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1.
Biomedicines ; 11(4)2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37189731

RESUMO

Identifying target microRNAs (miRNAs) might serve as a basis for developing advanced therapies for Parkinson's disease (PD) and Alzheimer's disease. This review aims to identify the main therapeutic targets of miRNAs that can potentially act in Parkinson's and Alzheimer's diseases. The publication research was conducted from May 2021 to March 2022, selected from Scopus, PubMed, Embase, OVID, Science Direct, LILACS, and EBSCO. A total of 25 studies were selected from 1549 studies evaluated. The total number of miRNAs as therapeutic targets evidenced was 90 for AD and 54 for PD. An average detection accuracy of above 84% for the miRNAs was observed in the selected studies of AD and PD. The major signatures were miR-26b-5p, miR-615-3p, miR-4722-5p, miR23a-3p, and miR-27b-3p for AD and miR-374a-5p for PD. Six miRNAs of intersection were found between AD and PD. This article identified the main microRNAs as selective biomarkers for diagnosing PD and AD and therapeutic targets through a systematic review and meta-analysis. This article can act as a microRNA guideline for laboratory research and pharmaceutical industries for treating Alzheimer's and Parkinson's diseases and offers the opportunity to evaluate therapeutic interventions earlier in the disease process.

2.
Materials (Basel) ; 16(3)2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36770041

RESUMO

Cell tracking in cell-based therapy applications helps distinguish cell participation among paracrine effect, neovascularization, and matrix deposition. This preliminary study examined the cellular uptake of gold nanoparticles (AuNPs), observing cytotoxicity and uptake of different sizes and AuNPs concentrations in Adipose-derived stromal cells (ASCs). ASCs were incubated for 24 h with Laser ablated Albumin functionalized spherical AuNPs (LA-AuNPs), with average sizes of 2 nm and 53 nm in diameter, in four concentrations, 127 µM, 84 µM, 42 µM, and 23 µM. Cytotoxicity was examined by Live/Dead assay, and erythrocyte hemolysis, and the effect on the cytoskeleton was investigated by immunocytochemistry for ß-actin. The LA-AuNPs were internalized by the ASCs in a size and concentration-dependent manner. Clusters were observed as dispersed small ones in the cytosol, and as a sizeable perinuclear cluster, without significant harmful effects on the cells for up to 2 weeks. The Live/Dead and hemolysis percentage results complemented the observations that the larger 53 nm LA-AuNPs in the highest concentrated solution significantly lowered cell viability. The demonstrated safety, cellular uptake, and labelling persistency with LA-AuNPs, synthesized without the combination of chemical solutions, support their use for cell tracking in tissue engineering applications.

3.
Membranes (Basel) ; 12(9)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36135892

RESUMO

Mesenchymal stem cells (MSC) are promising for regenerative medicine as they have a vast differentiation capacity, immunomodulatory properties and can be isolated from different tissues. Among them, the umbilical cord is considered a good source of MSC, as its collection poses no risk to donors and is unrelated to ethical issues. Furthermore, umbilical cord mesenchymal stem cells (UC-MSC) can differentiate into several cell lines, including neural lineages that, in the future, may become an alternative in the treatment of neurodegenerative diseases. This study used a natural functional biopolymer matrix (NFBX) as a membrane to differentiate UC-MSC into neurospheres and their Neural precursors without using neurogenic growth factors or gene transfection. Through the characterization of Neural precursors and differentiated cells, it was possible to demonstrate the broad potential for the differentiation of cells obtained through cultivation on this membrane. To demonstrate these Neural precursors' potential for future studies in neurodegenerative diseases, the Neural precursors from Wharton's jelly were differentiated into Schwann cells, oligodendrocytes, cholinergic-, dopaminergic- and GABAergic-like neurons.

