Efficiency analysis of commercial polymeric membranes for bone regeneration in rat cranial defects

Purpose: To evaluate the in vivo efficiency of commercial polymeric membranes for guided bone regeneration. Methods: Rat calvarial critical size defects was treated with LuminaCoat (LC), Surgitime PTFE (SP), GenDerm (GD), Pratix (PR), Techgraft (TG) or control (C-) and histomorphometric analysis determined the percentage of new bone, connective tissue and biomaterial at 1 or 3 months. Statistical analysis used ANOVA with Tukey's post-test for means at same experimental time and the paired Student's t test between the two periods, considering p < 0.05. Results: New bone at 1 month was higher for SP, TG and C-, at 3 months there were no differences, and between 1 and 3 months PR had greater increase growthing. Connective tissue at 1 month was higher for C-, at 3 months for PR, TG and C-, and between 1 and 3 months C- had sharp decline. Biomaterial at 1 month was higher for LC, in 3 months for SP and TG, and between 1 and 3 months, LC, GD and TG had more decreasing mean. Conclusion: SP had greater osteopromotive capacity and limitation of connective ingrowth, but did not exhibit degradation. PR and TG had favorable osteopromotion, LC less connective tissue and GD more accelerated biodegradation.

Five-year outcomes of biodegradable versus second-generation durable polymer drug-eluting stents used in complex percutaneous coronary intervention / 中华医学杂志(英文版)

BACKGROUND@#There are few data comparing clinical outcomes of complex percutaneous coronary intervention (CPCI) when using biodegradable polymer drug-eluting stents (BP-DES) or second-generation durable polymer drug-eluting stents (DP-DES). The purpose of this study was to investigate the safety and efficacy of BP-DES and compare that with DP-DES in patients with and without CPCI during a 5-year follow-up.@*METHODS@#Patients who exclusively underwent BP-DES or DP-DES implantation in 2013 at Fuwai Hospital were consecutively enrolled and stratified into two categories based on CPCI presence or absence. CPCI included at least one of the following features: unprotected left main lesion, ≥2 lesions treated, ≥2 stents implanted, total stent length >40 mm, moderate-to-severe calcified lesion, chronic total occlusion, or bifurcated target lesion. The primary endpoint was major adverse cardiac events (MACE) including all-cause death, recurrent myocardial infarction, and total coronary revascularization (target lesion revascularization, target vessel revascularization [TVR], and non-TVR) during the 5-year follow-up. The secondary endpoint was total coronary revascularization.@*RESULTS@#Among the 7712 patients included, 4882 (63.3%) underwent CPCI. Compared with non-CPCI patients, CPCI patients had higher 2- and 5-year incidences of MACE and total coronary revascularization. Following multivariable adjustment including stent type, CPCI was an independent predictor of MACE (adjusted hazard ratio [aHR]: 1.151; 95% confidence interval [CI]: 1.017-1.303, P  = 0.026) and total coronary revascularization (aHR: 1.199; 95% CI: 1.037-1.388, P  = 0.014) at 5 years. The results were consistent at the 2-year endpoints. In patients with CPCI, BP-DES use was associated with significantly higher MACE rates at 5 years (aHR: 1.256; 95% CI: 1.078-1.462, P  = 0.003) and total coronary revascularization (aHR: 1.257; 95% CI: 1.052-1.502, P  = 0.012) compared with that of DP-DES, but there was a similar risk at 2 years. However, BP-DES had comparable safety and efficacy profiles including MACE and total coronary revascularization compared with DP-DES in patients with non-CPCI at 2 and 5 years.@*CONCLUSIONS@#Patients underwent CPCI remained at a higher risk of mid- to long-term adverse events regardless of the stent type. The effect of BP-DES compared with DP-DES on outcomes was similar in CPCI and non-CPCI patients at 2 years but had inconsistent effects at the 5-year clinical endpoints.

Eletrofiação aplicada a cicatrização de feridas: revisão de literatura / Electrospinning applied to wound healing: literature review / Electroalambre aplicado a la cicatrización de heridas: revisión de la literatura

