The purpose of this prospective, randomized, controlled clinical investigation is to evaluate the performance of the Motorized Ridge Expanders (MRE), and to compare its results with the ones achieved utilizing lateral ridge augmentation (LRA). Eight subjects with bilateral ridge deformities were selected. One technique was used on the right site and the other on the left site. Implants were placed six months after the bone augmentation procedures. All the measurements were recorded at 2 and 5 mm from the most coronal part of the crest. The augmentation achieved with both techniques was statistically significant, 1.2 mm in the LRA, 1.5 mm in MRE at 2 mm from the crest; 1.5 mm and 1.6 mm respectively at 5mm from the crest. The differences between the two techniques were statistically insignificant. The amount of expansion achieved in the MRE site appears to be negatively correlated (P-Value <0.05) with the thickness of the cancellous bone, and it is not affected by the thickness of the cortical plate. The MRE technique appears to be as effective as the LRA technique in augmenting the thickness of atrophic ridges. The defect treated with the MRE showed less bone width contraction during the first 6 months of healing. Histologically, the regenerated bone was vital, trabecular in nature and in direct contact with bone graft particles. / El propósito de esta investigación clínica prospectiva y aleatoria es comparar el aumento horizontal de la cresta alveolar obtenido con el uso de los expansores motorizados de cresta (EMC) y con regeneración ósea guiada (ROG). Fueron selecccionados ocho pacientes con deformidades horizontales del reborde alveolar bilaterales que iban a recibir implantes dentales. Una técnica de regeneración se utilizó en el lado derecho y la otra en el lado izquierdo, para un total de 23 muestras, 13 en el lado experimental (EMC) y 10 en el lado control (ROG). Los implantes fueron colocados seis meses después de los procedimientos de aumento óseo, y se obtuvo una muestra de hueso para estudio histológico. Todas las mediciones clínicas se registraron a los 2 y 5 mm de la parte más coronal de la cresta. El aumento logrado con ambas técnicas fue estadísticamente significativo, de 1,2 mm en la ROG y 1,5 mm con los EMC a 2 mm de la cresta; y 1,5 mm y 1,6 mm, respectivamente, a 5mm de la cresta. Las diferencias entre las dos técnicas no fueron estadísticamente significativas. La cantidad de expansión lograda en el sitio de los EMC parece tener una correlación negativa (p <0,05) con el grosor del hueso esponjoso, y no se ve afectada por el grosor de la cortical. Histológicamente se observó osteoconductividad del injerto óseo y más partículas residuales del mismo en el lado experimental. La técnica de los EMC parece ser tan eficaz como la técnica de ROG en el aumento de la anchura de las crestas atróficas. Los defectos tratados con los EMC mostraron una menor contracción del injerto óseo durante los 6 meses de cicatrización. / El propòsit d'aquesta recerca clínica prospectiva i aleatòria és comparar l'augment horitzontal de la cresta alveolar obtingut amb l'ús dels expansors motoritzats de cresta (EMC) i amb regeneració òssiaguiada (ROG). Es van selecccionar vuit pacients amb deformitats horitzontals bilaterals de la cresta alveolar on es col.locaren implants dentals. Una tècnica de regeneració es va emprar en el costat dret i l'altra a la banda esquerra, per a un total de 23 mostres, 13 al costat experimental (EMC) i 10 en el costat control (ROG). Els implants van ser col.locats sis mesos després dels procediments d'augment ossi, i es va obtenir una mostra d'os per estudi histològic.Totes les mesures clíniques es van registrar als 2 i 5 mm de la part més coronal de la cresta. L'augment aconseguit amb ambdues tècniques va ser estadísticament significatiu, de 1,2 mm a la ROG i 1,5 mm amb els EMC a 2 mm de la carena, i 1,5 mm i 1,6 mm, respectivament, a 5mm de la cresta. Les diferències entre les duestècniques no van ser estadísticament significatives. La quantitat d'expansió aconseguida en el lloc dels EMC sembla tenir una correlació negativa (p<0,05) amb el gruix de l'os esponjós, i no es veu afectada per el gruix de la cortical. Histològicament es observar osteoconductividad l'empelt ossi i més partícules residuals d'aquest en el costat experimental. La tècnica dels EMC sembla ser tan eficaç com la tècnica de ROG en l'augment de l'amplada de les crestes atròfiques. Els defectes tractats amb els EMC mostrar una menor contracció de l'empelt ossi durant els 6 mesos de cicatrització.

