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1.
Vet Clin North Am Small Anim Pract ; 50(1): 1-15, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31635916

RESUMO

This article reviews the biomechanical parameters of fracture repair that influence construct stiffness and strength. The stiffness influences the relative motion between fracture fragments, known as gap strain, and, thus, callus development. Construct strength determines the magnitude and number of load events that the repair can resist before failure. Surgeons must optimize these parameters in order to achieve satisfactory outcomes for the patients.


Assuntos
Fixação de Fratura/veterinária , Fraturas Ósseas/veterinária , Animais , Fenômenos Biomecânicos , Osso e Ossos/fisiologia , Consolidação da Fratura/fisiologia
2.
Radiol Med ; 125(3): 313-318, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31883053

RESUMO

OBJECTIVES: Bone strain index (BSI) is a dual-energy X-ray absorptiometry (DXA)-derived index of bone strength obtained from lumbar densitometric scan. We estimated the reproducibility of BSI in healthy women with different body mass index. METHODS: We enrolled postmenopausal women (mean age ± SD: 66 ± 10 years) divided into three groups (A, B and C) according to body mass index (BMI: < 25; 25-29.9; ≥ 30 kg/m2) and two groups (D and E) according to waist circumference (WC: ≤ 88; > 88 cm), each of 30 subjects. They underwent two DXA examinations with in-between repositioning, according to the International Society for Clinical Densitometry guidelines for precision estimation. Bone mineral density (BMD) and BSI were expressed as g/cm2 and absolute value, respectively. The coefficient of variation (CoV) was calculated as the ratio between root-mean-square standard deviation and mean; least significant change percentage (LSC%) as 2.77 × CoV; reproducibility as the complement to 100% LSC. RESULTS: BSI increased proportionally to BMI and WC and significantly in group C compared to B and A (p = 0.032 and 0.006, respectively). BSI was significantly higher in E compared to D (p = 0.017), whereas no differences were observed in BMD. Although BSI reproducibility was slightly lower in group C (89%), the differences were not significant between all groups. BMD reproducibility did not significantly differ between all groups. CONCLUSIONS: BSI reproducibility was significantly lower than that of BMD and decreased proportionally to BMI and WC increase. This reduction of BSI reproducibility was more pronounced in patients with BMI ≥ 30 and WC > 88, as expected, being BSI a parameter sensible to weight.


Assuntos
Absorciometria de Fóton/métodos , Índice de Massa Corporal , Osso e Ossos/diagnóstico por imagem , Circunferência da Cintura , Idoso , Densidade Óssea , Osso e Ossos/fisiologia , Feminino , Humanos , Pessoa de Meia-Idade , Posicionamento do Paciente , Estudos Prospectivos , Reprodutibilidade dos Testes , Coluna Vertebral/diagnóstico por imagem
3.
J Shoulder Elbow Surg ; 29(1): 157-166, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31401128

RESUMO

BACKGROUND: The purpose of this study was to evaluate the biomechanical and histologic properties of rotator cuff repairs using a vented anchor attached to a bioresorbable interpositional scaffold composed of aligned PLGA (poly(l-lactide-co-glycoside)) microfibers in an animal model compared to standard anchors in an ovine model. METHODS: Fifty-six (n = 56) skeletally mature sheep were randomly assigned to a repair of an acute infraspinatus tendon detachment using a innovative anchor-PLGA scaffold device (Treatment) or a similar anchor without the scaffold (Control). Animals were humanely euthanized at 7 and 12 weeks post repair. Histologic and biomechanical properties of the repairs were evaluated and compared. RESULTS: The Treatment group had a significantly higher fibroblast count at 7 weeks compared to the Control group. The tendon bone repair distance, percentage perpendicular fibers, new bone formation at the tendon-bone interface, and collagen type III deposition was significantly greater for the Treatment group compared with the Control group at 12 weeks (P ≤ .05). A positive correlation was identified in the Treatment group between increased failure loads at 12 weeks and the following parameters: tendon-bone integration, new bone formation, and collagen type III. No statistically significant differences in biomechanical properties were identified between Treatment and Control Groups (P > .05). CONCLUSIONS: Use of a vented anchor attached to a bioresorbable interpositional scaffold composed of aligned PLGA microfibers improves the histologic properties of rotator cuff repairs in a sheep model. Improved histology was correlated with improved final construct strength at the 12-week time point.


