Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2017-10-18T18:04:12Z No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-19T10:29:32Z (GMT) No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-19T10:29:32Z (GMT). No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-30 / The economic relevance of equine breeding in Brazil indicates the importance of the development of new economically viable treatments to promote tissue healing. Skin grafts and Platelet Rich Plasma (PRP) are available alternatives for improving the wound healing process in these animals. This study aimed to establish a simple method for autologous PRP production, as well as to evaluate its action on cutaneous wounds containing skin autografts in horses. Eight healthy horses were used, ranging in age from 3 to 18 years and mean live weight of 350 kg. For PRP obtention, a double centrifugation protocol was used. Two 6 x 6 cm wounds were performed on each side of the gluteal region. After the wound was filled by granulation tissue, punch autografts were obtained, with fragments harvested from the neck. Left-sided wounds were treated with PRP (GT) and right-sided wounds were not treated (GC). The protocol used to obtain PRP resulted in platelet concentration, on average, three times higher than that of whole blood. In the evaluation of PRP action in the healing of autografts, macroscopic and microscopic variables were considered. There was no significant difference between the groups (p> 0.05) for the variables inflammatory infiltrate, young fibroblasts, collagenization, epidermal thickness, macroscopic and microscopic integration of the autografts and retraction of the wound edges. However, neovascularization was significantly greater (p = 0.0191) in the PRP group, on the 14 th day after insertion of the autografts. It is concluded that the double centrifugation method results in PRP with adequate platelet concentration for therapeutic use. As for the action of PRP, this favors the process of skin repair with autografts in horses, since it increases the neovascularization in the initial phase of wound healing. Moreover, PRP seems to positively influence the integration of skin autografts and retraction of the wound edges, which is of fundamental importance for the reduction of hospitalization time and consequently of the therapeutic costs. / A relevância econômica da criação de equinos no Brasil denota a importância do desenvolvimento de novos tratamentos, economicamente viáveis, para promover a cicatrização tecidual. Os enxertos de pele e o Plasma Rico em Plaquetas (PRP) são alternativas disponíveis para a melhoria do processo de cicatrização nesses animais. Este estudo teve por objetivo estabelecer um método simples para produção de PRP autólogo, assim como avaliar sua ação sobre feridas cutâneas contendo autoenxertos de pele em equinos. Foram utilizados oito equinos hígidos, com idade variando entre três e 18 anos e peso vivo médio de 350 kg. Na obtenção do PRP, foi utilizado protocolo em dupla centrifugação. Foram realizadas duas feridas de 6 x 6 cm, em cada um dos lados da região glútea. Após o preenchimento da ferida por tecido de granulação, foram realizados autoenxertos do tipo punch, com fragmentos colhidos do pescoço. As feridas do lado esquerdo receberam tratamento com PRP (GT) e as feridas do lado direito não receberam tratamento (GC). O protocolo utilizado na obtenção do PRP resultou em concentração plaquetária, em média, três vezes acima daquela do sangue total. Na avaliação da ação do PRP na cicatrização dos autoenxertos, foram consideradas variáveis macroscópicas e microscópicas. Não houve diferença significativa entre os grupos (p>0,05) quanto às variáveis infiltrado inflamatório, fibroblastos jovens, colagenização, espessura da epiderme, integração macroscópica e microscópica dos autoenxertos e retração das bordas da ferida. Contudo, a neovascularização foi significativamente maior (p=0,0191) no grupo tratado com o PRP, no 14º dia após a inserção dos autoenxertos. Conclui-se que o método de dupla centrifugação resulta em PRP com concentração plaquetária adequada ao uso terapêutico. Quanto à ação do PRP, este favorece o processo de reparo da pele com autoenxertos em equinos, já que aumenta a neovascularização na fase inicial da cicatrização da ferida. Ainda, o PRP parece influenciar positivamente a integração dos autoenxertos de pele e a retração das bordas da ferida, o que é de fundamental importância para a redução do tempo de internação dos animais e, consequentemente, dos custos terapêuticos.