feridas correspondem a interrupção da continuidade da pele, com a perda de uma ou mais camadas do tecido cutâneo. Curativos tradicionalmente aplicados em feridas cutâneas buscam principalmente fornecer uma barreira de proteção e permitir o desenvolvimento dos eventos celulares e bioquímicos que compreendem a cicatrização. Objetivou-se com este estudo apresentar sob a forma de revisão de literatura narrativa os principais eventos relacionados ao processo de reparo tecidual da pele, bem como abordar a aplicabilidade da técnica de eletrofiação no desenvolvimento de curativos funcionais biocompatíveis. Foram selecionados artigos voltados à caracterização dos eventos chave ocorridos a nível tecidual durante a cicatrização e, na sequência, buscou-se artigos voltados à produção, caracterização e aplicação de filmes nanoeletrofiados com ênfase na utilização de biopolímeros e substâncias bioativas. Observou-se que a maioria dos trabalhos recentes, voltados a pesquisa de base, descrevem a resposta vascular como o principal evento do processo cicatricial, sendo responsável pelas etapas que se desenrolam a seguir, que compreendem as fases inflamatória, proliferativa e de remodelamento, classicamente já descritas. Os curativos funcionais baseados em polímeros eletrofiados apresentam resultados superiores quanto testados in vitro e in vivo. As características morfoestruturais mimetizam a matriz extracelular e podem atuar em tecidos alvo como dispositivos de entrega de substâncias. Conclui-se que a atualização e reorganização de conceitos relativos à cicatrização podem contribuir no desenvolvimento de inovações, como os curativos produzidos por eletrofiação. Embora promissora, as desvantagens da técnica encontram-se principalmente no processo de obtenção e disponibilidade, que limitam a aplicação clínica em escala comercial.

Wounds correspond to the interruption of skin continuity, with the loss of one or more layers of skin tissue. Dressings traditionally applied to cutaneous wounds mainly seek to provide a protective barrier and allow the development of cellular and biochemical events that comprise healing. The objective of this study was to present, in the form of a narrative literature review, the main events related to the skin tissue repair process, as well as to address the applicability of the electrospinning technique in the development of biocompatible functional dressings. Articles focused on the characterization of the key events that occurred at the tissue level during healing were selected and, subsequently, articles focused on the production, characterization and application of nanoelectrospun films with emphasis on the use of biopolymers and bioactive substances were sought. It was observed that most recent works, focused on basic research, describe the vascular response as the main event of the healing process, being responsible for the steps that follow, which include the inflammatory, proliferative and remodeling phases, classically already described. Functional dressings based on electrospun polymers show superior results when tested in vitro and in vivo. The morphostructural features mimic the extracellular matrix and can act in target tissues as substance delivery devices. It is concluded that the updating and reorganization of concepts related to healing can contribute to the development of innovations, such as dressings produced by electrospinning. Although promising, the technique's disadvantages lie mainly in the process of obtaining and availability, which limit clinical application on a commercial scale.

Las heridas corresponden a la interrupción de la continuidad de la piel, con la pérdida de una o más capas de tejido cutáneo. Los apósitos aplicados tradicionalmente a las heridas cutáneas buscan principalmente proporcionar una barrera protectora y permitir el desarrollo de los eventos celulares y bioquímicos que comprenden la curación. El objetivo de este estudio fue presentar en forma de revisión bibliográfica narrativa los principales acontecimientos relacionados con el proceso de reparación tisular de la piel, así como abordar la aplicabilidad de la técnica de electrodeposición en el desarrollo de apósitos funcionales biocompatibles. Se seleccionaron artículos dirigidos a la caracterización de los eventos chave ocurridos a nivel técnico durante la cicatrización y, a continuación, se buscaron artículos dirigidos a la producción, caracterización y aplicación de películas nanoelectrofíricas con énfasis en el uso de biopolímeros y sustancias bioativas. Se observa que la mayoría de los trabajos recientes, realizados en la investigación de base, describen la respuesta vascular como el principal evento del proceso cicatricial, siendo responsable de las etapas que se desarrollan a continuación, que comprenden las fases inflamatoria, proliferativa y de remodelación, clásicamente descritas. Los apósitos funcionales basados en polímeros electro-tejidos presentan resultados superiores cuando se prueban in vitro e in vivo. Las características morfoestruturales mimetizan la matriz extracelular y pueden actuar en tejidos alvos como dispositivos de entrega de sustancias. Se concluye que la actualización y la reorganización de los conceptos relativos a la cicatrización pueden contribuir al desarrollo de innovaciones, como las curativas producidas por la electrofagia. Aunque es prometedora, las desventajas de la técnica radican principalmente en el proceso de obtención y la disponibilidad, que limitan la aplicación clínica a escala comercial.

Stents farmacológicos: estado atual / Drug-eluting stents: state-of-the-art

Stents farmacológicos foram desenvolvidos para reduzir a resposta proliferativa neointimal e consequentemente a reestenose, mais frequente limitação da intervenção coronária percutânea com balão e stents não faramcológicos. O desenvolvimento destes dispositivos baseia-se no maior entendimento da biologia da reestenose, na seleção de fármacos anti-proliferativos adequados para os diversos mecanismos envolvidos nesta complicação e no uso de plataformas/polímeros adequados para entrega do fármaco. Consequentemente o desempenho destes dispositivos depende da perfeita interação de todos estes elementos. As abordagens atuais para minimizar a reestenose são revisados neste capítulo. Embora a primeira geração dos stents farmacológicos tenha sido focada na eficácia em reduzir a reestenose, questões relacionadas à sua segurança surgiram, comprometendo seu uso mais disseminado. As novas gerações de stents farmacológicos com polímeros duráveis ou bioabsorvíveis conseguiu reduzir as taxas de nova intervenção e de trombose. Embora o modelo ideal de stent farmacológico ainda esteja em investigação, é certo que esta tecnologia já se estabeleceu como primeira linha na intervenção coronária percutânea contemporânea

