RESUMO
Bioactive glasses (BG) are known for their ability to bond to bone tissue. However, in critical situations, even the osteogenic properties of BG may be not enough to induce bone consolidation. Thus, the enrichment of BG with polymers such as Poly (D, L-lactic-co-glycolic) acid (PLGA) and associated to photobiomodulation (PBM) may be a promising strategy to promote bone tissue healing. The aim of the present study was to investigate the in vivo performance of PLGA supplemented BG, associated to PBM therapy, using an experimental model of cranial bone defect in rats. Rats were distributed in 4 different groups (Bioglass, Bioglass/PBM, Bioglas/PLGA and BG/PLGA/PBM). After the surgical procedure to induce cranial bone defects, the pre-set samples were implanted and PBM treatment (low-level laser therapy) started (808 nm, 100 mW, 30 J/cm2). After 2 and 6 weeks, animals were euthanized, and the samples were retrieved for the histopathological, histomorphometric, picrosirius red staining and immunohistochemistry analysis. At 2 weeks post-surgery, it was observed granulation tissue and areas of newly formed bone in all experimental groups. At 6 weeks post-surgery, BG/PLGA (with or without PBM) more mature tissue around the biomaterial particles. Furthermore, there was a higher deposition of collagen for BG/PLGA in comparison with BG/PLGA/PBM, at second time-point. Histomorphometric analysis demonstrated higher values of BM.V/TV for BG compared to BG/PLGA (2 weeks post-surgery) and N.Ob/T.Ar for BG/PLGA compared to BG and BG/PBM (6 weeks post-surgery). This current study concluded that the use of BG/PLGA composites, associated or not to PBM, is a promising strategy for bone tissue engineering.
Assuntos
Substitutos Ósseos/uso terapêutico , Cerâmica/uso terapêutico , Fraturas Ósseas/terapia , Luz , Ácido Poliglicólico/uso terapêutico , Crânio/lesões , Cicatrização/efeitos dos fármacos , Animais , Substitutos Ósseos/química , Substitutos Ósseos/efeitos da radiação , Transplante Ósseo/métodos , Cimentação/métodos , Cerâmica/química , Terapia Combinada , Masculino , Teste de Materiais , Osteogênese/efeitos dos fármacos , Osteogênese/efeitos da radiação , Fototerapia/métodos , Ácido Poliglicólico/química , Ratos , Ratos Wistar , Crânio/efeitos dos fármacos , Crânio/efeitos da radiação , Engenharia TecidualRESUMO
OBJECTIVE: To evaluate clinically and radiographically, in humans, the healing of maxillary third molars postextraction sockets after application of different ridge preservation techniques 3 months after tooth extraction. MATERIALS AND METHODS: Twenty-six sockets (13 patients) were randomly assigned to 4 treatment modalities: deproteinized bovine bone mineral with 10% collagen (DBBM-C), poly(D,L-lactide-co-glycolide) with hydroxyapatite/ß-TCP scaffold (PLGA/HA), PLGA/HA/ß-TCP with 2.0% simvastatin scaffold (PLGA/HA/S), and spontaneous healing (control). Clinical complications were assessed, and cone-beam computed tomographies were taken in 5 patients 3 months after surgeries. For statistical purposes, the Fisher exact test was used (P < 0.05). RESULTS: After 3 months, 6 of 9 grafts from the PLGA/HA group were lost (P < 0.05). PLGA/HA/S' loss was only 2 of 8 (P > 0.05), but no loss was observed in the DBBM-C group. Pain was present in 3 of 8 sites that lost the graft (37.5%) (P > 0.05) and infection in 1 of 8 (12.5%) (P > 0.05), with these only occurring in the PLGA/HA group. CONCLUSIONS: Poly (D, L-lactide-co-glycolide) with hydroxyapatite/ß-TCP (PLGA/HA/ß-TCP) scaffolds, with and without simvastatin, failed to obtain the initial expected results and presented more complications. Scaffolds with simvastatin showed to be superior, with less clinical complications than scaffolds without simvastatin.
