Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.044
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-32559039

RESUMO

Twenty-six patients with a horizontal ridge defect were entered into this 4-month randomized, controlled, blinded clinical trial to compare a cancellous block allograft to a demineralized bone matrix (DBM) allograft for ridge augmentation. Six patients were excluded from the study, leaving 20 for data interpretation. Both groups had a xenograft overlay and a collagen membrane. For the Block group there was a significant gain of 4.8 ± 1.9 mm (P = .00002; 95% confidence interval [CI]: 3.49 to 6.21), while the DBM group gained 4.6 ± 2.4 mm (P = .0002; 95% CI: 2.88 to 6.36). Vertical change was minimal for both groups (P > .05). The Block group had a mean of 40% vital bone while the DBM group had 35%.


Assuntos
Aumento do Rebordo Alveolar , Transplante Ósseo , Aloenxertos , Matriz Óssea , Humanos , Transplante Homólogo
2.
Artigo em Inglês | MEDLINE | ID: mdl-32032400

RESUMO

The aim of this histologic, single-blind, parallel, randomized clinical trial was to compare vertical bone augmentation grafting with 100% autogenous bone (group AB) vs 50% deproteinized bovine bone matrix (DBBM)/50% autogenous bone (group BOAB) using the Fence Technique in a two-stage implant placement. A biopsy was performed in the regenerated area at implant insertion 6 months after the augmentation surgery. The results reflect a sample size of four patients treated per group. At implant placement, 6 months after grafting, no significant differences were evident in the histomorphometric comparisons, even if the percentage of residual graft was obviously greater in the BOAB group (P = .0314).


Assuntos
Aumento do Rebordo Alveolar , Substitutos Ósseos , Animais , Matriz Óssea , Transplante Ósseo , Bovinos , Implantação Dentária Endo-Óssea , Humanos , Método Simples-Cego
3.
J Craniofac Surg ; 31(2): 577-582, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31895856

RESUMO

BACKGROUND: Demineralized bone matrices (DBMs) were demonstrated to be a promising candidate for bone regeneration by previous studies. However, the limited osteoinductivity of DBMs was insufficient for a better repairing of bone defect. Osteoblasts (OBs), the major cellular component of bone tissues, play an important role in the formation of new bone. The extracellular matrix (ECM) of OB is one of the main components of bone formation niche. OBJECTIVE: To combine the DBMs with the ECM of OBs to construct a novel scaffold that could be used for bone reconstruction. METHODS: In this study, OBs were cultured on the surface of DBMs for 10 days and removed by Triton X-100 and ammonium hydroxide to prepare the OBs-ECM-DBMs (OEDBMs). A series of material features such as residues of OBs and ECM, cytotoxity, and osteoinductive capability of OEDBMs were evaluated. RESULTS: Low cell residues and low content of DNA were observed in OEDBMs. Compared with DBMs, OEDBMs possessed more bone tissues organic matrix proteins, such as osteocalcin, osteopontin, and collagen I. Rat bone marrow mesenchymal stem cells (rBMSCs) presented a good viability when cultured on both 2 materials. The significant upregulations of osteogenic genes and proteins of rBMSCs were observed in OEDBMs group compared with DBMs group. CONCLUSION: Taken together, these findings suggested that the OB-secreted ECM may be qualified as an ideal modification method for enhancing the performance of engineered bone scaffold.


Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Osteogênese , Animais , Medula Óssea , Matriz Óssea/metabolismo , Bovinos , Células Cultivadas , Matriz Extracelular , Ratos
4.
Am J Physiol Cell Physiol ; 318(1): C111-C124, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31532718

RESUMO

Bone differs from other connective tissues; it is isolated by a layer of osteoblasts that are connected by tight and gap junctions. This allows bone to create dense lamellar type I collagen, control pH, mineral deposition, and regulate water content forming a compact and strong structure. New woven bone formed after degradation of mineralized cartilage is rapidly degraded and resynthesized to impart structural order for local bone strength. Ossification is regulated by thickness of bone units and by patterning via bone morphogenetic receptors including activin, other bone morphogenetic protein receptors, transforming growth factor-ß receptors, all part of a receptor superfamily. This superfamily interacts with receptors for additional signals in bone differentiation. Important features of the osteoblast environment were established using recent tools including osteoblast differentiation in vitro. Osteoblasts deposit matrix protein, over 90% type I collagen, in lamellae with orientation alternating parallel or orthogonal to the main stress axis of the bone. Into this organic matrix, mineral is deposited as hydroxyapatite. Mineral matrix matures from amorphous to crystalline hydroxyapatite. This process includes at least two-phase changes of the calcium-phosphate mineral as well as intermediates involving tropocollagen fibrils to form the bone composite. Beginning with initiation of mineral deposition, there is uncertainty regarding cardinal processes, but the driving force is not merely exceeding the calcium-phosphate solubility product. It occurs behind a epithelial-like layer of osteoblasts, which generate phosphate and remove protons liberated during calcium-phosphate salt deposition. The forming bone matrix is discontinuous from the general extracellular fluid. Required adjustment of ionic concentrations and water removal from bone matrix are important details remaining to be addressed.


