RESUMO
PURPOSE: This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration. METHODS: Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter. RESULTS: There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05. CONCLUSIONS: Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.
Assuntos
Células-Tronco Mesenquimais , Plasma Rico em Plaquetas , Animais , Regeneração Óssea , Osso Parietal/cirurgia , Ratos , Ratos WistarRESUMO
Abstract Purpose: This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration. Methods: Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter. Results: There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05. Conclusions: Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.
Assuntos
Animais , Ratos , Plasma Rico em Plaquetas , Células-Tronco Mesenquimais , Osso Parietal/cirurgia , Regeneração Óssea , Ratos WistarRESUMO
OBJECTIVES: This study sought to describe events related to the degradation/resorption of a device composed of polylactic acid (PLA) after implantation into Wistar rats. METHODS: Five-millimeter-diameter PLA rigid scaffolds and flexible analogs were elaborated, bioactivated through culture with osteoblasts, and implanted into the parietal bones of adult Wistar rats after 15 days. After 3 months, the samples were recovered and analyzed via optical microscopy (histochemical techniques) and scanning electron microscopy. This research was approved by the animal ethics review committee of Universidad of Valle in Cali, Colombia, according to the endorsement of the ethics committee CEAS 001-016. RESULTS: Initially, there was surface erosion and fragmentation of the device, inducing an inflammatory response compatible with the foreign body reaction, in addition to the presence of a pseudocapsule and a mixed inflammatory infiltrate that was responsible for phagocytosis of the material. Regeneration of the defect via the apposition of new bone occurred simultaneously with resorption of the material. CONCLUSIONS: The results illustrated that the degradation/resorption of PLA occurs in a centripetal pattern.
Assuntos
Implantes Absorvíveis , Regeneração Óssea , Quitosana/química , Implantes Experimentais , Osso Parietal/citologia , Poliésteres/química , Alicerces Teciduais , Animais , Materiais Biocompatíveis/química , Células Cultivadas , Desenho de Equipamento , Hidrólise , Osso Parietal/cirurgia , Ratos , Ratos Wistar , Engenharia TecidualRESUMO
Photobiomodulation (PBM) therapy displays relevant properties for tissue healing and regeneration, which may be of interest for the tissue engineering field. Here, we show that PBM is able to improve cell survival and to interact with recombinant human Bone Morphogenetic Protein 4 (rhBMP4) to direct and accelerate odonto/osteogenic differentiation of dental derived mesenchymal stem cells (MSCs). MSCs were encapsulated in an injectable and thermo-responsive cell carrier (Pluronic® F-127) loaded with rhBMP4 and then photoactivated. PBM improved MSCs self-renewal and survival upon encapsulation in the Pluronic® F-127. In the presence of rhBMP4, cell odonto/osteogenic differentiation was premature and markedly improved in the photoactivated MSCs. An in vivo calvarial critical sized defect model demonstrated significant increase in bone formation after PBM treatment. Finally, a balance in the reactive oxygen species levels may be related to the favorable results of PBM and rhBMP4 association. PBM may act in synergism with rhBMP4 and is a promise candidate to direct and accelerate hard tissue bioengineering.
