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STATEMENT OF PROBLEM: The influence of different glaze firing protocols and cooling on the behavior of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is unclear. PURPOSE: The purpose of this in vitro study was to investigate the influence of different glaze firing protocols on the abrasion resistance, surface roughness, microhardness, and brittleness index of CAD-CAM ceramics. MATERIAL AND METHODS: Rectangular specimens of IPS e.max CAD (MAX), IPS Empress CAD (PRE), and CEREC Blocs (CER) were obtained and divided into 5 groups according to the glaze firing protocol (n=8): control (CO), 1 conventional glaze firing (GF), 2 conventional glaze firings (GF2), 1 extended glaze firing (EG), and 2 extended glaze firings (EG2). The coefficient of friction (µ) was determined with the pin-on-disk test, and specimens were analyzed with an optical interferometer to calculate volume loss and roughness. Vickers microhardness and the brittleness index were obtained with a microdurometer. Microhardness data were evaluated by 2-way ANOVA and the Sidak tests (α=.05). Data from other tests were assessed with nonparametric ANOVA and Bonferroni tests (α=.05). RESULTS: Groups GF2, EG, and EG2 of MAX and PRE and all groups of CER presented higher levels of coefficient of friction. Groups EG and EG2 of MAX and CER showed high volume loss and surface roughness. Groups EG and EG2 of MAX and PRE showed lower hardness, as did all groups of CER. MAX-CO and groups GF and EG of PRE showed a lower brittleness index (P<.05), while CER groups showed no significant differences (P>.05). CONCLUSIONS: Ceramic specimens with conventional glaze firing presented less surface wear than those with extended glaze firing. The number of firings did not have a statistically significant influence.
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Cerâmica , Porcelana Dentária , Desenho Assistido por Computador , Teste de Materiais , Propriedades de SuperfícieRESUMO
This work introduces an alternative way to perform the T2 - T2 Exchange NMR experiment. Rather than varying the number of π pulses in the first CPMG cycle of the T2 - T2 Exchange NMR pulse sequence, as used to obtain the 2D correlation maps, it is fixed and small enough to act as a short T2-filter. By varying the storage time, a set of 1D measurements of T2 distributions can be obtained to reveal the effects of the migration dynamics combined with relaxation effects. This significantly reduces the required time to perform the experiment, allowing a more in-depth study of exchange dynamics and relaxation processes with improved signal-to-noise ratio. These aspects stand as basis of this novel experiment, T2-Filtered T2 - T2 Exchange NMR or simply T2 F-TREx.
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Many aspects relating to equipment configuration affect users' actions in a manual wheelchair, determining the overall mobility performance. Since the equipment components and configuration determine both stability and mobility efficiency, configuring the wheelchair with the most appropriate set-up for individual users' needs is a difficult task. Several studies have shown the importance of seat/backrest assembly and the relative position of the rear wheels to the user in terms of the kinetics and kinematics of manual propulsion. More recently, new studies have brought to light evidence on the inertial properties of different wheelchair configurations. Further new studies have highlighted the handrim as a key component of wheelchair assembly, since it is the interface through which the user drives the chair. In light of the new evidence on wheelchair mechanics and propulsion kinetics and kinematics, this article presents a review of the most important aspects of wheelchair configuration that affect the users' actions and mobility.