The outcomes of two different bulking agents (dextranomer hyaluronic acid copolymer and polyacrylate-polyalcohol copolymer) in the treatment of primary vesico-ureteral reflux

ABSTRACT Purpose Subureteral injection of bulking agents in the endoscopic treatment of vesicoureteral reflux is widely accepted therapy with high success rates. Although the grade of vesicoureteric reflux and experience of surgeon is the mainstay of this success, the characteristics of augmenting substances may have an effect particularly in the long term. In this retrospective study, we aimed to evaluate the clinical outcomes of the endoscopic treatment of vesicoureteric reflux (VUR) with two different bulking agents: Dextranomer/hyaluronic acid copolymer (Dx/HA) and Polyacrylate polyalcohol copolymer (PPC). Materials and Methods A total 80 patients (49 girls and 31 boys) aged 1-12 years (mean age 5.3 years) underwent endoscopic subureteral injection for correction of VUR last six years. The patients were assigned to two groups: subureteral injections of Dx/HA (45 patients and 57 ureters) and PPC (35 patients and 45 ureters). VUR was grade II in 27 ureters, grade III in 35, grade IV in 22 and grade V in 18 ureters. Results VUR was resolved in 38 (66.6%) of 57 ureters and this equates to VUR correction in 33 (73.3%) of the 45 patients in Dx/HA group. In PPC group, overall success rate was 88.8% (of 40 in 45 ureters). Thus, Thus, this equates to VUR correction in 31 (88.5%) of the 35 patients. Conclusions Our short term data show that two different bulking agent injections provide a high level of reflux resolution and this study revealed that success rate of PPC was significantly higher than Dx/HA with less material.

Resposta vascular após implante de stents liberadores de biolimus A9 compolímero bioabsorvível e stents liberadores de everolimus com polímero durável. Resultados da análise de tomografia de coerência óptica do estudo randomizado BIOACTIVE / Vascular response after implantation of biolimus A9-eluting stent with bioabsorbable polymer and everolimus-eluting stents with durable polymer. Results of the optical coherence tomography analysis of the BIOACTIVE randomized trial

No estudo BIOACTIVE, avaliamos as respostas vasculares após implante do stent eluidor de biolimus A9 (SEB; BioMatrix®) e o stent eluidor de everolimus (SEE; XIENCE V®). Apresentamos a análise detomografia de coerência óptica (OCT) 6 meses pós-intervenção. Métodos: Os pacientes foram randomizados para tratamento com SEB (n = 22) ou SEE (n = 18). O desfecho primário foi a frequência de hastes não cobertas e mal apostas pela OCT. Resultados: A OCT foi realizada em 26 pacientes (SEB: n = 15; SEE: n = 11) e foram analisadas 749 imagens tomográficas e 7.725 hastes de stent. SEB e SEE apresentaram áreas luminais e dos stents semelhantes.A área de hiperplasia neointimal, a espessura neointimal e o porcentual de obstrução intra-stent (8,44 ± 5,10% vs. 9,21 ± 6,36%; p = 0,74) foram similares. As taxas de hastes não cobertas (SEB: 2,10 ± 3,60% vs. SEE: 2,46 ± 2,15%; p = 0,77) e mal apostas (SEB: 0,48 ± 1,48% vs. SEE 0,44 ± 1,05%; p = 0,94) foram baixas e semelhantes. A frequência de frames com sinais compatíveis com infiltrado inflamatório peri-haste foi baixa e similar entre SEB (15,53 ± 20,77%) e SEE (11,70 ± 27,51%; p = 0,68).Conclusões: Stents farmacológicos de segunda geração SEB e SEE se mostraram igualmente eficientes emsuprimir a formação neointimal aos 6 meses, com respostas vasculares favoráveis. A frequência de framescom sinais de infiltrado peri-haste por paciente foi baixa, e menor do que a historicamente observada comos stents farmacológicos de primeira geração...