Assuntos
Densidade Óssea , Matriz Óssea/metabolismo , Diferenciação Celular , Proteínas de Membrana Transportadoras/metabolismo , Osteoblastos/metabolismo , Osteogênese , Animais , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Humanos , Modelos Biológicos , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
5.
J Biomed Nanotechnol ; 15(12): 2363-2375, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748017

RESUMO

Breast cancer tends to spread to other organs and bone metastasis has the highest frequency in breast cancer metastasis, while its mechanisms are not clear and the current treatments are not very effective. To better study the mechanisms and facilitate drug screening for breast cancer bone metastasis, an in vivo mouse model needs to be constructed. However, the construction of the humanized mouse model for cancer bone metastasis which will mimick real interactions between cancer tissue and bone tissue in the human microenvironment remains a challenge. In this study, we constructed a human engineering bone tissue composed with the human osteoblast-like cells (SaOS-2 cells) and the silica nanoparticlesincorporated human demineralized bone matrix (Si/DBM). The engineered bone was then transplanted into a nude mouse to build a humanized bone microenvironment. The human breast cancer cells were then injected into the fat pads of the nude mouse to form an orthotopic tumor. The results showed that the engineered bone tissue-constructed humanized bone microenvironment had significant advantages when inducing human cancer cells to metastasize into the engineered bone tissue. Further, the SaOS-2/Si/DBM had a stronger ability to entice cancer-bone metastasis through promoting osteogenesis compared to the SaOS-2/DBM. Accordingly, this study highlights a novel, facile and effective mouse model for human cancer-bone metastasis, which will provide a platform to explore the mechanisms and anti-tumor drug screening for cancer-bone metastasis.


Assuntos
Neoplasias Ósseas , Nanopartículas , Animais , Matriz Óssea , Humanos , Camundongos , Dióxido de Silício , Engenharia Tecidual , Microambiente Tumoral
6.
Medicine (Baltimore) ; 98(48): e18115, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31770237

RESUMO

INTRODUCTION: The aim of this report is to present a case of an apically involved tooth with successful regeneration by only applying enamel matrix derivative. The root of the tooth was planed and the defect area was well debrided using various instruments, including curettes and an ultrasonic scaler, and the root surface of the tooth and the defect area were loaded with enamel matrix derivative. PATIENT CONCERNS: A 32-year-old man visited the clinic due to a referral for the evaluation of his mandibular left first molar. DIAGNOSIS: The clinical and radiographic assessment displayed the loss of the periodontium around the tested tooth with apical involvement of the mesial root. Bleeding upon probing was noted at the mandibular first molar, with the deepest periodontal probing depth of 15 mm. INTERVENTIONS: A nonsurgical approach was firstly performed on the tooth, and the deepest probing depth was reduced to 12 mm. After re-evaluation, elevation of a full-thickness flap was done, the root of the tooth was planed, and the defect area was well debrided using various instruments, including curettes and an ultrasonic scaler. The defect area on the mandibular left first molar was grafted with enamel matrix derivative. OUTCOMES: The 7-month postoperative clinical and radiographic evaluation showed healthy gingiva and an increase in radiopacity. The final 1-year and 9-month postoperative evaluation showed that regeneration of bony defect was well maintained up to the final evaluation with reduction of probing depth. CONCLUSION: In conclusion, a case of apically involved tooth can be treated only with enamel matrix derivative after meticulous debridement with curettes and an ultrasonic scaler.