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This study aimed to produces and characterize bovine hydroxyapatite (HA) bioceramic with 3Y-TZP addition and analyze different sintering curves. HA was extracted from bovine bones and nanoparticulated. HA discs (0, 1, 5 and 10 wt% 3Y-TZP) were subjected to uniaxial and isostatic pressing. Dilatometry analysis was performed and the groups were sintered using 3 different firing curves (conventional, 1300 °C; 2-step, 1292 °C; 2-step, 1420 °C). The samples were analyzed by X-ray diffraction (XRD), biaxial flexural strength (BFS), Vickers microhardness (VH) and Field emission scanning electron microscopy (FE-SEM). The dilatometry results signaled the need for sintering optimization in groups added with 3Y-TZP. XRD demonstrated the characteristic crystallographic peaks of HA in the pure groups and with 1% 3Y-TZP, and decomposition of HA into ß-TCP and formation of calcium zirconate in the groups with 5 and 10% 3Y-TZP. Considering each composition, the groups of pure HA (131.3 ± 13.5 MPa; 401 ± 12.7 GPa) sintered by the conventional curve and HA+1%3Y-TZP (145 ± 8.6 MPa; 507 ± 47.9 GPa), HA+5%3Y-TZP (68.1 ± 14.2 MPa; 183 ± 9.8 GPa) and HA+10%3Y-TZP (55.6 ± 5.1 MPa; 96.1 ± 7.64 GPa) sintered by the 2-step curve at 1420 °C, combined the best BFS and VH results. The addition of 1 wt% 3Y-TZP and optimization in the sintering process improved the mechanical and microstructural properties of HA bioceramics and maintenance of its crystalline characteristics. Refinement in material processing is necessary for the future use of this bioceramic in dentistry.
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Cerâmica , Durapatita , Teste de Materiais , Ítrio , Zircônio , Animais , Durapatita/química , Zircônio/química , Bovinos , Ítrio/química , Cerâmica/química , Dureza , Materiais Biocompatíveis/química , Fenômenos MecânicosRESUMO
Abutment components (i.e., fixtures associated with oral implants) are essentially made of titanium (Ti), which is continuously exposed to the hash oral environment, resulting in scratching. Thus, such components need to be protected, and surface treatments are viable methods for overcoming long-term damage. Diamond-like carbon (DLC), an excellent protective material, is an alternative surface-treatment material for Ti abutments. Here, we demonstrate that a silicon interlayer for DLC film growth and the pulsed-direct current plasma-enhanced chemical vapor deposition (DC-PECVD) method enables the deposition of an enhanced protective DLC film. As a result, the DLC film demonstrated a smooth topography with a compact surface. Furthermore, the DLC film enhanced the mechanical (load-displacement, hardness, and elastic modulus) and tribological properties of Ti as well as increased its corrosion resistance (16-fold), which surpassed that of a bare Ti substrate. The biofilm formed (Streptococcus sanguinis) after 24 h exhibited an equal bacterial load (â¼7 Log colony-forming units) for both the groups (Ti and DLC). In addition, the DLC film exhibited good cytocompatibility, owing to its noncytotoxicity toward human gingival fibroblast cells. Therefore, DLC deposition via DC-PECVD can be considered to be a promising protective and cytocompatible alternative for developing implant abutments with enhanced mechanical, tribological, and electrochemical properties.
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Biofilmes , Carbono , Humanos , Carbono/química , Próteses e Implantes , Titânio/química , GasesRESUMO
The inorganic part of marine sponges, called Biosilica (BS), presents an osteogenic potential and the ability of consolidating fractures. Moreover, 3D printing technique is highly effective for manufacturing scaffolds for tissue engineering proposals. Thus, the aims of this study were to characterize the 3D rinted scaffolds, to evaluate the biological effects in vitro and to investigate the in vivo response using an experimental model of cranial defects in rats. The physicochemical characteristics of 3D printed BS scaffolds were analyzed by FTIR, EDS, calcium assay, evaluation of mass loss and pH measurement. For in vitro analysis, the MC3T3-E1 and L929 cells viability was evaluated. For the in vivo evaluation, histopathology, morphometrical and immunohistochemistry analyses were performed in a cranial defect in rats. After the incubation, the 3D printed BS scaffolds presented lower values in pH and mass loss over time. Furthermore, the calcium assay showed an increased Ca uptake. The FTIR analysis indicated the characteristic peaks for materials with silica and the EDS analysis demonstrated the main presence of silica. Moreover, 3D printed BS demonstrated an increase in MC3T3-E1 and L929 cell viability in all periods analyzed. In addition, the histological analysis demonstrated no inflammation in days 15 and 45 post-surgery, and regions of newly formed bone were also observed. The immunohistochemistry analysis demonstrated increased Runx-2 and OPG immunostaining. Those findings support that 3D printed BS scaffolds may improve the process of bone repair in a critical bone defect as a result of stimulation of the newly formed bone.