4.
Life (Basel) ; 12(7)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35888052

RESUMO

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized as an inflammatory demyelinating disease. Given the need for improvements in MS treatment, many studies are mainly conducted through preclinical models such as experimental allergic encephalomyelitis (EAE). This study analyzes the relationships between histopathological and clinical score findings at EAE. Twenty-three female Rattus norvegicus Lewis rats from 6 to 8 weeks were induced to EAE. Nineteen rats underwent EAE induction distributed in six groups to establish the evolution of clinical signs, and four animals were in the control group. Bordetella pertussis toxin (PTX) doses were 200, 250, 300, 350 and 400 ng. The clinical scores of the animals were analyzed daily, from seven to 24 days after induction. The brains and spinal cords were collected for histopathological analyses. The results demonstrated that the dose of 250 ng of PTX induced a higher clinical score and reduction in weight. All induced groups demonstrated leukocyte infiltration, activation of microglia and astrocytes, and demyelinated plaques in the brains in histopathology. It was concluded that the dose of 250 ng and 350 ng of PTX were the best choices to trigger the brain and spinal cord demyelination lesions and did not correlate with clinical scores.

5.
Molecules ; 27(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35566173

RESUMO

Background: Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder. Levodopa (L-DOPA) remains the gold-standard drug available for treating PD. Curcumin has many pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anti-amyloid, and antitumor properties. Copolymers composed of Poly (ethylene oxide) (PEO) and biodegradable polyesters such as Poly (ε-caprolactone) (PCL) can self-assemble into nanoparticles (NPs). This study describes the development of NH2-PEO-PCL diblock copolymer positively charged and modified by adding glutathione (GSH) on the outer surface, resulting in a synergistic delivery of L-DOPA curcumin that would be able to pass the blood-brain barrier. Methods: The NH2-PEO-PCL NPs suspensions were prepared by using a nanoprecipitation and solvent displacement method and coated with GSH. NPs were submitted to characterization assays. In order to ensure the bioavailability, Vero and PC12 cells were treated with various concentrations of the loaded and unloaded NPs to observe cytotoxicity. Results: NPs have successfully loaded L-DOPA and curcumin and were stable after freeze-drying, indicating advancing into in vitro toxicity testing. Vero and PC12 cells that were treated up to 72 h with various concentrations of L-DOPA and curcumin-loaded NP maintained high viability percentage, indicating that the NPs are biocompatible. Conclusions: NPs consisting of NH2-PEO-PCL were characterized as potential formulations for brain delivery of L-DOPA and curcumin. The results also indicate that the developed biodegradable nanomicelles that were blood compatible presented low cytotoxicity.


Assuntos
Curcumina , Nanopartículas , Doença de Parkinson , Animais , Curcumina/farmacologia , Portadores de Fármacos , Levodopa , Doença de Parkinson/tratamento farmacológico , Poliésteres/farmacologia , Polietilenoglicóis , Polímeros , Ratos
6.
Curr Eye Res ; 47(3): 450-460, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34749546

RESUMO

PURPOSE: This study aimed to evaluate a cell therapy strategy with human neural precursor cells (hNPCs) to treat diabetic retinopathy (DR) in Wistar rats induced to diabetes by injecting streptozotocin. MATERIAL AND METHODS: The Wharton's jelly mesenchymal stem cells (WJ-MSCs) were isolated, expanded, and seeded onto a biopolymer substrate to develop neurospheres and obtain the hNPCs. The animals were divided into three groups: non-diabetic (ND) n = four, diabetic without treatment (DM) n = nine, and diabetic with cell therapy (DM + hNPCs) n = nine. After 8 weeks of diabetes induction and DR characteristics installed, intravitreal injection of hNPCs (1 × 106 cell/µL) was performed in the DM + hNPCs group. Optical Coherence Tomography (OCT) and Electroretinography (ERG) evaluations were conducted before and during diabetes and after cell therapy. Four weeks posttreatment, histopathological and immunohistochemistry analyses were performed. RESULTS: The repair of the retinal structures in the treated group (DM + hNPCs) was observed by increased thickness of neuroretinal layers, especially in the ganglion cell and photoreceptor layers, higher ERG oscillatory potentials (OPs) amplitudes, and transplanted hNPCs integration into the Retinal Pigment Epithelium. CONCLUSIONS: The results indicate that hNPCs reduced DR progression by a neuroprotective effect and promoted retinal repair, making them potential candidates for regenerating the neuroretinal tissue.