Assuntos
Produtos Biológicos/uso terapêutico , Matriz Óssea/transplante , Esmalte Dentário/transplante , Ápice Dentário/cirurgia , Doenças Dentárias/cirurgia , Adulto , Raspagem Dentária/métodos , Humanos , Masculino , Mandíbula/cirurgia , Dente Molar/patologia , Dente Molar/cirurgia , Periodonto/patologia , Periodonto/cirurgia , Ápice Dentário/patologia , Doenças Dentárias/patologia
7.
Med Sci Monit ; 25: 7342-7350, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566195

RESUMO

BACKGROUND This study aimed to evaluate an autologous bone mesenchymal stem cell (MSC)-derived extracellular matrix (ECM) scaffold in two animal models of cartilage repair. MATERIAL AND METHODS A rabbit model (n=16) and a minipig model (n=8) of cartilage repair were created with cartilage defects of the knee joints treated with bone marrow stimulation (BMS). In the ECM group, autologous bone MSC-derived ECM scaffolds were implanted into the cartilage defects after bone marrow stimulation. In the BMS group, the cartilage defects were treated by bone marrow stimulation only. The renewal capacity of bone MSCs was measured with a colony-forming unit fibroblast (CFU-F) in vitro assay. The extent of cartilage repair was as-sessed at 6 months after surgery. RESULTS In the rabbit model, the macroscopic appearance of the exudate of the healing wounds in the ECM group showed less fibrosis, and the histology showed more evenly distributed chondrocytes compared with the BMS group. The CFU-F assay showed that the number of bone MSCs in the ECM group was approximately was twice that of the BMS group. In the minipig model, the macroscopic appearance and magnetic resonance imaging (MRI) findings of the ECM group were improved when compared with the BMS group. The repaired tissue in ECM group had similar histological characteristics and biochemical content to normal hyaline cartilage. CONCLUSIONS In two animal models of knee joint cartilage repair, the use of an ECM scaffold increased the number of bone MSCs and improved the extent of cartilage repair.


Assuntos
Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Transplante de Células-Tronco Mesenquimais/métodos , Animais , Medula Óssea , Matriz Óssea/patologia , Osso e Ossos , Células Cultivadas , Condrócitos , Matriz Extracelular , Articulação do Joelho/cirurgia , Células-Tronco Mesenquimais/metabolismo , Modelos Animais , Coelhos , Suínos , Porco Miniatura , Engenharia Tecidual/métodos , Tecidos Suporte
8.
J Bone Joint Surg Am ; 101(21): 1904-1911, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31567665

RESUMO

UPDATE: This article was updated on November 7, 2019, because of a previous error. On page 1909, in the section entitled "Discussion," the sentence that had read "Radiographic nonunion rates of 69.2% and 45.6% were observed at 6 months for ACBM and autograft, respectively, as measured on CT scans; however, these nonunion rates do account for patients who were considered to have attained fusion according to traditional methods, including absence of pain and swelling and presence of arthrodesis on radiographs" now reads "Radiographic nonunion rates of 69.2% and 45.6% were observed at 6 months for ACBM and autograft, respectively, as measured on CT scans; however, these nonunion rates do not account for patients who were considered to have attained fusion according to traditional methods, including absence of pain and swelling and presence of arthrodesis on radiographs."An erratum has been published: J Bone Joint Surg Am. 2019 XXX. BACKGROUND: Subtalar arthrodesis effectively treats subtalar joint arthritis when other interventions have failed. Nonunion is a known complication of subtalar arthrodesis, with reported rates ranging from 5% to 45%. Historically, open arthrodesis has been performed with use of autologous bone graft; however, there are inherent disadvantages to autologous bone graft, including donor-site morbidity. Mesenchymal stem cells, when placed on a cellular scaffold, have shown promise as an alternative to autologous bone graft. The purpose of this multicenter, randomized controlled trial was to assess the safety and efficacy of an adipose-derived cellular bone matrix (ACBM) composite made with live cells compared with autograft in subtalar arthrodesis. METHODS: A total of 140 patients were enrolled in a prospective, randomized (1:1) controlled trial performed at 6 clinical sites in the U.S. End points, including radiographic, clinical, and functional outcomes, were assessed over 2 years of follow-up. RESULTS: A total of 109 patients underwent arthrodesis with ACBM (52 patients) and autograft (57 patients). At 6 months, fusion was achieved in 16 patients (30.8%) in the ACBM group and 31 patients (54.4%) in the autograft group as measured on computed tomography (p = 0.024), and in 41 patients (78.8%) in the ACBM group and 50 patients (87.7%) in the autograft group as assessed on clinical and radiographic evaluation (p = 0.213). Quality-of-life outcome measures demonstrated significant functional improvement from baseline for both groups. Fewer cases of serious adverse events occurred in the autograft group (10.5%) compared with the ACBM group (23.1%) (p = 0.078). CONCLUSIONS: In patients who require subtalar arthrodesis, the use of ACBM demonstrated lower rates of radiographic fusion compared with treatment with autograft. The nonunion rate in the autologous group, as measured on computed tomography, was high. Good clinical outcomes were achieved in spite of the high non-union rates. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.