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Poríferos , Alicerces Teciduais , Animais , Ratos , Alicerces Teciduais/química , Cálcio , Poríferos/química , Dióxido de Silício , Impressão TridimensionalRESUMO
OBJECTIVES: This study evaluated the effect of TiO2 nanoparticles + dense hydroxyapatite (HA) on human osteoblast cells (SAOS-2). METHODS: Particulate bovine HA powder with or without the addition of either 5 or 8 % TiO2 (HA, HA/TiO2Np5 % or HA/TiO2Np8 %) were pressed into disks (Ø = 12.5 mm; thickness = 1.3 mm) uniaxially (100 MPa) and isostatically (200 MPa/1 min) and sintered at 1300 °C. Y-TZP disks were used as control. The following tests were performed: Scanning Electron Microscopy and Dispersive Energy Spectroscopy (SEM/EDS), Atomic Force Microscopy (AFM), cell viability assay (Alamar Blue-AB) and mineralized matrix deposition (Alizarin Red-AR). AB and AR data were submitted to 2-way ANOVA/Tukey tests and ANOVA/Tukey tests, respectively. RESULTS: SEM revealed that the surface of HA/TiO2Np5% resembles DPBHA surface, but also contains smaller granules. HA/TiO2Np8% characteristics resembles HA/TiO2Np5% surface, but with irregular topography. Y-TZP showed a typical oxide ceramic surface pattern. EDS revealed Ca, O, and P in all samples. C, O, and Zr appeared in Y-TZP samples. AFM data corroborates SEM analysis. AB test revealed excellent cellular viability for HA/TiO2Np5% group. AR test showed that all groups containing TiO2np had more mineralized matrix deposition than all other groups, with statistically differences between HA/TiO2Np8% and HA cultivated in non-osteogenic medium. Culture in osteogenic medium exhibited much more mineralized matrix deposition by TiO2np groups. SIGNIFICANCE: In conclusion, the addition of TiO2np showed chemical, superficial, and biological changes in the reinforced materials. HA/TiO2Np5% showed the best results for cell viability and HA/TiO2Np8% for mineralized matrix deposition.
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Durapatita , Nanopartículas , Animais , Bovinos , Durapatita/química , Durapatita/farmacologia , Humanos , Microscopia Eletrônica de Varredura , Osteoblastos , Óxidos/farmacologia , Pós , Propriedades de Superfície , Titânio/química , Titânio/farmacologiaRESUMO
PURPOSE: To analyze and compare the reactions at the interface between the composite, composed of fragmented heterologous mineralized bone matrix (MOMHF) and polymethylmethacrylate (PMMA), and the rabbit's tibias, through macroscopic evaluation and scanning electron microscopy (SEM) in different periods. METHODS: In this study, 12 New Zealand adult rabbits were used (E1: n = 3, E2: n = 3, E3: n = 3 and E4: n = 3). They had the right tibial defects filled with composite and were evaluated immediately after surgery and at 30, 60, 90, and 120 days. RESULTS: The composites were incorporated and integrated into the recipient beds in 100% of the cases, defined by the MOMHF osseointegration and the PMMA fibrointegration, with no sign of infection, migration, or rejection. CONCLUSIONS: The behavior of the composites in the recipient beds demonstrates that these biomaterials have the potential to be used in bone defect repairs, offering, thus, better quality of life to the orthopedic patient.
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Matriz Óssea , Polimetil Metacrilato , Animais , Materiais Biocompatíveis , Humanos , Osseointegração , Qualidade de Vida , Coelhos , Tíbia/cirurgiaRESUMO
This study aimed to produce a new SiO2+Y-TZP ceramic via uniaxial/isostatic compression that was structurally and chemically characterized relating to its translucency and flexural strength. SiO2 and Y-TZP were mixed using a ball mill, pressed and sintered at 1150 °C. The optical and mechanical properties of the specimens were compared to lithium disilicate (LD) and zirconia-reinforced lithium silicate (ZLS) (Kruskal-Wallis, α = 0.05). The Fourier Transform Infrared Spectroscopy bands suggested an interaction between Si, O and Zr. Contrast ratio and translucency parameter of the experimental ceramic were higher and lower, (p = 0.000001) respectively, than those of the LD and ZLS. The experimental ceramic presented similar flexural strength to ZLS, but lower than LD (p < 0.0001). It can be concluded that this processing method is efficient to obtain a SiO2+Y-TZP ceramic and 1150 °C crystallizes SiO2 without inducing t-m transformation. The SiO2+Y-TZP ceramic presented lower translucency and higher masking ability than the commercially available glass-ceramics, but similar flexural strength to one glass-ceramics.
