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2.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(5): 740-746, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34622586

RESUMO

Nano hydroxyapatite (nHAp), a main component of the inorganic composition of human bones and teeth, is widely used in bone tissue engineering, bone defect repair and replacement, for example, for its biocompatibility, bioactivity, bioaffinity and the ability to induce bone regeneration. Nano hydroxyapatite contains calcium and phosphorus, elements that can be replaced through the normal metabolic channels of the human body. Therefore, after implantation, it can be partially or completely absorbed and replaced by human tissues and can effectively assist bone regeneration, which makes it an ideal material for bone repair. However, traditional nHAp material is brittle and hard to be degraded in human body. In addition, nHAp has poor stability due to its high surface energy and tendency for agglomeration, which causes rapid attenuation of its mechanical strength and limits its clinical application. At present, the mechanical properties and biocompatibility of nHAp can be effectively improved by loading the related growth factors, proteins, peptides and other bioactive molecules, so as to better meet the biological requirements of bone repair materials. However, the traditional physicochemical modification methods are complicated and may interfere with the bioactivity of nHAp. It is simple to biomimetically synthesize nanomaterials by direct utilization of the molecular recognition and self-assemble capabilities of biomolecules or living microorganisms. Furthermore, the properties of the synthesized nanomaterials are stable, and the method has been extensively studied in recent years. Due to the unique crystaline structure and physicochemical properties of nHAp, results of a large number of studies have shown that its affinity with biological molecules can be used to produce bioactive nHAp by biomimetic synthesis methods. Biomimetically synthesized nHAp is expected to become the mainstream bone tissue engineering scaffold material. Analyzing and summarizing the biomimetic synthetic process and the characteristics of different nHAp materials will facilitate further development of bone defect repair materials with better mechanical and biological properties. Herein we reviewed methods of biomimetic synthesis of nHAp based on different biomolecular templates. Furthermore, we also discussed applications of biomimetic synthesized nHAp in bone tissue engineering, which can used as reference information for further research and development of new-generation bone repair biomaterials.


Assuntos
Durapatita , Engenharia Tecidual , Biomimética , Osso e Ossos , Humanos , Tecidos Suporte
3.
BMC Musculoskelet Disord ; 22(1): 841, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34592967

RESUMO

BACKGROUND: The implantation of screws is a standard procedure in musculoskeletal surgery. Heat can induce thermal osteonecrosis, damage the bone and lead to secondary problems like implant loosening and secondary fractures. The aim of this study was to investigate whether screw insertion generates temperatures that can cause osteonecrosis. METHODS: We measured the temperature of twenty human femur diaphysis in a total of 120 measurements, while screws of different material (stainless steel and titanium alloy) and different design (locking and cortex screw) were inserted in three different screwing modes (manual vs. machine screwing at full and reduced rotational speed) with 6 thermocouples (3 cis and 3 trans cortex). Each was placed at a depth of 2 mm with a distance of 1.5 mm from the outer surface of the screw. RESULTS: The screw design (cortical > locking), the site of measurement (trans-cortex > cis-cortex) and the type of screw insertion (hand insertion > machine insertion) have an influence on the increase in bone temperature. The screw material (steel > titanium), the site of measurement (trans-cortex > cis-cortex) and the type of screw insertion (machine insertion > hand insertion) have an influence on the time needed to cool below critical temperature values. The combination of the two parameters (maximum temperature and cooling time), which is particularly critical for osteonecrosis, is found only at the trans-cortex. CONCLUSION: Inserting a screw hast the potential to increase the temperature of the surrounding bone tissue above critical values and therefore can induce osteonecrosis. The trans-cortex is the critical area for the development of temperatures above the osteonecrosis threshold, making effective cooling by irrigation difficult. It would be conceivable to cool the borehole with cold saline solution before inserting the screw or to cool the screw in cold saline solution. If possible, insertion by hand should be considered.