Assuntos
Artrite/cirurgia , Artrodese/métodos , Matriz Óssea/transplante , Transplante Ósseo/métodos , Articulação Talocalcânea/cirurgia , Tecido Adiposo/citologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Transplante Autólogo
9.
Bull Exp Biol Med ; 167(5): 681-684, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31630302

RESUMO

The effects of bone graft materials on the inflammatory response and biochemical markers of bone remodeling were studied on a rabbit model of fracture augmentation with the following grafts: ß-tricalcium phosphate, demineralized bone matrix, nanostructured carbon implant, and porous titanium implant made by additive 3D printing. The markers of bone remodeling and the blood system response in the postoperative period were studied. It was found that porous titanium implant and ß-tricalcium phosphate induced osteogenesis and minimized osteoclastic resorption. Augmentation with nanostructured carbon implant and demineralized bone matrix stimulated the processes of osteoclastic resorption.


Assuntos
Materiais Biocompatíveis/farmacologia , Transplante Ósseo/métodos , Fosfatos de Cálcio/farmacologia , Cementoplastia/métodos , Fraturas Intra-Articulares/terapia , Osseointegração/efeitos dos fármacos , Titânio/farmacologia , Fosfatase Alcalina/sangue , Fosfatase Alcalina/genética , Animais , Biomarcadores/metabolismo , Técnica de Desmineralização Óssea , Matriz Óssea/química , Remodelação Óssea , Reabsorção Óssea/metabolismo , Carbono/metabolismo , Carbono/farmacologia , Colágeno Tipo I/sangue , Colágeno Tipo I/genética , Feminino , Fraturas Intra-Articulares/metabolismo , Fraturas Intra-Articulares/cirurgia , Nanoestruturas/química , Osseointegração/fisiologia , Osteocalcina/sangue , Osteocalcina/genética , Peptídeos/sangue , Peptídeos/genética , Porosidade , Coelhos , Tíbia/efeitos dos fármacos , Tíbia/lesões , Tíbia/metabolismo , Tíbia/cirurgia
10.
Microsc Res Tech ; 82(12): 2072-2078, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31576638

RESUMO

Death of osteocytes is synonymous of bone death. Aseptic osteonecrosis of the femoral head is a lesion characterized by the death of osteocytes occurring after major vascular changes. The evolution may lead to hip osteoarthritis, which requires total hip arthroplasty in most cases. Evolution of aseptic osteonecrosis in four radiological stages is well known. We analyzed 24 femoral heads from patients with osteonecrosis or osteoarthritis, retrieved at the time of surgery for a hip arthroplasty. The aim of the study was to clearly identify the necrotic bone from the living bone in the histological samples. The femoral heads were sawed, and a large sample was harvested in the superior zone; it was stained en-bloc with rhodamine dissolved in formalin to make the osteocytes fluorescent under UV light microscopy. Undecalcified sections, 7 µm thick, were obtained on a heavy-duty microtome. A micrographic analysis using two UV excitation wavelengths visualized the living osteocytes (in green) and the bone matrix (in blue). A simple method to prepare combined images is described. In addition, the blocks can be analyzed by confocal microscopy to visualize more details. It is possible to identify at low magnification the osteocytes within the bone matrix and the osteonecrotic areas where osteocytes have disappeared. Identification of osteocytes showed that newly formed bone packets are laid on dead trabeculae in patients with aseptic osteonecrosis or with osteoarthritis. In the osteosclerotic areas, the enlarged trabeculae have a dead central core surrounded by recently apposed bone structure units.