Vários estudos têm abordado fatores que governam a longevidade dos enxertos ósseos \"onlay\". Entretanto, poucas informações têm sido disponibilizadas sobre eventos moleculares que ocorrem ao longo do tempo. Os enxertos de calota craniana têm sido reportados produzir respostas superiores em relação a outras regiões doadoras nas reconstruções maxilo-faciais, mas sem a devida comprovação científica. Este estudo tem por objetivos (1) estudar o padrão morfológico de enxertos ósseos \"onlay\" de calota craniana e compará-los com os eventos biológicos através de respostas imunoistoquímicas e (2) estabelecer os efeitos das perfurações no leito receptor sobre a manutenção do volume e densidade óssea. Sessenta coelhos do tipo New-Zealand White foram submetidos à enxertia óssea \"onlay\" de calota craniana na mandíbula. Em trinta coelhos o leito receptor foi perfurado (grupo perfurado) enquanto nos demais o leito foi mantido intacto (grupo não perfurado). Seis animais de cada grupo foram sacrificados aos 5, 7, 10, 20 e 60 dias após a cirurgia. Cortes histológicos foram preparados da região enxertada para análises imunoistoquímica e histológica. Na avaliação imunoistoquímica se observou marcações das proteínas Osteoprotegerina (OPG), \"Receptor Activator of Nuclear Factor-ß ligand\" (RANKL), Fosfatase Alcalina (ALP), Osteopontina (OPN), \"Vascular Endothelial Growth Factor\" (VEGF), \"Tartrate-Resistant Acid Phosphatase\" (TRAP), Colágeno do tipo I (COL I) e Osteocalcina (OC). O exame tomográfico foi realizado após a cirurgia e no sacrifício dos animais. Os achados histológicos revelaram que as perfurações contribuíram para uma maior deposição óssea nos períodos iniciais na interface entre o enxerto e o leito receptor, acelerando o processo de incorporação. Os resultados tomográficos mostraram menor reabsorção para o grupo perfurado (P≤0,05) e ambos os grupos mostraram altas taxas de densidade óssea aos 60 dias. Estas evidências são corroboradas pelos resultados imunoistoquímicos que mostraram maior marcação de proteínas ligadas a revascularização e osteogênese (VEGF, OPN, TRAP e ALP) no grupo perfurado. Esses achados indicam que o volume ósseo de enxertos da calota craniana é mais bem conservado quando o leito receptor é perfurado, provavelmente em razão de uma mais efetiva revascularização do enxerto e maior deposição óssea. / Several studies have discussed factors that govern the longevity of onlay bone grafts. However, little information has been made available on molecular events that occur over time. Cranial bone grafts have been reported to produce greater responses compared to other donor regions in maxillofacial reconstructions, but necessary scientific verification was still lacking. The objectives of this study are (1) to study the morphological pattern of cranial onlay bone grafts and compare them to the biological events through immunohistochemical responses, and (2) to establish the effects of perforations on maintaining the volume and bone density of the receptor bed. Sixty New Zealand White rabbits were submitted to cranial onlay bone grafts of the mandible. In thirty rabbits, the receptor bed was perforated (perforated group), while for the remaining specimens the bed was kept intact (non-perforated group). Six animals from each group were culled at 5, 7, 10, 20 and 60 days after surgery. Histological cuts from the grafted area were prepared for immunohistochemical and histological analyses. During the immunohistochemical evaluation, markers were found for proteins Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor-ß ligand (RANKL), Alkaline Phosphatase (ALP), Osteopontin (OPN), Vascular Endothelial Growth Factor (VEGF), Tartrate-Resistant Acid Phosphatase (TRAP), Type I Collagen (COL I) and Osteocalcin (OC). The tomography examination (CT scan) was conducted after surgery and at culling. The histological findings revealed that the perforations contributed to higher bone deposition during the initial stages at the graft-receptor bed interface, accelerating the incorporation process. The results of the CT scan showed lower resorption for the perforated group (P≤0.05), and both groups showed high bone density rates at 60 days. This set of evidence is corroborated by the immunohistochemical results, which showed more markers of proteins associated with revascularization and osteogenesis (VEGF, OPN, TRAP and ALP) in the perforated group. These findings indicate that the bone volume of cranial dome grafts is better maintained when the receptor bed is perforated, probably resulting from more effective graft revascularization and greater bone deposition.