Assuntos
Diáfises , Temperatura Alta , Fenômenos Biomecânicos , Parafusos Ósseos/efeitos adversos , Osso e Ossos , Diáfises/diagnóstico por imagem , Diáfises/cirurgia , Humanos , Aço Inoxidável
4.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(5): 501-509, 2021 Oct 01.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34636196

RESUMO

The maintenance of bone homeostasis is critical for bone health. It is vulnerable to cause bone loss, even severely osteoporosis when the balance between bone formation and absorption is interrupted. Growing evidence has shown that energy metabolism disorders, such as abnormal glucose metabolism, irregular amino acid metabolism, and aberrant lipid metabolism, can damage bone homeostasis, causing or exacerbating bone mass loss and osteoporosis-related fractures. Here, we summarize the studies of energy metabolism in osteoblasts and osteoclasts and provide a better appreciation of how energy metabolism, especially glucose metabolism maintains bone homeostasis. With this knowledge, new avenues will be unraveled to understand and cue bone-related diseases such as osteoporosis.


Assuntos
Osteoblastos , Osteoclastos , Osso e Ossos , Metabolismo Energético , Osteogênese
5.
Wiad Lek ; 74(8): 1856-1862, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34537733

RESUMO

OBJECTIVE: The aim: To study the structural and functional state of bone tissue in men with ankylosing spondylitis and to asses its relationship with the course of the disease. PATIENTS AND METHODS: Materials and methods: the study was conducted involving 105 men, aged 40.74 ± 0.87 years and 25 generally healthy individuals of the certain age and sex, who formed the control group. The functional ability was assessed by the BASFI index and the disease activity was calculated by ASDAS-CRP and BASDAI. Laboratory criteria for the activity of the inflammatory process were considered erythrocyte sedimentation rate and C-reactive protein. Bone mineral density of the lumbar spine and femoral neck was determined by dual energy X-ray absorptiometry. RESULTS: Results: osteoporosis and osteopenic syndrome were identified in men with ankylosing spondylitis in 27,7% and 29,5% consequently. Disorder of the structural and functional state of bone tissue was closely related to the total indicators of inflammatory activity in ASDAS-CRP (r = -0,36), BASDAI (r = -0,51), the functional index BASFI (r = -0,30), C-reactive protein (r = -0,30) and the cumulative dose of glucocorticoids (r = -0.32). The comparative analysis of densitometric parameters in groups of patients depending on the form of the disease has not shown statistically significant differences. CONCLUSION: Conclusions: The decrease in bone mineral density in patients with ankylosing spondylitis does not depend on age and duration of the disease, but is associated with the cumulative dose of glucocorticoids and high activity of the inflammatory process.


Assuntos
Espondilite Anquilosante , Sedimentação Sanguínea , Osso e Ossos/diagnóstico por imagem , Humanos , Vértebras Lombares/diagnóstico por imagem , Índice de Gravidade de Doença , Espondilite Anquilosante/complicações , Espondilite Anquilosante/diagnóstico por imagem
6.
Georgian Med News ; (316-317): 46-52, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34511443

RESUMO

In a significant number of patients with fibrous dysplasia, among various orthopedic pathologies, bone pain, its deformation and pathological fractures, disorders of bone tissue and its metabolism are leading. Issues of correction of clinical and orthopedic manifestations of the disease and changes in the structural and functional state of bone tissue are insufficiently studied and need improvement The purpose of the study is to improve drug antiosteoporotic therapy for patients with fibrous dysplasia in order to reduce their pain, improve the condition of bone tissue and its metabolism. In the department of pediatric traumatology and orthopedics of the SI "ITO NAMSU" in the period from 2015 to 2020, 16 patients with FD were treated (with polyosal form - 6 patients, with Albright syndrome - 5, with Campanacci syndrome - 5), who have been used drug antiosteoporotic therapy, in particular with the use of antiresorbents (pamidronic acid preparations). The age of patients ranged from 6 to 28 years, 13 patients were children. Qualitative and quantitative assessment of the therapy results and reduction of pain was performed by applying the "VAS" scale, improving the condition of bone tissue and its metabolism by studying the mineral density of bone tissue and markers of bone metabolism. The article presents the rationale, general principles and features of antiosteoporotic therapy; indications and contraindications to it; calculations of doses and schemes of application of these or those drugs, including from group of bisphosphonates at a fibrous dysplasia. The presented drug therapy has been successfully tested in 16 patients with fibrous dysplasia. The effectiveness of the treatment is confirmed by the reduction or elimination of pain, stopping the progression of pathological bone disease of the lower limbs, improving structural condition of bone tissue and its metabolism. The results of drug therapy in patients with fibrous dysplasia indicates its effectiveness and appropriateness of use, which is shown by the relief of pain, improving the structural condition of bone tissue and its metabolism.