Assuntos
Diabetes Mellitus Experimental , Retinopatia Diabética , Células-Tronco Neurais , Animais , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Retinopatia Diabética/patologia , Retinopatia Diabética/terapia , Humanos , Ratos , Ratos Wistar , Retina/patologia
7.
Life (Basel) ; 11(9)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34575028

RESUMO

Acellular amniotic membrane (AM) has been studied, with promising results on the reconstruction of lesioned tissues, and has become an attractive approach for tracheal repair. This study aimed to evaluate the repair of the trachea with human umbilical cord mesenchymal stem cells (hucMSCs) differentiated in chondrocytes, grown on an experimental model. Tracheal defects were induced by surgical tracheostomy in 30 New Zealand rabbits, and the acellular amniotic membrane, with or without cells, was covering the defect. The hucMSCs were isolated and cultivated with chondrogenic differentiation over the culture of 14 days, and then grown on the AM. In this study, the AM was biocompatible and hucMSCs differentiated into chondrocytes. Our results demonstrated an important role for AM with cultured cells in the promotion of immature collagen, known to produce tissue regeneration. In addition, cartilaginous tissue was found at the tracheal defects, demonstrated by immunohistology results. This study suggests that this biomaterial implantation can be an effective future therapeutic alternative for patients with tracheal injury.

8.
Membranes (Basel) ; 11(9)2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34564504

RESUMO

Adipose tissue-derived mesenchymal stem cells (ADMSCs) are promising candidates for regenerative medicine, as they have good cell yield and can differentiate into several cell lines. When induced to the neuronal differentiation, they form neurospheres composed of neural precursors (NPs) that can be an alternative in treating neurodegenerative diseases. This study aimed to characterize NPs from neurospheres obtained after seeding ADMSCs on a natural polyisoprene-based membrane. The ADMSCs were isolated from adipose tissue by enzymatic dissociation, were subjected to trilineage differentiation, and were characterized by flow cytometry for specific ADMSC surface markers. For neuronal differentiation, the cells were seeded on polystyrene flasks coated with the membrane and were characterized by immunocytochemistry and RT-PCR. The results demonstrated that the isolated cells showed characteristics of ADMSCs. At 15 to 25 days, ADMSCs seeded on the natural membrane developed neurospheres. Then, after dissociation, the cells demonstrated characteristic neuronal markers expressed on NPs: nestin, ß-III tubulin, GFAP, NeuN, and the YAP1/AMOT in the cytoplasm. In conclusion, it was demonstrated that this membrane differentiates the ADMSCs to NPs without any induction factors, and suggests that their differentiation mechanisms are related to mechanotransduction regulated by the YAP and AMOT proteins.

9.
Membranes (Basel) ; 11(8)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34436369

RESUMO

Periodontitis is a prevalent disease characterized by the loss of periodontal supporting tissues, bone, periodontal ligament, and cementum. The application of a bone tissue engineering strategy with Decellularized Human Amniotic Membrane (DAM) with adipose-derived stromal cells (ASCs) has shown to be convenient and valuable. This study aims to investigate the treatments of a rat periodontal furcation defect model with DAM, ASCs, and a mineralized extracellular matrix (ECM). Rat ASCs were expanded, cultivated on DAM, and with a bone differentiation medium for four weeks, deposited ECM on DAM. Periodontal healing for four weeks was evaluated by micro-computed tomography and histological analysis after treatments with DAM, ASCs, and ECM and compared to untreated defects on five consecutive horizontal levels, from gingival to apical. The results demonstrate that DAM preserves its structure during cultivation and healing periods, supporting cell attachment, permeation, bone deposition on DAM, and periodontal regeneration. DAM and DAM+ASCs enhance bone healing compared to the control on the gingival level. In conclusion, DAM with ASC or without cells and the ECM ensures bone tissue healing. The membrane supported neovascularization and promoted osteoconduction.