No description available.

Burn wounds tend to be a critical problem with a complicated healing process. Although advancements have been made and the treatment of burn wounds has improved significantly, the healing process for deep-partial thickness burn wounds remains problematic. The purpose of this thesis is to review the available literature on an innovate biotechnology, autologous skin cell-spray transplantation, to more effectively treat burn wounds and potentially other injuries in the future. This study was conducted by critically researching and comparing (N=7) peer-reviewed research articles focusing not only on burn wounds using traditional treatments, but also the treatment of burn wounds using revolutionary cell-spray autographing technologies. The findings in this thesis show significant enhancement using this innovative approach for the treatment of burn injuries, and presents pivotal information for future nursing research, clinical practice as well as policy and education.

INTRODUCTION. La guérison rapide des sites donneurs des greffes cutanées favorise la survie des victimes de brûlures graves (>50 % de superficie brûlée). La mortalité élevée de ces patients est attribuable au fait que la superficie des brûlures excède celle de la peau saine. Des cultures épithéliales autologues (CEA) sont des feuillets de kératinocytes produits en culture à partir de la peau du patient. Cette étude a évalué l’effet des CEA sur l'épithélialisation des sites donneurs chez les grands brûlés. MÉTHODES. Tous les patients recevant des CEA ont été prospectivement inclus. Les plaies des sites donneurs ont été recouvertes de CEA, sauf pour une région contrôle randomisée de 7 x 7 cm. Des biopsies faites sur la greffe de peau ont permis de contrôler la profondeur des plaies sur les sites donneurs. Il y avait deux types de contrôles, avec gaze non adhérente trempée dans le milieu de culture ou dans le salin. L’épithélialisation était quantifiée globalement (% d’épithélialisation par photographie) et histologiquement (par biopsie au poinçon) à simple insu. La guérison des zones de contrôle et CEA était comparée par analyse de variance et par le test de Student. RÉSULTATS. Entre 2008 et 2009, 6 patients furent recrutés avec un total de 11 sites donneurs. Ces patients avaient en moyenne 43.5 ans, 56 % de superficie brûlée, 45% de brûlure pleine épaisseur, 66% avaient une brûlure d’inhalation, 75 jours de séjour. Il n’y a aucune corrélation entre le pourcentage d’épithélialisation et l’épaisseur du prélèvement des greffes (Pearson 0.19). Le score photographique est significativement influencé par le traitement (CEA vs Contrôle; p = 0,039) et par le jour postopératoire (p < 0,001). Le temps moyen pour atteindre un score photographique de guérison pour les zones contrôles fut de 10.2 jours contre 8.6 jours pour le CEA (p = 0,021). A l’évaluation histologique, les sites donneurs traités par le milieu de culture ont évolué aussi favorablement que ceux traités par des feuillets de CEA. CONCLUSION. L’utilisation de CEA sur les sites donneurs semble accélérer leur épithélialisation chez les victimes de brûlures graves. Cet effet est probablement le résultat d’une stimulation de la réépithélialisation innée de la plaie, plutôt que par une adhérence des feuillets de kératinocytes cultivés à la surface de la plaie. / RATIONALE: Prompt healing of split thickness skin graft donor sites is primordial to the survival of severely burned patients. Increased mortality of patients with >50 % TBSA is attributable to the limited availability of donor sites. This study evaluated the effect of Cultured Epithelial Autograft (CEA) application on skin graft donor site healing. METHODS: All burn patients receiving CEA were prospectively included. Donor site wounds were covered with CEA except a randomly designated 7x7 cm control region. Autograft biopsies were taken to document graft harvest thickness. One half of the controls were covered with non-adherent gauze soaked in the culture media and the other controls only received a non-adherent gauze dressing. Epithelialization was objectively evaluated by scoring blinded photographs with an analogue scale. Punch biopsies of the donor sites were