Assuntos
Displasia Fibrosa Óssea , Preparações Farmacêuticas , Adolescente , Adulto , Osso e Ossos/diagnóstico por imagem , Criança , Difosfonatos/uso terapêutico , Displasia Fibrosa Óssea/tratamento farmacológico , Estado Funcional , Humanos , Adulto Jovem
7.
Talanta ; 235: 122796, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517654

RESUMO

Bone metastasis of malignant solid tumors has become one of the most serious complications, especially in breast cancer, which was particularly challenging for early detection and treatment in clinical practice. In this work, we reported a new fluorescently labeled bisphosphonate for bone metastasis detection of breast cancer. The designed probes were based on Rhodamine B and bisphosphonate as recognition group, which can specifically target hydroxyapatite (HA) existed in bone tissue. After the osteoclasts were adsorbed on the bone surface, the surrounding microenvironment was acidified, causing the HA to locally dissolve. The probe bound to the HA was then released, and realized the fluorescence turn on under acidic conditions. In vitro experiments showed that G0 was more excellent than G2 owing to shorter connecting arm. Subsequently, we proved that G0 could combine with HA rapidly and exhibit excellent response in solid state. More importantly, we established a model of bone metastasis with MDA-MB-231 cells which was similar to the clinical cases and evaluated the theranostics value of G0 prospectively, which provide the potential application prospect in clinical.


Assuntos
Neoplasias Ósseas , Neoplasias da Mama , Neoplasias Ósseas/tratamento farmacológico , Osso e Ossos , Neoplasias da Mama/tratamento farmacológico , Difosfonatos , Feminino , Humanos , Osteoclastos , Medicina de Precisão , Microambiente Tumoral
8.
An Acad Bras Cienc ; 93(suppl 2): e20201239, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34468486

RESUMO

Aetosauria represents a remarkable clade of armored pseudosuchians in which some of its oldest members are recovered from late Carnian units of Brazil. Three species are known: the mid-sized aetosaur Aetosauroides scagliai, which also occurs in Argentina, and two small-sized species, Aetobarbakinoides brasiliensis and Polesinesuchus aurelioi. We provide a detailed description and comparative analysis of the axial skeleton of Aetosauroides, identifying some diagnostic features as variable. These include the deep pocket pit lateral to the base of the neural spine, the presence of the infradiapophyseal laminae and the lateral fossa ventral to the neurocentral suture. These features are not found in smaller and immature Aetosauroides specimens, resembling the condition found in Polesinesuchus, which is based solely on a juvenile individual, as revealed by osteoderm microstructure analysis. As Polesinesuchus cannot be anatomically differentiated from other small individuals of Aetosauroides, we propose it as a junior synonym of Aetosauroides scagliai. Our results shrink the number of putative 'dwarf' aetosaurs, indicating that morphological variation related to ontogeny affects aetosaur taxonomy and phylogeny.


Assuntos
Osso e Ossos , Fósseis , Argentina , Brasil , Humanos , Filogenia
9.
Zhen Ci Yan Jiu ; 46(8): 656-62, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34472750

RESUMO

OBJECTIVE: To investigate the effect of internal heat-type acupuncture needle on the expression of osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), and receptor activator of NF-κB (RANK) in knee osteoarthritis (KOA) rabbits, so as to explore its mechanisms in relieving KOA. METHODS: Thirty New Zealand rabbits were randomly divided into control, model and treatment groups, with 10 rabbits in each group. The KOA model was established by using Hulth method. The rabbits of the treatment group received internal heat-type acupuncture needles (42 ℃) on the left hind limb 20 min, once a week for 4 weeks. The behavioral scores were assessed according to the pain severity, gait, joint motion range and articular swelling severity in reference to the modified Lequesne's methods. Toluidine Blue staining was performed to observe the structure of the subchondral bone and to analyze the difference of morphometric parameters. The protein and mRNA expressions of OPG, RANKL and RANK were detected by Western blot and real-time PCR, respectively. RESULTS: Compared with the control group, the Lequesne total score, the separation degree of trabecular bone, the protein and mRNA expressions of RANKL and RANK in subchondral bone tissues were significantly increased in the model group, while the percentage of trabecular bone area, number of trabecular bone, the expression of OPG protein and mRNA were decreased (P<0.05, P<0.01). The above indexes were all reversed in the treatment group relevant to those of the model group (P<0.05). CONCLUSION: The internal heat-type acupuncture needle therapy can improve the motor function of rabbits with KOA, which may be related to its effects in up-regulating the expression of OPG and down-regulating the RANKL and RANK in subchondral bone tissue.