In BIOACTIVE study, we evaluated vascular responses after the implant of biolimus A9-eluting stent (BES; BioMatrixTM) and the everolimus-eluting stent (EES; XIENCE VTM). In this study, we present the optical coherence tomography analysis (OCT) 6 months post-intervention. Methods: Patients were randomized to treatment with BES (n = 22) or EES (n = 18). The primary outcome was the frequency of non-covered, poorly positioned struts by OCT.Results: OCT was performed in 26 patients (BES: n = 15; EES: n = 11) and 749 tomographic images and 7,725stent struts were analyzed. BES and EES showed similar luminal and stent areas. Neointimal hyperplasia area, neointimal thickness and the percentage of in-stent obstruction (8.44 ± 5.10% vs. 9.21 ± 6.36%; p = 0.74) were similar. The rates of not covered struts (BES: 2.10 ± 3.60% vs. ESS: 2.46 ± 2.15%, p = 0.77) and poorly positioned struts (BES: 0.48 ± 1.48% vs. EES 0.44 ± 1.05%, p = 0.94) were similarly low. The frequency of frames with signs consistent with peri-strut inflammatory infiltrate was low and similar between BES (15.53 ± 20.77%) and EES (11.70 ± 27.51%; p = 0.68). Conclusions: The second-generation drug-eluting stents BES and EES were equally effective at suppressing the neointimal formation after 6 months, with favorable vascular responses. The frequency of frameswith peri-strut infiltrate signals per patient was low, and lower than that observed historically with firstgenerationdrug-eluting stents...

Hard tissue regeneration using bone substitutes: an update on innovations in materials

Bone is a unique organ composed of mineralized hard tissue, unlike any other body part. The unique manner in which bone can constantly undergo self-remodeling has created interesting clinical approaches to the healing of damaged bone. Healing of large bone defects is achieved using implant materials that gradually integrate with the body after healing is completed. Such strategies require a multidisciplinary approach by material scientists, biological scientists, and clinicians. Development of materials for bone healing and exploration of the interactions thereof with the body are active research areas. In this review, we explore ongoing developments in the creation of materials for regenerating hard tissues.

Resultados angiográficos e do seguimento clínico de 5 Anos após implante de stents farmacológicos com revestimento biodegradável em pacientes com alto risco de reestenose: análise de subgrupo do estudo randomizado PAINT / Angiographic and 5-year clinical follow-up after implantation of drug-eluting stents with biodegradable coating in patients at high risk of restenosis: the PAINT randomized trial

Introdução: Polímeros biodegradáveis foram desenvolvidos para reduzir a reação de hipersensibilidade associada aos polímeros duráveis dos stents farmacológicos de primeira geração, mantendo sua eficácia antiproliferativa e aumentado sua segurança. Avaliamos os resultados angiográficos de 9 meses e os resultados clínicos de longo prazo dos stents farmacológicos com polímeros biodegradáveis em pacientes com alto risco de reestenose. Métodos: Pacientes com diâmetro de referência ≤ 2,5 mm, extensão da lesão ≥ 15 mm, diabetes, ou uma combinação dessas características foram selecionados da população do estudo PAINT. Esses pacientes foram previamente randomizados e alocados para intervenção coronária percutânea recebendo os stents farmacológicos com polímeros biodegradáveis com sirolimus ou com paclitaxel ou stents metálicos, na razão 2:2:1. Resultados: Cento e setenta e oito pacientes foram tratados com stents farmacológicos com polímeros biodegradáveis (n = 142) ou stents metálicos (n = 36). No acompanhamento angiográfico de 9 meses, os primeiros mostraram menor perda tardia (0,40 ± 0,42 mm vs. 0,90 ± 0,47 mm; p < 0,01) e reestenose binária (7,4% vs. 25%; p < 0,01). No acompanhamento clínico de 5 anos, o grupo com stents farmacológicos com polímeros biodegradáveis mostrou menores taxas do desfecho combinado de morte cardíaca, infarto do miocárdio e revascularização do vaso-alvo (16,2% vs. 38,0%; p = 0,03), principalmente devido à redução da revascularização do vaso-alvo (9,9% vs. 36,1%; p < 0,01). Morte total, morte cardíaca e infarto do miocárdio não foram diferentes entre os grupos. A trombose do stent, provável ou definitiva, ocorreu em 2,8% vs. 0% (p = 0,30). Conclusões: Os stents farmacológicos com polímeros biodegradáveis eluidores de paclitaxel ou sirolimus foram eficazes na redução de reestenose angiográfica aos 9 meses e na necessidade de reintervenção por reestenose clínica em 5 anos, sem aumentar o risco de...