Assuntos
Osso e Ossos/fisiologia , Lesões do Manguito Rotador/cirurgia , Tendões/fisiologia , Tecidos Suporte , Cicatrização , Implantes Absorvíveis , Animais , Materiais Biocompatíveis/uso terapêutico , Fenômenos Biomecânicos , Osso e Ossos/cirurgia , Contagem de Células , Colágeno Tipo III/metabolismo , Modelos Animais de Doenças , Feminino , Fibroblastos , Osteogênese , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/uso terapêutico , Estudos Prospectivos , Lesões do Manguito Rotador/patologia , Ovinos , Técnicas de Sutura , Tendões/cirurgia
4.
Int J Nanomedicine ; 14: 6615-6630, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695360

RESUMO

Background: Nanocomposites produced by reinforcement of polysaccharide matrix with nanoparticles are widely used in engineering of biomaterials. However, clinical applications of developed novel biomaterials are often limited due to their poor biocompatibility. Purpose: The aim of this work was to comprehensively assess biocompatibility of highly macroporous chitosan/agarose/nanohydroxyapatite bone scaffolds produced by a novel method combining freeze-drying with a foaming agent. Within these studies, blood plasma protein adsorption, osteoblast (MC3T3-E1 Subclone 4 and hFOB 1.19) adhesion and proliferation, and osteogenic differentiation of mesenchymal stem cells derived from bone marrow and adipose tissue were determined. The obtained results were also correlated with materials' surface chemistry and wettability to explain the observed protein and cellular response. Results: Obtained results clearly showed that the developed nanocomposite scaffolds were characterized by high biocompatibility and osteoconductivity. Importantly, the scaffolds also revealed osteoinductive properties since they have the ability to induce osteogenic differentiation (Runx2 synthesis) in undifferentiated mesenchymal stem cells. The surface of biomaterials is extremely hydrophilic, prone to protein adsorption with the highest affinity toward fibronectin binding, which allows for good osteoblast adhesion, spreading, and proliferation. Conclusion: Produced by a novel method, macroporous nanocomposite biomaterials have great potential to be used in regenerative medicine for acceleration of the bone healing process.


Assuntos
Regeneração Óssea , Osso e Ossos/fisiologia , Quitosana/química , Durapatita/química , Nanocompostos/química , Osteoblastos/citologia , Sefarose/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Adsorção , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Biomarcadores/metabolismo , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Cães , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Camundongos , Osteogênese/efeitos dos fármacos , Molhabilidade
5.
Elife ; 82019 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-31588901

RESUMO

Mechanical loading, such as caused by exercise, stimulates bone formation by osteoblasts and increases bone strength, but the mechanisms are poorly understood. Osteocytes reside in bone matrix, sense changes in mechanical load, and produce signals that alter bone formation by osteoblasts. We report that the ion channel Piezo1 is required for changes in gene expression induced by fluid shear stress in cultured osteocytes and stimulation of Piezo1 by a small molecule agonist is sufficient to replicate the effects of fluid flow on osteocytes. Conditional deletion of Piezo1 in osteoblasts and osteocytes notably reduced bone mass and strength in mice. Conversely, administration of a Piezo1 agonist to adult mice increased bone mass, mimicking the effects of mechanical loading. These results demonstrate that Piezo1 is a mechanosensitive ion channel by which osteoblast lineage cells sense and respond to changes in mechanical load and identify a novel target for anabolic bone therapy.


Assuntos
Osso e Ossos/citologia , Osso e Ossos/fisiologia , Canais Iônicos/metabolismo , Osteócitos/metabolismo , Osteogênese , Estresse Mecânico , Animais , Linhagem Celular , Técnicas de Silenciamento de Genes , Canais Iônicos/administração & dosagem , Canais Iônicos/agonistas , Camundongos
6.
Adv Exp Med Biol ; 1164: 153-160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31576547

RESUMO

Skeletal aging begins after peak bone mass is reached; progressive bone loss then occurs. Peak bone mass may occur at different ages in different skeletal sites and varies between sexes. Accelerated loss of bone occurs in the perimenopausal period in women, whereas more gradual but progressive loss of bone occurs in aging men. Changes in bone quality as well as bone quantity occur during growth and subsequent aging. These include changes in bone microarchitecture which may differ between cortical and trabecular compartments and in different sites, and may impact on bone size and geometry. Changes in material properties of bone matrix may also occur with aging. Loss of bone quantity and altered bone quality with aging may weaken bones and culminate in osteoporosis with an increased risk of fractures. Both genetic and epigenetic mechanisms may predispose to osteoporosis. Cellular and molecular events underlie the alterations in bone quantity and quality. Osteoclastic bone resorption and osteoblastic bone formation, tightly regulated by hormones, growth factors, and cytokines, are organized in coordinated activities resulting in remodeling and modeling. Malignancies, and anti-neoplastic therapies, may impact on the cellular and molecular events in the aging skeleton and produce focal or diffuse skeletal lesions and fractures.