Assuntos
Terapia por Acupuntura , Osteoartrite do Joelho , Animais , Osso e Ossos , Temperatura Alta , Ligantes , Agulhas , Osteoartrite do Joelho/genética , Osteoartrite do Joelho/terapia , Osteoprotegerina/genética , Coelhos , Receptor Ativador de Fator Nuclear kappa-B
10.
Adv Exp Med Biol ; 1345: 225-239, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34582026

RESUMO

Decellularization technology is a process that uses different methods such as physical, chemical or enzymatic methods in order to eliminate cellular remnants from original tissues or organs while minimizing any adverse effect on the structural properties, biological activity, and mechanical integrity of the remaining ECM. Regenerative medicine uses the most promising therapies to replace or regenerate tissues and organs in human, restore or establish normal functions lost due to disease or injury. By the combination between new biomaterials and cells, one of the goals of regenerative medicine is to create autologous grafts for transplantation therapies in the future.Various decellularization methods have been developed include chemical treatment, biological treatment and physical treatment. The aim of this chapter is to evaluate the decellularization method and all available materials that preserves the matrix without structural disruption.


Assuntos
Engenharia Tecidual , Tecidos Suporte , Osso e Ossos , Matriz Extracelular , Humanos , Medicina Regenerativa
11.
Nano Lett ; 21(19): 7998-8007, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34529430

RESUMO

With the aging of the population, postmenopausal osteoporosis becomes increasingly widespread and severe as fractures caused by osteoporosis may lead to permanent disabilities and even death. Inspired by extracellular vesicles that participate in bone remodeling, we present a biomimicking polymer vesicle for bone-targeted ß-estradiol (E2) delivery. This vesicle is self-assembled from a poly(ε-caprolactone)28-block-poly[(l-glutamic acid)7-stat-(l-glutamic acid-alendronic acid)4] (PCL28-b-P[Glu7-stat-(Glu-ADA)4]) diblock copolymer. The alendronic acid (ADA) on the coronas endows the polymer vesicles with a high bone affinity and acts synergistically with E2 to achieve an enhanced therapeutic effect. As confirmed with ovariectomized osteoporosis rat models, bone loss was significantly reversed as the recovery rates of total BMD (bone mineral density) and trabecular BMD were 70.4% and 99.3%, respectively. Overall, this work provides fresh insight into the treatment of osteoporosis.


Assuntos
Osteoporose , Polímeros , Animais , Densidade Óssea , Osso e Ossos , Osteoporose/tratamento farmacológico , Ratos
12.
Biomed Res Int ; 2021: 3087071, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34513989

RESUMO

Methods: Three models of a single internal connection bone level-type implant inserted into a posterior mandible bone section were constructed using a 3D finite element software: one control model without marginal bone loss and two test models, both with a circumferential peri-implant bone defect, one with a 3 mm high defect and the other one 6 mm high. A 150 N static load was tested on the central fossa at 6° relative to the axial axis of the implant. Results: The results showed differences in the magnitude of strain and stress transferred to the bone between models, being the higher strain found in the trabecular bone around the implant with greater marginal bone loss. Stress distribution differed between models, being concentrated at the cortical bone in the control model and at the trabecular bone in the test models. Conclusion: Marginal bone loss around dental implants under occlusal loading influences the magnitude and distribution of the stress transferred and the deformation of peri-implant bone, being higher as the bone loss increases.


