‐indentation, biomechanical detection, confocal Raman microspectroscopy, and histological and histomorphometric analysis at 4, 8, and 12 weeks post‐implantation, respectively. Messenger RNA (mRNA) expression and protein expression of the related growth factors around the implant were analyzed using real‐time polymerase chain reaction and Western blots.ResultsAt 4, 8 and 12 weeks, micro‐CT scanning, hematoxylin‐eosin (HE) staining, Gieson's acid‐magenta staining, and fluorescent labeled staining showed disorder in the bone tissue arrangement, a lack of new bone tissue, poor maturity and continuity, and poor trabecular bone parameters around the implant in the DM group. At 4, 8, and 12 weeks, the interfacial bone binding rate in the DM group was significantly lower (16.2% ± 4.8%, 25.7% ± 5.7%, 42.5% ± 5.8%, respectively) than that in the control group (23.6% ± 5.2%, 40.8% ± 6.3%, 64.2% ± 7.3%, respectively; P < 0.05). At 8 and 12 weeks, the elastic modulus (17.0 ± 1.8 and 15.1 ± 1.5 GPa, respectively) and trabecular bone hardness (571 ± 39 and 401 ± 37 MPa, respectively) in the DM group were significantly lower than the elastic modulus (23.4 ± 2.3 and 23.8 ± 1.8 GPa, respectively) and trabecular bone hardness (711 ± 45 and 719 ± 46 MPa, respectively) in the control group (P < 0.05). The maximum load required for the prosthesis pull‐out experiment in the DM group at 4, 8, and 12 weeks (55.14 ± 6.74 N, 73.34 ± 8.43 N, and 83.45 ± 8.32 N, respectively) was significantly lower than that in the control group (77.45 ± 7.48 N, 93.28 ± 8.29 N, and 123.62 ± 9.43 N, respectively, P < 0.05). At 8 and 12 weeks, the mineral‐to‐collagen ratio in the DM group (6.56 % ± 1.35% and 4.45%± 1.25%, respectively) was significantly higher than that in the control group (5.31% ± 1.42% and 3.62% ± 1.33%, respectively, P < 0.05). At 12 weeks, mRNA and protein expression levels of bone morphogenetic protein 2, transforming growth factor‐β1, vascular endothelial growth factor, osteopontin, osteocalcin, and runt‐related transcription factor 2 in the DM group were significantly lower than that in the control group.ConclusionsDM can negatively affect bone osseointegration, manifesting as disorder in bone tissue arrangement around the implant, a lack of new bone tissue, poor maturity and continuity, poor trabecular bone parameters and lower expression of the related growth factors.

Reaction Sintering of Biocompatible Al2O3-hBN Ceramics.

Biocompatible Al2O3–hBN ceramic was sintered from AlN and B2O3 precursors by reaction hot pressing at 1750 °C and 30 MPa for 8 min. The ceramic was compared to nonreactive (NR) one sintered from Al2O3 and BN under the same sintering conditions. The NR ceramic possesses 9% porosity as opposed to only 2% porosity for the reaction sintered Al2O3–hBN. The reaction sintered ceramic has crack resistance in the region of 5.0 ± 0.1 MPa·m1/2, which is approximately 20% higher than previously reported pure Al2O3 or Al2O3–hBN sintered without reaction support. The higher amount of hBN in the developed Al2O3–hBN material (27 vol %) facilitates hardness lowering to the region of 6 GPa, which is closer to the bone hardness and makes the ceramic machinable. Reaction sintering of the Al2O3–hBN composite opens a new area of creation and formation of load-bearing Al2O3–hBN ceramic bioimplants.

KARAKTERISTIK OTAK-OTAK TULANG IKAN TODAK (Tylosurus crocodilus) DENGAN PENERAPAN TEKNOLOGI MODERN

Fishbone otak-otak is one of the processing the results of fisheries diversification. Fishbone otak-otak have a weakness, the bones in this product cannot be consumed, besides that the bones can cause mouth irritation, this is the application of modern technology is involved in overcoming weaknesses in consumption fishbone otak-otak. One of the modern technology namely with presto technology. The purpose of this research find outphysical (Organoleptic, Rendemen) and chemical (Proximate, Calcium, Bone Hardness) on the characteristics of the fishbone otak-otak swordfish (Tylosurus crocodilus). Method This uses a completely randomized design (CRD), consisting of 3 treatments, namely during 1 hour (T1), 1.5 hours (T2), 2 hours (T3) and 3 replications at a temperature of 115-120 oC. Result the best organoleptic testing is 1.5 hours treatment gave an average appearance value (2.47%), Odor (2.60%), Taste (2.60%) and Texture (2.50%). The results of the yield analysis were 1 hour (60%) 1.5 hours (59%) 2 hours (58%). Proximate analysis results based on treatment best get scorerate-ratewater content (54.44%) ash content (19.21%) fat content (5.64%) protein content (9.70%) carbohydrate content (22.04%). The highest result of calcium analysis is 6594.11 mg/ 100 g. The results of the analysis of bone hardness were 1061.75 g.