-
Journal of Orthopaedic Surgery and... Jan 2019Polyetheretherketone (PEEK) exhibits stable chemical properties, excellent biocompatibility, and rational mechanical properties that are similar to those of human...
BACKGROUND
Polyetheretherketone (PEEK) exhibits stable chemical properties, excellent biocompatibility, and rational mechanical properties that are similar to those of human cortical bone, but the lack of bioactivity impedes its clinical application.
METHODS
In this study, hydroxyapatite (HA) was incorporated into PEEK to fabricate HA/PEEK biocomposite using a compounding and injection-molding technique. The tensile properties of the prepared HA/PEEK composites (HA content from 0 to 40 wt%) were tested to choose an optimal HA content. To evaluate the bioactivity of the composite, the cell attachment, proliferation, spreading and alkaline phosphatase (ALP) activity of MC3T3-E1 cells, and apatite formation after immersion in simulated body fluid (SBF), and osseointegration in a rabbit cranial defect model were investigated. The results were compared to those from ultra-high molecular weight polyethylene (UHMWPE) and pure PEEK.
RESULTS
By evaluating the tensile properties and elastic moduli of PEEK composite samples/PEEK composites with different HA contents, the 30 wt% HA/PEEK composite was chosen for use in the subsequent tests. The results of the cell tests demonstrated that PEEK composite samples/PEEK composite exhibited better cell attachment, proliferation, spreading, and higher ALP activity than those of UHMWPE and pure PEEK. Apatite islands formed on the HA/PEEK composite after immersion in SBF for 7 days and grew continuously with longer time periods. Animal tests indicated that bone contact and new bone formation around the HA/PEEK composite were more obvious than those around UHMWPE and pure PEEK.
CONCLUSIONS
The HA/PEEK biocomposite created by a compounding and injection-molding technique exhibited enhanced osteogenesis and could be used as a candidate of orthopedic implants.
Topics: Animals; Benzophenones; Biocompatible Materials; Cell Line; Drug Evaluation, Preclinical; Durapatite; Female; Ketones; Parietal Bone; Polyethylene Glycols; Polymers; Rabbits; Tensile Strength
PubMed: 30683125
DOI: 10.1186/s13018-019-1069-1 -
PloS One 2020The outer cortical table of the parietal bone has been commonly used as a calvarial bone graft site for the craniofacial reconstruction. However, little is known about...
The outer cortical table of the parietal bone has been commonly used as a calvarial bone graft site for the craniofacial reconstruction. However, little is known about how removing the outer table may affect the function and structure of the inner table, and how the knowledge of the biomechanics and material properties of cortical bones will help the calvarial graft to better integrate into the biological and mechanical functions of its surrounding native tissues. In this study, it was hypothesized that there were significant differences in both density and material properties between inner and outer cortical plates in cranial bones. Twelve cylindrical specimens, including inner-outer layers, of cortical parietal bone of a female baboon were collected. Cortical thicknesses and densities were measured, and elastic properties were assessed using an ultrasonic technique. Results demonstrated remarkable difference in both thickness (t = 8.248, p ≤0.05) and density (t = 4.926, p≤0.05) between inner and outer cortical paired samples. Orthotropic characteristics of the cortical plates were detected as well, these findings suggest that there are differences in biomechanical properties between two surfaces of cranial bones at both tissue and organ levels. How these differences are linked to the stress environments of the inner and outer cranial cortical layers awaits further studies. Further study will greatly enhance our ability to address questions derived from both morphological and craniofacial medicine fields about the development and biomechanics of craniofacial skeletons.
Topics: Animals; Biomechanical Phenomena; Bone Density; Cortical Bone; Elasticity; Female; Organ Specificity; Papio; Parietal Bone; Transducers; Ultrasonics
PubMed: 32126093
DOI: 10.1371/journal.pone.0229244 -
Effect of direct oral anticoagulant dabigatran on early bone healing: An experimental study in rats.Journal of Advanced Periodontology &... 2023Dabigatran belongs to the new generation of direct oral anticoagulants (DOACs). Its advantages are oral administration and no need for international normalized ratio...
BACKGROUND
Dabigatran belongs to the new generation of direct oral anticoagulants (DOACs). Its advantages are oral administration and no need for international normalized ratio (INR) monitoring. Although its use has increased, its potential side effects on bone healing and remodeling have not been fully investigated. The present study aimed to evaluate the possible effects of dabigatran on early bone healing.