Assuntos
Perda do Osso Alveolar/cirurgia , Implantes Dentários/efeitos adversos , Mandíbula/cirurgia , Fenômenos Biomecânicos , Osso e Ossos/fisiologia , Osso e Ossos/cirurgia , Simulação por Computador , Análise do Estresse Dentário , Análise de Elementos Finitos , Humanos , Modelos Biológicos , Próteses e Implantes/efeitos adversos , Software , Estresse Mecânico
13.
Sensors (Basel) ; 21(18)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34577474

RESUMO

BACKGROUND: The preparation of bone for the insertion of an osseointegrated transfemoral implant and the insertion process are performed at very low speeds in order to avoid thermal damages to bone tissue which may potentially jeopardize implant stability. The aim of this study was to quantify the temperature increase in the femur at different sites and insertion depths, relative to the final implant position during the stepwise implantation procedure. METHODS: The procedure for installation of the osseointegrated implant was performed on 24 femoral specimens. In one specimen of each pair, the surgery was performed at the clinically practiced speed, while the speed was doubled in the contralateral specimen. Six 0.075 mm K fine gauge thermocouples (RS Components, Sorby, UK) were inserted into the specimen at a distance of 0.5 mm from the final implant surface, and six were inserted at a distance of 1.0 mm. RESULTS: Drilling caused a temperature increase of <2.5 °C and was not statistically significantly different for most drill sizes (0.002 < p < 0.845). The mean increase in temperature during thread tapping and implant insertion was <5.0 °C, whereas the speed had an effect on the temperature increase during thread tapping. CONCLUSIONS: Drilling is the most time-consuming part of the surgery. Doubling the clinically practiced speed did not generate more heat during this step, suggesting the speed and thus the time- and cost-effectiveness of the procedure could be increased. The frequent withdrawal of the instruments and removal of the bone chips is beneficial to prevent temperature peaks, especially during thread tapping.


Assuntos
Prótese Ancorada no Osso , Implantes Dentários , Temperatura Corporal , Osso e Ossos , Temperatura Alta , Temperatura , Termômetros
14.
J Mech Behav Biomed Mater ; 123: 104727, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34492615

RESUMO

Bone drilling is an indispensable and demanding operation among many orthopaedic operations. A dedicated drill bit that can achieve low-trauma and self-centring drilling is in urgent need. In this study, a three-step orthopaedic low-traumatic drill bit design was proposed. In order to evaluate the drilling performance of the proposed drill, comprehensive comparison tests were carried out with various commercial medical drills in terms of skiving force, thrust force, temperature rise, and surface quality. The experimental results show that the proposed three-step drill design with the optimal point angle, a small chisel edge, transition arc and web thinning can obtain lower and more stable thrust force, slighter bending force, smaller temperature rise, and higher hole quality compared with the commercial drill bits. The proposed drill shows satisfactory drilling performance and has great application potential in clinical surgery.


Assuntos
Procedimentos Ortopédicos , Ortopedia , Osso e Ossos , Fenômenos Mecânicos , Temperatura
15.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34548398

RESUMO

Skeletal ciliopathies (e.g., Jeune syndrome, short rib polydactyly syndrome, and Sensenbrenner syndrome) are frequently associated with nephronophthisis-like cystic kidney disease and other organ manifestations. Despite recent progress in genetic mapping of causative loci, a common molecular mechanism of cartilage defects and cystic kidneys has remained elusive. Targeting two ciliary chondrodysplasia loci (ift80 and ift172) by CRISPR/Cas9 mutagenesis, we established models for skeletal ciliopathies in Xenopus tropicalis Froglets exhibited severe limb deformities, polydactyly, and cystic kidneys, closely matching the phenotype of affected patients. A data mining-based in silico screen found ttc30a to be related to known skeletal ciliopathy genes. CRISPR/Cas9 targeting replicated limb malformations and renal cysts identical to the models of established disease genes. Loss of Ttc30a impaired embryonic renal excretion and ciliogenesis because of altered posttranslational tubulin acetylation, glycylation, and defective axoneme compartmentalization. Ttc30a/b transcripts are enriched in chondrocytes and osteocytes of single-cell RNA-sequenced embryonic mouse limbs. We identify TTC30A/B as an essential node in the network of ciliary chondrodysplasia and nephronophthisis-like disease proteins and suggest that tubulin modifications and cilia segmentation contribute to skeletal and renal ciliopathy manifestations of ciliopathies in a cell type-specific manner. These findings have implications for potential therapeutic strategies.


