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Submitted by MARIA ROSA FELIX DE SOUSA GOMIDE GUIMARÃES (DINTER) null (mariarosa@saolucas.edu.br) on 2016-11-25T14:46:15Z No. of bitstreams: 1 TESE DOUTORADO Maria Rosa Final.pdf: 1423380 bytes, checksum: 7002561449c42c6a10d037b7ac5e7381 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-11-29T13:58:37Z (GMT) No. of bitstreams: 1 guimaraes_mrfsg_dr_araca.pdf: 1423380 bytes, checksum: 7002561449c42c6a10d037b7ac5e7381 (MD5) / Made available in DSpace on 2016-11-29T13:58:37Z (GMT). No. of bitstreams: 1 guimaraes_mrfsg_dr_araca.pdf: 1423380 bytes, checksum: 7002561449c42c6a10d037b7ac5e7381 (MD5) Previous issue date: 2016-11-22 / Objetivos: Analisar histologicamente e histometricamente o efeito do RTR® em defeitos ósseos cirúrgicos críticos em tíbias de ratos no processo de reparo ósseo. Materiais e Métodos: Defeitos ósseos críticos foram criados nas tíbias de 32 ratos Wistar divididos em dois grupos: Grupo Coágulo e Grupo RTR®. Após o período experimental de 30 e 90 dias, os animais foram sacrificados e as peças incluídas em parafina, cortadas e coradas com hematoxilina e eosina. Dois parâmetros foram analisados: a área óssea total neoformada (AON) e a área óssea da cortical neoformada (ACN). A análise estatística foi realizada nos dois períodos de observação pela análise de variância (ANOVA) e pelo Teste de Tukey. Resultados: Todos os grupos demonstraram reparo ósseo superior quando comparados ao Grupo Coágulo 30 dias nos dois parâmetros analisados. O Grupo RTR®, em 30 e 90 dias, apresentou reparo da cortical óssea e formações de tecido ósseo na região central do defeito maior do que no Grupo Coágulo de 90 dias, que apresentou reparo parcial da cortical óssea e poucas formações de tecido ósseo na região do defeito (p<0,05). Conclusões: O RTR® favoreceu a neoformação óssea no modelo experimental adotado podendo ser indicado em casos de cavidades ósseas de tamanho crítico. / Objectives: To analyze histologically and histometrically the effect of RTR® on critical surgical bone defects in rat tibiae in the bone repair process. Materials and Methods: Critical bone defects were created in the tibia of 32 Wistar rats divided into two groups: Clot Group and RTR® Group. After the experimental period of 30 and 90 days, the animals were sacrificed and the paraffin embedded pieces were cut and stained with hematoxylin and eosin. Two parameters were analyzed: total neoformed bone area (AON) and bone area of neoformed cortical (ACN). Statistical analysis was performed in the two observation periods by analysis of variance (ANOVA) and Tukey's test. Results: All groups demonstrated superior bone repair when compared to the Clot Group 30 days in the two analyzed parameters. The RTR® Group, in 30 and 90 days, presented repair of the cortical bone and bone tissue formations in the central region of the defect greater than in the 90-day Clot Group, which presented partial repair of the cortical bone and few bone tissue formations in the region of the defect (p <0.05). Conclusions: The RTR® favored the bone neoformation in the adopted experimental model and can be indicated in cases of bone of critical size.