evaluated histologically. Repeated measures ANOVA and T-test were used. RESULTS: Between 2008 and 2009, 6 patients were enrolled for a total of 11 donor sites. The patients averaged 43.5 years, 56 % TBSA, 45 % FT-TBSA, 66 % had inhalation injury and mean length of stay was 75 days. As expected, dermatome settings and autograft thickness measured by microscope did not correlate (Pearson 0.19). There was no correlation between the percentage of epithelialization of the punch biopsies of the donor sites and the thickness of the harvest. Photographic score was significantly influenced by its treatment CEA vs Control (p=0.039) and by postoperative day (p<0.001). Mean time to healing was 8.6 days for CEA compared to 10.2 days for controls (p=0.021). Infection was noted on only one donor site. On histologic analysis, the control sites dressed with gauze soaked in the culture media healed as nicely and promptly as the CEA sheet treated region. CONCLUSION: Use of CEA on donor sites appears to stimulate epithelialization. This effect is probably mediated by stimulation of local wound healing processes rather than by engraftment of keratinocytes from the CEA sheets.

Bone formation and bone healing were studied in the mandible, tibia and skull bones in adult, healthy and estrogen deficient rabbits implanted with different bone substitutes. In the first study an evaluation of the differences in bone regeneration in and around solid (Alveograf *) and porous hydroxyapatite (Interpore 200*) was undertaken. The implant material was placed into experimentally made bone defects and in half of the defects hydroxyapatite was mixed with a fibrin sealant (Tisseel *). The material alone or mixed with Tisseel was also placed subperiostally in the mandible. The observation time was six month. No difference in bone regeneration was found between solid or porous hydroxyapatite granulas and the addition of Tisseel* did not seem to disturb the bone healing process. The implant material placed subperiostally did not induce bone formation nor did it provoke any bone resorption. The addition of Tisseel made the implant material much easier to handle and retain in the tissue during surgery. Bone healing around hydroxyapatite implants was also evaluated in the second study. Experimental cavities in the mandible and tibia were filled with hydroxyapatite in granules or blocks (Interpore 200*) but now with or without autolyzed, antigen-extracted, allogeneic bone (AAA). Also in this study Tisseel* was used to facilitate the handling of the material. All cavities implanted with AAA-bone, regardless of the combination with hydroxyapatite or Tisseel, demonstrated excessive bone formation resembling exostosis formation. Thus, hydroxyapatite, both as granules and blocks, can be successfully combined with AAA bone utilizing the bone inductive capacity of AAA bone. The same model was used to study the healing in ovariectomized animals in the third study. Bone cavities were implanted with or without AAA bone and left to heal. The results indicate that the osteoinductive capacity of AAA bone is in operation also in animals deprived of a normal estrogen production. The effect of using AAA bone prior to implant insertion was studied in paper four. The bone-implant contact was significant higher when AAA bone had been used. The implant stability did not seem to be affected. In paper five defects were made in skull and tibial bone in estrogen deficient animals. The deficiency of estrogen was confirmed through blood analysis, the decrease in the weight of uterus and bone mineral density. The whole body scanning with DEXA showed that the ovariectomized animals developed osteopenia. Various degree of bone formation was seen in the defects due to the influence of the bone inductive substance AAA bone. The studies indicate that a conductive material like hydroxyapatite in granules or blocks could be useful in oral reconstructive surgery. The combination with AAA bone enhanced the bone formation in calvarial and tibial bone in healthy and estrogen deficient animals. Tisseel* could be used to facilitate handling and retention of the material in the intended position during the healing process without negative effects.