Assuntos
Envelhecimento , Reabsorção Óssea , Osso e Ossos , Densidade Óssea , Osso e Ossos/fisiologia , Feminino , Humanos , Masculino , Osteoporose , Fatores Sexuais
7.
Nat Commun ; 10(1): 4825, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645555

RESUMO

Natural creatures, from fish and cephalopods to snakes and birds, combine neural control, sensory feedback and compliant mechanics to effectively operate across dynamic, uncertain environments. In order to facilitate the understanding of the biophysical mechanisms at play and to streamline their potential use in engineering applications, we present here a versatile numerical approach to the simulation of musculoskeletal architectures. It relies on the assembly of heterogenous, active and passive Cosserat rods into dynamic structures that model bones, tendons, ligaments, fibers and muscle connectivity. We demonstrate its utility in a range of problems involving biological and soft robotic scenarios across scales and environments: from the engineering of millimeter-long bio-hybrid robots to the synthesis and reconstruction of complex musculoskeletal systems. The versatility of this methodology offers a framework to aid forward and inverse bioengineering designs as well as fundamental discovery in the functioning of living organisms.


Assuntos
Bioengenharia , Simulação por Computador , Articulação do Cotovelo/fisiologia , Plumas/fisiologia , Fenômenos Fisiológicos Musculoesqueléticos , Asas de Animais/fisiologia , Animais , Osso e Ossos/fisiologia , Humanos , Ligamentos/fisiologia , Músculo Esquelético/fisiologia , Sistema Musculoesquelético , Amplitude de Movimento Articular/fisiologia , Robótica , Tendões/fisiologia
8.
Int J Nanomedicine ; 14: 7947-7962, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632010

RESUMO

Purpose: Hydroxyapatite (HA) is a biologically active ceramic which promotes bone growth, but it suffers from relatively weak mechanical properties. Multi-walled carbon nanotubes (MWCNTs) have high tensile strength and a degree of stiffness that can be used to strengthen HA; potentially improving the clinical utility of the bone implant. Methods: HA was precipitated by the wet precipitation method in the presence of pristine (p) or functionalised (f) MWCNTs, and polyvinyl alcohol (PVA) or hexadecyl trimethyl ammonium bromide (HTAB) as the surfactant. The resulting composites were characterised and the diametral tensile strength and compressive strength of the composites were measured. To determine the biocompatibility of the composites, human osteoblast cells (HOB) were proliferated in the presence of the composites for 7 days. Results: The study revealed that both the MWCNTs and surfactants play a crucial role in the nucleation and growth of the HA. Composites made with f-MWCNTs were found to have better dispersion and better interaction with the HA particles compared to composites with p-MWCNTs. The mechanical strength was improved in all the composites compared to pure HA composites. The biocompatibility study showed minimal LDH activity in the media confirming that the composites were biocompatible. Similarly, the ALP activity confirmed that the cells grown on the composites containing HTAB were comparable to the control whereas the composites containing PVA surfactant showed significantly reduced ALP activity. Conclusions: The study shows that the composites made of f-MWCNTs HTAB are stronger than pure HA composites and biocompatible making it a suitable material to study further.


Assuntos
Materiais Biocompatíveis/química , Osso e Ossos/fisiologia , Durapatita/química , Teste de Materiais , Nanocompostos/química , Nanotubos de Carbono/química , Próteses e Implantes , Fosfatase Alcalina/metabolismo , Forma Celular , Força Compressiva , Eletrólitos/química , Humanos , L-Lactato Desidrogenase/metabolismo , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Osteoblastos/citologia , Osteoblastos/enzimologia , Osteoblastos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Difração de Raios X
9.
Int J Nanomedicine ; 14: 8149-8159, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632024