Assuntos
Cabeça do Fêmur/patologia , Osteoartrite/patologia , Osteócitos/patologia , Osteonecrose/patologia , Coloração e Rotulagem/métodos , Artroplastia de Quadril , Matriz Óssea/citologia , Matriz Óssea/fisiologia , Humanos , Microscopia Confocal , Rodaminas
11.
Orthop Surg ; 11(5): 725-737, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31496049

RESUMO

Reconstruction of massive bone defects is challenging for orthopaedic clinicians, especially in cases of severe trauma and resection of tumors in various locales. Autologous iliac crest bone graft (ICBG) is the "gold standard" for bone grafting. However, the limited availability and complications at donor sites resulted in seeking other options like allografts and bone graft substitutes. Demineralized bone matrix (DBM) is a form of allograft using acidic solution to remove mineral components, while leaving much of the proteinaceous components native to bone, with small amounts of calcium-based solids, inorganic phosphates, and some trace cell debris. It is an osteoconductive and osteoinductive biomaterial and is approved as a medical device for use in bone defects and spinal fusion. To pack consistently into the defect sites and stay firmly in the filling parts, DBM products have various forms combined with biocompatible viscous carriers, including sponges, strips, injectable putty, paste, and paste infused with chips. The present review aims to summarize the properties of various kind of viscous carriers and their clinical use combined with DBM in commercially available products. Given DBM'mercially available products. Given DBM;s long clinical track record and commercial accessibility in standard forms, opportunities to further develop and validate DBM as a versatile bone biomaterial in orthopaedic repair and regenerative medicine contexts are attractive.


Assuntos
Materiais Biocompatíveis/química , Técnica de Desmineralização Óssea/métodos , Matriz Óssea/química , Substitutos Ósseos/química , Transplante Ósseo/métodos , Aloenxertos , Regeneração Óssea , Humanos
12.
Molecules ; 24(14)2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31331121

RESUMO

Although betulin (BET), a naturally occurring pentacyclic triterpene, has a variety of biological activities, its osteogenic potential has not been investigated so far. The aim of this study was to assess the effect of BET on differentiation of human osteoblasts (hFOB 1.19 and Saos-2 cells) in vitro in osteogenic (with ascorbic acid as an osteogenic supplement) and osteoinductive (without an additional osteogenic supplement) conditions. Osteoblast differentiation was evaluated based on the mRNA expression (RT-qPCR) of Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), type I collagen-α1 (COL1A1), and osteopontin (OPN). Additionally, ALP activity and production of COL1A1 (western blot analysis) and OPN (ELISA) were evaluated. The level of mineralization (calcium accumulation) was determined with Alizarin red S staining. BET upregulated the mRNA level of RUNX2 and the expression of other osteoblast differentiation markers in both cell lines (except the influence of BET on ALP expression/activity in the Saos-2 cells). Moreover, it increased mineralization in both cell lines in the osteogenic conditions. BET also increased the mRNA level of osteoblast differentiation markers in both cell lines (except for ALP in the Saos-2 cells) in the osteoinductive conditions, which was accompanied with increased matrix mineralization. The osteoinductive activity of BET in the hFOB 1.19 cells was probably mediated via activation of MAPKs (JNK and ERK1/2) and mTOR, as the specific inhibitors of these kinases abolished the BET-induced osteoblast differentiation. Our results suggest that BET has the potential to enhance osteogenesis.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Triterpenos/farmacologia , Biomarcadores , Matriz Óssea/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Osteoblastos/citologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
13.
Q J Nucl Med Mol Imaging ; 63(2): 98-111, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31298015

RESUMO

Bone metastases remain a common feature of advanced cancers and are associated with significant morbidity and mortality. Recent research has identified promising novel treatment targets to improve current treatment strategies for bone metastatic disease. This review summarizes the well-known and recently discovered molecular biology pathways in bone that govern normal physiological remodeling or drive the pathophysiological changes observed when bone metastases are present. In the rapidly changing world of targeted cancer treatments, it is important to recognize the specific treatment effects induced in bone by these agents and the potential impact on common imaging strategies. The osteoclastic targets (bisphosphonates, LGR4, RANKL, mTOR, MET-VEGFR, cathepsin K, Src, Dock 5) and the osteoblastic targets (Wnt and endothelin) are discussed, and the emerging field of osteo-immunity is introduced as potential future therapeutic target. Finally, a summary is provided of available trial data for agents that target these pathways and that have been assessed in patients. The ultimate goal of research into novel pathways and targets involved in the tumor-bone microenvironment is to tackle one of the great remaining unmet needs in oncology, that is finding a cure for bone metastatic disease.