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Dióxido de Silício , Zircônio , Cerâmica , Porcelana Dentária , Teste de Materiais , Propriedades de Superfície , ÍtrioRESUMO
Biomaterials and bone grafts, with the ability of stimulating tissue growth and bone consolidation, have been emerging as very promising strategies to treat bone fractures. Despite its well-known positive effects of biosilicate (BS) on osteogenesis, its use as bone grafts in critical situations such as bone defects of high dimensions or in non-consolidated fractures may not be sufficient to stimulate tissue repair. Consequently, several approaches have been explored to improve the bioactivity of BS. A promising strategy to reach this aim is the inclusion of an organic part, such as collagen, in order to mimic bone structure. Thus, the present study investigated the biological effects of marine spongin (SPG)-enriched BS composites on the process of healing, using a critical experimental model of cranial bone defect in rats. Histopathological and immunohistochemistry analyzes were performed after two and six weeks of implantation to investigate the effects of the material on bone repair (supplemental material-graphical abstract). Histological analysis demonstrated that for both BS and BS/SPG, similar findings were observed, with signs of material degradation, the presence of granulation tissue along the defect area and newly formed bone into the area of the defect. Additionally, histomorphometry showed that the control group presented higher values for Ob.S/BS (%) and for N.Ob/T.Ar (mm2) (six weeks post-surgery) compared to BS/SPG and higher values of N.Ob/T.Ar (mm2) compared to BS (two weeks post-surgery). Moreover, BS showed higher values for OV/TV (%) compared to BS/SPG (six weeks post-surgery). Also, VEGF immunohistochemistry was increased for BS (two weeks post-surgery) and for BS/SPG (six weeks) compared to CG. TGFb immunostaining was higher for BS compared to CG. The results of this study demonstrated that the BS and BS/SPG scaffolds were biocompatible and able to support bone formation in a critical bone defect in rats. Moreover, an increased VEGF immunostaining was observed in BS/SPG.
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Materiais Biocompatíveis/química , Vidro/química , Poríferos/química , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/uso terapêutico , Masculino , Ratos Wistar , Crânio/lesões , Crânio/patologia , Crânio/ultraestrutura , Engenharia Tecidual/métodosRESUMO
OBJECTIVES: A bovine dense hydroxyapatite ceramic (HA) was produced as new biomaterial, however, the production of a material with consistently high flexural strength remains challenging. The objective of this study was to evaluate the effects of ZnO nanoparticles, TiO2 nanoparticles, and TiO2 nanotubes (1%, 2%, and 5% by weight) on the microstructure and flexural strength of a bovine dense hydroxyapatite ceramic (HA). METHODS: Discs (Ø=12.5mm; thickness=1.3mm) were prepared and subjected to X-ray diffraction (XRD), and observation with a field emission scanning electron microscope (FE-SEM), biaxial flexural strength (BFS) testing, and Vickers hardness (VH) testing. The BFS and VH data were subjected to ANOVA and Tukey post-hoc tests (α=0.05) and Weibull analysis. RESULTS: The XRD showed that the addition of nanomaterials caused the formation of a secondary phase when 5% of the ZnO nanoparticles was used, or when all percentages of the TiO2 nanoparticles/nanotubes were used, and the HA crystallographic planes were maintained. Differences were not observed between the higher BFS values obtained with pure HA and those obtained with the 5% addition of TiO2 nanoparticles. However, the results were different compared with the other groups (α=0.05). The results obtained by Weibull analysis revealed that the 1%, 2%, and 5% addition of TiO2 nanotubes, and the 1% and 2% addition of TiO2 nanoparticles decreased the HA characteristic strength (σ0), while the Weibull modulus (m) increased when 5% of TiO2 nanoparticles, 1% and 2% of ZnO nanoparticles, and 2% of TiO2 nanoparticles were added, but with no statistical difference from the pure HA. The 5% addition of ZnO2 nanoparticles decreased the σ0 without changing m. Moreover, the 5% addition of TiO2 nanoparticles resulted in an m closest to that of pure HA. Regarding the VH results, the blend of HA with 1% and 2% addition of TiO2 nanoparticles exhibited the higher values, which were similar between the different addition ratios (p=0.102). Moreover, the addition of 5% TiO2 nanoparticles resulted in higher value compared with pure HA. SIGNIFICANCE: This study demonstrated that the HA blend with 5% of TiO2 nanoparticles has the greatest potential as a bovine HA dense bioceramic reinforcement.