No description available.

Bone is a remarkable multifunctional tissue with the ability to regenerate and remodel without generating any scar tissue. However, bone loss due to injury or diseases can be a great challenge and affect the patient significantly. Transplanting bone graft from one site in the patient to the site of fracture or bone void, i.e. autologous bone grafting is commonly used throughout the world. The transplanted bone not only fills voids, but is also bone inductive, housing the particular cells that are needed for bone regeneration. Nevertheless, a regenerative complement to autograft is of great interest and importance because the benefits from an off-the-shelf product with as good of healing capacity as autograft will circumvent most of the drawbacks with autograft. With a regenerative-medicine approach, the use of biomaterials loaded with bioactive molecules can avoid donor site morbidity and the problem of limited volume of material. Two such regenerative products that utilize bone morphogenetic protein 7 and 2 have been used for more than a decade in the clinic. However, some severe side effects have been reported, such as severe swelling due to inflammation and ectopic bone formation. Additionally, the products require open surgery, use of supra physiological doses of the BMPs due to poor localization and retention of the growth factors. The purpose of this thesis was to harness the strong inductive capability of the BMP-2 by optimizing the carrier of this bioactive protein, thereby minimizing the side effects that are associated with the clinical products and facilitating safe and localized bone regeneration at the desired site. We focused on an injectable hyaluronan-based carrier. The strategy was to use the body’s own regenerative pathway to stimulate and enhance bone healing in a manner similar to the natural bone-healing process. The hyaluronan-based carrier has a similar composition to the natural extracellular matrix and is degraded by resident hyaluronidase enzymes. Earlier studies have shown a more controlled release and improved mechanical properties when adding a weight of 25 percent of hydroxyapatite, a calcium phosphate that constitutes the inorganic part of the bone matrix. In Paper I, the aim was to improve the carrier by adding other forms of calcium phosphate. The results indicated that the bone formation was enhanced when using nano-sized hydroxyapatite. We wished to further develop the carrier system but were lacking an animal model with high output and easy access. We also wanted to provide paired data and were committed to the 3 Rs of refinement, reduction and replacement. To meet these challenges, we developed and refined an animal model, and this is described in Paper II. In Paper III, we characterized and optimized the handling properties of the carrier. In Paper IV, we discovered the importance of crushing the material, thus enhancing permeability and enlarging the surface area. In Paper V, we sought to further optimize biomaterial properties of the hydrogel through covalently bonding of bisphosphonates to the hyaluronan hydrogel. The results demonstrated exceptional retention of the growth factor BMP-2. In Paper VI, the in vivo response related to the release of the growth factor was examined by combining a SPECT/PET/µCT imaging method to visualize both the retention of the drug, and the in-vivo response in terms of mineralization.