Background: Biodegradable polymers were developed to reduce the hypersensitivity reaction associated to durable polymers found with the first generation drug-eluting stents, while maintaining antiproliferative efficacy and increasing safety. This study evaluated the 9-month angiographic follow-up and long-term clinical outcomes of biodegradable polymer-coated drug-eluting stents compared with identical platform metallic stents in patients with high-risk for restenosis. Methods: Patients with a reference diameter ≤ 2.5 mm, lesion length ≥ 15 mm, diabetes, or a combination of these characteristics were selected from the population of the PAINT trial. These patients were previously randomized and allocated for percutaneous coronary intervention with either a sirolimus-eluting biodegradable polymer-coated stent, a paclitaxel-eluting biodegradable polymer-coated stent, or an identical metallic platform stent, at a ratio of 2:2:1. Results: One hundred and seventy-eight patients were treated with biodegradable polymer-coated drug-eluting stents (n = 142) or bare metal stents (n = 36). At the 9-month angiographic follow-up, biodegradable polymercoated drug-eluting stents had lower rates of late loss (0.40 ± 0.42 mm vs. 0.90 ± 0.47 mm; p < 0.01) and binary restenosis (7.4% vs. 25%; p <0.01). In the 5-year clinical follow-up, the group with biodegradable polymer-coated drug-eluting stents had lower rates of the composite endpoint of cardiac death, myocardial infarction, and target vessel revascularization (16.2% vs. 38.0%; p = 0.03), especially due to the reduction of target vessel revascularization (9.9% vs. 36.1%; (p 0.01). Total death, cardiac death and myocardial infarction were not different among groups. 0% (p = 0.30). Conclusions: Paclitaxel or sirolimus-eluting biodegradable polymer-coated stents were effective in reducing angiographic restenosis at 9 months and the need of reintervention for clinical restenosis in 5...

Tissue response evaluation of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant

PURPOSE: To evaluate the tissue response of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant. METHODS: A total of 20 male guinea pigs were divided into 2 groups. After paracentesis in both ears, a biodegradable polymer of poly lactic-co-glycolic acid was implanted in only one middle ear. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively). RESULTS: Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2. CONCLUSION: The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant. .

Sistemas de pulido de un o múltiples pasos de resinas compuestas hibridas y su alteración en la estabilidad del color y rugosidad superficial / One and multiple steps polishment system of hybrid resin composites and the color stability and surface roughness

El presente estudio evaluó la rugosidad y pigmentación de dos resinas compuestas nanohíbridas, Tetric EvoCeram (TE) y Ceram X Duo (CD) después del uso de dos técnicas de pulido: de paso único Pogo (P) y múltiples pasos Sof-Lex Discs (S). Sesenta especímenes fueron confeccionados con dimensiones de 7mm x 2mm, subdivididos en grupos (n=10): G1- TE+ P;G2- TE+S; G3- TE control; G4- CD + P;G5- CD + P; G6- CD control. Se realizó la toma de color a través de espectrofotómetro VITA Easyshade y lectura de la rugosidad superficial por el rugosímetro Surf-Corder. Los especímenes fueron inmersos en solución de café soluble por siete días, dejando dos especímenes de cada grupo almacenados en agua destilada durante el periodo del experimento. Después de ese tiempo, se realizó una nueva toma de color de los especímenes y los datos fueron analizados estadísticamente a través del test de Anova y Tukey. Para los dos sistemas de pulido hubo diferencia estadísticamente significante en relación a las dos resinas compuestas (p<0,05). El grupo control presentó superficies más lisas que las demás, mientras que en los especímenes pulidos con sistema Sof-Lex presentaron superficies más lisas que las pulidas con Pogo. Los especímenes pulidos con sistema de "múltiples pasos" obtuvieron valores menores de variación de color (?E*), mientras que las muestras tratadas con tira de poliéster fueron las que más se pigmentaron. Cuando se comparan las dos técnicas de pulido, la técnica de múltiples pasos resultó tener una mayor lisura superficial y menor variación de color.

This study compared two different nanohybrid composite resins, Tetric EvoCam and Ceram X Duo about its roughness and staining, after two polishing techniques, "one step" Pogo and "multiple steps" Sof-Lex Disc. Sixty test-samples were fabricated with dimensions of 7mm x 2mm, divided into groups: (n=10): G1- TE+ P;G2- TE+S; G3- TE control; G4- CD + P;G5- CD + P; G6- CD control. A color check was performed with VITA Easyshade spectrophotometer and a reading of the surface roughness by the Surf-Corder (Kosaka Lab. SE 1700). So, the specimens were immersed in a solution of solved coffee (Nescafe) for seven days, with two specimens of each group stored in distilled water during the study period. After this period, it was performed another color check of the specimens and the data was statistically analyzed by ANOVA and Tukey test. For both polishing systems there was statistically significant differences, on both resin composites (p<0.05). The control group showed smoother surfaces than the others, while that the ones polished with Sof-Lex presented smoother surfaces than the ones polished with the Pogo system. The specimens polished with the "multiple steps" system had lower values of color variation (?E*), while that the specimens treated with polyester strips were the most stained ones. When comparing the two polishing techniques, the technique of "multiples steps" resulted in greater smoothness surface and less color variation.