Assuntos
Proteína Morfogenética Óssea 4/administração & dosagem , Portadores de Fármacos , Terapia com Luz de Baixa Intensidade/métodos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos da radiação , Poloxâmero/química , Engenharia Tecidual/métodos , Alicerces Teciduais , Adolescente , Adulto , Animais , Proteína Morfogenética Óssea 4/química , Regeneração Óssea , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Autorrenovação Celular/efeitos dos fármacos , Autorrenovação Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Humanos , Hidrogéis , Injeções , Lasers Semicondutores , Terapia com Luz de Baixa Intensidade/instrumentação , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Camundongos Nus , NF-kappa B/metabolismo , Osteogênese/efeitos dos fármacos , Osteogênese/efeitos da radiação , Osso Parietal/lesões , Osso Parietal/patologia , Osso Parietal/cirurgia , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo , Adulto JovemRESUMO
Introdução: A craniectomia descompressiva é uma cirurgia indicada no tratamento da hipertensão intracraniana em situações graves de traumas cranioencefálicos. Esta cirurgia confere uma aparência bizarra ao paciente, como se "parte da cabeça" houvesse sido retirada. Após a regressão do edema cerebral e quando o paciente reunir boas condições clínicas, a reconstrução craniana está indicada. A reconstrução da calota craniana poderá ser realizada com osso autólogo ou com materiais aloplásticos. Este estudo objetiva apresentar a experiência do autor com reconstruções de calota craniana utilizando próteses customizadas de PMMA. Métodos: Foram selecionados 14 pacientes submetidos à craniectomia descompressiva que, após serem liberados clinicamente pela Neurocirurgia, realizaram a reconstrução da calota craniana com próteses de PMMA customizadas por prototipagem entre os anos de 2014 e 2015 e com, no mínimo, 6 meses de pós-operatório. Sinais e sintomas de síndrome do Trefinado, tomografia computadorizada e aparência estética dos pacientes foram analisadas no pré e no 6º mês pós-operatório. Resultados: Todos os pacientes apresentaram melhora sintomatológica, melhora estética e expansão cerebral após a cirurgia. Conclusão: A reconstrução da calota craniana com prótese customizada de PMMA promoveu a melhora dos sinais e sintomas e da aparência estética de todos os 14 pacientes operados. A utilização de protótipos para customizar próteses cranianas facilitou a técnica operatória e possibilitou a recuperação de um contorno craniano muito próximo da normalidade.
Introduction: Decompressive craniectomy is indicated for the treatment of intracranial hypertension in cases of serious traumatic brain injury. This surgery results in a bizarre appearance, as if "part of the head" had been. After regression of cerebral edema and when the patient is in good clinical condition, the reconstruction of the skull is indicated. Reconstruction of the skull can be performed with autologous bone or with alloplastic materials. This study sought to present the experience of the author with skull reconstructions using custom PMMA prostheses. Methods: In between 2014 and 2015, fourteen patients with previous (longer than 6 months) decompressive craniectomies were selected after Neurosurgery medical clearance and underwent skull reconstruction with customized PMMA prototyped prostheses. Signs and symptoms of syndrome of the trephined, computed tomography, and aesthetic appearance of the patients were analyzed preoperatively and at 6 months after reconstruction. Results: All patients presented with improved symptomatology, aesthetic improvement and expansion of the brain after surgery. Conclusion: Reconstruction of the skull with customized prototyped PMMA prostheses improved the signs and symptoms and the aesthetic appearance in all 14 patients of this series. The use of prototypes to customize cranial prostheses facilitates the operative technique and enables patients to develop a nearly normal cranial contour.
Assuntos
Humanos , Masculino , Criança , Adolescente , Adulto , História do Século XXI , Osso Parietal , Próteses e Implantes , Crânio , Estudos Prospectivos , Hipertensão Intracraniana , Polimetil Metacrilato , Estética , Craniectomia Descompressiva , Traumatismos Craniocerebrais , Osso Parietal/cirurgia , Osso Parietal/transplante , Crânio/cirurgia , Hipertensão Intracraniana/cirurgia , Hipertensão Intracraniana/patologia , Hipertensão Intracraniana/terapia , Polimetil Metacrilato/uso terapêutico , Procedimentos de Cirurgia Plástica , Procedimentos de Cirurgia Plástica/métodos , Estética/psicologia , Craniectomia Descompressiva/métodos , Traumatismos Craniocerebrais/cirurgia , Traumatismos Craniocerebrais/patologia , Traumatismos Craniocerebrais/terapiaRESUMO
Multisuture craniosynostosis with a mild cloverleaf deformity is rare but associated with high morbidity and mortality. Conventional treatment to alleviate intracranial hypertension in a young infant involves multisuturectomy and relies on passive correction of the deformity followed by additional staged reconstruction later in infancy. Early regional craniectomy and rigid reconstruction have been described, but the cranial bone has limited stability to tolerate plate fixation and extensive dissection of the bone-dura interface may devascularize the cranial bone flap and limit its durability. The authors report an interesting technique to treat a mild form of cloverleaf skull deformity using early, nondevascularizing osteotomies followed by application of semiburied cranial distractors in multiple planes to increase intracranial volume and treat the deformity, and its attendant volumetric constriction, in a single stage.