RESUMO

Introduction: Recently several new approaches were emerging in bone tissue engineering to develop a substitute for remodelling the damaged tissue. In order to resemble the native extracellular matrix (ECM) of the human tissue, the bone scaffolds must possess necessary requirements like large surface area, interconnected pores and sufficient mechanical strength. Materials and methods: A novel bone scaffold has been developed using polyurethane (PE) added with wintergreen (WG) and titanium dioxide (TiO2). The developed nanocomposites were characterized through field emission scanning electron microscopy (FESEM), Fourier transform and infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measurement, thermogravimetric analysis (TGA), atomic force microscopy (AFM) and tensile testing. Furthermore, anticoagulant assays, cell viability analysis and calcium deposition were used to investigate the biological properties of the prepared hybrid nanocomposites. Results: FESEM depicted the reduced fibre diameter for the electrospun PE/WG and PE/WG/TiO2 than the pristine PE. The addition of WG and TiO2 resulted in the alteration in peak intensity of PE as revealed in the FTIR. Wettability measurements showed the PE/WG showed decreased wettability and the PE/WG/TiO2 exhibited improved wettability than the pristine PE. TGA measurements showed the improved thermal behaviour for the PE with the addition of WG and TiO2. Surface analysis indicated that the composite has a smoother surface rather than the pristine PE. Further, the incorporation of WG and TiO2 improved the anticoagulant nature of the pristine PE. In vitro cytotoxicity assay has been performed using fibroblast cells which revealed that the electrospun composites showed good cell attachment and proliferation after 5 days. Moreover, the bone apatite formation study revealed the enhanced deposition of calcium content in the fabricated composites than the pristine PE. Conclusion: Fabricated nanocomposites rendered improved physico-chemical properties, biocompatibility and calcium deposition which are conducive for bone tissue engineering.


Assuntos
Osso e Ossos/fisiologia , Poliuretanos/farmacologia , Engenharia Tecidual/métodos , Tecidos Suporte/química , Osso e Ossos/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Teste de Materiais , Nanocompostos/química , Nanocompostos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Termogravimetria , Titânio/farmacologia , Molhabilidade , Difração de Raios X
10.
Int J Nanomedicine ; 14: 5831-5848, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534327

RESUMO

Purpose: In order to accelerate the tendon-bone healing processes and achieve the efficient osteointegration between the tendon graft and bone tunnel, we aim to design bioactive electrospun nanofiber membranes combined with tendon stem/progenitor cells (TSPCs) to promote osteogenic regeneration of the tendon and bone interface. Methods: In this study, nanofiber membranes of polycaprolactone (PCL), PCL/collagen I (COL-1) hybrid nanofiber membranes, poly(dopamine) (PDA)-coated PCL nanofiber membranes and PDA-coated PCL/COL-1 hybrid nanofiber membranes were successfully fabricated by electrospinning. The biochemical characteristics and nanofibrous morphology of the membranes, as well as the characterization of rat TSPCs, were defined in vitro. After co-culture with different types of electrospun nanofiber membranes in vitro, cell proliferation, viability, adhesion and osteogenic differentiation of TSPCs were evaluated at different time points. Results: Among all the membranes, the performance of the PCL/COL-1 (volume ratio: 2:1 v/v) group was superior in terms of its ability to support the adhesion, proliferation, and osteogenic differentiation of TSPCs. No benefit was found in this study to include PDA coating on cell adhesion, proliferation and osteogenic differentiation of TSPCs. Conclusion: The PCL/COL-1 hybrid electrospun nanofiber membranes are biocompatible, biomimetic, easily fabricated, and are capable of supporting cell adhesion, proliferation, and osteogenic differentiation of TSPCs. These bioactive electrospun nanofiber membranes may act as a suitable functional biomimetic scaffold in tendon-bone tissue engineering applications to enhance tendon-bone healing abilities.


Assuntos
Materiais Biocompatíveis/farmacologia , Osso e Ossos/fisiologia , Membranas Artificiais , Nanofibras/química , Células-Tronco/citologia , Tendões/citologia , Engenharia Tecidual/métodos , Animais , Osso e Ossos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colágeno Tipo I/metabolismo , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Nanofibras/ultraestrutura , Osteogênese , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos
11.
BMC Musculoskelet Disord ; 20(1): 429, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31521141