Assuntos
Aumento do Rebordo Alveolar/métodos , Materiais Biocompatíveis/uso terapêutico , Substitutos Ósseos/uso terapêutico , Fosfatos de Cálcio/uso terapêutico , Colágeno/uso terapêutico , Durapatita/uso terapêutico , Ácido Láctico/uso terapêutico , Maxila/cirurgia , Minerais/uso terapêutico , Dente Serotino/cirurgia , Ácido Poliglicólico/uso terapêutico , Sinvastatina/uso terapêutico , Alicerces Teciduais , Extração Dentária , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Projetos Piloto , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Porosidade , Estudos Prospectivos , Adulto JovemRESUMO
PURPOSE: To compare sciatic nerve regeneration in rats using three different techniques of repair. METHODS: Fifteen isogonics rats were divided into three groups according to the method used to repair a 5-mm long defect created in the sciatic nerve: autogenous graft (Group A), polyglycolic acid tube (PGAt) (Group B), and of the association of PGAt with the graft (Group C). Histological analysis, regenerated myelinated axon number count and functional analysis were used to compare after six weeks. RESULTS: There was no difference in fiber diameter and degree of myelinization presented by Groups A, B and C. Group B presented the lowest number of regenerated axons. The groups did not display any significant functional difference after walking track analysis (p<0.05). CONCLUSION: No differences between the three groups in terms of functional recovery, although there were histological differences among them.
Assuntos
Implantes Absorvíveis , Regeneração Nervosa/fisiologia , Ácido Poliglicólico/uso terapêutico , Nervo Isquiático/fisiologia , Nervo Isquiático/transplante , Animais , Axônios/fisiologia , Contagem de Células , Fibras Nervosas Mielinizadas/fisiologia , Ratos Endogâmicos Lew , Recuperação de Função Fisiológica , Fatores de Tempo , Transplante Autólogo , Resultado do TratamentoRESUMO
PURPOSE: To compare sciatic nerve regeneration in rats using three different techniques of repair. METHODS: Fifteen isogonics rats were divided into three groups according to the method used to repair a 5-mm long defect created in the sciatic nerve: autogenous graft (Group A), polyglycolic acid tube (PGAt) (Group B), and of the association of PGAt with the graft (Group C). Histological analysis, regenerated myelinated axon number count and functional analysis were used to compare after six weeks. RESULTS: There was no difference in fiber diameter and degree of myelinization presented by Groups A, B and C. Group B presented the lowest number of regenerated axons. The groups did not display any significant functional difference after walking track analysis (p<0.05). CONCLUSION: No differences between the three groups in terms of functional recovery, although there were histological differences among them. .
Assuntos
Animais , Implantes Absorvíveis , Regeneração Nervosa/fisiologia , Ácido Poliglicólico/uso terapêutico , Nervo Isquiático/fisiologia , Nervo Isquiático/transplante , Axônios/fisiologia , Contagem de Células , Fibras Nervosas Mielinizadas/fisiologia , Ratos Endogâmicos Lew , Recuperação de Função Fisiológica , Fatores de Tempo , Transplante Autólogo , Resultado do TratamentoRESUMO
The purpose of this study was to evaluate the association of the combination of polylactic/polyglycolic acid around implants installed with and without primary stability through the histometric analysis of bone-implant interface. We used male rabbits, each of which received 2 titanium implants in each tibial metaphysis. The animals were divided into 4 groups: control with primary stability (CPS), control without primary stability (C), polymer with primary stability (PPS), and polymer without primary stability (P). Euthanasia was performed at postoperative days 40 and 90. The pieces were embedded in resin, sectioned, scraped, and stained with alizarin red and Stevenel blue. Histometric analysis evaluated the linear extension of contact between the bone and implant surface on the implant collar (CIC) and contact between the bone and implant surface on the first thread (CFT). Also evaluated was the area of newly formed bone (ANB) in the first thread. The results showed that there was new bone formation in all groups and during all periods. At 40 days, the ANB was higher in the PPS group than in the P group (P < .001); the CFT was statistically higher in the CPS group than the PPS group (P < .001) and was higher in the CPS group than the C group (P < .001). At 40 and 90 days, the CIC was higher in the P group than in the C group (P < .001). In conclusion, the copolymer had biocompatibility, enhanced bone healing, and presented osteoconductive properties, thus raising the contact between bone and implant, even without primary stability.