Submitted by EDUARDA DE LIMA GRACIANO BELEM null (eduarda.belem@hotmail.com) on 2016-09-19T17:45:24Z No. of bitstreams: 1 Dissertação - Eduarda de Lima Graciano Belem (19-09-16).pdf: 1696256 bytes, checksum: 5d66d1f4ebfc8533efcd6e4b3df8a441 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-09-22T14:58:30Z (GMT) No. of bitstreams: 1 belem_elg_me_araca_par.pdf: 642200 bytes, checksum: cfac5618a8e05e501e2a63bd42199005 (MD5) / Made available in DSpace on 2016-09-22T14:58:30Z (GMT). No. of bitstreams: 1 belem_elg_me_araca_par.pdf: 642200 bytes, checksum: cfac5618a8e05e501e2a63bd42199005 (MD5) Previous issue date: 2016-08-26 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este estudo avaliou a influência do aspirado de medula óssea (AMO) e do plasma rico em plaquetas (PRP) associados ou não à terapia com laser em baixa intensidade (LLLT) no reparo ósseo de defeitos de tamanho crítico (DTC), criados cirurgicamente em calvárias de ratos. 96 ratos foram divididos em 6 grupos: C, PRP, AMO, LLLT, PRP/LLLT e AMO/LLLT. Um DTC de 5 mm de diâmetro foi criado na calvária de cada animal. No grupo C, o defeito foi preenchido com coágulo sanguíneo somente. Nos grupos PRP e AMO, o defeito foi preenchido com PRP e AMO, respectivamente. No grupo LLLT, o defeito recebeu aplicação da LLLT (InGaAlP), foi preenchido com coágulo sanguíneo e irradiado novamente. Nos grupos PRP/LLLT e AMO/LLLT, o defeito recebeu aplicação da LLLT, foi preenchido com PRP ou AMO, respectivamente e irradiado novamente. Os animais foram submetidos à eutanásia aos 10 ou 30 dias pós-operatórios. Foram realizadas análises histomorfométrica e imunoistoquímica. A área de osso neformado (AON) foi calculada como porcentagem da área total do defeito original. Foram realizadas reações imunoistoquímicas para detecção do antígeno nuclear de proliferação celular (PCNA), proteínas morfogenéticas ósseas 2/4 (BMP-2/4) e osteocalcina (OCN). As células PCNA-positivas, BMP-2/4-positivas e OCN-positivas foram quantificadas. Os dados foram analisados estatisticamente. Aos 10 dias pós-operatórios, o grupo AMO apresentou AON significativamente maior que o grupo C. Aos 30 dias pós-operatórios, o grupo AMO apresentou AON significativamente maior que os grupos C e LLLT, bem como números significativamente maiores de células BMP-2/4-positivas e OCN-positivas que o grupo C. Dentro dos limites deste estudo, pode-se concluir que a terapia com AMO promoveu a regeneração óssea em defeitos de tamanho crítico em calvárias de ratos, tanto aos 10 dias como aos 30 dias pós-operatórios. / This study evaluated the influence of bone marrow aspirate (BMA) and platelet-rich plasma (PRP) combined or not with low-level laser therapy (LLLT) on bone healing in surgically created critical-size defects (CSD) in rat calvaria. 96 rats were divided into 6 groups: C, PRP, BMA, LLLT, PRP/LLLT and BMA/LLLT. A 5 mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In groups PRP and BMA, the defects were filled with PRP and BMA, respectively. In Group LLLT, the defect received laser irradiation (InGaAlP laser), was filled with blood clot and irradiated again. In groups PRP/LLLT and BMA/LLLT, the defect received laser irradiation (InGaAlP laser), was filled with PRP or BMA, respectively, and irradiated again. Animals were euthanized at either 10 or 30 days postoperative. Histomorphometric and immunohistochemical analyses were performed. Newly formed bone area (NFBA) was calculated as a percentage of the total area of the original defect. Proliferating cell nuclear antigen (PCNA), bone morphogenetic protein 2/4 (BMP-2/4) and osteocalcin (OCN) immunohistochemical staining were performed. PCNA-positive, BMP-2/4-positive and OCNpositive cells were quantified. Data were statistically analyzed. At 10 days postoperative, Group BMA presented significantly greater NFBA than control. At 30 days postoperative, Group BMA presented significantly greater NFBA than control and Group LLLT, as well as significantly higher numbers of BMP-2/4-positive and OCN-positive cells than control. Within the limits of this study, it can be concluded that the treatment with BMA promoted bone regeneration in critical-size rat calvarial defects at both 10 and 30 days postoperative. / FAPESP: 2014/02094-5