10.
Calcif Tissue Int ; 108(5): 667-679, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33420810

RESUMO

Discarded tissues, like human amniotic membranes and adipose tissue, were investigated for the application of Decellularized Human Amniotic Membrane (DAM) as a viable scaffold for transplantation of Adipose-derived stromal cells (ASCs) in bone regeneration of non-healing calvarial defects in rats. Amniotic membrane was decellularized to provide a scaffold for male Wistar rats ASCs expansion and transplantation. ASCs osteoinduction in vitro promoted the deposition of a mineralized bone-like matrix by ASCs, as calcified globular accretions associated with the cells on the DAM surface and inside the collagenous matrix. Non-healing calvarial defects on male Wistar rats were randomly divided in control without treatment, treatment with four layers of DAM, or four layers of DAM associated with ASCs. After 12 weeks, tissue blocks were examined by micro-computed tomography and histology. DAM promoted osteoconduction by increasing the collagenous matrix on both DAM treatments. DAM with ASCs stimulated bone deposition, demonstrated by a higher percentage of bone volume and trabecular bone number, compared to control. Besides the osteogenic capacity in vitro, ASCs stimulated the healing of calvarial defects with significant DAM graft incorporation concomitant with higher host bone deposition. The enhanced in vivo bone regeneration by undifferentiated ASCs loaded onto DAM confirmed the potential of an easily collected autologous cell source associated with a broadly available collagenous matrix in tissue engineering.


Assuntos
Âmnio , Regeneração Óssea , Tecido Adiposo , Animais , Diferenciação Celular , Células Cultivadas , Masculino , Osteogênese , Ratos , Ratos Wistar , Tecidos Suporte , Microtomografia por Raio-X
11.
Curr Stem Cell Res Ther ; 14(6): 504-518, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30394216

RESUMO

This systematic review evaluated the transplantation of cells derived from adipose tissue for applications in dentistry. SCOPUS, PUBMED and LILACS databases were searched for in vitro studies and pre-clinical animal model studies using the keywords "ADIPOSE", "CELLS", and "PERIODONTAL", with the Boolean operator "AND". A total of 160 titles and abstracts were identified, and 29 publications met the inclusion criteria, 14 in vitro and 15 in vivo studies. In vitro studies demonstrated that adipose- derived cells stimulate neovascularization, have osteogenic and odontogenic potential; besides adhesion, proliferation and differentiation on probable cell carriers. Preclinical studies described improvement of bone and periodontal healing with the association of adipose-derived cells and the carrier materials tested: Platelet Rich Plasma, Fibrin, Collagen and Synthetic polymer. There is evidence from the current in vitro and in vivo data indicating that adipose-derived cells may contribute to bone and periodontal regeneration. The small quantity of studies and the large variation on study designs, from animal models, cell sources and defect morphology, did not favor a meta-analysis. Additional studies need to be conducted to investigate the regeneration variability and the mechanisms of cell participation in the processes. An overview of animal models, cell sources, and scaffolds, as well as new perspectives are provided for future bone and periodontal regeneration study designs.


Assuntos
Adipócitos , Regeneração Óssea , Periodonto/fisiologia , Medicina Regenerativa/métodos , Transplante de Células-Tronco/métodos , Animais , Humanos , Modelos Animais , Osteogênese , Regeneração , Engenharia Tecidual/métodos
12.
Int J Nanomedicine ; 13: 5823-5836, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30319253

RESUMO

BACKGROUND: Posttransplant cell tracking, via stem cell labeling, is a crucial strategy for monitoring and maximizing benefits of cell-based therapies. The structures and functionalities of polysaccharides, proteins, and lipids allow their utilization in nanotechnology systems. MATERIALS AND METHODS: In the present study, we analyzed the potential benefit of curcumin-loaded nanoparticles (NPC) using Vero cells (in vitro) and NPC-labeled adipose-derived mesenchymal stem cells (NPC-ADMSCs) (in vivo) in myocardial infarction and sciatic nerve crush preclinical models. Thereafter, transplantation, histological examination, real time imaging, and assessment of tissue regeneration were done. RESULTS: Transplanted NPC-ADMSCs were clearly identified and revealed potential benefit when used in cell tracking. CONCLUSION: This approach may have broad applications in modeling labeled transplanted cells and in developing improved stem cell therapeutic strategies.