METHODS
Sixteen male Wistar rats were divided into two groups; in group A, 20-mg/kg dabigatran dose was administered orally daily for 15 days, while group B served as a control. Two circular bone defects (d=6 mm) were created on either side of the parietal bones. Two weeks after surgery and euthanasia of the animals, tissue samples (parietal bones that contained the defects) were harvested for histological and histomorphometric analysis. Statistical analysis was performed with a significance level of α=0.5.
RESULTS
No statistically significant differences were found between the two groups regarding the regenerated bone (21.9% vs. 16.3%, =0.172) or the percentage of bone bridging (63.3% vs. 53.5%, =0.401).
CONCLUSION
Dabigatran did not affect bone regeneration, suggesting that it might be a safer drug compared to older anticoagulants known to lead to bone healing delay.
PubMed: 38357331
DOI: 10.34172/japid.2023.020 -
BMC Musculoskeletal Disorders Mar 2013Bone is a slowly regenerating tissue influenced by various physiological processes, including proliferation, differentiation, and angiogenesis, under the control of...
BACKGROUND
Bone is a slowly regenerating tissue influenced by various physiological processes, including proliferation, differentiation, and angiogenesis, under the control of growth factors. Shortening this healing time is an important and popular clinical research focus in orthopedics. Negative pressure can stimulate angiogenesis, improve blood circulation, promote granulation tissue growth and accelerate tissue wound healing. We sought to determine whether negative pressure could reduce bone healing time in a rabbit cranial defect model.
METHODS
Four symmetrical holes (diameter, 3.5 mm) were drilled into the skulls of 42 New Zealand white rabbits, with two holes in each parietal bone. For each rabbit, the two sides were then randomly assigned into experimental and control groups. Using negative pressure suction tubes, experimental holes were treated with -50 kPa for 15 minutes, four times per day, whereas the control holes remained untreated. After 4 weeks, the negative pressure suction tubes were removed. At 2, 4, 6 and 8 weeks, three-dimensional (3D) reconstruction computed tomography (CT), X-ray radiopacity, and two-photon absorptiometry were used to evaluate new bone formation. Histological changes were determined by hematoxylin and eosin (H.E) staining. At weekly intervals until 6 weeks, the mRNA expression levels of vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-2 were evaluated by RT-PCR. A paired student's t-test was employed to compare X-ray radiopacity and bone density measurements between the experimental and control groups.
RESULTS
3D-reconstruction CT showed that new bone regeneration in the experimental group was greater than that in the control group at 4 and 6 weeks. At these time points, the experimental group presented with higher X-ray radiopacity and increased bone density (P < 0.05) as compared with the control group. Cartilage islands and new bone were observed by H.E staining at 2 weeks in the experimental group. By 6 weeks, the new bone had matured into lamellar bone in the experimental group. RT-PCR results showed that VEGF and BMP-2 were highly expressed in the experimental group as compared with control.
CONCLUSIONS
Intermittent negative pressure can promote the regeneration of bone possibly by enhancing the expression of VEGF and BMP-2.
Topics: Absorptiometry, Photon; Animals; Bone Density; Bone Morphogenetic Protein 2; Bone Regeneration; Female; Imaging, Three-Dimensional; Male; Models, Animal; Negative-Pressure Wound Therapy; Parietal Bone; RNA, Messenger; Rabbits; Radiographic Image Interpretation, Computer-Assisted; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Staining and Labeling; Time Factors; Tomography, X-Ray Computed; Up-Regulation; Vascular Endothelial Growth Factor A; Wound Healing
PubMed: 23452626
DOI: 10.1186/1471-2474-14-76 -
Clinical Case Reports Nov 2020A neonatal parietal bone fracture was complicated by subgaleal and subdural hematomas after a vacuum extraction delivery. Low-dose computer tomography visualized a...
A neonatal parietal bone fracture was complicated by subgaleal and subdural hematomas after a vacuum extraction delivery. Low-dose computer tomography visualized a comminuted skull fracture. Close observation of infants delivered by vacuum extraction, conservative management after a skull fracture, and further studies on vacuum traction monitoring are warranted.
PubMed: 33235736
DOI: 10.1002/ccr3.2119 -
Tissue Engineering. Part A Aug 2018The Wnt/β-catenin signaling pathway plays an integral role in skeletal biology, spanning from embryonic skeletal patterning through bone maintenance and bone repair....