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/uso terapêutico , Implantes Dentários , Ácido Láctico/uso terapêutico , Osseointegração/efeitos dos fármacos , Ácido Poliglicólico/uso terapêutico , Animais , Cimentos Ósseos/química , Cimentos Ósseos/uso terapêutico , Regeneração Óssea/fisiologia , Substitutos Ósseos/química , Retenção em Prótese Dentária , Ácido Láctico/química , Estudos Longitudinais , Masculino , Osseointegração/fisiologia , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Tíbia/citologia , Tíbia/efeitos dos fármacos , Tíbia/cirurgiaRESUMO
Objectives: The purpose of this clinical study is to determine the efficacy of Fisiograft as a bone graft materialin the treatment of three wall vertical defects in generalized chronic periodontitis patients and theirclinical and radiological evaluation. Materials and methods: Twenty patients (with 30 defects) diagnosedwith generalized chronic periodontitis having two or more three wall vertical defects were selected for thisstudy. Clinical parameters like plaque index, gingival index, probing pocket depth and clinical attachmentlevels were recorded at different points of time over six months. Radiographic evaluation included the depthof the bone defect and the percentage of bone defect fill, and was carried out for both the groups at baseline,three months and six months. After recording clinical parameters and administering phase-1 therapy, thesites were randomly treated either with Fisiograft or open flap debridement only. Results: At the end of sixmonths there was a significant reduction in the plaque and gingival scores in both test and control groups.There was 64% decrease in probing pocket depth for the test site as compared to 55% decrease seen for thecontrol group. Similarly there was an 85% gain in clinical attachment level from the baseline to six monthspost operatively for the experimental group in comparison to 69% gain for the control group. Furthermore,44% bone fill was observed for the experimental site whereas only 18% of bone fill was evident in the controlsite. Conclusion: Fisiograft improves healing outcomes, leads to a reduction of probing depth, a resolutionof osseous defects and a gain in clinical attachment, compared with open flap debridement by itself.
Objetivo: O objetivo do presente estudo clínico foi determinar a eficácia do Fisiograft®, como material de enxerto ósseo, no tratamento de defeitos ósseos verticais de três paredes em pacientes com periodontite crônica,bem como avaliações clínica e radiográfica. Materiais e métodos: Vinte pacientes (com 30 defeitos)diagnosticados com periodontite crônica generalizada, portando dois ou mais defeitos ósseos verticais detrês paredes foram selecionados para o estudo. Parâmetros clínicos como índice de placa, índice gengival,profundidade de bolsa à sondagem e níveis clínicos de inserção foram registrados em diferentes intervalos de tempo até seis meses. Avaliações radiográficas incluíram a profundidade do defeito ósseo e a porcentagem de preenchimento do defeito ósseo, sendo realizadas em ambos os grupos imediatamente (baseline),em três meses e seis meses. Após registrar os parâmetros clínicos e administrar a terapia de fase-1, os locais foram tratados aleatoriamente com Fisiograft® ou retalho de espessura total somente. Resultados: Ao fim do período de seis meses houve redução significativa nos índices de placa e gengival em ambos os grupos,controle e experimental. Houve redução de 64% na profundidade de bolsa à sondagem para os locais de teste comparado, 55% de redução no grupo controle. Similarmente, houve ganho de 85% no nível clínico de inserção do baseline para o período de seis meses de pós-operatório para o grupo experimental em comparação ao ganho de 69% para o grupo controle. Adicionalmente, um preenchimento ósseo de 44% foi observado para os locais experimentais, enquanto somente 18% de preenchimento foi evidente nos locais de controle.Conclusão: O Fisiograft® melhora os resultados de cicatrização, promove redução na profundidade de sondagem,constitui uma resolução para os defeitos ósseos e aumento na inserção clínica, comparado ao retalho de espessura total somente.
Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Substitutos Ósseos , Doenças Periodontais/cirurgia , Materiais Biocompatíveis/uso terapêutico , Transplante Ósseo/métodos , Ácido Láctico/uso terapêutico , Ácido Poliglicólico/uso terapêutico , Doenças Periodontais , Polímeros/uso terapêutico , Resultado do TratamentoRESUMO
BACKGROUND: Complex urethral problems can occur as a result of injury, disease, or congenital defects and treatment options are often limited. Urethras, similar to other long tubularised tissues, can stricture after reconstruction. We aimed to assess the effectiveness of tissue-engineered urethras using patients' own cells in patients who needed urethral reconstruction. METHODS: Five boys who had urethral defects were included in the study. A tissue biopsy was taken from each patient, and the muscle and epithelial cells were expanded and seeded onto tubularised polyglycolic acid:poly(lactide-co-glycolide acid) scaffolds. Patients then underwent urethral reconstruction with the tissue-engineered tubularised urethras. We took patient history, asked patients to complete questionnaires from the International Continence Society (ICS), and did urine analyses, cystourethroscopy, cystourethrography, and flow measurements at 3, 6, 12, 24, 36, 48, 60, and 72 months after surgery. We did serial endoscopic cup biopsies at 3, 12, and 36 months, each time in a different area of the engineered urethras. FINDINGS: Patients had surgery between March 19, 2004, and July 20, 2007. Follow-up was completed by July 31, 2010. Median age was 11 years (range 10-14) at time of surgery and median follow-up was 71 months (range 36-76 months). AE1/AE3, α actin, desmin, and myosin antibodies confirmed the presence of cells of epithelial and muscle lineages on all cultures. The median end maximum urinary flow rate was 27·1 mL/s (range 16-28), and serial radiographic and endoscopic studies showed the maintenance of wide urethral calibres without strictures. Urethral biopsies showed that the engineered grafts had developed a normal appearing architecture by 3 months after implantation. INTERPRETATION: Tubularised urethras can be engineered and remain functional in a clinical setting for up to 6 years. These engineered urethras can be used in patients who need complex urethral reconstruction. FUNDING: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health.
Assuntos
Procedimentos de Cirurgia Plástica/métodos , Engenharia Tecidual , Uretra/patologia , Uretra/cirurgia , Estreitamento Uretral/cirurgia , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Adolescente , Criança , Colágeno/uso terapêutico , Cistoscopia , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , México , Mucosa Bucal/transplante , Ácido Poliglicólico/uso terapêutico , Transplante de Pele , Engenharia Tecidual/métodos , Alicerces Teciduais , Resultado do Tratamento , Uretra/lesões , Estreitamento Uretral/etiologiaRESUMO
Apesar do desenvolvimento da tecnologia envolvendo o campo da regeneração em nervos periféricos, ainda não existe uma técnica para recuperação do tecido nervoso que apresente resultados totalmente satisfatórios, fato que desperta o interesse de vários pesquisadores em todo mundo e representa um desafio para os cirurgiões que realizam procedimentos reconstrutivos e estéticos. Embora o enxerto autólogo de nervo seja a melhor alternativa para a recuperação de nervos periféricos lesados, as técnicas que envolvem o reparo tubular têm alcançado excelentes resultados através da utilização de materiais sintéticos e biológicos, sob a forma de tubos, no reparo de extensos segmentos nervosos. Hoje, através dos avanços da engenharia tecidual, novos materiais estão em desenvolvimento, com o objetivo de aliar características microscópicas às técnicas cirúrgicas existentes. O colágeno, que é sabidamente um elemento promotor da proliferação celular e do reparo tecidual, tem sido amplamente utilizado em estudos de regeneração nervosa. Da mesma maneira, o ácido poli-láctico-poli-glicólico (PLGA), um copolímero sintético, tem apresentado algumas características favoráveis ao processo de regeneração, como biocompatibilidade e propriedades mecânicas adequadas. Com o propósito de facilitar a regeneração nervosa quando ocorre perda tecidual, uma técnica já difundida pode ser destacada: o enxerto de veia invertida, em que a veia jugular externa é utilizada ao avesso, funcionando como um tubo, criando um microambiente para a regeneração nervosa, através da exposição de elementos fundamentais da camada mais externa do vaso (túnica adventícia). Neste trabalho, agregamos como diferencial a utilização de dois tipos de membranas, especialmente desenvolvidas para fins odontológicos, que visam neoformação óssea, em um estudo que visa à regeneração de um nervo periférico misto, o nervo isquiático. As membranas de colágeno e PLGA foram colocadas na região do enxerto, sob a forma de tubo...