Nas últimas décadas tem aumentado o interesse pelos enxertos de pele humana radioesterilizadas, para aplicação principalmente em queimaduras extensas e profundas. Isto se deve ao fato destes enxertos apresentarem rápida aderência e menor potencial antigênico, em comparação com os demais tratamentos utilizados. A proposta deste estudo foi avaliar a histoarquitetura do enxerto de pele humana irradiada com doses de 25 kGy, 50 kGy e não irradiada, durante o processo de reparação tecidual, em camundongos Nude submetidos a enxertia de pele na região dorsal. Três grupos de animais receberam enxertos de pele humana irradiada (25 kGy e 50 kGy) e não irradiada e foram eutanasiados no 3º, 7º e 21º dia após a realização da cirurgia. Após os procedimentos histológicos de rotina, as amostras de tecido foram coradas com hematoxilina e eosina (HE) para a quantificação de queratinócitos, fibroblastos, células de defesa e vasos sanguíneos e a reação de imunofluorescência (IF) foi realizada para a determinação da expressão de colágeno do tipo I humano e do colágeno dos tipos I e III de camundongo. A quantificação, tanto das células quanto dos tipos de colágeno foi realizada por análise de imagem, utilizando o programa Image-Pro PLus 6.0. Os resultados histológicos demostraram que a pele humana irradiação, quando enxertada, influencia o aumento do número de células no local de cicatrização ao longo do tempo, principalmente na dose de 25 kGy, além de proporcionar uma melhor dispersão destas células. No 21º dia, os três grupos de animais com enxertia de pele humana tiveram parte do enxerto incorporado no processo de cicatrização. O grupo não irradiado apresentou maior incorporação do enxerto (43%), porém menor produção de colágeno do tipo III de camundongo (22%). Já os grupos com enxertia de pele irradiada apresentaram menor incorporação do enxerto (6 e 15%), mas com maior produção de colágeno do tipo III de camundongo (35% e 28%, para 25 kGy e 50 kGy, respectivamente). Com este estudo pôde-se concluir que o grupo irradiado a 25 kGy, apresenta maior proliferação celular e formação de vasos,além de melhor remodelamento da região de cicatrização. / Over the last few years it has increased the interest in the human skin grafts radio sterilized for application mainly in extensive and deep burns. Because these grafts quickly grip and present antigenic lower potential, compared with other treatments used. The purpose of this study was to evaluate the histoarchitecture of human skin grafts irradiated with doses 25 kGy, 50 kGy and non-irradiated during the pepair tissue process in nude mice submitted by skin grafting in the dorsal region. Three groups of animals received irradiated human skin grafts (25 kGy and 50 kGy) and non-irradiated and were euthanized on the 3rd, 7th and 21th day after the surgery. Indeed, routine histologic procedures, tissue samples were stained with hematoxylin and eosin (HE) for quantification of keratinocytes, fibroblasts, immune cells and blood vessels and immunofluorescence (IF) was performed to determine the expression human collagen type I and collagen type I and III mouse. Therefore, quantification of both the cells and the collagen types was performed by image analysis using Image-Pro Plus 6.0 software. Histologic results demonstrated at a dose of 25 kGy that human skin irradiation when grafted influences the increase in the number of cells in wound site over time and it provides better dispersion of these cells. In addition, on the 21st day, three groups of animals with human skin graft were embedded part of the graft in the healing process. On the other hand, the group not irradiated showed greater incorporation of the graft (43 %), but less production of collagen type III mouse (22 %). Since the groups irradiated skin graft showed lower graft incorporation (6 and 15%), but with greater production of collagen type III mice (35 % and 28 % to 25 kGy and 50 kGy, respectively). In conclusion, this study presented that the group irradiated to 25 kGy and it has a higher cell proliferation and vessel formation, and better remodeling of the healing area.