Combination of poly L-lactic acid nanofiber scaffold with omentum graft for bone healing in experimental defect in tibia of rabbits / Combinação de poli L-ácido láctico nanofibras com enxerto de omento para reparo ósseo em defeito experimental em tíbia de coelhos

PURPOSE: To investigate the osteoconductive properties and biological performance of Poly L-lactic acid (PLLA) with omentum in bone defects. METHODS: PLLA nanofiber scaffolds were prepared via electrospinning technique. Forty four New Zealand white female rabbits randomly divided into three groups of 18 rabbits each. Created defects in right tibias were filled in group I with omentum, in group II with PLLA nanofiber scaffold and in group III with combination of the omentum and PLLA. The same defects were created in left tibia of all groups but did not receive any treatment (control group). Histological and histomorphometric evaluations were performed at two, four and six weeks after the implantation. RESULTS: Histological changes on all groups along with the time course were scored and statistical analysis showed that the average scores in group III were significantly higher than the other groups. CONCLUSION: Histomorphometric analysis of bone healing was shown to be significantly improved by the combined PLLA with omentum compared with the other groups, suggesting this biomaterial promote the healing of cortical bone, presumably by acting as an osteoconductive scaffold.

OBJETIVO: Investigar as propriedades de osteocondução e desempenho biológico do ácido L láctico-Poly (PLLA) com omento em defeitos ósseos. MÉTODOS: Andaimes PLLA nanofibras foram preparados via eletrofiação técnica. Cinquenta e quatro coelhos fêmeas Nova Zelândia brancos foram distribuídos aleatoriamente em três grupos de 18 coelhos cada. Defeitos criados em tíbias direitas foram preenchidos no grupo I com omento, no grupo II com PLLA nanofibras e no grupo III com a combinação do omento e PLLA. Os mesmos defeitos foram criados na tíbia esquerda de todos os grupos, mas não receberam qualquer tratamento (grupo controle). As avaliações histológicas e histomorfométricas foram realizadas em duas, quatro e seis semanas após a implantação. RESULTADOS: As alterações histológicas em todos os grupos, juntamente com o curso de tempo foram marcados e análise estatística mostrou que as pontuações médias do grupo III foram significativamente mais elevadas do que os outros grupos. CONCLUSÃO: Análise histomorfométrica da cicatrização óssea mostrou-se significativamente melhor com o PLLA combinado com omento em comparação com os outros grupos, sugerindo que este biomaterial promove a cicatrização do osso cortical, provavelmente atuando como osteocondutor.

Biocompatibilidade do polímero da mamona comparada ao implante de titânio para corações artificiais: estudo experimental em cobaias / Biocompatibility of Ricinus comunnis polymer compared to titanium implant used in artificial hearts: experimental study in guinea pigs

OBJETIVO: Determinar se a reação tecidual do implante retroperitoneal do polímero de óleo de mamona (Pm) é significativa ou não por meio de análise histopatológica, tendo como controle o implante de titânio (Ti). MÉTODOS: Estudo experimental, intervencionista e randomizado com 32 cobaias. Os animais foram divididos em quatro grupos iguais e eutanasiados com 7, 20, 30 e 40 dias após o ato cirúrgico. Foram confeccionadas lâminas em hematoxilina-eosina e em tricrômio de Masson. Na comparação dos tipos de material em relação a variáveis quantitativas, foi considerado o teste não-paramétrico de Wilcoxon. Em relação a essas variáveis, os grupos definidos pelo dia do sacrifício foram comparados usando-se o teste não-paramétrico de Kruskal-Wallis. Os resultados obtidos no estudo da fibrose foram expressos por frequências e percentuais. Para a comparação entre os grupos definidos pelo dia do sacrifício, em relação a variáveis qualitativas dicotômicas da fibrose, foi considerado o teste exato de Fisher. Para avaliar a diferença entre os materiais titânio e polímero em cada grupo, ainda em se tratando da fibrose, foi considerado o teste binomial. Valores de P<0,05 indicaram significância estatística. RESULTADOS: A análise das variáveis quantitativas não demonstrou diferença nas reações teciduais entre os materiais (P>0,05). A análise da variável qualitativa também não demonstrou diferença entre as reações teciduais dos materiais (P>0,05). CONCLUSÃO: Não foi encontrada significância estatística entre a reação tecidual do Pm e do Ti.

OBJECTIVE: The aim of the present investigation is to determine if the tissue reaction to the Riccinus communis (mamona) polymer has significant statistical difference compared to the tissue reaction provoked by the titanium implant. METHODS: Thirty two Cavia porcellus were divided into four groups containing eight animals each one. We implanted the two types of materials in the retroperitoneal space of all the animals. They were sacrificed at 7, 20, 30 and 40 days after surgery and the samples were submitted to histological study. RESULTS: The quantitative analysis did not show difference between the tissue reaction of the two materials (P>0.05). The analysis of the qualitative variable also did not show difference between the tissue reaction of the materials (P>0.05). CONCLUSION: Macroscopic and microscopic results showed that the castor oil polymer implant has no significant statistical difference compared to the titanium implant tissue reaction.