Despite the development of technology involved in peripheral nerve regeneration, there is no technique that presents a recovery of the nervous tissue with completely satisfactory results. This fact arouses interest of several researchers around the word. Although the autologous nerve grafting is the current gold standard for the repair of large nerve gaps, over the past decades the development of artificial nerve conduits has therefore been of great interest due to the excellent results achieved. Through the advances in tissue engineering, new materials, synthetic and biological, have been used for construct nerve guides. The collagen is one of the oldest natural polymers used as a biomaterial, and it is known as a promoter of cell proliferation and of tissue repair. In the same way, the synthetic copolymer, poly lactic-co-glycolic acid (PLGA), have been used for nerve regeneration, and it have shown some favorable characteristics to nerve repair such as stability, biocompatibility, and mechanical properties. With the purpose of facilitating the regeneration in large nerve gaps, the inside-out vein graft is a widespread technique, where the vein works as a conduit, and it provides a good microenvironment for axon regeneration through the exposition of some primordial elements of its adventitial layer. In this work, we join as a differential the use of two materials, specially developed for dental purposes, which are normally used to facilitate the osteogenesis, in a nerve regeneration study. We performed the surgical procedures in the sciatic nerve, with two types of membranes (PLGA and collagen), which were used as tubes, in order to promote the regeneration of this nerve. The collagen and PLGA membranes were used with the objective of a recovery in a 10-mm sciatic nerve gap model. These tubular implants were filled with a 5 mm segment of the jugular vein in order to verify the effectiveness of some biological molecules of the adventitia...
Assuntos
Animais , Masculino , Ratos , Ácido Láctico/uso terapêutico , Ácido Poliglicólico/uso terapêutico , Colágeno/uso terapêutico , Nervo Isquiático/fisiologia , Regeneração Nervosa/fisiologia , Veias Jugulares/cirurgia , Fibras Nervosas Mielinizadas/fisiologia , Microscopia Eletrônica de Varredura , Materiais Biocompatíveis/uso terapêutico , Membranas/fisiologiaRESUMO
The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC) and poly (glycolic)-poly (lactic acid) (PLGA) material or a calcium hydroxide [Ca(OH)2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH)2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH)2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.
Assuntos
Materiais Biocompatíveis/uso terapêutico , Hidróxido de Cálcio/uso terapêutico , Capeamento da Polpa Dentária/métodos , Polpa Dentária/efeitos dos fármacos , Animais , Cimentos Ósseos/uso terapêutico , Fosfatos de Cálcio/uso terapêutico , Polpa Dentária/patologia , Dentina/patologia , Modelos Animais de Doenças , Durapatita/uso terapêutico , Ácido Láctico/uso terapêutico , Ácido Poliglicólico/uso terapêutico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Fatores de TempoRESUMO
The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC) and poly (glycolic)-poly (lactic acid) (PLGA) material or a calcium hydroxide [Ca(OH)2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH)2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH)2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.