Assuntos
Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Terapia de Alvo Molecular/métodos , Animais , Matriz Óssea/efeitos dos fármacos , Matriz Óssea/metabolismo , Matriz Óssea/patologia , Neoplasias Ósseas/imunologia , Neoplasias Ósseas/patologia , Humanos , Imunidade Inata/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Osteoclastos/patologia , Microambiente Tumoral/efeitos dos fármacos
14.
Implant Dent ; 28(6): 613-620, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31246662

RESUMO

PURPOSE: The primary aim of this randomized, controlled, blinded, clinical trial was to compare a mix of particulate allograft and harvested autogenous particles (Autogenous) to an osteoinductive demineralized bone matrix (DBM) allograft on clinical and histologic outcomes for horizontal ridge augmentation procedure. MATERIALS AND METHODS: Fourteen patients with a horizontal ridge defect with at least 1 adjacent tooth were entered into this study. The test group of 7 subjects received corticocancellous particulate allograft (Mineross) mixed with autogenous bone chips (70:30) harvested using a bone scraper (SafeScraper TWIST). Seven subjects in the control group received DBM (Optecure-CCC). Both groups had a corticocancellous particulate allograft overlay and an acellular dermis membrane (ADMG) (AlloDerm GBR) to cover the grafts. RESULTS: For the Autogenous group, there was a gain of 3.5 ± 1.4 mm while the DBM group gained 3.8 ± 1.6 mm (P < 0.05). Vertical change was minimal for both groups (P > 0.05). The Autogenous group had a mean of 35% vital bone while the DBM had 39% (P > 0.05). CONCLUSIONS: Both treatments provided similar gain of ridge width and minimal loss of ridge height. The autogenous bone chips did not provide any additional benefit when compared with allograft alone that had lot verified osteoinductive activity.


Assuntos
Aumento do Rebordo Alveolar , Transplante Ósseo , Aloenxertos , Matriz Óssea , Humanos
15.
Int J Mol Sci ; 20(12)2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31197079

RESUMO

Wnt signaling plays a pivotal role in maintaining bone mass. Secreted pathway modulators such as sclerostin (SOST) and Dickkopfs (DKKs) may influence bone mass inhibiting the canonical Wnt pathway. We evaluated whether bone protein content of secreted Wnt antagonists is related to age, bone mass, and strength in postmenopausal osteoporosis. We measured cortical and trabecular bone contents of SOST and Dickkopf-1 (DKK1) in combined extracts obtained after ethylenediaminetetraacetic acid and guanidine hydrochloride extraction in 56 postmenopausal women aged 47-74 (mean, 63) yr with a previous distal forearm fracture and a hip or spine Z-score less than 0. Our findings were (i) SOST and DKK1 protein levels were higher in trabecular bone, (ii) cortical and trabecular DKK1 and trabecular SOST correlated positively with bone matrix levels of osteocalcin (r between 0.28 and 0.45, p < 0.05), (iii) cortical DKK1 correlated with lumbar spine bone mineral density (BMD) (r = 0.32, p < 0.05) and femoral neck BMD (r = 0.41, p < 0.01), and (iv) cortical DKK1 and SOST correlated with apparent bone volumetric density and compressive strength (r between 0.34 and 0.51, p < 0.01). In conclusion, cortical bone matrix levels of DKK1 and SOST were positively correlated with bone mass and bone strength in postmenopausal osteoporotic women.


Assuntos
Matriz Óssea/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Osteoporose Pós-Menopausa/metabolismo , Idoso , Densidade Óssea , Proteínas Morfogenéticas Ósseas/genética , Feminino , Marcadores Genéticos/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Pessoa de Meia-Idade , Osteocalcina/genética , Osteocalcina/metabolismo , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/patologia
16.
J R Soc Interface ; 16(151): 20180911, 2019 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-30958180

RESUMO

With ageing and various diseases, the vascular pore volume fraction (porosity) in cortical bone increases, and the morphology of the pore network is altered. Cortical bone elasticity is known to decrease with increasing porosity, but the effect of the microstructure is largely unknown, while it has been thoroughly studied for trabecular bone. Also, popular micromechanical models have disregarded several micro-architectural features, idealizing pores as cylinders aligned with the axis of the diaphysis. The aim of this paper is to quantify the relative effects on cortical bone anisotropic elasticity of porosity and other descriptors of the pore network micro-architecture associated with pore number, size and shape. The five stiffness constants of bone assumed to be a transversely isotropic material were measured with resonant ultrasound spectroscopy in 55 specimens from the femoral diaphysis of 29 donors. The pore network, imaged with synchrotron radiation X-ray micro-computed tomography, was used to derive the pore descriptors and to build a homogenization model using the fast Fourier transform (FFT) method. The model was calibrated using experimental elasticity. A detailed analysis of the computed effective elasticity revealed in particular that porosity explains most of the variations of the five stiffness constants and that the effects of other micro-architectural features are small compared to usual experimental errors. We also have evidence that modelling the pore network as an ensemble of cylinders yields biased elasticity values compared to predictions based on the real micro-architecture. The FFT homogenization method is shown to be particularly efficient to model cortical bone.