Made available in DSpace on 2016-08-03T16:31:13Z (GMT). No. of bitstreams: 1 FERNANDA CEPERA1.pdf: 1386143 bytes, checksum: e65fb1bc0260136677b2aaa4f7962ade (MD5) Previous issue date: 2009-03-30 / The proposal of the following study was to evaluate the effects of low intensity laser, in the procedure of rapid palatal expansion. 27 individuals were utilized, with age average of 10.2 years-old, splitted in two groups: laser group (n=14), pertaining rapid palatal expansion with laser application, and laserless group (n=13), pertaining only rapid palatal expansion. The expansion bolt activation patttern utilized was 1 complete turn at the first day, and half turn every day until the overcorrection. A diodo laser was utilized (TWIN Laser MMOptics®, São Carlos), according to the following application pattern: wave lenght 780nm, power 40mW, density 10J/cm2, accross 10 spots localized around the median palatine suture. The application stages were: L1 (from first to fifh day), L2 (bolt's lock and the 3 subsequent days), L3, L4 and L5 (after 7, 14 and 21 days after L2, respectively). Occlusal radiographies were taken with the aid of an aluminum scale for densitometric referencial, in different timing: T1 (initial), T2 (bolt's locking day), T3 (3 to 5 days from T2), T4 (30 days from T3), T5 (60 days from T4). The x-ray pictures were digitized and submitted to an image treatment program (Image Tool - UTHSCSA, Texas, USA), for optical density mensuration, on the previsouly selected areas. To realize the statistical tests, it was used the covariance analysis using as covariate the time for the evaluated phase. It all tests it was adopted the significance level of 5% (p<0,05). For the Laser Group the data shows a significant density reduction during the bolt aperture (opening) (T2-T1), a significant density increase in the final evaluation period (T5-T2), and another increase during the regeneration period (T5-T2). From the moment the expander bolt aperture phase ended. While in the Laserless Group the density did not show a statistically significant difference in none of the analyzed periods. The results indicated that the laser generated considerable better openining of the median palatine suture besides the influence in the suture bone regeneration process, accelerating its recovery process.(AU) / A proposta do presente estudo foi avaliar os efeitos do laser de baixa intensidade na regeneração óssea no procedimento de expansão rápida da maxila. Utilizou-se 27 indivíduos com média de idade de 10,2 anos, divididos em dois grupos: grupo laser (n=14), no qual se realizou a expansão rápida da maxila, associada ao laser e grupo sem laser (n=13), que realizou somente a expansão rápida da maxila. O protocolo de ativação do parafuso expansor foi de 1 volta completa no primeiro dia e ½ volta diária até a sobrecorreção. O laser utilizado foi o de diodo (TWIN Laser MMOptics®, São Carlos), seguindo o protocolo de aplicação: comprimento de onda de 780nm, potência de 40mW, densidade de 10J/cm2, em 10 pontos localizados ao redor da sutura palatina mediana. Os estágios de aplicação foram: L1 (do primeiro ao quinto dia de aplicação), L2 (travamento do parafuso e 3 dias seguidos), L3, L4 e L5 (após 7, 14 e 21 dias do L2, respectivamente). Radiografias oclusais da maxila foram realizadas com auxílio de uma escala de alumínio, para referencial densitométrico, em diferentes tempos: T1 (inicial), T2 (dia de travamento do parafuso), T3 (3 a 5 dias do T2), T4 (30 dias do T3), T5 (60 dias do T4). As radiografias foram digitalizadas e submetidas a um programa de imagem (Image Tool - UTHSCSA, Texas, USA), para mensuração da densidade óptica das áreas previamente selecionadas. Para realização do teste estatístico, utilizou-se a Análise de Covariância usando como covariável o tempo para a fase avaliada. Em todos os testes foi adotado nível de significância de 5% (p<0,05).Para o Grupo Laser, os dados mostram que houve uma queda significante de densidade durante a abertura do parafuso (T2-T1), um aumento significante da mesma no período final de avaliação (T5-T4), e um aumento também da densidade no período de regeneração propriamente dito (T5-T2), ou seja, a partir do momento em que finalizou a fase de abertura do parafuso expansor. Enquanto que no Grupo Sem Laser, a densidade não mostrou diferença estatisticamente significantemente em nenhum período analisado. Os resultados mostraram que o laser propiciou consideravelmente uma melhor abertura da sutura palatina mediana, além de influenciar no processo de regeneração óssea da sutura, acelerando seus processos de reparo.(AU)