Assuntos
Osso e Ossos/anormalidades , Ciliopatias/patologia , Craniossinostoses/patologia , Proteínas do Citoesqueleto/metabolismo , Displasia Ectodérmica/patologia , Embrião não Mamífero/patologia , Anormalidades Musculoesqueléticas/patologia , Doenças Renais Policísticas/patologia , Tubulina (Proteína)/química , Animais , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Ciliopatias/genética , Ciliopatias/metabolismo , Craniossinostoses/genética , Craniossinostoses/metabolismo , Proteínas do Citoesqueleto/genética , Modelos Animais de Doenças , Displasia Ectodérmica/genética , Displasia Ectodérmica/metabolismo , Embrião não Mamífero/metabolismo , Anormalidades Musculoesqueléticas/genética , Anormalidades Musculoesqueléticas/metabolismo , Fenótipo , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Tubulina (Proteína)/metabolismo , Xenopus laevis
16.
Mater Sci Eng C Mater Biol Appl ; 128: 112300, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474851

RESUMO

The present experimental study aims to extend know-how on resorbable polycaprolactone/hydroxyapatite (PCL/HA, 70/30 wt%) scaffolds, produced by Laser Powder Bed Fusion (LPBF) technology, to geometrically complex lattice structures and micro porous struts. Using optimized LPBF printing parameters, micro- and macro-porous scaffolds for bone tissue regeneration were produced by regularly repeating in space Diamond (DO) and Rhombic Dodecahedron (RD) elementary unit cells. After production, scaffolds were submitted to structural, mechanical, and biological characterization. The interaction of scaffolds with human Mesenchymal Stem Cells (hMSCs) allowed studying the degradative processes of the PCL matrix. Biomechanical performances and biodegradation of scaffolds were compared to literature results and bone tissue data. Mechanical compression test, biological viability up to 4 days of incubation and degradation rate evidenced strong dependence of scaffold behavior on unit cell geometry as well as on global geometrical features.


Assuntos
Engenharia Tecidual , Tecidos Suporte , Osso e Ossos , Durapatita , Humanos , Lasers , Poliésteres , Porosidade , Pós
17.
Adv Exp Med Biol ; 1334: 181-204, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34476750

RESUMO

The anatomical collections at the National Museum of Health and Medicine (NMHM) contain skeletal specimens that highlight the history of military and civilian medicine dating from the American Civil War and the founding of the museum as the Army Medical Museum in 1862. Today, NMHM curates over 6400 gross skeletal specimens consisting primarily of pathological or anomalous single bone elements that display a variety of pathological conditions, including congenital anomalies, neoplasms, healed and unhealed trauma and infectious diseases, and surgical interventions such as amputations and excisions. In an effort to increase accessibility to these pathological specimens, NMHM is collaborating with Virginia Commonwealth University (VCU) and the Laboratory Division of the Federal Bureau of Investigation (FBI) to digitize and disseminate high-quality 3D models via online portals, enabling scholars and educators to manipulate, analyze, and 3D print the models from anywhere in the world. Many institutions with courses in paleopathology and forensic anthropology do not have reference collections or access to museum collections for hands-on teaching. Therefore a digital repository of osteological specimens can provide an unprecedented and unique resource of exemplars for scholars and educators. The sharing of these military medical assets improves historical knowledge and diagnostic capabilities in the fields of medicine and anthropology. This chapter outlines the digitization processes that are being utilized to increase access to these pathological skeletal specimens through multimodal 3D capture.


Assuntos
Medicina , Militares , Osso e Ossos , Humanos , Laboratórios , Museus
18.
Comput Methods Programs Biomed ; 210: 106353, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34500142

RESUMO

BACKGROUND AND OBJECTIVE: Capturing the population variability of bone properties is of paramount importance to biomedical engineering. The aim of the present paper is to describe variability and correlations in bone mineral density with a spatial random field inferred from routine computed tomography data. METHODS: Random fields were simulated by transforming pairwise uncorrelated Gaussian random variables into correlated variables through the spectral decomposition of an age-detrended correlation matrix. The validity of the random field model was demonstrated in the spatiotemporal analysis of bone mineral density. The similarity between the computed tomography samples and those generated via random fields was analyzed with the energy distance metric. RESULTS: The random field of bone mineral density was found to be approximately Gaussian/slightly left-skewed/strongly right-skewed at various locations. However, average bone density could be simulated well with the proposed Gaussian random field for which the energy distance, i.e., a measure that quantifies discrepancies between two distribution functions, is convergent with respect to the number of correlation eigenpairs. CONCLUSIONS: The proposed random field model allows the enhancement of computational biomechanical models with variability in bone mineral density, which could increase the usability of the model and provides a step forward in in-silico medicine.