Assuntos
Matriz Óssea , Osso Cortical , Elasticidade/fisiologia , Modelos Biológicos , Anisotropia , Matriz Óssea/metabolismo , Matriz Óssea/ultraestrutura , Osso Cortical/metabolismo , Osso Cortical/ultraestrutura , Humanos , Porosidade
17.
Mater Sci Eng C Mater Biol Appl ; 101: 330-340, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029326

RESUMO

Extracellular matrices (ECMs) derived from native tissues/organs have been used as biomaterials for tissue engineering and regenerative medicine in a wide range of preclinical and clinical settings. The success or failure of these applications is largely contingent on the host responses to the matrices in vivo. Despite retaining their native structural and functional proteins, bone ECM-based transplants have been reported to evoke adverse immune responses in many cases; thus, optimizing the immunomodulatory properties of bone ECMs is critical for ensuring downstream regenerative outcomes. Using a simple digestion-neutralization protocol, we transformed the commonly used bone-derived filler particles into gel bioscaffolds. Instead of inducing macrophages toward proinflammatory (M1) polarization, as reported in the literature and confirmed in the present study for ECM particles, the ECM gels were found to be more likely to polarize macrophages toward regulatory/anti-inflammatory (M2) phenotypes, leading to enhanced tissue regeneration in a rat periodontal defect model. The present work demonstrates a simple, practical and economical strategy to modify the immunomodulatory properties of bone ECMs before their in vivo transplantation and hence has important implications that may facilitate the use of ECM-based bioscaffolds derived from diverse sources of tissues for regenerative purposes.


Assuntos
Materiais Biocompatíveis/química , Matriz Óssea/química , Regeneração Óssea , Matriz Extracelular/química , Géis/química , Macrófagos/metabolismo , Tecidos Suporte/química , Animais , Matriz Óssea/ultraestrutura , Células Cultivadas , Matriz Extracelular/ultraestrutura , Regulação da Expressão Gênica , Macrófagos/ultraestrutura , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Osteogênese/genética , Periodonto/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Suínos
18.
Forensic Sci Int ; 298: 384-392, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30928778

RESUMO

Human bone histological analysis is a useful tool to assess post mortem diagenesis and to predict successful nuclear DNA typing of forensic material. This study is part of a series of studies developed by the authors intended to improve the understanding of post mortem diagenesis and to develop applications for DNA analysis of skeletal species from tropical soils, in order to optimize genetic and anthropological protocols. The aim of this study was to analyze the impact of burial period on the integrity of exhumed compact bone microstructure from tropical climate. In fragments of exhumed human femora from 39 individuals from the same cemetery (exhumed group) and 5 fresh femora from routine autopsies (control group), sections stained by hematoxylin-eosin were analyzed in order to measure bone microstructural integrity. We found that bone integrity index in exhumed group was negatively influenced by the period of burial (r = -0.37, p < 0.05) and highly significantly decreased (p < 0.0001) in comparison to control group. The period of burial and nitric acid decalcification time was positively correlated (r = 0.51; p < 0.01), leading to imply a bone petrification process during inhumation. Exhumed group showed higher level of matrix bone loss (p < 0.001), as expected, and 87% of cases analyzed were "tunneled" as described by Hackett. Bone integrity index and bone matrix tend to decrease in bones buried in tropical soil between 8-14 years of inhumation. This period is short if we consider cases in which there are preserved bones interred for longer periods in other environments. These data must be considered in cases where genetic identification of exhumed skeletons from tropical environment is required. The diagenesis in these bones and the variations of results found are discussed, clarifying some challenges for forensic laboratories, especially in DNA analysis.