L'anévrisme de l'aorte abdominale est une pathologie devant être traitée par chirurgie quand son diamètre atteint 5.5cm, en raison d’un risque de rupture qui est souvent mortelle. La chirurgie endovasculaire consiste à déployer une endoprothèse dans l’anévrisme pour l’exclure de la circulation sanguine. Cette chirurgie souffre cependant d'un taux relativement élevé de complications post-opératoires à long terme, nécessitant des interventions coûteuses. Ces complications sont principalement d’origine mécanique et pourraient être anticipées grâce à la simulation numérique.Cette thèse a pour objectif d'élaborer une méthodologie de simulation personnalisée de déploiement d'endoprothèses dans des anévrismes, dans le but final de fournir un outil d'aide à la décision aux praticiens hospitaliers pour améliorer leur planning pré-opératoire.Une méthodologie permettant de déployer numériquement des endoprothèses bifurquées, composées de plusieurs modules, dans des anévrismes aortiques personnalisés, de géométries quelconques, a été conçue. Des simulations numériques ont été effectuées sur cinq cas cliniques réels, dont des cas fortement tortueux et complexes àplanifier pour les praticiens hospitaliers. La méthodologie a été validée par comparaison des résultats numériques avec la position des stents sur les scanners post-opératoires.La capacité de la méthodologie numérique à simuler le déploiement d’endoprothèses dans des géométries personnalisées d’anévrismes aortiques a été démontrée. Ces simulations possèdent un fort potentiel, en pouvant permettre de mieux adapter les endoprothèses aux patients et d’anticiper les complications post-opératoires dès le planning pré-opératoire. / Abdominal aortic aneurysm is a pathology which needs to be treated by surgery when its diameter reaches 5.5cm, due to high risk of rupture that is often lethal. Endovascular repair consists in deploying a stent-graft inside the aneurysmal sac to exclude it from the blood flow. However, the drawback of this surgery is the relatively important post-operative complication rate at long-term, requiring costly secondary interventions. The origin of these complications is mainly related to mechanics and therefore, they could be prevented thanks to numerical simulation.The objective of this thesis is to elaborate a simulation methodology to deploy in silico stent-grafts in patient-specific aneurysms. The ultimate goal is to provide practioners with a computer aided decision tool to improve their pre-operative planning.A methodology was developed to simulate the deployment of bifurcated stent-grafts, composed of several modules, in patient-specific aortic aneurysms, whatever their geometry. Finite-element analyses were performed on several clinical cases from real patients, some of them which were highly tortuous and complex for practioners to achieve an accurate preoperative planning. The methodology was validated by comparing numerical results with the position of the stents in the post-operative scans.The ability of finite-element analyses to simulate stent-graft deployment in patient-specific aortic aneurysm geometries was proved in this thesis. Simulations have great potential for adapting stent-grafts to each patient and for anticipating possible post-operative complications at the stage of pre-operative planning.

<p>Bone formation and bone healing were studied in the mandible, tibia and skull bones in adult, healthy and estrogen deficient rabbits implanted with different bone substitutes. </p><p>In the first study an evaluation of the differences in bone regeneration in and around solid (Alveograf *) and porous hydroxyapatite (Interpore 200*) was undertaken. The implant material was placed into experimentally made bone defects and in half of the defects hydroxyapatite was mixed with a fibrin sealant (Tisseel *). The material alone or mixed with Tisseel was also placed subperiostally in the mandible. The observation time was six month. No difference in bone regeneration was found between solid or porous hydroxyapatite granulas and the addition of Tisseel* did not seem to disturb the bone healing process. The implant material placed subperiostally did not induce bone formation nor did it provoke any bone resorption. The addition of Tisseel made the implant material much easier to handle and retain in the tissue during surgery.</p><p>Bone healing around hydroxyapatite implants was also evaluated in the second study. Experimental cavities in the mandible and tibia were filled with hydroxyapatite in granules or blocks (Interpore 200*) but now with or without autolyzed, antigen-extracted, allogeneic bone (AAA). Also in this study Tisseel* was used to facilitate the handling of the material. All cavities implanted with AAA-bone, regardless of the combination with hydroxyapatite or Tisseel, demonstrated excessive bone formation resembling exostosis formation. Thus, hydroxyapatite, both as granules and blocks, can be successfully combined with AAA bone utilizing the bone inductive capacity of AAA bone.