RESUMO

BACKGROUND: Various cross-sectional studies provide an abundance of evidence that shows a relationship between bone quantity and muscle health. However, one question remains, less-often studied: is their development - or decline - associated? The aim of the research was to conduct a systematic review and meta-analysis to summarize the studies exploring the association between changes in bone mineral density (BMD) and changes in muscle parameters (registration CRD42018093813). METHODS: We searched for prospective studies, both in children and adults, by consulting electronic databases (Ovid-MEDLINE, Ovid-AMED, Scopus). Each review steps were performed by two independent reviewers. For outcomes reported by less of 3 studies, we synthetized the results narratively. In other cases, a meta-analysis was performed, giving an overall r coefficient and its 95% confidence interval (CI). RESULTS: Fifteen papers were included. In connection with the change of BMD, 10 studies concerned the parallel change of lean mass, 4 were about grip strength, and 1 was about physical performance. Children were the population of interest for 5 studies, while the aging population was the focus of the other studies. The correlation between hip BMD and lean mass was significant, with an overall coefficient r = 0.37 (95% CI 0.23-0.49). High heterogeneity was observed between studies but the length of follow-up, sex and study quality did not seem to significantly influence results. The systematic review allowed some other highlights: a significant link between changes in BMD and changes in muscle strength was observed (p-value < 0.05 in the 4 studies), in addition to changes in performance (1 study, r = 0.21, p-value = 0.004). CONCLUSION: Despite the heterogeneity between studies, we highlighted a significant association between the change of BMD and the change of various muscle parameters. Future studies should investigate preventive and therapeutic strategies that are based on a single entity: the 'muscle-bone unit'.


Assuntos
Densidade Óssea/fisiologia , Força Muscular/fisiologia , Adulto , Osso e Ossos/fisiologia , Criança , Humanos , Músculo Esquelético/fisiologia , Desempenho Físico Funcional
12.
Mater Sci Eng C Mater Biol Appl ; 105: 110032, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546347

RESUMO

Removing malignant bone tumors results in critical size bone defects. These voids in bones should be filled by a proper scaffold that not only can support cell ingrowth and bone regeneration but also it has to show a desirable ability in long-term releasing anticancer drugs in order to prevent the growth of remaining cancer cells. Applying this scaffold can significantly improve the outcome of bone tumors treatment. In this study, a novel way is proposed for immobilization of doxorubicin (DOX)-loaded polycaproloactone (PCL) microparticles on the hardystonite (HT) scaffold surfaces. High interconnected porous HT scaffolds with immobilized DOX-encapsulated PCL microparticles can be successfully fabricated by modified water/oil/water method. In the present work, we verify a slow release of DOX over 30 days from PCL microparticles inside HT scaffold. Our developed HT scaffolds with the long-term release of DOX are more effective in reduction of Saos-2 cancer cells viability and induce higher degrees of apoptosis compared to DOX dip coated HT scaffolds. Encapsulating DOX into PCL microparticles significantly improves the anti-tumor activity of DOX by regulating the expression of apoptosis-related genes. Our results suggest that by immobilization of polymeric vehicles on the ceramic scaffold for controlled drug release, we can achieve high efficiency in apoptosis of cancer cells.


Assuntos
Osso e Ossos/fisiologia , Sistemas de Liberação de Medicamentos/métodos , Engenharia Tecidual/métodos , Apoptose/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Caspases/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Microesferas , Estresse Oxidativo/efeitos dos fármacos , Poliésteres/química , Porosidade , Silicatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tecidos Suporte/química
13.
Mater Sci Eng C Mater Biol Appl ; 105: 110138, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546409

RESUMO

In the present study, porous (about 70 vol%) nanocomposite scaffolds made of polycaprolactone (PCL) and different amounts (0 to 15 wt%) of 45S bioactive glass (BG) nanoparticles (with a particle size of about 40 nm) containing 7 wt% strontium (Sr) were fabricated by solvent casting technique for bone tissue engineering. Then, a selected optimum scaffold was coated with a thin layer of chitosan containing 15 wt% Sr-substituted BG nanoparticles. Several techniques such as X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), tensile test, and water contact angle measurement were used to characterize the fabricated samples. In vitro experiments including degradation, bioactivity, and biocompatibility (i.e., cytotoxicity, alkaline phosphate activity, and cell adhesion) tests of the fabricated scaffold were performed. The biomedical behavior of the fabricated PCL-based composite scaffold was interpreted by considering the presence of the porosity, Sr-substituted BG nanoparticles, and the chitosan coating. In conclusion, the fabricated chitosan-coated porous PCL/BG nanocomposite containing 15 wt% BG nanoparticles could be utilized as a good candidate for bone tissue engineering.