Les nanotechnologies sont en train de révolutionner le domaine biomédical et plus particulièrement l’ingénierie tissulaire. Elles permettent aujourd’hui, non seulement de réparer mais aussi de régénérer les tissus. Cette nanomédecine régénérative est particulièrement adaptée pour répondre aux besoins importants liés aux maladies dégénératives, au vieillissement et aux traumatismes.Mon travail de thèse s’inscrit dans ce contexte et concerne l’élaboration de biomatériaux nanofibreux et microporeux actifs pour la régénération osseuse. Notre objectif essentiel est de réaliser un implant biodégradable nanostructuré permettant d’accélérer la réparation du tissu osseux. Notre stratégie innovante repose non seulement sur la mise en oeuvre de membranes par électrospinning mais aussi sur leur fonctionnalisation par des facteurs de croissance. Cette fonctionnalisation originale a consisté à enrober ces principes actifs dans des nanoréservoirs en utilisant la technique multicouche de polyélectrolytes. Des membranes de polycaprolactone (PCL) nanofibreuses et microporeuses ont été obtenues par électrospinning puis les fibres ont été enrobées de réservoirs contenant le facteur ostéoinducteur, la protéine morphogénique osseuse 2 (BMP-2). L’induction osseuse engendrée par ces réservoirs actifs a été mise en évidence in vitro après culture d’ostéoblastes humains primaires. Des expérimentations in vivo chez la souris ont permis de confirmer l’accélération de la régénération osseuse grâce à ces nanoréservoirs.Cette même stratégie a été validée in vivo, chez la souris, en utilisant des membranes de collagène d’origine animal commerciales utilisées en clinique. L’activité de ces membranes fonctionnalisées par des nanoréservoirs de BMP-2 est en cours d’analyse dans le cadre de tests précliniques pour une application maxillofaciale et parodontale. / Nanobiotechnology enables the emergence of entirely new classes of bioactive devices intended for targeted intracellular delivery for more efficiency and less toxicities. Tissue engineering is an interdisciplinary field that has attempted to implement a variety of processing methods for synthetic and natural polymers to fabricate tissue and organ regeneration scaffolds.We report here the first demonstration of bone regeneration by using a strategy based on a synthetic nanostructured membrane. This electrospun membrane is manufactured by using a FDA approved polymer, PCL, (polycaprolactone), and functionalized with nanoreservoirs of a growth factor (BMP-2). Our expected outcomes are the development of clinical applications in the field of tissue engineering and nanomedecine and particularly in bone regeneration.We propose the development of smart nanostructured active implants for regenerative medicine. Our strategycombines a synthetic biodegradable electrospun nanofibrous membrane based on PCL and a bioactive growth factor (BMP-2) entrapped into polymer nanoreservoirs built atop the nanofibers according to the layer-by-layer technology. In this study, by using primary osteoblasts, we have shown the capacity of these sophisticated implants to promote and accelerate not only in vitro bone induction; but also, in vivo, bone formation (mouse model).We have also validated our strategy, in vivo (mouse model), by using an already used in the clinic collagen membrane (animal origin) to accelerate bone regeneration. This unique strategy is used to entrap, protect and stabilize the therapeutic agent into polymer coating acting as nanoreservoirs enrobing fibers of membranes.