Assuntos
Craniossinostoses/cirurgia , Craniotomia/métodos , Osteogênese por Distração/métodos , Procedimentos de Cirurgia Plástica/métodos , Suturas Cranianas/anormalidades , Suturas Cranianas/cirurgia , Craniotomia/instrumentação , Seguimentos , Osso Frontal/cirurgia , Humanos , Imageamento Tridimensional/métodos , Recém-Nascido , Fixadores Internos , Hipertensão Intracraniana/cirurgia , Masculino , Órbita/cirurgia , Osteogênese por Distração/instrumentação , Osso Parietal/cirurgia , Procedimentos de Cirurgia Plástica/instrumentação , Tomografia Computadorizada por Raios X/métodos , Procedimentos Cirúrgicos Ultrassônicos/métodosRESUMO
This study evaluated the bone regeneration process in rabbit calvaria induced by three types of biomaterials: two xenogenous, consisting of deproteinized bovine bone, while the other was alloplastic, based on biphasic calcium phosphate. Five New Zealand white rabbits weighing between 2,900 and 3,500 g were submitted to four standard 8 mm-diameter perforations at the parietal bone. Three perforations were filled with three grafts and biomaterials, two of them received bovine Bio-Oss® and Endobon® Xenograft Granules, and the other consisted of fully alloplastic Straumann® Bone Ceramic. The fourth remaining cavity was used as control with coagulum. After eight weeks, the animals were sacrificed, and the samples were prepared for morphometric and qualitative analysis. The cavities filled with alloplastic biomaterials showed higher percentages of newly formed bone (p<0.05), while the cavities with xenogenous biomaterials showed higher amount of residual graft (p<0.05). Although the results showed greater bone formation with Straumann® Bone Ceramic, further studies are required to prove which is the more effective biomaterial for bone induction process.
Assuntos
Materiais Biocompatíveis/uso terapêutico , Regeneração Óssea/fisiologia , Substitutos Ósseos/uso terapêutico , Animais , Doenças Ósseas/patologia , Doenças Ósseas/cirurgia , Matriz Óssea/transplante , Transplante Ósseo/métodos , Bovinos , Cerâmica , Tomografia Computadorizada de Feixe Cônico/métodos , Xenoenxertos/transplante , Hidroxiapatitas/uso terapêutico , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Masculino , Minerais/uso terapêutico , Osteogênese/fisiologia , Osso Parietal/patologia , Osso Parietal/cirurgia , Coelhos , Fatores de TempoRESUMO
The present study analyzes the repair process of autogenous bone graft in a block fixed with ethyl cyanoacrylate and 2-octyl cyanoacrylate adhesives in rat calvaria. Forty-eight rats, divided into 3 groups, received round osteotomies at the right parietal bone for the attainment of autogenous bone graft fragment, which was fixed at the opposite side to the donor site with ethyl cyanoacrylate (ethyl group) and 2-octyl cyanoacrylate (octyl group) adhesives. In the control group, bone fragment was only juxtaposed at the parietal bone surface without any fixation material. The animals were euthanized after 10 and 60 postoperative days. The calvariae were processed in a laboratory for the attainment of slides stained through the hematoxylin and eosin technique for histological and histometric analysis. The qualitative analysis showed a discrete inflammatory infiltrate in the control group and moderate inflammatory infiltrate in the ethyl and octyl groups at the 10-day period, which remained at the 60-day period, mainly in the octyl group. The bone fragment remained bonded to the recipient site through the adhesive, but graft incorporation was not observed in any of the specimens. Resorption was higher in the octyl group followed by the ethyl and control groups, both at the 10- and 60-day periods, but with no statistical significance (P < .05). Although promoting graft fixation and its maintenance at the recipient site, both studied adhesives did not allow the graft incorporation, producing a localized and discrete inflammatory reaction, which persisted at 60 days, being more intense in the octyl cyanoacrylate group.