Assuntos
Fosfatase Alcalina/metabolismo , Osso e Ossos/fisiologia , Quitosana/química , Vidro/química , Nanocompostos/química , Poliésteres/química , Estrôncio/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Adesão Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Difusão Dinâmica da Luz , Humanos , Nitrogênio/química , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Molhabilidade , Difração de Raios X
14.
Mater Sci Eng C Mater Biol Appl ; 105: 110015, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546430

RESUMO

Titanium (Ti) based porous alloys have been widely used as orthopedic implants. However, the successful applications of these porous Ti alloys need to have the ability to mimic the mechanical properties of natural bone. Novel porous Ti35Zr28Nb scaffolds were fabricated via powder metallurgy (PM), and the fabricated scaffold with 61.1% porosity exhibited favorable mechanical properties with a compression yield strength of 132.5 ±â€¯3.5 MPa and an elastic modulus of 2.9 ±â€¯0.4 GPa, which are desired mechanical properties for bone implant material applications. The extracts of the porous Ti35Zr28Nb scaffolds showed no toxic effect on cell proliferation in vitro and their cytotoxicity grade was at level 0, similar to that of as-cast pure Ti and Ti-6Al-4 V alloy. Additionally, the extracellular alkaline phosphatase (ALP) level of MC3T3-E1 indicated that the bone matrix synthesis on the porous Ti35Zr28Nb scaffolds was slightly higher than that of as-cast Ti-6Al-4 V and pure Ti alloys. After implantation in rat distal femurs for 8 weeks, the porous Ti35Zr28Nb scaffolds were surrounded by new bone tissue, and the numbers of red blood cells, white blood cells, immunocyte cells, and neutrophil cells returned to the normal levels, which indicate that the porous Ti35Zr28Nb scaffolds possess good in vivo osteointegration ability and hemocompatibility. It hence can be concluded that the PM-fabricated Ti35Zr28Nb scaffolds, which have desired mechanical properties and excellent biocompatibility and osteointegration, are a promising candidate alloy for bone-tissue engineering applications in orthopedics.


Assuntos
Ligas/química , Osso e Ossos/fisiologia , Metalurgia , Osseointegração , Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Fenômenos Biomecânicos , Linhagem Celular , Forma Celular , Implantes Experimentais , Masculino , Camundongos , Porosidade , Pós , Ratos Sprague-Dawley , Difração de Raios X , Microtomografia por Raio-X
15.
Int J Mol Sci ; 20(17)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480518

RESUMO

The aim of the study was to explore the possible role of Trefoil Factor Family peptide 3 (TFF3) for skeletal repair. The expression of TFF3 was analyzed in human joint tissues as well as in a murine bone fracture model. Serum levels of TFF3 following a defined skeletal trauma in humans were determined by ELISA. The mRNA expression of TFF3 was analyzed under normoxia and hypoxia. Expression analysis after stimulation of human mesenchymal progenitor cells (MPCs) with TFF3 was performed by RT2 Profiler PCR Array. The effect of recombinant human (rh)TFF3 on MPCs was analysed by different migration and chemotaxis assays. The effect on cell motility was also visualized by fluorescence staining of F-Actin. TFF3 was absent in human articular cartilage, but strongly expressed in the subchondral bone and periosteum of adult joints. Strong TFF3 immunoreactivity was also detected in murine fracture callus. Serum levels of TFF3 were significantly increased after skeletal trauma in humans. Expression analysis demonstrated that rhTFF3 significantly decreased mRNA of ROCK1. Wound healing assays showed increased cell migration of MPCs by rhTFF3. The F-Actin cytoskeleton was markedly influenced by rhTFF3. Cell proliferation was not increased by rhTFF3. The data demonstrate elevated expression of TFF3 after skeletal trauma. The stimulatory effects on cell motility and migration of MPCs suggest a role of TFF3 in skeletal repair.


Assuntos
Citoesqueleto de Actina/metabolismo , Osso e Ossos/fisiologia , Movimento Celular , Fator Trefoil-3/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Osso e Ossos/metabolismo , Feminino , Consolidação da Fratura , Regulação da Expressão Gênica , Humanos , Hipóxia , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Fator Trefoil-3/fisiologia , Quinases Associadas a rho/genética
16.
Carbohydr Polym ; 224: 115176, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472871