Os defeitos da calota craniana causados por traumas severos, neoplasias, cirurgias ou deformidades congênitas representam um grande desafio para os cirurgiões. O uso de enxertia óssea autóloga continua sendo o método de tratamento padrão ouro, embora apresente morbidade na área doadora e seja considerado insuficiente para reconstrução de grandes defeitos. Recentemente, com o advento da bioengenharia tecidual, novas expectativas surgiram na regeneração óssea. O objetivo deste estudo foi desenvolver um modelo experimental em ratos para o estudo de deformidades craniofaciais e verificar se as células-tronco humanas provenientes de dentes decíduos seriam capazes de regenerar defeitos críticos em calota craniana de ratos não imunossuprimidos. Foram realizados dois defeitos ósseos de espessura total com diâmetro de 5 x 8 mm na região biparietal. O lado esquerdo foi preenchido com membrana de colágeno, enquanto o lado direito com membrana de colágeno associada a células-tronco humanas provenientes de dentes decíduos. Essas células foram caracterizadas previamente in vitro como células mesenquimais. A eutanásia dos animais foi realizada no 7º, 21º, 30º e 60º dia de pós-operatório e amostras de tecido ósseo foram extraídas para realização da análise histológica. A análise da presença de células humanas no novo osso formado foi confirmada através do estudo molecular. A linhagem de células-tronco humanas provenientes de dentes decíduos foi positiva para células-tronco mesenquimais e sua diferenciação em tecido ósseo também foi evidenciada in vitro. Foi observada a formação óssea após 21 dias de cirurgia nos dois lados, sendo o lado direito um osso mais maduro. A reação da cadeia de polimerase para DNA humano foi amplificada apenas no lado direito demonstrando que existiam células humanas nesse novo osso formado. O uso de células-tronco de dentes decíduos humanas em ratos não imunossuprimidos não evidenciou rejeição durante o período estudado. Os achados sugerem que o modelo experimental descrito poderá ser utilizado para o estudo dos defeitos ósseos cranianos em cirurgia craniofacial e que o uso de células-tronco humanas provenientes de dentes decíduos associado à membrana de colágeno parece representar uma importante estratégia para a reconstrução de tecidos ósseos e seu uso pode ser considerado uma opção para o reparo de grandes defeitos ósseos cranianos. / Repair of bone defects caused by severe trauma, resection of tumors, and congenital deformity remains a big challenge to surgeons. As a gold standard for the treatment of bone defects in clinic, autologous bone grafts are usually limited by considerable donor site mobility and available supply of tissue that can be harvested. Recently, tissue engineering has become a promising approach for bone regeneration. The main aim of this study is to create an experimental surgical protocol and evaluate the capacity of human dental pulp stem cells isolated from deciduous teeth, to reconstruct critical size cranial bone defects in nonimmunosuppressed rats. Bilateral 5 x 8 mm cranial full-thickness defects of parietal bone were created. The left side was supplied with collagen membrane only and the right side with collagen membrane and human dental pulp stem cells. Cells were used after in vitro characterization as mesenchymal cells. Animals were euthanized at 7, 21, 30 and 60 days postoperatively and cranial tissue samples were taken from the defects for histologic analysis. Analysis of the presence of human cells in the new bone was confirmed by molecular analysis. The human dental pulp stem cells lineage was positive for the four mesenchymal cell markers tested and showed osteogenic in vitro differentiation. The bone formation was observed 21 days after surgery on both sides, but a more mature bone was present in the right side. Human DNA was polymerase chain reaction-amplified only at the right side, indicating that this new bone had human cells. The use of human dental pulp stem cells in nonimmunosuppressed rats did not cause any graft rejection during this period. Our findings suggest that surgical protocol created may ultimately be used in experimental studies of cranial bone defects in craniofacial surgery and the use of human dental pulp stem cells together with collagen membrane seems to be a promising strategy for in vivo bone tissue reconstruction and their use might provide an option to repair human large cranial bone defects.