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Nanopartículas , Nanotubos , Óxido de Zinco , Animais , Bovinos , Cerâmica , Durapatita , Teste de Materiais , Propriedades de Superfície , Titânio , Difração de Raios XRESUMO
PURPOSE: To evaluate the shear bond strength (SBS) between Y-TZP and a resin luting agent, after 1 of 2 enhancing strategies with TiO2--nts was applied, either to the resin luting agent or the Y-TZP mass, in different concentrations. METHODS: In the Strategy TiO2-nts on ceramic, the resin luting agent Panavia F2.0™ (Kuraray) and an experimental Y-TZP with added concentrations of TiO2--nts (0%, 1%, 2%, and 5% vol/vol) and a commercial Y-TZP, comprised 5 different groups (n = 10). In the Strategy TiO2-nts on cement, the resin luting agent RelyX U200™ (3 M ESPE) was added with different concentrations of TiO2--nts (0%, 0.3%, 0.6%, 0.9% wt/wt) luted to a commercial Y-TZP, comprising 4 different groups (n = 10). The Y-TZP discs were included in acrylic bases, and a cylinder (3 × 3 mm) of the correspondent luting agent for each respective group was applied over them. After 24 h, specimens were subjected to SBS assessments in a universal testing machine. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy analyses were also performed on Y-TZP surfaces. Data were analyzed via analysis of variance and Tukey tests (α = 0.05). RESULTS: TiO2-nts on ceramic influenced the bond strength significantly, but not linearly; TiO2-nts on cement did not influence bond strength when analyzed separately, nor in comparison with the first. CONCLUSION: Y-TZP enhancements with TiO2-nts led to a higher SBS with Panavia F2.0, a 5% TiO2--nt concentration presented the highest bond strength. Modified Rely X U200 did not improve SBS.
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Colagem Dentária , Nanotubos , Cimentos Dentários , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície , Titânio , Ítrio , ZircônioRESUMO
One of the most promising strategies to improve the biological performance of bone grafts is the combination of different biomaterials. In this context, the aim of this study was to evaluate the effects of the incorporation of marine spongin (SPG) into Hydroxyapatite (HA) for bone tissue engineering proposals. The hypothesis of the current study is that SPG into HA would improve the biocompatibility of material and would have a positive stimulus into bone formation. Thus, HA and HA/SPG materials were produced and scanning electron microscopy (SEM) analysis was performed to characterize the samples. Also, in order to evaluate the in vivo tissue response, samples were implanted into a tibial bone defect in rats. Histopathological, immunohistochemistry, and biomechanical analyses were performed after 2 and 6 weeks of implantation to investigate the effects of the material on bone repair. The histological analysis demonstrated that composite presented an accelerated material degradation and enhanced newly bone formation. Additionally, histomorphometry analysis showed higher values of %BV/TV and N.Ob/T.Ar for HA/SPG. Runx-2 immunolabeling was higher for the composite group and no difference was found for VEGF. Moreover, the biomechanical analysis demonstrated similar values for all groups. These results indicated the potential of SPG to be used as an additive to HA to improve the biological performance for bone regeneration applications. However, further long-term studies should be carried out to provide additional information regarding the material degradation and bone regeneration.