Assuntos
Rastreamento de Células/métodos , Curcumina/farmacologia , Nanopartículas/química , Animais , Diferenciação Celular , Chlorocebus aethiops , Fluorescência , Proteínas de Fluorescência Verde/metabolismo , Imunofenotipagem , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Nanopartículas/ultraestrutura , Compressão Nervosa , Ratos Wistar , Nervo Isquiático/patologia , Células Vero
13.
Braz. j. oral sci ; 15(3)July-Sept. 2016. tab
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-875034

RESUMO

Aim: This study investigated the effect of an in-office bleaching technique on lightness, color and surface roughness of two commercially available materials: a resin-modified glass-ionomer cement and a nanohybrid resin composite. Methods: Twelve disk-shaped specimens were prepared with both materials. The samples were bleached with 35% hydrogen peroxide. Bleaching was tested initially onto a smooth surface and later onto a polished one of the same specimens. The effect of the treatments on lightness and color was verified with a spectrophotometer. Surface roughness was measured with a digital surface roughness tester. The data were statistically analyzed by repeated measures ANOVA and post hoc Tukey's test (alpha = 0.05). Results: Significant variation in lightness and color was observed on the resin-modified glass-ionomer cement after the first bleaching procedure. Roughness increased significantly only after polishing the resin-modified glass-ionomer cement surface. Composite color variation was evident in the last observation period, but roughness and lightness variation due to bleaching and polishing was not significant. Conclusion: The bleaching treatment caused significant color alterations on the materials tested. This study observed that the application of in-office bleaching onto the glass-ionomer cement promoted clinically observable color alteration, and polishing after bleaching is contraindicated for this material. (AU)


Assuntos
Resinas Compostas , Cimentos de Ionômeros de Vidro , Peróxido de Hidrogênio , Espectrofotômetros , Clareamento Dental
14.
Braz. j. oral sci ; 15(2): 144-150, Apr.-June 2016. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-848251

RESUMO

Aim: To evaluate the effect of different activation protocols on the polymerization of a self-adhesive dual cured resin-based cement. Methods: Thirty disc-shaped specimens were prepared with the resin cement RelyX U200 (3M ESPE) and divided according to three protocols: immediate light-activation for 40 s, delayed light-activation (10 min after manipulation, for 40 s) or self-curing without light-activation. The specimens were desiccated, kept in water at 37 °C for 7 days and desiccated again to calculate water sorption, solubility and mass variation. Data were analyzed by Shapiro-Wilk Test and Wilcoxon tests (α=0.05). Images after the specimens' final desiccation were also made. Results: The Wilcoxon test revealed a significant difference for sorption and mass variation (p<0.05) and the highest value was observed in self-curing or chemical activation group (CA), followed by delayed light-activation (DL) and immediate light-activation (IL). Besides the water sorption parameters, there were also microvoids on the discs from the delayed and no light-activation groups. Conclusions: The light-activation immediately after manipulation is recommended for the evaluated resin cement (Au)


Assuntos
Cura Luminosa de Adesivos Dentários , Polimerização , Guias como Assunto/métodos , Cimentos de Resina/análise , Autocura de Resinas Dentárias , Solubilidade
15.
RSBO (Impr.) ; 11(1): 19-27, Jan.-Mar. 2014. ilus, tab
Artigo em Inglês | LILACS | ID: lil-718002