</p><p>The same model was used to study the healing in ovariectomized animals in the third study. Bone cavities were implanted with or without AAA bone and left to heal. The results indicate that the osteoinductive capacity of AAA bone is in operation also in animals deprived of a normal estrogen production.</p><p>The effect of using AAA bone prior to implant insertion was studied in paper four. The bone-implant contact was significant higher when AAA bone had been used. The implant stability did not seem to be affected.</p><p>In paper five defects were made in skull and tibial bone in estrogen deficient animals. The deficiency of estrogen was confirmed through blood analysis, the decrease in the weight of uterus and bone mineral density. The whole body scanning with DEXA showed that the ovariectomized animals developed osteopenia. Various degree of bone formation was seen in the defects due to the influence of the bone inductive substance AAA bone. </p><p>The studies indicate that a conductive material like hydroxyapatite in granules or blocks could be useful in oral reconstructive surgery. The combination with AAA bone enhanced the bone formation in calvarial and tibial bone in healthy and estrogen deficient animals. Tisseel* could be used to facilitate handling and retention of the material in the intended position during the healing process without negative effects. </p>

The goal of this study is to assess the osteogenic potential of two types of dental stem cell lines within a tissue engineering application. More specifically, the goal of this study is to find a readily abundant cell source with capacity to express an osteogenic phenotype. There are two parameters utilized to evaluate tissue engineering potential of cells: proliferation rate and differentiation potential. Briefly, proliferation rate is the speed at which cells divide and differentiation potential determines if cells are capable of committing towards specific lineages (e.g. osteogenic). These components are important, because if cells are not expanding at a specific rate and are not differentiating towards the lineage desired, the tissue engineered will not mirror the characteristics of native tissue. Therefore, both components are necessary for osteogenic tissue engineering applications. Several stem cell lines have been isolated from different sources (e.g. umbilical, bone marrow) and characterized for their proliferative capacity and their potency. Among these progenitor or stem cell lines, are those isolated from human dental tissue. Due to the similarities between teeth and bone, this specific cell line may be useful in osteogenic tissue engineering applications. In this study, stem cells extracted from human exfoliated deciduous teeth (SHEDs) and periodontal ligament stem cells (PERIOs), were evaluated and compared. Briefly, to evaluate the proliferation rate an ex-vivo expansion study was conducted. This experiment found that both SHEDs and PERIOs were proliferative lines with doubling times of 23 hours and 19 hours respectively. Subsequently, osteogenic differentiation of SHEDs and PERIOs was assessed utilizing a 3-D fibrin gel suspension treated with osteogenic media containing either dexamethasone (DEX) or Retinoic Acid (RA) for 28 days. At day 28, osteogenic markers for collagen 1 (Col1), osteocalcin (OCN), and alkaline phosphatase (ALP) were evaluated using qPCR. Results demonstrated both SHEDs and PERIOs exhibited significant (p<0.05) increases in osteogenic gene expression under the influences of DEX and RA. However the most significant increases were expressed by the SHEDs that received the DEX treatment. Additionally, the synergistic ability of TGF-beta 3 on the osteogenic differentiation of the stem cells was evaluated. Cells were cultured in a 3-D fibrin gel suspension and allowed to differentiate in DEX osteogenic media with and without the supplementation of TGF-beta 3 for 21 days. Using qPCR the cells were evaluated for expression of Col1, OCN, and ALP. In both the SHEDs and PERIOs, the samples treated with TGF-beta 3 the osteogenic gene expression increased in reference to the control, but had a hindering effect compared to cells treated in DEX without the TGF-beta 3. These results from this study suggested, SHED cells grown in 3-D fibrin gel suspension, may be better than PERIO cells for osteogenic tissue engineering applications when treated with DEX media without the supplementation of TGF-beta 3.