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Osso e Ossos/efeitos dos fármacos , Colágeno/farmacologia , Durapatita/farmacologia , Poríferos/química , Cicatrização/efeitos dos fármacos , Animais , Materiais Biocompatíveis , Osso e Ossos/lesões , Masculino , Ratos Wistar , Tíbia/efeitos dos fármacos , Tíbia/lesões , Alicerces Teciduais/químicaRESUMO
This study evaluated physical-chemical characteristics of a vacuumed collagen-impregnated bioglass (BG) scaffolds and bone marrow stromal cells (BMSCs) behavior on those composites. scanning electron microscope and energy dispersive x-ray spectroscope demonstrated collagen (Col) was successfully introduced into BG. Vacuum impregnation system has showed efficiency for Col impregnation in BG scaffolds (approximately 20 wt %). Furthermore, mass weight decreasing and more stabilized pH were observed over time for BG/Col upon incubation in phosphate buffered saline compared to plain BG under same conditions. Calcium evaluation (Ca assay) demonstrated higher calcium uptake for BG/Col samples compared to BG. In addition, BG samples presented hydroxyapatite crystals formation on its surface after 14 days in simulated body fluid solution, and signs of initial degradation were observed for BG and BG/Col after 21 days. Fourier transform infrared spectroscopy spectra for both groups indicated peaks for hydroxyapatite formation. Finally, a significant increase of BMSCs viability for both composites was observed compared to control group, but no increase of osteogenic differentiation-related gene expressions were found. In summary, BG/Col scaffolds have improved degradation, pH equilibrium and Ca mineralization over time, accompanied by hydroxyapatite formation. Moreover, both BG and BG/Col scaffolds were biocompatible and noncytotoxic, promoting a higher cell viability compared to control. Future investigations should focus on additional molecular and in vivo studies in order to evaluate biomaterial performance for bone tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 211-222, 2019.
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Células da Medula Óssea/metabolismo , Diferenciação Celular , Proliferação de Células , Cerâmica/química , Colágeno/química , Células-Tronco Mesenquimais/metabolismo , Alicerces Teciduais/química , Animais , Células da Medula Óssea/citologia , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Ratos , Ratos WistarRESUMO
This study reports the development of a servo-controlled power-assisted wheelchair, designed to reduce the loads on the upper limbs while maintaining the drivability of a manual chair. It is presented the concept and implementation of an assisted propulsion system, focusing on the assistance controlling and the torque transmission.
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Desenho de Equipamento , Cadeiras de Rodas , Fenômenos Biomecânicos , Humanos , Torque , Extremidade SuperiorRESUMO
BACKGROUND: Implants or implantable devices should integrate into the host tissue faster than fibrous capsule formation, in which the design of the interface is one of the biggest challenges. Generally, bioactive materials are not viable for load-bearing applications, so inert biomaterials are proposed. However, the surface must be modified through techniques such as coating with bioactive materials, roughness and sized pores. The aim of this research was to validate an approach for the evaluation of the tissue growth on implants of porous alumina coated with bioactive materials. METHODS: Porous alumina implants were coated with 45S5 Bioglass® (BG) and hydroxyapatite (HA) and implanted in rat tibiae for a period of 28 days. Ex vivo resections were performed to analyze osseointegration, along with histological analysis, Scanning Electron Microscopy with Energy Dispersive X-Ray spectroscopy (SEM-EDX) line scanning, radiography and biomechanical testing. RESULTS: Given that the process of implant integration needs with the bone tissue to be accelerated, it was then seen that BG acted to start the rapid integration, and HA acted to sustaining the process. CONCLUSIONS: Inert materials coated with bioglass and HA present a potential for application as bone substitutes, preferably with pores of diameters between 100 µm and 400 µm and, restrict for smaller than 100 µm, because it prevents pores without organized tissue formation or vacant. Designed as functional gradient material, stand out for applications in bone tissue under load, where, being the porous surface responsible for the osseointegration and the inner material to bear and to transmit the loads.