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Submitted by JOÃO PAULO BONARDI null (joao_bonardi@hotmail.com) on 2017-03-06T16:15:16Z No. of bitstreams: 1 Dissertação João Paulo corrigido.pdf: 3605304 bytes, checksum: d85c867eef7490b5298db3147e3a1be1 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-03-09T20:16:15Z (GMT) No. of bitstreams: 1 bonardi_jp_me_araca.pdf: 3605304 bytes, checksum: d85c867eef7490b5298db3147e3a1be1 (MD5) / Made available in DSpace on 2017-03-09T20:16:15Z (GMT). No. of bitstreams: 1 bonardi_jp_me_araca.pdf: 3605304 bytes, checksum: d85c867eef7490b5298db3147e3a1be1 (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivos: Comparar através de análise hitométrica e imunoistoquimica o comportamento do ChronOs® (β-TCP) e do Bio-Oss® (Osso bovino inorgânico ) puros e misturados ao osso autógeno na proporção 1:1 em seios maxilares de humanos. Metodologia: 30 pacientes foram convidados para participar deste trabalho, resultando em 30 seios enxertados com osso autógeno puro (grupo A (controle)), ChronOs® puro (grupo C), ChronOs® em adição de osso autógeno na proporção 1:1(grupo CA), Bio-Oss® puro (grupo B) e Bio-Oss® em adição de osso autógeno na proporção de 1:1 (grupo BA), onde foram realizadas biopsias 6 meses após a realização desses enxertos e analisadas através de histometria (analisadas através do software ImageJ) e imunoistoquimica (RUNX2, VEGF e Osteocalcina). Os resultados foram tabulados, o teste de Shapiro-Wilk foi aplicado para avaliação da normalidade, em seguida foram aplicado os testes Kruskal-Wallis e Anova 1 fator para os dados paramétricos e não paramétricos sucetivamente e o teste de Tukey como pós teste. Resultados: Para neoformação óssea o grupo A foi maior que os grupos B e BA e o grupo CA foi maior que o grupo BA (p<0,05). Para os remanescentes de biomateriais o grupo BA apresentou um número maior que os grupos Chronos C, CA e A (p<0,05). Para tecido mole o grupo C foi maior que o grupo B (p<0,05). O resultado das imunomarcações mostrou marcação fraca para RUNX 2 nos grupos A, C, B e BA e marcação moderada para o grupo CA. Marcação intensa para VEGF nos grupos B e CA, moderada nos grupos A e C e fraca no grupo BA. Para a Osteocalcina houve uma marcação intensa em todos os grupos. Conclusão: Conclui-se que o Chronos puro ou misturado apresentam comportamento mais próximo ao osso autógeno em termos de quantidade de tecido ósseo neoformado e remanescentes de biomateriais que o Bio Oss puro ou associado ao osso autógeno. / Objectives: To compare the performance of ChronOs® (β-TCP) and Bio-Oss® (Inorganic bovine bone) pure and mixed with autogenous bone in a 1: 1 ratio in maxillary sinuses of humans through histometric and immunohistochemical analysis. Metodology: 30 patients were invited to participate of this study, resulting in 30 grafted sinuses with pure autogenous bone (group A (control)), pure ChronOs® (group C), ChronOs® in addition 1: 1 autogenous bone (group CA), pure Bio-Oss®(group B) and Bio-Oss® in addition1: 1 (group BA), which biopsies were performed 6 months after the grafting and analyzed by histology (analyzed using ImageJ software) and immunohistochemistry (RUNX2, VEGF and Osteocalcin). The results were tabulated, the Shapiro-Wilk test was applied to evaluate the normality, then the Kruskal-Wallis and Anova 1 tests were applied for the parametric and non-parametric data and Tukey test as post test was applied. Results: The group A was higher than B and BA groups, and the group CA was higher than the BA group (P <0.05). For the remainder of biomaterials, BA group presented a higher number than Chronos C, CA and A groups (P <0.05). For soft tissue, group C was greater than group B (P <0.05). The immunolabeling results showed poor labeling for RUNX 2 in groups A, C, B and BA and moderate labeling for CA group. Intense labeling for VEGF in B and CA groups, moderate in groups A and C and weak in BA group. For Osteocalcin, there was an intense marking in all groups. Conclusion: It was concluded that pure or mixed Chronos present behavior closer to the autogenous bone in terms of amount of neoformed bone tissue and biomaterial remnants than the pure or mixed Bio Oss.

No description available.

The focus of this dissertation is on the development of a solid freeform fabrication (SFF) process for the design and manufacture of porous biodegradable orthopaedic implants from calcium polyphosphate (CPP). Porous CPP structures are used as bone substitutes for regenerating bone defects and/or as substrates in formation of so-called “biphasic” implants for repair of damaged osteochondral tissues. The CPP implants can be utilized in the treatment of many musculoskeletal diseases, osteochondral defects, and bone tumours while replacement of the defect site is required. In this study, the fabrication of CPP structures was developed through a powder-based SFF technique known as adhesive bonding 3D-printing. SFF is an advanced alternative to the “conventional” fabrication method consisting of gravity sintering of CPP pre-forms followed by machining to final form, as SFF enables rapid manufacturing of complex-shaped bio-structures with controlled internal architecture. To address the physical and structural properties of the porous SFF-made components, they were characterized using scanning electron microscopy, micro-CT scanning and mercury intrusion porosimetry. Specific surface area and permeability of the porous structures were also determined. Additionally, the chemical properties (crystallinity) of the specimens were identified by X-ray diffraction. The mechanical properties of the crystalline CPP material were also measured by micro- and nano-indentation. Moreover, the porous structures were tested by uniaxial and diametral mechanical compression to determine the compressive and tensile strengths, respectively. Furthermore, the effect of the stacked-layer orientation on the mechanical properties of the SFF-made constructs was investigated through the production of samples with horizontal or vertical stacked-layers. The properties of the SFF-made samples were compared with those of the conventionally-made CPP constructs. The SFF-made implants showed drastically higher compressive mechanical strength compared to the conventionally-formed samples with identical porosity. It was also shown that the orientation of the stacked-layer has substantial influence on the mechanical strengths. Moreover, this thesis examined the ability of in vitro forming of cartilaginous tissue on the SFF-made substrates where the chondrocytes cellular response to the CPP implants was evaluated histologically and biochemically. In addition, an initial in vivo assessment of the CPP structures as bone substitutes was conducted using a rabbit medial femoral site model. Significant amount of new-bone was formed within the CPP porous constructs during the 6-week implantation period demonstrating appropriate biological response of SFF-made CPP structures for bone substitute applications. Another accomplishment of this thesis was the development of a mathematical model which predicts the compact density of powder layers spread by a counter-rotating roller in the SFF technique. The results may be used in the control of the apparent density of the final implant. The potential of the developed SFF method as an efficient and reproducible technique for the production of porous CPP structures for use in orthopaedics and musculoskeletal tissue regenerative applications was concluded.