Assuntos
Autoenxertos/transplante , Transplante Ósseo/métodos , Cianoacrilatos/uso terapêutico , Adesivos Teciduais/uso terapêutico , Animais , Autoenxertos/patologia , Remodelação Óssea/fisiologia , Reabsorção Óssea/patologia , Proliferação de Células , Tecido Conjuntivo/patologia , Fibroblastos/patologia , Sobrevivência de Enxerto , Masculino , Neovascularização Fisiológica/fisiologia , Osteócitos/patologia , Osteogênese/fisiologia , Osteotomia/métodos , Osso Parietal/patologia , Osso Parietal/cirurgia , Periósteo/patologia , Periostite/patologia , Distribuição Aleatória , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Autogenous bone grafting is the gold-standard technique for bone augmentation procedures prior to implant placement. If the amount of available intraoral donor bone is insufficient, it is necessary to harvest bone graft from extraoral sites, such as calvaria. Although this technique is well established, only a few case reports show the histological analysis of the grafted bone at the moment of implant placement. This article reports the case of a 48-year-old female patient with a critical atrophic maxillary ridge reconstructed using autogenous calvarial bone graft prior to implant placement, with clinical and histological evaluation. Bone was collected under general anesthesia from the parietal bone. The outer cortical originated the bone blocks, and the medullar bone layer between was collected to be used in the sinus augmentation procedure, together with 5 of the bone blocks triturated. Six months after bone augmentation, 8 implants were placed in the grafted area and 2 biopsies were retrieved (anterior and the posterior regions), allowing the visualization of the bone-remodeling process in the grafted areas. The patient had a stable recovery. Our results showed that although necrotic bone could still be seen in the outer layer of the grafted area, the interface between this necrotic bone and the already remodeled bone was consistent with biocompatibility. Two-year radiographic evaluation showed success of the grafts and the implants in supporting an esthetic and functionally stable prosthesis. Summarizing, calvarial bone grafts are a viable alternative for the attainment of adequate bone volume prior to implant placement.
Assuntos
Aumento do Rebordo Alveolar/métodos , Autoenxertos/transplante , Transplante Ósseo/métodos , Implantes Dentários , Maxila/cirurgia , Osso Parietal/cirurgia , Levantamento do Assoalho do Seio Maxilar/métodos , Sítio Doador de Transplante/cirurgia , Atrofia , Biópsia , Remodelação Óssea/fisiologia , Prótese Dentária Fixada por Implante , Estética Dentária , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Arcada Edêntula/patologia , Arcada Edêntula/cirurgia , Maxila/patologia , Pessoa de Meia-Idade , Necrose , Resultado do TratamentoRESUMO
Several reconstructive methods of the alveolar ridge have been reported to make possible future rehabilitations with implants. Many of these methods come from studies done in animals, mainly rats. With this clinical practice based on scientific evidence, any experimental procedure that can be undertaken in real life is fundamental. Thus, any research that emulates as closely as possible those techniques used in humans are important. This study describes the modification of the technique for block bone graft fixation (onlay) in rats using the "lag screw"-type technique, normally used in clinical procedures for grafts in humans. The conclusion was that the execution of the described procedures minimizes interference of blood flow in the area because of the maintenance of the muscle insertion in the buckle aspect of the most anterior region of the mandible, providing better stability to the graft and better contact interface of the graft and receptor bed.