RESUMO

Introduction: Silorane-based composites have low polymerization shrinkage and good color stability. However, the effectiveness and the best surface treatment to carry out repairs to this type of restoration is unclear. Objective: To evaluate the effect of different types of repair made on a silorane-based composite. Material and methods: 80 disks of silorane-based composite were prepared (Filtek P90, 3M ESPE) and divided into eight groups (n = 10), according to the surface treatment being carried out before repairs of either the same silorane composite or a dimethacrylate material (Filtek Z350, 3M ESPE) were conducted. In two groups the immediate adhesion without repair (positive control) was evaluated. In other two groups repairs without any surface treatment (negative control) were evaluated. Surface treatments before the repair of the four remaining groups included the application of adhesive systems specific to silorane (Silorane System Adhesive, 3M ESPE) or to dimethacrylate (Adper Single Bond 2, 3M ESPE) and roughening followed by application of adhesive system. All groups were stored into distilled water at 37°C for 1 week prior to the microshear bond strength evaluation. Results: The group immediate adhesion silorane-dimethacrylate and group repair silorane-dimethacrylate without surface treatment showed lower microshear bond strength values and were statistically different from groups with surface treatment and immediate adhesion silorane-silorane (p < 0.05). Conclusion: Surface treatments with application of adhesive systems compatible with the repair material or roughening prior to the application of these adhesive systems are suitable for repairing silorane-based composites.

16.
RSBO (Impr.) ; 10(3): 240-244, Jul.-Sep. 2013. tab
Artigo em Inglês | LILACS | ID: lil-695943

RESUMO

Introduction: When repairs are needed in restorations made with methacrylate-based resin composites, the clinician still has doubts whether it is possible to use a silorane-based material and which is the best procedure. Objective: To evaluate the shear bond strength between a methacrylate-based resin composite and a silorane-based material using different surface treatments. Material and methods: Eighty flat bases made with methacrylate resin composite (Filtek Z350 XT) were prepared (n = 8). The bases were stored into water at 37°C for one week. Ten groups were evaluated: G1 (control - no repair); G2 (surface grinding, washing, drying, adhesive and repair with Filtek Z350 XT); G3 (surface grinding, washing, drying, adhesive and repair with silorane - Filtek P90); G4 (surface grinding, washing, drying, adhesive, silane and repair with Filtek Z350 XT); G5 (surface grinding, washing, drying, application of silane, adhesive and repair with silorane - Filtek P90). All groups were kept at 37°C for 24 h in either water (G1 to G5) or ethanol (G6 to G10). The results were analyzed with one-way ANOVA and Tukey test (α = 0.05). Results: There were significant differences between groups (p < 0.001). Only repairs made with silane and Z350 XT (G4 = 46.2 ± 12.9; G9 = 48.1 ± 16.3) resulted in values similar to controls (G1 = 59.2 ± 15.8; G6 = 62.3 ± 15.9) (p = 0.33). The smallest value occured when the repair was performed with silane and silorane-based based and stored into ethanol (G10 = 29.9 ± 12.4). The storage media had little influence on the results. Conclusion: The silorane-based resin composite was not effective for repair of the methacrylate-based material.

17.
RSBO (Impr.) ; 9(2): 137-142, Apr.-Jun. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-748103

RESUMO

Introduction : The mechanical aspects of tightening screws over implants are important to ensure a successful prosthetic rehabilitation. Screw loosening is a common problem that can be avoided with passive adaptation of the components and an increased tensile force developed in the screw, a preload. Objective: This in vitro study evaluated the effect on preload of a carbon lubricant deposited on the surface of titanium alloy prosthetic screws: conventional Ti6Al4V and surface enhanced. Material and methods: Conventional titanium alloy prosthetic (n = 7) and carbon coating surface enhanced screws (n = 7) were compared. Each prosthetic screw supporting a metallic UCLA over an implant was tightened with the manufacturer’s recommended torque of 32 N.cm. The removal torque values, recorded for ten consecutive cycles of tightening and removal, were used to estimate the preload. Implant blocks were then sectioned and the interfaces were observed by light microscopy.Results: The lowest removal torque, and consequently the highest preload values, was achieved for the lubricated group in most cycles. The contacts between threads were located at the coronal aspect of all observed screw mating threads.Conclusion: Data indicate that the lower coefficient of friction of a carbon lubricant can generate higher preload. The machining precision observed produced the adaptation and regular contact interfaces.