RESUMO

Weak mechanical properties, lack biocompatibility and relatively bioinert are formidable obstruct in application of bone repair materials. Multifunctional composite materials have been considered as a viable solution to this problem. Here, a new double network (DN) hydrogel was constructed by physical cross-linking of medical grade poly (vinyl alcohol) (PVA) and chitosan in KOH/urea dissolution system. The obtained hydrogel demonstrated excellent tensile strength (0.24 MPa), elongation at break (286%), and high compressive strength (0.11 MPa on the strain of 60%). Our studies showed that the prepared hydrogel had excellent biocompatibility in vitro and the introduction of hydroxyapatite (HAp) by surface mineralization imparted hydrogel the ability to induce rat bone marrow stem cells (rBMSCs) differentiation. The in vivo experiments revealed that the surface mineralized double network hydrogel significantly accelerated simultaneous regeneration of bone defects in a rabbit bone defect model. All the results indicated that this hydrogel has the potential as a bone repair material.


Assuntos
Osso e Ossos/efeitos dos fármacos , Quitosana/química , Hidrogéis/química , Hidrogéis/farmacologia , Minerais/química , Álcool de Polivinil/química , Adsorção , Animais , Osso e Ossos/citologia , Osso e Ossos/fisiologia , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Força Compressiva , Hidróxidos/química , Osteogênese/efeitos dos fármacos , Compostos de Potássio/química , Coelhos , Soroalbumina Bovina/química , Propriedades de Superfície , Resistência à Tração , Engenharia Tecidual , Ureia/química
17.
Colloids Surf B Biointerfaces ; 182: 110386, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31369954

RESUMO

Effective methods of accelerating the bone regeneration healing process are in demand for a number of bone-related diseases and trauma. This work developed scaffolds with improved properties for bone tissue engineering by electrospinning composite polycaprolactone-gelatin-hydroxyapatite-niobium pentoxide (PGHANb) membranes. Composite membranes, with average fiber diameters ranging from 123 to 156 nm, were produced by adding hydroxyapatite (HA) and varying concentrations of niobium pentoxide (Nb2O5) particles (0, 3, 7, and 10 wt%) to a polycaprolactone (PCL) and gelatin (GL) matrix prior to electrospinning. The morphology, mechanical, chemical and biological properties of resultant membranes were evaluated. Bioactivity was assessed using simulated body fluid (SBF) and it confirmed that the presence of particles induced the formation of hydroxyapatite crystals on the surface of the membranes. Samples were hydrophilic and cell metabolism results showed that the niobium-containing membranes were non-toxic while improving cell proliferation and differentiation compared to controls. This study demonstrated that electrospun membranes containing HA and Nb2O5 particles have potential to promote cell adhesion and proliferation while exhibiting bioactive properties. PGHANb membranes are promising candidates for bone tissue engineering applications.


Assuntos
Osso e Ossos/fisiologia , Durapatita/química , Gelatina/química , Membranas Artificiais , Nióbio/química , Óxidos/química , Poliésteres/química , Engenharia Tecidual/métodos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração Óssea , Osso e Ossos/ultraestrutura , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas Eletroquímicas/métodos , Humanos , Microscopia Eletrônica , Tamanho da Partícula , Tecidos Suporte/química
18.
Int J Nanomedicine ; 14: 4975-4989, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371942

RESUMO

The porous surface of a polyetheretherketone (PK)-nanoporous lithium-doped magnesium silicate (NLS) blend (PKNLS) was fabricated on a PK surface by layer-by-layer pressuring, sintering, and salt-leaching. As controls, porous surfaces of a PK/lithium-doped magnesium silicate blend (PKLS) and PK were fabricated using the same method. The results revealed that porosity, water absorption, and protein absorption of the porous surface of PKNLS containing macropores and nanopores were obviously enhanced compared to PKLS and PK containing macropores without nanopores. In addition, PKNLS, with both macroporostiy and nanoporosity, displayed the highest ability of apatite mineralization in simulated body liquid, indicating excellent bioactivity. In vitro responses (including adhesion, proliferation, and differentiation) of MC3T3E1 cells to PKNLS were significantly enhanced compared to PKLS and PK. In vivo implantation results showed that new bone grew into the macroporous surface of PKNLS, and the amount of new bone for PKNLS was the highest. In short, PKNLS integration with PK significantly promoted cells/bone-tissue responses and exhibited excellent osteogenesis in vivo, which might have great potential for bone repair.