Assuntos
Densidade Óssea , Osso e Ossos , Tomografia Computadorizada por Raios X
19.
Arch Oral Biol ; 131: 105266, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34571394

RESUMO

OBJECTIVE: To analyze the lack of 5-lipoxygenase (5LO) on dental socket healing and post-natal phenotype of intramembranous and endochondral bones. DESIGN: Wild type (WT) 129/SvEv (n = 20) and 5LO knockout (5LOKO) (n = 20) male mice underwent tooth extraction of the upper right incisor and were euthanized after 7, 14, and 30 day time points for the evaluation of dental socket healing and histological phenotyping of intramembranous (IM) and endochondral (EC) bones. Microscopic analysis of alveolar sockets included histopathological description, histomorphometry, and immunohistochemistry for 5LO, cyclooxygenase 2 (COX2), and tartrate resistant acid phosphatase (TRAP). RESULTS: Histological phenotyping revealed thicker cortical bone in EC bones (femur and vertebra) of 5LOKO mice compared to WTs, with no differences in collagenous content. Although dental socket healing was similarly observed in both groups, WT mice revealed increased numbers of COX-2+ and 5LO+ cells during bone maturing stage, with a decrease of TRAP+ cells at day 30. On the other hand, an increased quantity of fibroblasts was observed at day 7 in 5LOKO group, as well as increased inflammatory infiltrate and significantly decreased TRAP+ cells at final stages of alveolar socket healing in comparison to WTs. CONCLUSIONS: The lack of 5LO in 5LOKO mice resulted in thicker cortical of EC, but not of IM post natal bones. Furthermore, genetic deletion of 5LO in the 5LOKO mice directly affected the inflammatory response during socket healing, influencing initial and late phases of bone repair in a model of post-tooth extraction in 129Sv WT and 5LOKO mice.


Assuntos
Araquidonato 5-Lipoxigenase , Extração Dentária , Alvéolo Dental , Cicatrização , Animais , Araquidonato 5-Lipoxigenase/genética , Osso e Ossos , Masculino , Camundongos , Camundongos Knockout , Osteogênese
20.
ACS Appl Mater Interfaces ; 13(33): 39142-39156, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433244

RESUMO

The reconstruction of the intra/interfibrillar mineralized collagen microstructure is extremely important in biomaterial science and regeneration medicine. However, certain problems, such as low efficiency and long period of mineralization, are apparent, and the mechanism of interfibrillar mineralization is often neglected in the present literature. Thus, we propose a novel model of biomimetic collagen mineralization that uses molecules with the dual function of cross-linking collagen and regulating collagen mineralization to construct the intrafibrillar and interfibrillar collagen mineralization of the structure of mineralized collagen hard tissues. In the present study completed in vitro, N-2-(3,4-dihydroxyphenyl) acrylamide (DAA) is used to bind and cross-link collagen molecules and further stabilize the self-assembled collagen fibers. The DAA-collagen complex provides more affinity with calcium and phosphate ions, which can reduce the calcium phosphate/collagen interfacial energy to promote hydroxyapatite (HA) nucleation and accelerate the rate of collagen fiber mineralization. Besides inducing intrafibrillar mineralization, the DAA-collagen complex mineralization template can realize interfibrillar mineralization with the c-axis of the HA crystal on the surface of collagen fibers and between fibers that are parallel to the long axis of collagen fibers. The DAA-collagen complex, as a new type of mineralization template, may provide a new collagen mineralization strategy to produce a mineralized scaffold material for tissue engineering or develop bone-like materials.


Assuntos
Acrilamida/química , Materiais Biomiméticos/química , Colágeno/química , Dopamina/química , Osso e Ossos , Cálcio/química , Cálcio/metabolismo , Fosfatos de Cálcio/química , Reagentes para Ligações Cruzadas/química , Cristalização , Durapatita/química , Durapatita/metabolismo , Matriz Extracelular/metabolismo , Humanos , Simulação de Dinâmica Molecular , Polimerização , Medicina Regenerativa , Propriedades de Superfície , Engenharia Tecidual
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