Notre équipe a développé une stratégie innovante de fonctionnalisation d’implants nanofibreux synthétiques à base de nanoréservoirs actifs pour la médecine régénérative osseuse. Notre objectif essentiel est de proposer un implant synthétique, biodégradable, et nanostructuré permettant d’accélérer la réparation du tissu osseux. Ces nouveaux implants synthétiques représentent un choix alternatif aux membranes de collagène d’origine animale. Notre stratégie consiste à construire des nanoréservoirs de chitosane, contenant des facteurs ostéoinducteurs tels que la BMP-2 afin d’enrober les nanofibres de nos implants. L’implant synthétique et biomimétique a été conçu à partir du le poly(ε-caprolactone) (PCL),polymère biocompatible et biodégradable approuvé par la FDA, et élaboré grâce à la technique de l’electrospinning afin de mimer la matrice extracellulaire. L’optimisation de ce procédé a permis la mise en oeuvre d’implants d’épaisseurs différentes (jusqu’à 10mm). La double fonctionnalisation de l’implant a permis de le rendre bioactif et vivant en utilisant la combinaison de facteur de croissance et de cellules souches mésenchymateuses. L’efficacité de la double fonctionnalisation des implants de PCL a ainsi été mise en évidence par l’accélération de la régénération osseuse in vivo.L’activité de ces implants fonctionnalisés de nanoréservoirs bioactifs est en cours d’analyse dans le cadre de tests précliniques pour une application maxillo-faciale, parodontale et orthopédique en vu d’obtenir un marquage CE. De plus, une start-up (ARTiOS NanoMed) basée sur cette nanotechnologie a été crée. En conclusion, nous pensons que la technologie développée par notre laboratoire a permis une avancée dans le domaine de la régénération osseuse et que cette technologie présente un fort potentiel d’application en clinique. / Our team has developped a novel and unique strategy to functionnalize nanofibrous and synthetic implants based on active nanoreservoirs for bone regeneration. We propose a new synthetic biodegradable and nanostructured implant to accelarate restoration of bone tissue. These new implants could replace collagen membranes from animal origin. The nanoreservoirs are based on chitosan containing osteoinductive growth factors such as BMP-2. Poly(ε-caprolactone) (PCL) is a biodegradable and biocompatible polymer approved by FDA and has been used to produce the synthetic and biomimetic implants by electrospinning in order to mimic the bone extracellular matrix. Optimization of this process has allowed the elaboration of nanofibrous implants with different thicknesses reaching 10 mm. Using the combination of growth factors and mesenchymal stem cells in a double functionalization created a bioactive and living implant. This strategy has been validated in vitro and in vivo thanks to bone site implantation in murin model. Acceleration of bone regeneration in vivo has brought to light the efficiency of the double functionalization onto the PCL implants.The functionalized implants bioactivity is still currently in study for pre-clinical trials in order to obtain authorization for applications in maxillo-facial, parodontal, and orthopaedic fields. Moerover, astat-up (ARTiOS NanoMed) based on this nanotechnology has been founded.To conclude, we believe that our nanotechnology could lead to a new generation of engineered bone implants which has a great potential to be used in the clinic.