The Wnt/β-catenin signaling pathway plays an integral role in skeletal biology, spanning from embryonic skeletal patterning through bone maintenance and bone repair. Most experimental methods to antagonize Wnt signaling in vivo are either systemic or transient, including genetic approaches, use of small-molecule inhibitors, or neutralizing antibodies. We sought to develop a novel, localized model of prolonged Wnt/β-catenin signaling blockade by the application and validation of a lentivirus encoding β-catenin short hairpin RNA (shRNA). Efficacy of lentiviral-encoded β-catenin shRNA was first confirmed in vitro using bone marrow mesenchymal stromal cells, and in vivo using an intramedullary long bone injection model in NOD SCID mice. Next, the effects of β-catenin knockdown were assessed in a calvarial bone defect model, in which the frontal bone demonstrates enhanced bone healing associated with heightened Wnt/β-catenin signaling. Lentivirus encoding either β-catenin shRNA or random sequence shRNA with enhanced green fluorescent protein (control) was injected overlying the calvaria of NOD SCID mice and bone defects were created in either the frontal or parietal bones. Among mice treated with lentivirus encoding β-catenin shRNA, frontal bone defect healing was significantly reduced by all radiographic and histologic metrics. In contrast, parietal bone healing was minimally impacted by β-catenin shRNA. In aggregate, our data document the application and validation of a lentivirus encoding β-catenin shRNA model that represents an easily replicable tool for examining the importance of locoregional Wnt/β-catenin signaling in bone biology and regeneration.
PubMed: 29929440
DOI: 10.1089/ten.TEA.2017.0465 -
Neurologia Medico-chirurgica 2013Both intraosseous and microcystic meningiomas are rare tumor types. We report the case of a 66-year-old woman with intraosseous microcystic meningioma without a mass... (Review)
Review
Both intraosseous and microcystic meningiomas are rare tumor types. We report the case of a 66-year-old woman with intraosseous microcystic meningioma without a mass lesion. She presented with a rare intraosseous microcystic meningioma manifesting as pain. Radiological examination revealed an osteolytic lesion in the right parietal bone. Magnetic resonance (MR) images showed iso- to hypointensity on T1-weighted images and hyperintensity on T2-weighted images corresponding to the lesion. T1-weighted MR imaging with gadolinium enhancement better defined the marginal area. The inner table of the skull was disrupted prominently, and both sides of the outer table were eroded. There was fluid leakage during surgery but no obvious tumor mass. Histological examination revealed microcystic meningioma in the inner part of the defective bone. A macroscopic lesion was not found, because most of the tumor comprised microcysts, and their contents leaked out during the surgical procedure. Intraosseous microcystic meningioma may be considered as one of the differential diagnoses when the intraosseous tumor in the skull has fluid leakage and does not have a mass lesion during the surgery.
Topics: Aged; Craniotomy; Diagnosis, Differential; Dura Mater; Female; Headache; Humans; Magnetic Resonance Imaging; Meningioma; Neoplasm Invasiveness; Osteolysis; Parietal Bone; Skull Neoplasms; Tomography, X-Ray Computed
PubMed: 24064568
DOI: 10.2176/nmc.cr2012-0124 -
Journal of Bone and Mineral Research :... Aug 1988Primary bone cell cultures are used widely to examine the regulation of bone metabolism by growth factors and hormones. Characterization of this model system is now...
Primary bone cell cultures are used widely to examine the regulation of bone metabolism by growth factors and hormones. Characterization of this model system is now being conducted at the molecular level to define modulation of gene expression. Cells were obtained from rat parietal bone by sequential collagenase digestions. Cell populations were evaluated for bone-related products, including collagen isoform expression and mRNA levels, alkaline phosphatase activity, and osteocalcin production. Serum-deprived, confluent cultures of the first and second collagenase-released populations produced a lower percentage of total protein as collagen than the third, fourth, and fifth populations, while co-culturing the third through fifth populations resulted in the highest level. Collagen typing on SDS-polyacrylamide gels revealed an abundance of mature type I collagen in all cell populations; type III collagen synthesis was undetectable by this method. This is in contrast to the presence of cytoplasmic mRNA for both type I and type III collagen in all cell populations, suggesting post-transcriptional modulation of type III collagen synthesis. The expression of alkaline phosphatase and osteocalcin was highest in cultures of later released cells, indicating that these cell populations display phenotypic characteristics associated with cells of the osteoblast lineage.
Topics: Alkaline Phosphatase; Animals; Bone and Bones; Calcium-Binding Proteins; Cells, Cultured; Collagen; Nucleic Acid Hybridization; Osteocalcin; Parietal Bone; Protein Biosynthesis; RNA, Messenger; Rats; Rats, Inbred Strains
PubMed: 3265577
DOI: 10.1002/jbmr.5650030406 -
BMC Neurology Aug 2022Sinus pericranii is a rare cranial venous malformation resulting in a subcutaneous mass due to abnormal communication between intracranial and...