18.
RSBO (Impr.) ; 6(2): 176-184, jun. 2009. ilus
Artigo em Inglês | LILACS | ID: lil-514886

RESUMO

Introduction: The search for less invasive treatments, with fast and effective bone regeneration, has lead to the development of synthetic bioresorbable alternatives for bone graft. The commercial product FisiograftTM gel (Ghimas Spa, Italy), based on lactide-glycolide copolymer, is used as an injectable biocompatible and bioresorbable material for filling bone defects in dental surgery applications. These polymers are also used in the production of suture threads, pins and plates for bone fixation, and barriers for guided tissue regeneration. Objective: The main objective of this pilot study was to observe the initial bone healing response after the application of polylactide-glycolide graft material in adult animals. Material and methods: Bone defects were prepared in right and left femora of 12 month-old male Wistar rats. The defects in one leg received the synthetic graft material and the contra-lateral defects did not receive any treatment. After four days, the animals were subjected to euthanasia, the femora were removed, and tissue blocks were prepared for histological analysis. Results: Blood clot remained in the centre of control defects with initial connective tissue organization on the edges. The graft material was observed in the centre of the treated defects, restricted to the area where it was applied, with neovascularization next to the graft material. The pattern of bone healing did not differ between groups, starting from the margins of the defects and from bone fragments, with neovascularization followed by deposition of non-mineralized bone matrix towards the centre. Conclusion: The results indicate that the lactide-glycolide copolymer gel was effective as a filling and osteoconductive material, allowing tissue healing during its resorption process. Additional studies are necessary to verify its capacity to promote bone regeneration.


Introdução: A busca de tratamentos menos invasivos, com rápida e efetiva regeneração óssea, tem levado ao desenvolvimento de alternativas sintéticas e biorreabsorvíveis para enxertos ósseos. O material sintético à base de copolímeros de ácidos polilático e poliglicólico (PLGA), no produto comercial FisiograftTM gel (Ghimas Spa, Itália), é indicado pelo fabricante como dispositivo biorreabsorvível e biocompatível para preenchimento de defeitos ósseos em periodontia, cirurgia bucomaxilofacial e implantodontia. Esses polímeros são usados também na fabricação de fios de sutura, pinos e placas para fixação óssea em ortopedia e barreiras para regeneração tecidual. Objetivo: Este estudo piloto in vivo teve como objetivo principal observar o período inicial da resposta óssea na aplicação de PLGA em animais adultos. Material e métodos: Foram produzidos defeitos ósseos em cada fêmur de ratos machos Wistar com 12 meses de idade. Metade dos defeitos foi preenchido com FisiograftTM gel, e defeitos contralaterais não receberam material de preenchimento. Os animais foram submetidos a eutanásia após quatro dias do pós-operatório, e os blocos de tecido foram preparados para análise histológica. Resultados: O centro do defeito no grupo controle encontrou-se preenchido com coágulo sanguíneo, enquanto o tecido conjuntivo se organizou próximo às bordas. Nos defeitos enxertados foi verificado que o gel se manteve restrito ao local em que foi aplicado, com neovascularização próxima ao copolímero. O padrão de deposição óssea não diferiu entre os grupos, sempre a partir das margens do defeito e da superfície dos fragmentos ósseos, representado pela deposição de matriz não mineralizada em direção ao centro do defeito. Conclusão: Neste trabalho, a utilização do gel mostrou-se eficaz como material de preenchimento e osteocondutor, possibilitando neovascularização e reparo tecidual inicial durante sua reabsorção. Estudos adicionais são necessários para verificar o efeito desse...

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