Ce travail a consisté à optimiser la synthèse de phosphates de calcium (CaP) déposés sur tissus de fibres de carbone (TFC) par procédé de sono-électrodéposition afin d’obtenir des revêtements uniformes. Les paramètres électrochimiques clés optimisés sont le type et la durée de polarisation cathodique ainsi que la température de l’électrolyte. Pour un potentiel constant de -1 V à 70 °C, un régime d’électrolyse contrôlé de l’eau conduit à la formation d’un revêtement plaquettaire d’hydroxyapatite déficitaire en calcium (CDA) carbonatée. Les plaquettes sont composées de particules lamellaires (de quelques dizaines à centaines de nm) constituées de CDA carbonatée de structure ordonnée au coeur et de structure désordonnée car hydratée en surface des particules, organisation typique des apatites biomimétiques. Le matériau hybride a été dopé en strontium, engendrant la formation de revêtements où les ions Ca²+ sont substitués par des ions Sr²+ de manière contrôlée, conférant au biomatériau de nouvelles propriétés en vue d’une application en régénération osseuse. Ce travail a aussi démontré la possibilité d’adsorber de façon sélective des principes actifs ciblés (tétracycline, naproxène, aspirine) dans chaque constituant du matériau hybride. Les courbes de désorption ont mis en évidence deux modes de libération selon le principe actif.Une évaluation biologique des différentes matériaux hybrides a été réalisée. L’étude in vitro a porté sur la viabilité et la prolifération d’ostéoblastes humains en surface des biomatériaux hybrides, démontrant leur biocompatibilité. L’intérêt d’un dopage (Sr²+, aspirine et naproxène) sur l’activité des ostéoblastes a été démontré. Une expérience pilote in vivo a été menée, consistant à créer un défaut osseux dans des fémurs de rats et à étudier l’influence du type de biomatériaux TFC/CaP sur les évolutions quantitative et qualitative de la régénération osseuse. / Optimization of the synthesis of calcium phosphates (CaP) on carbon fiber cloths (TFC) was performed in using sono-electrodeposition process in order to obtain uniform coatings. The electrochemical potential applied and the electrolyte temperature during the synthesis were determined as being key parameters. For a constant potential of -1 V at 70 ° C, a controlled water electrolysis regime results in the deposit of plate-like calcium-deficient apatite (CDA). This plate-like particles (from a few tens to hundreds of nm in length) consist in an ordered structure of carbonated CDA in their core and in a disordered structure in the hydrated surface, a typical organization of biomimetic apatites. The hybrid material was doped with strontium, resulting in a carbonated CDA coating where the Ca²+ ions are controllably substituted by Sr²+ ions, leading to new properties for a bone regeneration application. This work has also shown the possibility of selectively adsorb targeted active molecules (tetracycline, naproxen, aspirin) in each component of the hybrid material. The desorption curves revealed two modes of release depending on the active molecule.A biological evaluation of the different hybrid materials was carried out. The in vitro study investigated the viability and proliferation of human osteoblasts at the surface of hybrid materials, demonstrating their biocompatibility. The interest of a doping (Sr²+, aspirin and naproxen) on osteoblast activity was demonstrated. An in vivo pilot experiment was conducted, through the creation of a bone defect in rat thighbones to study the influence of TFC/CaP biomaterials on the quantitative and qualitative evolutions of bone regeneration.

No / Infection is the major reason of GTR/GBR membrane failure in clinical application. In this work, we developed GTR/GBR nanofiber membranes with localized drug delivery function to prevent infection. Metronidazole (MNA), an antibiotic, was successfully incorporated into electrospun polycaprolactone (PCL) nanofibers at different concentrations (0, 1, 5, 10, 20, 30, and 40 wt% polymer). To obtain the optimum anti-infection membrane, we systematically investigated the physical-chemical and mechanical properties of the nanofiber membranes with different drug contents. The interaction between PCL and MNA was identified by molecular dynamics simulation. MNA released in a controlled, sustained manner over 2 weeks and the antibacterial activity of the released MNA remained. The incorporation of MNA improved the hydrophilicity and in vitro biodegradation rate of PCL nanofibers. The nanofiber membranes allowed cells to adhere to and proliferate on them and showed excellent barrier function. The membrane loaded with 30% MNA had the best comprehensive properties. Analysis of subcutaneous implants demonstrated that MNA-loaded nanofibers evoked a less severe inflammatory response than pure PCL nanofibers. These results demonstrate the potential of MNA-loaded nanofiber membranes as GTR/GBR membrane with antibacterial and anti-inflammatory function for extensive biomedical applications.