Assuntos
Osso e Ossos/fisiologia , Cetonas/farmacologia , Lítio/farmacologia , Silicatos de Magnésio/farmacologia , Nanoporos , Osteoblastos/citologia , Polietilenoglicóis/farmacologia , Adsorção , Fosfatase Alcalina/metabolismo , Animais , Apatitas/química , Osso e Ossos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Imagem Tridimensional , Masculino , Camundongos , Nanoporos/ultraestrutura , Osteoblastos/efeitos dos fármacos , Osteoblastos/ultraestrutura , Osteogênese/efeitos dos fármacos , Porosidade , Coelhos , Água/química , Difração de Raios X
19.
J Bone Joint Surg Am ; 101(15): 1413-1419, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31393435

RESUMO

Worldwide, osteoporosis management is in crisis because of inadequate delivery of care, competing guidelines, and confusing recommendations. Additionally, patients are not readily accepting the diagnosis of poor bone health and often are noncompliant with treatment recommendations. Secondary fracture prevention, through a program such as Own the Bone, has improved the diagnosis and medical management after a fragility fracture. In patients who undergo elective orthopaedic procedures, osteoporosis is common and adversely affects outcomes. Bone health optimization is the process of bone status assessment, identification and correction of metabolic deficits, and initiation of treatment, when appropriate, for skeletal structural deficits. The principles of bone health optimization are similar to those of secondary fracture prevention and can be initiated by all orthopaedic surgeons. Patients who are ≥50 years of age should be assessed for osteoporosis risk and, if they are in a high-risk group, bone density should be measured. All patients should be counseled to consume adequate vitamin D and calcium and to discontinue use of any toxins (e.g., tobacco products and excessive alcohol consumption). Patients who meet the criteria for pharmaceutical therapy for osteoporosis should consider delaying surgery for a minimum of 3 months, if feasible, and begin medication treatment. Orthopaedic surgeons need to assume a greater role in the care of bone health for our patients.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Saúde Global , Programas de Rastreamento/organização & administração , Osteoporose/prevenção & controle , Fraturas por Osteoporose/prevenção & controle , Absorciometria de Fóton/métodos , Idoso , Osso e Ossos/fisiologia , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Determinação de Necessidades de Cuidados de Saúde , Ortopedia/organização & administração , Osteoporose/epidemiologia , Prevenção Secundária/métodos , Sociedades Médicas/organização & administração , Vitamina D/uso terapêutico
20.
Cell Prolif ; 52(5): e12658, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31297910

RESUMO

OBJECTIVES: The bone tissue engineering primarily focuses on three-dimensional co-culture systems, which physical and biological properties resemble the cell matrix of actual tissues. The complex dialogue between bone-forming and endothelial cells (ECs) in a tissue-engineered construct will directly regulate angiogenesis and bone regeneration. The purpose of this study was to investigate whether co-culture between osteogenic and angiogenic cells derived by bone mesenchymal stem cells (MSCs) could affect cell activities and new bone formation. MATERIALS AND METHODS: Mesenchymal stem cells were dually induced to differentiate into osteogenic cells (OMSCs) and ECs; both cell types were co-cultured at different ratios to investigate their effects and underlying mechanisms through ELISA, RT-qPCR and MTT assays. The selected cell mixture was transplanted onto a nano-hydroxyapatite/polyurethane (n-HA/PU) scaffold to form a cell-scaffold construct that was implanted in the rat femoral condyles. Histology and micro-CT were examined for further verification. RESULTS: ELISA and gene expression studies revealed that co-cultured OMSCs/ECs (0.5/1.5) significantly elevated the transcription levels of osteogenic genes such as ALP, Col-I and OCN, as well as transcription factors Msx2, Runx2 and Osterix; it also upregulated angiogenic factors of vascular endothelial growth factor (VEGF) and CD31 when compared with cells cultured alone or in other ratios. The optimized OMSCs/ECs group had more abundant calcium phosphate crystal deposition, further facilitated their bone formation in vivo. CONCLUSIONS: The OMSCs/ECs-scaffold constructs at an optimal cell ratio (0.5/1.5) achieved enhanced osteogenic and angiogenic factor expression and biomineralization, which resulted in more effective bone formation.


Assuntos
Materiais Biomiméticos/química , Regeneração Óssea/fisiologia , Osso e Ossos/fisiologia , Células-Tronco Mesenquimais/citologia , Tecidos Suporte/química , Animais , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Diferenciação Celular , Células Cultivadas , Técnicas de Cocultura , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Durapatita/química , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Ratos , Ratos Sprague-Dawley , Engenharia Tecidual , Fatores de Transcrição/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
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