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Substitutos Ósseos , Materiais Revestidos Biocompatíveis , Osseointegração , Próteses e Implantes , Óxido de Alumínio , Animais , Cerâmica , Durapatita , Vidro , Masculino , Microscopia Eletrônica de Varredura , Porosidade , Ratos , Ratos Wistar , Propriedades de SuperfícieRESUMO
ABSTRACT Purpose To analyze and compare the reactions at the interface between the composite, composed of fragmented heterologous mineralized bone matrix (MOMHF) and polymethylmethacrylate (PMMA), and the rabbit's tibias, through macroscopic evaluation and scanning electron microscopy (SEM) in different periods. Methods In this study, 12 New Zealand adult rabbits were used (E1: n = 3, E2: n = 3, E3: n = 3 and E4: n = 3). They had the right tibial defects filled with composite and were evaluated immediately after surgery and at 30, 60, 90, and 120 days. Results The composites were incorporated and integrated into the recipient beds in 100% of the cases, defined by the MOMHF osseointegration and the PMMA fibrointegration, with no sign of infection, migration, or rejection. Conclusions The behavior of the composites in the recipient beds demonstrates that these biomaterials have the potential to be used in bone defect repairs, offering, thus, better quality of life to the orthopedic patient.
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Matriz Óssea , Polimetil Metacrilato , Qualidade de Vida , Coelhos , Tíbia/cirurgia , Materiais Biocompatíveis , OsseointegraçãoRESUMO
Abstract This study characterized the morphological aspects of marine collagen - spongin (SPG) extract from marine sponges, as well as, evaluating its in vitro and in vivo biological performance. Aplysina fulva marine sponge was used for the SPG extraction. It was investigated the physicochemical and morphological properties of SPG by using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and compared to PMMA and bovine collagen. Additionally, the SPG cytotoxicity and its influence on cell proliferation, through in vitro tests. Moreover, the in vivo biological response was investigated using an experimental model of tibial bone defect. The results demonstrated that SPG presented an irregular granular aspect, with a composition of OH, C=O, NH, CN and an amorphous profile. Also, in vitro viability results for the L929 and MC3T3 cell lines cultured with SPG extracts demonstrated normal growth in comparison to controls, except for MC3T3 viability at day 3. For in vivo analysis, using tibial bone defects in rats, SPG treated animals presented an increased rate of material resorption and higher granulation and bone formation deposition in the region of the defect, mainly after 45 days. As a conclusion, SPG was successfully extracted. The in vitro and in vivo studies pointed out that SPG samples produced an increase in L929 and MC3T3 viability and improved the performance in tibial bone defects. It can be concluded that SPG can be used as a bone graft for bone regeneration.
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Materiais Biocompatíveis/química , Substitutos Ósseos/química , Cerâmica/química , Colágeno/química , Magnésio/química , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/metabolismo , Regeneração Óssea , Substitutos Ósseos/metabolismo , Cerâmica/metabolismo , Colágeno/metabolismo , Reagentes de Ligações Cruzadas/química , Magnésio/metabolismo , Masculino , Fenômenos Mecânicos , Modelos Animais , Osteogênese , Polimetil Metacrilato/síntese química , Polimetil Metacrilato/metabolismo , Próteses e Implantes , Ratos Wistar , Fatores de Tempo , Engenharia TecidualRESUMO
This study aimed to evaluate the osteointegration and genotoxic potential of a bioactive scaffold, composed of alumina and coated with hydroxyapatite and bioglass, after their implantation in tibias of rats. For this purpose, Wistar rats underwent surgery to induce a tibial bone defect, which was filled with the bioactive scaffolds. Histology analysis (descriptive and morphometry) of the bone tissue and the single-cell gel assay (comet) in multiple organs (blood, liver, and kidney) were used to reach this aim after a period of 30, 60, 90, and 180 days of material implantation. The main findings showed that the incorporation of hydroxyapatite and bioglass in the alumina scaffolds produced a suitable environment for bone ingrowth in the tibial defects and did not demonstrate any genotoxicity in the organs evaluated in all experimental periods. These results clearly indicate that the bioactive scaffolds used in this study present osteogenic potential and still exhibit local and systemic biocompatibility. These findings are promising once they convey important information about the behavior of this novel biomaterial in biological system and highlight its possible clinical application.