The use of vancomycin-loaded poly-l-lactic acid and poly-ethylene oxide microspheres for bone repair: an in vivo study

OBJECTIVE: The aim of this study was to investigate bone repair after the implantation of vancomycin-loaded poly-L-lactic acid/poly-ethylene oxide microspheres compared with vancomycin-unloaded poly-L-lactic acid/poly-ethylene oxide microspheres. METHODS: Poly-L-lactic acid/poly-ethylene oxide microspheres were implanted in rat tibiae and evaluated for periods of 2, 4, 8, and 12 days and 4, 8, 16, and 32 weeks. The groups implanted with vancomycin-loaded and vancomycin-unloaded microspheres were compared. Histopathologic (semi-quantitative) and histomorphometric analyses were performed to evaluate the bone formation process. RESULTS: During the first period (second day), fibrin and hemorrhaging areas were observed to be replaced by granulation tissue around the microspheres. Woven bone formation with progressive maturation was observed. All of the histopathological findings, evaluated by a semi-quantitative assay and a quantitative analysis (percentage of bone formation), were similar between the two groups. CONCLUSION: Vancomycin-loaded poly-L-lactic acid/poly-ethylene oxide microspheres are a good bone substitute candidate for bone repair. Local antibiotic therapy using vancomycin-loaded poly-L-lactic acid/poly-ethylene oxide microspheres should be considered after the microbiological evaluation of its efficacy.

FisiograftTM as a bone material in the treatment of periodontal vertical defects and its clinical and radiological evaluation: clinical study / FisiograftTM como material de enxerto ósseo no tratamento de defeitos periodontais verticais e sua avaliação clínica e radiográfica: um estudo clínico

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.

Resultados de los estudios experimentales y evolución clínica en la cirugía reconstructiva con polímero osteointegrable / Results of experimental studies and clinical evolution in reconstructive surgery with osseointegrated polymer

Introducción: Los sustitutos óseos son todos aquellos materiales elaborados. Se comercializan en diversas formas y han demostrado gran eficacia en diversos tipos de reconstrucción. Materiales y métodos: En el período comprendido entre marzo de 2003 y marzo de 2010 se realizaron 28 intervenciones quirúrgicas (17 mujeres y 11 varones) sobre la articulación de la cadera. En 26 casos fueron cirugías de revisión y sólo dos, artroplastias primarias. La edad promedio en el momento de la cirugía fue de 62,6 años (rango 52 a 88). Resultados: Los resultados se clasificaron en clínicoradiológicos y experimentales debiendo diferenciar distintos parámetros, a saber: la resistencia de carga a la compresión en diseños de cotilos, en fémures cadavéricos y en cotilos recuperados; imágenes de microscopia electrónica y el comportamiento volumétrico al final de su fase de expansión. Los resultados clínico-radiológicos se observaron a través de sus ventajas en la rehabilitación, la recuperación funcional, la ausencia de dolor, la osteointegración a lo largo del tiempo y la ausencia de subsidencias o migración de los implantes. Conclusiones: Como en el caso de todas las experiencias en medicina, este es el comienzo de nuevas técnicas que hasta el momento han servido para resolver problemas difíciles, de forma más rápida, práctica y segura.

Background: bone substitutes are man-made materials. They are supplied in various forms and have proven their effectiveness in different reconstruction types. Methods: From March 2003 to March 2010 twenty eight (17 females and 11 males) surgical interventions were performed on the hip joint. 26 cases were revision surgery and only 2 were primary arthroplasties. Average age at the time of surgery was 62.6 years (range 52-88). Results: The results were classified in clinical-radiological and experimental; different parameters were considered: resistance to compression in acetabular designs, cadaver femurs, and recovered acetabuli. Electron microscopy images were obtained and the volumetric behavior at the end of the expansion phase was measured. Clinical-radiological results were rated according to their advantages in the rehabilitation, functional recovery, absence of pain, osteointegration in time, and absence of implant subsidence or migration. Conclusions: As with all experiences in medicine, this is the beginning of new techniques that have served so far to solve difficult problems in a faster, safer and more practical manner.

Orthopaedic applications of bone graft & graft substitutes: a review.

Treatment of delayed union, malunion, and nonunion is a challenge to the orthopaedic surgeons in veterinary and human fields. Apart from restoration of alignment and stable fixation, in many cases adjunctive measures such as bone-grafting or use of bone-graft substitutes are of paramount importance. Bone-graft materials usually have one or more components: an osteoconductive matrix, which acts as scaffold to new bone growth; osteoinductive proteins, which support mitogenesis of undifferentiated cells; and osteogenic cells, which are capable of forming bone in the appropriate environment. Autologous bone remains the “gold standard” for stimulating bone repair and regeneration, but its availability may be limited and the procedure to harvest the material is associated with complications. Bone-graft substitutes can either substitute autologous bone graft or expand an existing amount of autologous bone graft. We review the currently available bone graft and graft substitutes for the novel therapeutic approaches in clinical setting of orthopaedic surgery.