The focus of this dissertation is on the development of an additive manufacturing system and methodology for fabricating structures with functionally graded porous internal properties and complex three-dimensional external characteristics. For this purpose, a multi-scale three-dimensional printing system was developed, with capabilities and fabrication methodologies refined in the context of, but not limited to, manufacturing of porous bone substitutes. Porous bone implants are functionally graded structures, where internally, the design requires a gradient in porosity and mechanical properties matching the functional transition between cortical and cancellous bone regions. Geometrically, the three-dimensional shape of the design must adhere to the anatomical shape of the bone tissue being replaced. In this work, control over functionally graded porous properties was achieved by integrating specialized modules in a custom-made additive manufacturing system and studying their effect on fabricated constructs. Heterogeneous porous properties were controlled by: (i) using a micro-syringe deposition module capable of embedding sacrificial elements with a controlled feature size within the structure, (ii) controlling the amount of binder dispersed onto the powder substrate using a piezoelectric printhead, (iii) controlling the powder type or size in real-time, and/or (iv) selecting the print layer stacking orientation within the part. Characterization methods included differential scanning calorimetry (DSC)-thermo gravimetric analysis (TGA) to establish the thermal decomposition of sacrificial elements, X-ray diffraction (XRD) and dispersive X-ray spectroscopy (EDAX) to investigate the chemical composition and crystallinity, scanning electron microscopy (SEM) and optical microscopy to investigate the physical and structural properties, uniaxial mechanical loading to establish compressive strength characteristics, and porosity measurements to determine the bulk properties of the material. These studies showed that the developed system was successful in manufacturing embedded interconnected features in the range of 100-500 $ \mu m $, with a significant impact on structural properties resulting in bulk porosities in the range of 30-55% and compressive strength between 2-50 MPa. In this work, control over the the three-dimensional shape of the construct was established iteratively, by using a silhouette extraction image processing technique to determine the appropriate anisotropic compensation factors necessary to offset the effects of shrinkage in complex-shaped parts during thermal annealing. Overall shape deviations in the range of +/- 5-7 % were achieved in the second iteration for a femoral condyle implant in a sheep model. The newly developed multi-scale 3DP system and associated fabrication methodology was concluded to have great potential in manufacturing structures with functionally graded properties and complex shape characteristics.

The focus of this dissertation is on the development of a solid freeform fabrication (SFF) process for the design and manufacture of porous biodegradable orthopaedic implants from calcium polyphosphate (CPP). Porous CPP structures are used as bone substitutes for regenerating bone defects and/or as substrates in formation of so-called “biphasic” implants for repair of damaged osteochondral tissues. The CPP implants can be utilized in the treatment of many musculoskeletal diseases, osteochondral defects, and bone tumours while replacement of the defect site is required. In this study, the fabrication of CPP structures was developed through a powder-based SFF technique known as adhesive bonding 3D-printing. SFF is an advanced alternative to the “conventional” fabrication method consisting of gravity sintering of CPP pre-forms followed by machining to final form, as SFF enables rapid manufacturing of complex-shaped bio-structures with controlled internal architecture. To address the physical and structural properties of the porous SFF-made components, they were characterized using scanning electron microscopy, micro-CT scanning and mercury intrusion porosimetry. Specific surface area and permeability of the porous structures were also determined. Additionally, the chemical properties (crystallinity) of the specimens were identified by X-ray diffraction. The mechanical properties of the crystalline CPP material were also measured by micro- and nano-indentation. Moreover, the porous structures were tested by uniaxial and diametral mechanical compression to determine the compressive and tensile strengths, respectively. Furthermore, the effect of the stacked-layer orientation on the mechanical properties of the SFF-made constructs was investigated through the production of samples with horizontal or vertical stacked-layers. The properties of the SFF-made samples were compared with those of the conventionally-made CPP constructs. The SFF-made implants showed drastically higher compressive mechanical strength compared to the conventionally-formed samples with identical porosity. It was also shown that the orientation of the stacked-layer has substantial influence on the mechanical strengths. Moreover, this thesis examined the ability of in vitro forming of cartilaginous tissue on the SFF-made substrates where the chondrocytes cellular response to the CPP implants was evaluated histologically and biochemically. In addition, an initial in vivo assessment of the CPP structures as bone substitutes was conducted using a rabbit medial femoral site model. Significant amount of new-bone was formed within the CPP porous constructs during the 6-week implantation period demonstrating appropriate biological response of SFF-made CPP structures for bone substitute applications. Another accomplishment of this thesis was the development of a mathematical model which predicts the compact density of powder layers spread by a counter-rotating roller in the SFF technique. The results may be used in the control of the apparent density of the final implant. The potential of the developed SFF method as an efficient and reproducible technique for the production of porous CPP structures for use in orthopaedics and musculoskeletal tissue regenerative applications was concluded.