BACKGROUND
Sinus pericranii is a rare cranial venous malformation resulting in a subcutaneous mass due to abnormal communication between intracranial and subperiosteal/interperiosteal veins. To date, to the best of our knowledge, there are no reports of sinus pericranii associated with syntelencephaly, a subtype of lobar holoprosencephaly. We herein report a case of sinus pericranii associated with syntelencephaly. This report can provide us better understanding of the etiology of sinus pericranii, the potential risks, and the treatment options for these patients.
CASE PRESENTATION
A 2-year-4-month old female patient who received the diagnosis of syntelencephaly as a neonate presented with a subcutaneous mass in the parietal region. The mass was soft, nonpulsatile, 3 × 2 cm in size, and showed enlargement in the lying position. Color cranial Doppler ultrasound, head magnetic resonance imaging (MRI), and cerebral angiography revealed a dilated vessel passing through the parietal bone and forming a communication between the superior sagittal sinus and scalp veins. Based on these findings, sinus pericranii was diagnosed. The head MRI also showed coronal craniosynostosis, a tight posterior fossa. At age 2 years and 7 months, the patient underwent a transection of the sinus pericranii and the mass resolved without any complications or recurrences for more than 2.5 years to date.
CONCLUSION
Sinus pericranii is a rare cranial and venous malformation sometimes accompanied by brain malformations or craniosynostosis that may become more apparent as the brain and skull develop. Since this condition can be complicated by intracranial hemorrhage and sinus thrombosis, early detection is necessary to determine the treatment options. Physicians should be alert to the possibility of this condition if they observe a soft cranial mass that appears to decrease in size in the sitting position and bulge in the lying position.
Topics: Cerebral Angiography; Child, Preschool; Craniosynostoses; Female; Holoprosencephaly; Humans; Infant; Infant, Newborn; Magnetic Resonance Imaging; Sinus Pericranii
PubMed: 36008788
DOI: 10.1186/s12883-022-02764-5 -
Alcohol (Fayetteville, N.Y.) Aug 2013Craniofacial bone dysmorphology is an important but under-explored potential diagnostic feature of fetal alcohol spectrum disorders. This study used longitudinal MicroCT...
Craniofacial bone dysmorphology is an important but under-explored potential diagnostic feature of fetal alcohol spectrum disorders. This study used longitudinal MicroCT 3D imaging to examine the effect of prenatal alcohol exposure on craniofacial bone growth in a mouse model. C57BL/6J dams were divided into 3 groups: alcohol 4.2% v/v in PMI® liquid diet (ALC), 2 weeks prior to and during pregnancy from embryonic (E) days 7-E16; pair-fed controls (PF), isocalorically matched to the ALC group; chow controls (CHOW), given ad libitum chow and water. The MicroCT scans were performed on pups on postnatal days 7 (P7) and P21. The volumes of the neurocranium (volume encased by the frontal, parietal, and occipital bones) and the viscerocranium (volume encased by the mandible and nasal bone), along with total skull bone volume, head size, and head circumference were evaluated using general linear models and discriminant analyses. The pups in the alcohol-treated group, when compared to the chow-fed controls (ALC vs CHOW) and the isocaloric-fed controls (ALC vs PF), showed differences in head size and circumference at P7 and P21, the total skull volume and parietal bone volume at P7, and volume of all the tested bones except nasal at P21. There was a growth trend of ALC < CHOW and ALC < PF. While covarying for gender and head size or circumference, the treatment affected the total skull and mandible at P7 (ALC > CHOW), and the total skull, parietal bone, and occipital bone at P21 (ALC < CHOW, ALC < PF). While covarying for the P7 measures, the treatment affected only the 3 neurocranial bones at P21 (ALC < CHOW, ALC < PF). Discriminant analysis sensitively selected between ALC and CHOW (AUC = 0.967), between ALC and PF (AUC = 0.995), and between PF and CHOW (AUC = 0.805). These results supported our hypothesis that craniofacial bones might be a reliable and sensitive indicator for the diagnosis of prenatal alcohol exposure. Significantly, we found that the neurocranium (upper skull) was more sensitive to alcohol than the viscerocranium (face).
Topics: Animals; Craniofacial Abnormalities; Ethanol; Female; Male; Mice; Pregnancy; Prenatal Exposure Delayed Effects; Sex Characteristics; X-Ray Microtomography
PubMed: 23809873
DOI: 10.1016/j.alcohol.2013.04.005