Assuntos
Sepultamento , Fêmur/patologia , Mudanças Depois da Morte , Solo , Clima Tropical , Adulto , Idoso , Idoso de 80 Anos ou mais , Matriz Óssea/patologia , Brasil , Estudos de Casos e Controles , Contagem de Células , Núcleo Celular/patologia , Osso Cortical/patologia , Descalcificação Patológica/patologia , Exumação , Antropologia Forense , Patologia Legal , Osteon/patologia , Humanos , Masculino , Microscopia , Pessoa de Meia-Idade , Osteócitos/patologia , Fatores de Tempo , Adulto Jovem
19.
Biofabrication ; 11(4): 045007, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-30917346

RESUMO

Three-dimensional (3D) printing of decellularized extracellular matrix (ECM) has been achieved to ensure real physiological environments for tissue engineering. However, the limited source, biocompatibility, and biosafety of decellularized ECM are deficiencies in its large clinical use. Autogenous ECM is biocompatible, bioactive, and biosafe, making it an optimal choice for future clinical applications of 3D printing. Here, we developed a multi-level customized 3D printing (MLC-3DP) strategy applying autogenous bone matrix (Auto-BM). This MLC-3DP includes shape specificity (shape), material specificity (Auto-BM), and cell specificity (autogenous cells) for true patient-specific repairs. Auto-BM (skull flaps) is readily accessible for specific patients after craniectomy, providing sufficient autogenous materials for MLC-3DP. Under mild conditions of this strategy, human-scale 3D printed samples can be fabricated using bioactive micron-sized Auto-BM particles. Multi-level customized autogenous bones (MLC-Auto-Bones) are finally obtained by combining autogenous bone marrow-derived mesenchymal stem cells (Auto-BMSCs). With autogenous materials and cells, MLC-Auto-Bones are inherently biocompatible and biosafe, providing good bioactivity for osteogenesis. In this implant, Auto-BMSCs can spontaneously differentiate into osteoblasts in vitro without additional osteogenic factors. In critical-sized skull defect models in vivo (3 months), implants integrate tightly to the defects' margin, facilitate mineralization, and generate vascularized mature bone. This work provides not only feasibility for patient-specific implants for skull defects, but also potential patient-specific solutions for other similar clinical requirements.


Assuntos
Implantes Experimentais , Impressão Tridimensional , Crânio/fisiologia , Engenharia Tecidual , Fosfatase Alcalina/metabolismo , Animais , Matriz Óssea/fisiologia , Regeneração Óssea , Diferenciação Celular , Células Cultivadas , Estudos de Viabilidade , Regulação da Expressão Gênica , Osteogênese/genética , Coelhos , Microtomografia por Raio-X
20.
Biochemistry (Mosc) ; 84(1): 20-32, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30927522

RESUMO

The aim of this work was to compare biological activities of three variants of bacterially expressed human recombinant erythropoietin (EPO) with additional protein domains: 6His-s-tag-EPO protein carrying the s-tag (15-a.a. oligopeptide from bovine pancreatic ribonuclease A) at the N-terminus and HBD-EPO and EPO-HBD proteins containing heparin-binding protein domains (HBD) of the bone morphogenetic protein 2 from Danio rerio at the N- and C-termini, respectively. The commercial preparation Epostim (LLC Pharmapark, Russia) produced by synthesis in Chinese hamster ovary cells was used for comparison. The EPO variant with the C-terminal HBD domain connected by a rigid linker (EPO-HBD) possesses the best properties as compared to HBD-EPO with the reverse domain arrangement. It was ~13 times more active in vitro (i.e., promoted proliferation of human erythroleukemia TF-1 cells) and demonstrated a higher rate of association with the erythropoietin receptor. EPO-HBD also exhibited the greatest binding to the demineralized bone matrix (DBM) and more prolonged release from the DBM among the four proteins studied. Subcutaneous administration of EPO-HBD immobilized on DBM resulted in significantly more pronounced vascularization of surrounding tissues in comparison with the other proteins and DBM alone. Therefore, EPO-HBD displayed better performance with regard to all the investigated parameters than other examined EPO variants, and it seems promising to study the possibility of its medical use.


Assuntos
Eritropoetina/genética , Escherichia coli/genética , Domínios Proteicos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Animais , Matriz Óssea/metabolismo , Proteína Morfogenética Óssea 2/genética , Proliferação de Células/efeitos dos fármacos , Eritropoetina/biossíntese , Escherichia coli/metabolismo , Humanos , Neovascularização Fisiológica/efeitos dos fármacos , Ligação Proteica , Proteínas Recombinantes/biossíntese , Peixe-Zebra
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA