Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
1.
Sci Rep ; 11(1): 7012, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33782429

RESUMO

Bone is a biological composite material consisting of two main components: collagen and mineral. Collagen is the most abundant protein in vertebrates, which makes it of high clinical and scientific interest. In this paper, we compare the composition and structure of cortical bone demineralized using several protocols: ethylene-diamine-tetraacetic acid (EDTA), formic acid (CH2O2), hydrochloric acid (HCl), and HCl/EDTA mixture. The efficiencies of these four agents were investigated by assessing the remaining mineral quantities and collagen integrity with various experimental techniques. Raman spectroscopy results show that the bone demineralized by the CH2O2 agent has highest collagen quality parameter. The HCl/EDTA mixture removes the most mineral, but it affects the collagen secondary structure as amide II bands are shifted as observed by Fourier transform infrared spectroscopy. Thermogravimetric analysis reveals that HCl and EDTA are most effective in removing the mineral with bulk measurements. In summary, we conclude that HCl best demineralizes bone, leaving the well-preserved collagen structure in the shortest time. These findings guide on the best demineralization protocol to obtain high-quality collagen from bone for clinical and scientific applications.


Assuntos
Técnica de Desmineralização Óssea/classificação , Técnica de Desmineralização Óssea/métodos , Colágeno/química , Osso Cortical/metabolismo , Animais , Suínos
2.
Forensic Sci Int Genet ; 51: 102448, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33373911

RESUMO

Recovering DNA from modern incinerated bones can be challenging and may require alteration of routine DNA extraction protocols. It has been postulated that incinerated bones share some similarities with ancient bones, including fragmented DNA, surface contamination and highly mineralised structure, all of which can inhibit the successful recovery of genetic material. For this reason, ancient DNA extraction protocols are often used for incinerated modern samples; however, their effectiveness is still somewhat unclear. Much of this uncertainty exists around the demineralisation step of extraction, specifically the length of incubation and retention or removal of supernatant. As obtaining human samples for forensic research can be challenging, porcine models (Sus scrofa domesticus) are often used as substitutes. This study developed real time PCR assays for porcine nuclear DNA in order to investigate the effects of modified demineralisation protocols on DNA yield from femurs exposed to either short (60 min) or prolonged (120 min) burning. Gradient PCR results indicated 56 °C was the ideal amplification temperature for targeted amplicons, with melt curve analysis showing short and long amplicons corresponded to 80.3 °C and 83 °C peaks respectively. Results of altered extraction protocol showed a trend towards higher DNA yields from longer demineralisation periods however this was not significant. By comparison, retaining supernatant post-demineralisation resulted in significantly greater DNA yields compared to discarding it (P < 0.009). Although DNA content yield decreased with burn duration, the demineralisation treatment variations appeared to have the same effect for all burn lengths. These results suggest that for incinerated modern bone retaining the supernatant following demineralisation can dramatically increase DNA yield.


Assuntos
Técnica de Desmineralização Óssea/métodos , DNA/análise , Fêmur/química , Incêndios , Animais , Restos Mortais , Núcleo Celular , Genética Forense/métodos , Modelos Animais , Reação em Cadeia da Polimerase em Tempo Real , Suínos
4.
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
5.
Methods Mol Biol ; 1914: 437-450, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30729481

RESUMO

Immunohistochemistry (IHC) is a routinely used technique in clinical diagnosis of pathological conditions and in basic and translational research. It combines anatomical, immunological, and biochemical methods and relies on the specific binding of an antibody to an antigen. Using the technique with mineralized tissues is more challenging than with soft tissues. Demineralizing the samples allows for embedding in paraffin wax, and also facilitates cryosectioning. This chapter describes methods for IHC on formaldehyde-fixed, demineralized, paraffin-embedded, or frozen sections to detect antigens in skeletal tissues.


Assuntos
Técnica de Desmineralização Óssea/métodos , Imunofluorescência/métodos , Articulação do Joelho/patologia , Animais , Técnica de Desmineralização Óssea/instrumentação , Imunofluorescência/instrumentação , Corantes Fluorescentes/química , Formaldeído/química , Secções Congeladas/instrumentação , Secções Congeladas/métodos , Camundongos , Inclusão em Parafina/instrumentação , Inclusão em Parafina/métodos , Fixação de Tecidos/instrumentação , Fixação de Tecidos/métodos
6.
Sci Rep ; 8(1): 10181, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29976928

RESUMO

Orthopaedic research necessitates accurate and reliable models of human bone to enable biomechanical discoveries and translation into clinical scenarios. Juvenile bovine bone is postulated to be a potential model of normal human bone given its dimensions and comparatively reduced ethical restrictions. Demineralisation techniques can reduce bone density and alter bone properties, and methods to model osteoporotic bone using demineralised juvenile bovine bone are investigated. Juvenile bovine long bones were quantitatively CT scanned to assess bone density. Demineralisation using hydrochloric acid (0.6, 1.2 and 2.4 M) was performed to create different bone density models which underwent biomechanical validation for normal and osteoporotic bone models. All long bones were found to have comparable features to normal human bone including bone density (1.96 ± 0.08 gcm-3), screw insertion torque and pullout strength. Demineralisation significantly reduced bone density and pullout strength for all types, with 0.6 M hydrochloric acid creating reductions of 25% and 71% respectively. Juvenile bovine bone is inexpensive, easy to source and not subject to extensive ethical procedures. This study establishes for the first time, the use of its long bones as surrogates for both normal and osteoporotic human specimens and offers preliminary validation for its use in biomechanical testing.


Assuntos
Técnica de Desmineralização Óssea/métodos , Teste de Materiais/métodos , Osteoporose/cirurgia , Fatores Etários , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Bovinos , Modelos Animais de Doenças , Fêmur , Humanos , Úmero , Ácido Clorídrico/administração & dosagem , Teste de Materiais/instrumentação , Parafusos Pediculares , Tíbia , Ulna
7.
J Forensic Sci ; 63(6): 1819-1823, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29411392

RESUMO

Bones are often recovered in forensic investigations, including missing persons and mass disasters. While traditional DNA extraction methods rely on grinding bone into powder prior to DNA purification, the TBone Ex buffer (DNA Chip Research Inc.) digests bone chips without powdering. In this study, six bones were extracted using the TBone Ex kit in conjunction with the PrepFiler® BTA™ DNA extraction kit (Thermo Fisher Scientific) both manually and via an automated platform. Comparable amounts of DNA were recovered from a 50 mg bone chip using the TBone Ex kit and 50 mg of powdered bone with the PrepFiler® BTA™ kit. However, automated DNA purification decreased DNA yield (p < 0.05). Nevertheless, short tandem repeat (STR) success was comparable across all methods tested. This study demonstrates that digestion of whole bone fragments is an efficient alternative to powdering bones for DNA extraction without compromising downstream STR profile quality.


Assuntos
Osso e Ossos/química , Impressões Digitais de DNA/métodos , DNA/isolamento & purificação , Repetições de Microssatélites , Restos Mortais , Técnica de Desmineralização Óssea/métodos , Humanos , Reação em Cadeia da Polimerase em Tempo Real
8.
J Proteome Res ; 17(1): 536-542, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29166020

RESUMO

Bone proteomics is an expanding field for understanding protein changes associated with disease as well as characterizing and detecting proteins preserved in fossil bone. Most previous studies have utilized a protocol with demineralization and extraction approach to isolate and characterize proteins from bone. Through near-complete EDTA demineralization, followed by solid digestion of the remaining bone pseudomorph, a total of 92 protein accessions were detected from dog bone. In the EDTA, 14 unique proteins were found, including osteocalcin, an important bone protein. Osteocalcin was not found in the solid digestion samples, demonstrating the importance of examining the demineralization supernatant. The solid-digestion samples were analyzed both with (11 unique accessions) and without (16 unique accessions) alkylation, resulting in a total of 78 protein accessions. In addition to the diversity of proteins detected, various post-translational modifications were observed, including phosphorylation and glycosylation. The solid-digestion approach will allow for characterization of proteins that are insoluble and would otherwise be missed by traditional bone protein extraction alone. All data are available at ftp://massive.ucsd.edu/MSV000081399 .


Assuntos
Técnica de Desmineralização Óssea/métodos , Osso e Ossos/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas/análise , Proteômica/métodos , Animais , Cães , Ácido Edético , Glicosilação , Fosforilação , Proteínas/metabolismo , Solubilidade
9.
Microsc Res Tech ; 80(4): 344-349, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28370969

RESUMO

The selection of an appropriate demineralizing solution in pathology laboratories depends on several factors such as the preservation of cellularity, urgency of diagnostic and financial costs. The aim of this study was to test different decalcification bone procedures in order to establish the best value of these in formalin-fixed and paraffin-embedded samples. Femurs were removed from 13 adult male Wistar rats to obtain 130 bone disks randomly divided into five groups that were demineralized in different concentrations of nitric acid (Group I); formic acid (Group II); acetic acid (Group III); EDTA, pH7.4 (Group IV) and Morsés solution (Group V). Serial, 3-µm-thick sections were obtained and stained with hematoxylin-eosin to calculate the percentage of osteocyte-occupied lacunae. The sections were also stained with Masson's trichrome in conjunction with picrosirius red under polarized light followed by a semi-quantitative analysis to verify the adjacent muscle-to-bone integrity and preservation of collagen fibres. The highest percentage of osteocyte-occupied lacunae was found with 10% acetic acid solution (95.64 ± 0.95%) and Group I (nitric acid) demanded the shorter time (0.8-5.7days). Of all solutions, 5% nitric acid incurred the lowest cost to achieve complete demineralization compared with other solutions (p < .001). Group IV (EDTA) had the highest integrity of muscle and collagen type I and III (P < 0.01). Demineralization with 10% acetic acid was the most effective at preserving bone tissue, while 5% EDTA was the best at maintaining collagen and adjacent muscle to bone. In conclusion, nitric acid at 5% showed the most efficient result as it balanced both time and cost as a demineralizing solution.


Assuntos
Técnica de Desmineralização Óssea/economia , Técnica de Desmineralização Óssea/métodos , Técnica de Descalcificação/economia , Técnica de Descalcificação/métodos , Fêmur/química , Estudos de Tempo e Movimento , Ácido Acético/química , Animais , Osso e Ossos/química , Colágeno Tipo I/análise , Colágeno Tipo III/análise , Ácido Edético/química , Formiatos/química , Masculino , Músculos/fisiologia , Ácido Nítrico/química , Ratos , Ratos Wistar , Coloração e Rotulagem/economia , Coloração e Rotulagem/métodos
10.
Bull Exp Biol Med ; 162(2): 273-276, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27905031

RESUMO

Osteoinductive characteristics of new osteoplastic materials based on demineralized bone matrix of xenogenic origin with high and controlled degree of purification were studied on the model of regeneration of critical-size cranial defects in rats using modern approaches, including histological analysis, evaluation of morphological parameters of the bone tissue obtained by micro-computed tomography, and estimation of bone tissue growth rate using in vivo fluorochrome label. Demineralized bone matrix and, to a much greater extent, its activated form containing modified recombinant growth factor rhBMP-2 with high content of the dimeric form exhibited osteoinductive activity.


Assuntos
Técnica de Desmineralização Óssea/métodos , Proteína Morfogenética Óssea 2/farmacologia , Regeneração Óssea/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Crânio/efeitos dos fármacos , Alicerces Teciduais , Animais , Materiais Biocompatíveis/farmacologia , Proteína Morfogenética Óssea 2/biossíntese , Proteína Morfogenética Óssea 2/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Corantes Fluorescentes , Expressão Gênica , Humanos , Proteínas Imobilizadas/biossíntese , Proteínas Imobilizadas/genética , Proteínas Imobilizadas/farmacologia , Masculino , Multimerização Proteica , Ratos , Ratos Wistar , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Crânio/lesões , Crânio/cirurgia , Engenharia Tecidual , Microtomografia por Raio-X
11.
Biomaterials ; 111: 13-26, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27718449

RESUMO

Tissue-engineered meniscus regeneration is a very promising treatment strategy for meniscus lesions. However, generating the scaffold presents a huge challenge for meniscus engineering as this has to meet particular biomechanical and biocompatibility requirements. In this study, we utilized acellular meniscus extracellular matrix (AMECM) and demineralized cancellous bone (DCB) to construct three different types of three-dimensional porous meniscus scaffold: AMECM, DCB, and AMECM/DCB, respectively. We tested the scaffolds' physicochemical characteristics and observed their interactions with meniscus fibrochondrocytes to evaluate their cytocompatibility. We implanted the three different types of scaffold into the medial knee menisci of New Zealand rabbits that had undergone total meniscectomy; negative control rabbits received no implants. The reconstructed menisci and corresponding femoral condyle and tibial plateau cartilage were all evaluated at 3 and 6 months (n = 8). The in vitro study demonstrated that the AMECM/DCB scaffold had the most suitable biomechanical properties, as this produced the greatest compressive and tensile strength scores. The AMECM/DCB and AMECM scaffolds facilitated fibrochondrocyte proliferation and the secretion of collagen and glycosaminoglycans (GAGs) more effectively than did the DCB scaffold. The in vivo experiments demonstrated that both the AMECM/DCB and DCB groups had generated neomeniscus at both 3 and 6 months post-implantation, but there was no obvious meniscus regeneration in the AMECM or control groups, so the neomeniscus analysis could not perform on AMECM and control group. At both 3 and 6 months, histological scores were better for regenerated menisci in the AMECM/DCB than in the DCB group, and significantly better for articular cartilage in the AMECM/DCB group compared with the other three groups. Knee MRI scores (Whole-Organ Magnetic Resonance Imaging Scores (WORMS)) were better in the AMECM/DCB group than in the other three groups at both 3 and 6 months. At both 3 and 6 months, RT-PCR demonstrated that aggrecan, Sox9, and collagen II content was significantly higher, and mechanical testing demonstrated greater tensile strength, in the AMECM/DCB group neomenisci compared with the DCB group.


Assuntos
Matriz Óssea/química , Matriz Extracelular/química , Regeneração Tecidual Guiada/instrumentação , Lesões do Menisco Tibial/patologia , Lesões do Menisco Tibial/terapia , Alicerces Teciduais , Animais , Materiais Biocompatíveis/síntese química , Técnica de Desmineralização Óssea/métodos , Sistema Livre de Células , Desenho de Equipamento , Regeneração Tecidual Guiada/métodos , Meniscectomia , Menisco/química , Coelhos , Regeneração/fisiologia , Lesões do Menisco Tibial/fisiopatologia , Resultado do Tratamento
12.
Biomaterials ; 108: 157-67, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27636153

RESUMO

Cartilage tissue engineering is the hotspot of cartilage repair. The allogenic chondrocytes appear to be a promising source of seed cells in cartilage tissue engineering. In this study, we aimed to transplant allogenic chondrocytes with chitosan hydrogel (CS)-demineralized bone matrix (DBM) hybrid scaffold (CS/DBM) to repair rabbit cartilage injury with one-step operation. After the CS/DBM scaffold was successfully fabricated, it showed that the porous CS filled the large pores of DBM, which improved the distribution of seed cells in the CS/DBM scaffold. The allogenic chondrocytes at second passage were transplanted with different scaffolds to repair rabbit cartilage injury. Twenty-four weeks after surgery, the cartilage defect in the CS/DBM group was successfully filled as shown by MRI. Moreover, the histological score of CS/DBM group was significantly higher than that of the other groups. On the aspect of biomechanical property, the regenerated cartilage in the CS/DBM group were superior to those in the other groups as determined by nanoindentation. Meanwhile, no obvious inflammatory response was observed after the transplantation of allogenic chondrocytes at 24 weeks post-surgery. Furtherly, gene expression profile for cells within the repair tissue was compared with the allogenic chondrocytes before transplantation using Agilent microarray and RT-qPCR. The results showed that some genes beneficial to cartilage regeneration, such as BMP-7, HGF, and IGF-1, were upregulated one month after transplantation. Consequently, our study demonstrated that the transplantation of allogenic chondrocytes with CS/DBM scaffold successfully repaired rabbit cartilage injury with only one-step operation, thereby providing new insights into cartilage tissue engineering.


Assuntos
Matriz Óssea/química , Quitosana/química , Condrócitos/citologia , Condrócitos/transplante , Fraturas de Cartilagem/fisiopatologia , Fraturas de Cartilagem/terapia , Alicerces Teciduais , Animais , Técnica de Desmineralização Óssea/métodos , Células Cultivadas , Condrócitos/fisiologia , Consolidação da Fratura , Fraturas de Cartilagem/patologia , Regeneração Tecidual Guiada/instrumentação , Regeneração Tecidual Guiada/métodos , Hidrogéis/química , Coelhos , Regeneração/fisiologia , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Transplante Homólogo/métodos , Resultado do Tratamento
13.
BMC Musculoskelet Disord ; 17: 3, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26728876

RESUMO

BACKGROUND: Although autogenous iliac bone graft (AIBG) remains the gold standard for spine fusion, harvesting morbidity has prompted the search for alternatives especially for multi-segment fusion. This study aimed to evaluate the efficacy of using demineralized bone matrix (DBM) as a substitute of AIBG for long instrumented posterolateral fusion (≧ three-level fusion). METHODS: A total of 47 consecutive patients underwent laminectomy decompression, and multi-level instrumented posterolateral fusions were reviewed. Group 1 comprised 26 patients having DBM with autologous laminectomy bone (ALB). Group 2 consisted of 21 patients having AIBG with ALB. The fusion success evaluation was based on findings using the 12-month anteroposterior and dynamic plain radiographs. RESULTS: Gender, age, and the number of fusion levels were similar for both groups. 21 of 26 (80.8%) patients in group 1 and 18 of 21 (85.7%) patients in group 2 were observed to achieve solid bony fusion. There was no statistical difference in the fusion success (p = 0.72). Blood loss was significantly more in group 2 (p = 0.02). The duration of the hospital stays and operative times being longer for group 2, but the difference was not significant. CONCLUSIONS: DBM combined with ALB and osteoconductive materials is as effective as an autologous iliac bone graft with respect to long multi-segment posterolateral fusion success. DBM can be used as an effective bone graft substitute and may decrease morbidities associated with iliac bone graft harvest.


Assuntos
Materiais Biocompatíveis , Técnica de Desmineralização Óssea/métodos , Matriz Óssea/transplante , Transplante Ósseo/métodos , Ílio/transplante , Fusão Vertebral/métodos , Idoso , Idoso de 80 Anos ou mais , Materiais Biocompatíveis/administração & dosagem , Matriz Óssea/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Ílio/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Transplante Autólogo/métodos
14.
Cell Tissue Bank ; 17(1): 91-104, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26084504

RESUMO

Due to the extensive use of bone allografts in bone reconstruction and periodontal therapy as suitable alternatives to autografts, they are now marketed under different commercial brands. Considering the controversial reports regarding the osteoinductive properties of bone allografts, this study sought to assess the effect of type (mineralized/demineralized), amount and particle size of several allografts on the proliferation and differentiation of MG-63 osteoblast-like cells. MG-63 cells (24-h culture) were exposed to 20 and 40 mg amounts of nine different commercially available freeze-dried bone allografts. After 24 and 72 h of incubation, the effect of water-soluble allograft released materials on cell viability and proliferation was assessed using methyl thiazol tetrazolium (MTT) assay after 24 and 72 h of exposure. Cell differentiation and mineralization was assessed by real-time quantitative reverse transcription PCR and alizarin red staining after 72 h of exposure. The amount and particle size of understudy allografts had significant effects on cell viability after 24 h of exposure (in contrast to 72 h). Higher rate of proliferation was seen in non-differentiated or slow-differentiated groups. The amount and particle size factors had no significant effect on the amount of calcified nodules or the expression of osteogenic marker genes in most groups. Faster and more distinct differentiation and mineralization was noted in mineralized compared to demineralized groups during the 3-day study period. Based on the results, the understudy mineralized (non-demineralized) bone allografts had greater effect on osteogenic differentiation of the MG-63 cells and showed more in vitro osteoinductive activity compared to partially demineralized and fully demineralized types.


Assuntos
Aloenxertos/transplante , Técnica de Desmineralização Óssea/métodos , Transplante Ósseo , Calcificação Fisiológica , Diferenciação Celular , Osteoblastos/citologia , Diferenciação Celular/genética , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Regulação da Expressão Gênica , Humanos
15.
Bauru; s.n; 2016. 119 p. tab, ilus, graf.
Tese em Português | BBO - Odontologia | ID: biblio-881573

RESUMO

O processo de desmineralização óssea tem sido mostrado vantajoso em procedimentos de enxertia óssea empregando blocos osseos, porem a sua utilização na periodontia em enxertos osseos autógenos particulados não esta ainda descrita na literatura. De acordo com a literatura é possível observar que existem diferentes agentes demineralizantes na pratica clinica os quais podem ser empregados no processo de desmineralização óssea, razão pela qual este estudo teve como objetivo comparar dois diferentes agentes desmineralizantes de enxertos ósseos autógenos particulados (ácido cítrico pH1 a 50% e tetraciclina hidroclorada a 50mg/ml) em diferentes tempos de aplicação, quanto ao efeito produzido no reparo de defeitos críticos em calvária de ratos. Foram utilizados 120 ratos adultos machos com aproximadamente 4 meses de vida. Neste estudo foi utilizado o modelo de defeito crítico de 8 mm, esses animais foram divididos em 8 grupos de estudo formados por 15 animais (5 em cada período experimental): CN (controle negativo): os defeitos permaneceram sem enxerto; CP (controle positivo): os defeitos foram preenchidos por osso particulado não desmineralizado; AC 15: os defeitos foram preenchidos com osso particulado desmineralizado por ácido cítrico durante 15 segundos; AC 30: os defeitos foram preenchidos com osso particulado desmineralizado por ácido cítrico durante 30 segundos; AC 60: os defeitos foram preenchidos com osso particulado desmineralizado por ácido cítrico durante 60 segundos; TCN 15: os defeitos foram preenchidos com osso particulado desmineralizado por tetraciclina durante 15 segundos; TCN 30: os defeitos foram preenchidos com osso particulado desmineralizado por tetraciclina durante 30 segundos; TCN 60: os defeitos foram preenchidos com osso particulado desmineralizado por tetraciclina durante 60 segundos. Foi realizada aeutanasia dos animais aos 7, 30 e 60 dias para realização de microtomografia computadorizada e analise histomorfometrica, para avaliar a área, volume e densidade óssea nos defeitos após os tempos experimentais definidos. Aos 7 dias, não era esperada formação de tecido ósseo significante, mas surpreendentemente, os espécimes desmineralizados com ácido cítrico demonstraram precocidade na produção de eventos regenerativos já nesse período. Durante os períodos experimentais foi possível observar como os espécimes tratados com acido cítrico apresentavam maior formação óssea nos defeito quando comparados com os controles e com os grupos onde empregados tetraciclina. Efeito provavelmente relacionado com a eliminação da parte mineral do osso e liberação de Proteinas morfogeneticas ósseas e fatores de crescimentos, liberados a partir da matriz ossea Concluiu-se que a desmineralização com ácido cítrico do osso autógeno particulado enxertado em defeitos críticos promoveu maior área, volume e densidade de formação óssea do que a desmineralização com tetraciclina e do que a não desmineralização. Observando-se melhores resultados aos 15 e 30 segundos de desmineralização.(AU)


Bone demineralization process has been shown useful in bone grafting procedures using onlay bone grafting, however its use in periodontics in bony autogenous particulate graft is not yet described in the literature. According to the literature you can see that there are different demineralizantes agents in clinical practice which can be used in bone demineralization process, which is why this study was to compare two different demineralization agents of bone autogenous particulate graft (citric acid pH1 the 50% tetracycline Hydrochloride and 50mg / ml) in different application time, the effect produced in the repair of critical defects in rat calvarium. 120 adult male rats with approximately 4 months of age were used. In this study we used the 8mm critical defect model, the animals were divided into 8 study groups consisting of 15 animals (5 in each experimental period): CN (negative control): the defect remained free graft; CP (positive control): the defects were filled by nondemineralized bone particles; AC 15: The defects were filled with demineralized bone particles of citric acid for 15 seconds; AC 30: defects were filled with demineralized bone particles of citric acid for 30 seconds; AC 60: The defects were filled with demineralized bone particles of citric acid for 60 seconds; TCN 15: defects were filled with demineralized bone particles tetracycline for 15 seconds; TCN 30: defects were filled with demineralized bone particles tetracycline for 30 seconds; TCN 60: defects were filled with demineralized bone particles tetracycline for 60 seconds. aeutanasia animals was performed at 7, 30 and 60 days for performing computed microtomography and histomorphometric analysis to assess the area, bone volume and density of the defects after the defined experimental times. At 7 days, it was not expected significant formation of bone tissue, but surprisingly, samples demineralized with citric acid demonstrated earliness in the production of regenerative events already during this period. During the experimental periods was possible to observe how the specimens treated with citric acid showed increased bone formation in defects when compared to controls and to groups where employees tetracycline. Effect probably related to the disposal of the mineral part of bone and release of bone morphogenetic proteins and factors of growth, released from the bone matrix concluded that the demineralisation by citric acid particulate autogenous bone graft in critical defects caused greater area, volume formation and bone density than tetracycline demineralization and demineralization that do not. Observing better results at 15 and 30 seconds demineralization.(AU)


Assuntos
Animais , Masculino , Ratos , Técnica de Desmineralização Óssea/métodos , Regeneração Óssea/efeitos dos fármacos , Transplante Ósseo/métodos , Ácido Cítrico/farmacologia , Tetraciclina/farmacologia , Ratos Wistar , Reprodutibilidade dos Testes , Crânio/transplante , Transplante Autólogo/métodos , Resultado do Tratamento
16.
ACS Appl Mater Interfaces ; 7(34): 18937-43, 2015 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-26266571

RESUMO

Using atomic force microscopy, we monitored the nanoscale surface morphology of human teeth at the dentin-enamel junction after performing successive demineralization steps with an acidic soft drink. Subsequently, we studied the remineralization process with a paste containing calcium and phosphate ions. Repeated atomic force microscopy imaging of the same sample areas on the sample allowed us to draw detailed conclusions regarding the specific mechanism of the demineralization process and the subsequent remineralization process. The about 1-µm-deep grooves that are caused by the demineralization process were preferentially filled with deposited nanoparticles, leading to smoother enamel and dentine surfaces after 90 min exposure to the remineralizing agent. The deposited material is found to homogeneously cover the enamel and dentine surfaces in the same manner. The temporal evolution of the surface roughness indicates that the remineralization caused by the repair paste proceeds in two distinct successive phases.


Assuntos
Técnica de Desmineralização Óssea/métodos , Esmalte Dentário/patologia , Dentina/patologia , Microscopia de Força Atômica , Remineralização Dentária/métodos , Condicionamento Ácido do Dente , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Pessoa de Meia-Idade
17.
Molecules ; 20(4): 5835-50, 2015 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-25849806

RESUMO

Bone material is composed of an organic matrix of collagen fibers and apatite nanoparticles. Previously, vibrational spectroscopy techniques such as infrared (IR) and Raman spectroscopy have proved to be particularly useful for characterizing the two constituent organic and inorganic phases of bone. In this work, we tested the potential use of high intensity synchrotron-based far-IR radiation (50-500 cm(-1)) to gain new insights into structure and chemical composition of bovine fibrolamellar bone. The results from our study can be summarized in the following four points: (I) compared to far-IR spectra obtained from synthetic hydroxyapatite powder, those from fibrolamellar bone showed similar peak positions, but very different peak widths; (II) during stepwise demineralization of the bone samples, there was no significant change neither to far-IR peak width nor position, demonstrating that mineral dissolution occurred in a uniform manner; (III) application of external loading on fully demineralized bone had no significant effect on the obtained spectra, while dehydration of samples resulted in clear differences. (IV) using linear dichroism, we showed that the anisotropic structure of fibrolamellar bone is also reflected in anisotropic far-IR absorbance properties of both the organic and inorganic phases. Far-IR spectroscopy thus provides a novel way to functionally characterize bone structure and chemistry, and with further technological improvements, has the potential to become a useful clinical diagnostic tool to better assess quality of collagen-based tissues.


Assuntos
Técnica de Desmineralização Óssea/métodos , Fêmur/química , Espectrofotometria Infravermelho/instrumentação , Espectrofotometria Infravermelho/métodos , Animais , Anisotropia , Apatitas/química , Densidade Óssea , Calcificação Fisiológica , Bovinos , Colágeno/química , Modelos Biológicos
18.
Cell Tissue Bank ; 16(4): 569-78, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25736401

RESUMO

Shaped demineralised bone matrices (DBM) made from cancellous bone have important uses in orthopaedic and dental procedures, where the properties of the material allow its insertion into confined defects, therefore acting as a void filler and scaffold onto which new bone can form. The sponges are often small in size, <1.0 cm(3). In this study, we report on an improved bone washing and demineralisation process that allows production of larger DBM sponges (3.375 or 8.0 cm(3)) from deceased donor bone. These sponges were taken through a series of warm water washes, some with sonication, centrifugation, 100 % ethanol and two decontamination chemical washes and optimally demineralised using 0.5 N hydrochloric acid under vacuum. Demineralisation was confirmed by quantitative measurement of calcium and qualitatively by compression. Protein and DNA removal was also determined. The DBM sponges were freeze dried before terminal sterilisation with a target dose of 25 kGy gamma irradiation whilst frozen. Samples of the sponges were examined histologically for calcium, collagen and the presence of cells. The data indicated lack of cells, absence of bone marrow and a maximum of 1.5 % residual calcium.


Assuntos
Técnica de Desmineralização Óssea/métodos , Matriz Óssea/química , Substitutos Ósseos/síntese química , Sistema Livre de Células/química , Detergentes/química , Feminino , Fêmur/química , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Porosidade , Tíbia/química
19.
J Biomed Mater Res B Appl Biomater ; 103(5): 1023-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25220892

RESUMO

Human demineralized bone matrix derived from cortical bone is used by surgeons due to its ability to promote bone formation. There is also a need for shaped demineralized bone matrices made from cancellous bone, where the properties of the material allow its insertion into defects, therefore acting as a void filler and scaffold onto which new bone can form. In this study, we report that demineralized bone sponges were prepared by dissecting and cutting knee bone into cancellous bone cubes of 1 cm(3) . These cubes were then taken through a series of warm water washes, some with sonication, centrifugation, and two decontamination chemical washes. The cubes were optimally demineralized into sponges with 0.5N hydrochloric acid under vacuum with constant pH measurement. Demineralization was confirmed by quantitative measurement of calcium and qualitatively by compression. The sponges were freeze dried before terminal sterilisation with a target dose of 25 kGy gamma radiation whilst frozen. Samples of the sponges were histologically examined for calcium and collagen and also tested for osteoinductivity. Data showed well defined collagen staining in the sponges, with little residual calcium. Sponges from two out of three donors demonstrated osteoinductivity when implanted into the muscle of an athymic mouse.


Assuntos
Técnica de Desmineralização Óssea/métodos , Ossos Sesamoides/química , Vácuo , Adulto , Idoso , Animais , Feminino , Xenoenxertos , Humanos , Ácido Clorídrico , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade
20.
Cell Tissue Bank ; 16(3): 371-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25385320

RESUMO

Demineralized freeze-dried bone allograft (DFDBA) has been used extensively in periodontal therapy. Questions have been raised however, about the osteogenic potential of the variety of grafts available. In India the cost factor is another important consideration. The aim of this study therefore was to evaluate the clinical efficiency of the low priced, indigenously prepared DFDBA obtained from the Tata Memorial Hospital (TMH) Tissue Bank, in periodontal regeneration in infrabony periodontal defects, as compared to DFDBA obtained from the Pacific Coast Tissue Bank (DEMBONE). The latter was used as the control. 16 patients with bilaterally similar periodontal infrabony defects were selected, and randomly allotted to the test and control groups. At baseline, using standardized protocol, recession, probing depths (PD), and clinical attachment levels (CAL) were measured, following which periodontal surgery was carried out, with placement of the respective graft materials. Patients were recalled after 6 months for re-assessment. Statistically significant improvement was obtained for PD reduction and CAL gain for both groups (p < 0.05). However, no significant difference was observed between the test and control groups. It was therefore concluded that both the materials from different tissue banks are equally effective clinically, with the test material being additionally cost effective.


Assuntos
Técnica de Desmineralização Óssea/métodos , Transplante Ósseo/métodos , Regeneração Tecidual Guiada Periodontal/métodos , Perda da Inserção Periodontal/diagnóstico , Perda da Inserção Periodontal/terapia , Esterilização/métodos , Adulto , Transplante Ósseo/instrumentação , Feminino , Liofilização/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/métodos , Doses de Radiação , Método Simples-Cego , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...