Diarrea por clostridium difficile / Clostridium difficile-associated diarrhea

Clostridium difficile (CD), es un bacilo gram positivo, anaerobio formador de esporas identificado como la principal causa de diarrea asociado al uso de antibióticos en pacientes hospitalizados. Los dos factores de riesgo más importantes para adquirir esta infección son el uso reciente de terapia antimicrobiana y la exposición al microorganismo productor de toxinas. La epidemiología de la enfermedad asociada a Clostridium difficile (EACD) ha cambiado sustancialmente en la última década, con un incremento sostenido en la incidencia y aparición de casos más severos, refractarios y recurrentes. La EACD abarca un amplio espectro de manifestaciones clínicas, que van de la portación asintomática, pasando por un cuadro de diarrea leve, hasta el desarrollo de colitis fulminante con una elevada tasa de mortalidad. El tratamiento antibiótico estándar es el metronidazol y vancomicina oral, con tasas de respuesta cercanas a un 95 por ciento por ; sin embargo, luego de la aparición de cepas “hipervirulentas” en el año 2003, la tasa de respuesta al metronidazol ha disminuido en forma significativa. Por ello, en los últimos años, se han comunicado una serie de estrategias y estudios con nuevos antimicrobianos con resultados alentadores. La terapia inmunológica pareciera tener un rol importante en la prevención de recurrencias así como en el manejo de pacientes con enfermedad severa. Se revisan aquellos aspectos más importantes relacionados con la infección asociada a CD.

Clostridium difficile (CD) is an anaerobic, gram-positive, spore-forming, toxin-producing bacillus. This is the leading cause of nosocomial diarrhea associated with antibiotic therapy in hospitalized patients. The two major risk factors for C. Difficile associated disease (CDAD) are recent exposure to an antibiotic and exposure to a toxin producing strain of the microorganism. Epidemiology of CDAD has changed substantially in the last decade, with an increase of incidence and occurrence of more severe, refractory and recurrent episodes. CDAD clinical spectrum varies from asymptomatic carriers, going from mild diarrhea to fulminant colitis with a high mortality rate. The standard antibiotic treatment is oral metronidazole and vancomycin, with response rates close to 90 percent, but after the appearance of “hypervirulent” strains in 2003, the response rate has decreased significantly. Therefore, in recent years many trials have reported a series of strategies and studies with new antimicrobial agents with promising results. Immunotherapy appears to play an important role in preventing recurrence and in the management of patients with a severe disease. The present article will review the most important aspects related to the infection associated with CD.

Uso de viscoelásticos na facoemulsificação em cães portadores de catarata: efeitos sobre a pressão intraocular, a morfologia das células endoteliais e a espessura corneana / Use of viscoelastic substances for the phacoemulsification in dogs with cataract: effects on the intraocular pressure, morphology of endothelial cells, and corneal thickness

Avaliaram-se as células endoteliais, a espessura corneana e a pressão intraocular (PIO) de cães portadores de catarata madura, empregando-se viscoelástico à base de hialuronato de sódio 3 por cento e sulfato de condroitina 4 por cento e hidroxipropilmetilcelulose 2 por cento, utilizando-se 20 cães, distribuídos entre os dois grupos dos viscoelásticos. A técnica cirúrgica adotada foi a da facoemulsificação bimanual. As avaliações tonométricas foram efetuadas antes e após o ato cirúrgico, aos 1, 7, 14, 21, 28 e 60 dias de pós-operatório, e a microscopia especular, antes e após 7, 28 e 60 dias. Não houve diferença estatística entre os grupos quanto à PIO, com exceção aos 14 dias, em que se observou maior PIO com o uso de hialuronato de sódio 3 por cento e sulfato de condroitina 4 por cento. Não houve diferença entre os grupos quanto aos parâmetros relacionados ao endotélio, com diminuição discreta da densidade celular endotelial e aumento da área celular com a utilização de hidroxipropilmetilcelulose 2 por cento. A utilização de ambos os dispositivos viscoelásticos analisados é recomendada para o procedimento de facoemulsificação em cães.

The endothelial cells, the corneal thickness, and the intraocular pressure (IOP) were evaluated in dogs with cataract, using viscoelastic substances based on 3 percent sodium hyaluronate and 4 percent chondroitin sulfate and comparing them with 2 percent hydroxypropylmethylcellulose. Twenty dogs were distributed in two groups of ten, each using one viscoelastic material. The surgical technique was bimanual phacoemulsification. The tonometric evaluations were made before and at one, seven, 14, 21, 28, and 60 days after the surgery and the specular microscopy before and after seven, 28, and 60 days. No statistical difference between groups was found according to IOP, except at 14 days, which was significantly higher with the use of 3 percent sodium hyaluronate and 4 percent chondroitin sulfate. There was no statistical difference between the groups considering the parameters related to the endothelium, with slight decrease in endothelial cell density and increase of cell area with the use of 2 percent hydroxypropylmethylcellulose. The use of both viscoelastic devices is recommended for the phacoemulsification in dogs.