Research Advances in Medical Materials and Products for Soft Tissue Repairs / 中国医疗器械杂志

Soft tissue is an indispensable tissue in human body. It plays an important role in protecting the body from external physical, chemical or biological factors. Mild soft tissue injuries can self-heal, while severe soft tissue injuries may require related treatment. Natural polymers (such as chitosan, hyaluronic acid, and collagen) and synthetic polymers (such as polyethylene glycol and polylactic acid) exhibit good biocompatibility, biodegradability and low toxicity. It can be used for soft tissue repairs for antibacterial, hemostatic and wound healing purposes. Their related properties can be enhanced through modification or preparation of composite materials. Commonly used soft tissue repairs include wound dressings, biological patches, medical tissue adhesives, and tissue engineering scaffolds. This study introduces the properties, mechanisms of action and applications of various soft tissue repair medical materials, including chitosan, hyaluronic acid, collagen, polyethylene glycol and polylactic acid, and provides an outlook on the application prospects of soft tissue repair medical materials and products.

Difference of Chemical Bonds Between UDMA Bonding Agents with Ethanol Solvent and Acetone Solvent on Dentin Collagen

ABSTRACT Objective: To investigate the difference of chemical bonds between urethane dimethacrylate (UDMA) bonding agents with ethanol solvent and acetone solvent on dentin collagen. Material and Methods: This experimental comparison study used three groups: G1 (Control): UDMA and collagen; G2: UDMA, collagen and ethanol; and G3: UDMA, collagen and acetone. The groups were then pelleted and analysed with FTIR, then the peak value of carbonyl absorption band from each study group was calculated. The result of FTIR analysis and the peak of carbonyl absorption band (P) was calculated using the formula: P = (BC / AB) X 100; AB. BC is measured in centimeters. The study of chemical bond differences between ethanol-solvent UDMA agents compared with acetone-solvent on dentin collagen resulted in a graph of peak of carbonyl absorption bands of UDMA and dentin collagen groups. To determine the chemical bonds of UDMA from the top of the carbonyl ester absorption bands with wavenumber absorption in range 1700-1750 cm-1, the decreasing peak of the carbonyl absorption bands is assumed as more chemical bonds that formed. Data were analysed using Anova one way and Tukey HSD test. Results: There were significant differences between the three study groups (p<0.05). Conclusion: UDMA bonding agents' chemical bonds with acetone solvent are much higher than the chemical bonds between UDMA bonding agents with ethanol solvent on dentin collagen.

Collagen as a source of bioactive peptides: a bioinformatics approach

BACKGROUND: Collagen is the most abundant protein in animals and can be obtained from residues of the food industry. Its hydrolysate has many desirable properties that make it suitable as an additive in foods and cosmetics, or as a component of scaffold materials to be used in biomedicine. RESULTS: We report here the characterization of type I collagen from five different sources, namely bovine, porcine, chicken, trout and salmon, as well as their hydrolysates by means of bioinformatics tools. As expected, the results showed that bovine and porcine collagen, as well as trout and salmon collagen, can be used interchangeably due to their high identity. This result is consistent with the evolution of proteins with highly identical sequences between related species. Also, 156 sequences were found as potential bioactive peptides, 126 from propeptide region and 30 from the central domain, according to the comparison with reported active sequences. CONCLUSIONS: Collagen analysis from a bioinformatic approach allowed us to classify collagen from 5 different animal sources, to establish its interchangeability as potential additive in diverse fields and also to determine the content of bioactive peptides from its in silico hydrolysis.

Efeito Biomodificador de Diferentes Agentes de Ligações Cruzadas nas Propriedades Mecânicas do Colágeno Dentinário / Biomodifying Effect of Different Cross-Linking Agents on the Mechanical Properties of Dentin Collagen

Objetivo: avaliar o efeito biomodificador dos agentes de ligações cruzadas nas propriedades mecânicas do colágeno dentinário. Material e Métodos: Trata-se de um estudo laboratorial in vitro, nos quais foram confeccionadas 18 barras de dentina a partir de terceiros molares humanos extraídos e livres de cárie. Os espécimes foram desmineralizados em ácido fosfórico a 10%, por 5 horas, distribuídos aleatoriamente nos grupos distintos e mantidos em suas respectivas soluções de pré-tratamento: água destilada (AD), Proantocianidina a 6,5% (PAC6,5) e Cardanol a 6,5% (CAR6,5) por períodos de 1 hora. Foram realizados os testes de flexão de três pontos para obtenção do módulo de elasticidade (ME) e modificação de massa (MM). Foram submetidos ao teste de Kolmogorov-Smirnoff seguido, do teste de ANOVA à um critério e pós teste de Tukey para a MM, e Dunns para diferença de ME (p<0,05). Resultados: Os valores obtidos no ME mostraram mudanças estatísticas notáveis em todos os grupos testados, quando comparados ao controle negativo (p<0,001), assim como na variação de massa foram encontradas diferenças estatísticas nos valores médios entre os grupos testados (p=0,012). Conclusão: o uso da PAC6,5 irá melhorar as propriedades mecânicas do colágeno

Objective: to evaluate the biomodifying effect of cross-linking agents on the mechanical properties of the teeth. Material and Methods: this is an in vitro laboratory study, in which 18 bars of dentin were made from extracted, caries-free human third molars. The samples were demineralized in 10% phosphoric acid for 5 hours, randomly distributed in different groups and kept in their pre-treatment solutions: distilled water (AD), Proanthocyanidin at 6.5% (PAC6.5) and Cardanol at 6.5% (CAR6.5) for periods of 1 hour. Three-point bending tests were performed to obtain the modulus of elasticity (ME) and mass modification (MM). They were submitted to the Kolmogorov-Smirnoff test followed by the Kruskal-Wallis' test and the Tukey's post-test for mass modification, and Kruskal-Wallis' test after a Dunn's test for difference in the modulus of elasticity(p <0.05). Results: the values selected in the ME show possible statistical changes in all groups tested, when compared to the negative control (p<0.001), as well as the mass variation. Data were shown in the average values between the groups tested (p = 0.012). Conclusion: The use of PAC6.5 will improve the mechanical properties of the collection

Biochemical and Utralmicroscopic Evaluation of Myofibril Proteins and Collagen during Ageing in Broiler Chicken PSE (Pale, Sof, Exudative) Meat

Abstract The aim of this work was to study the myofibril proteins and collagen fraction changes in broiler chickens PSE (pale, soft, exudative) meat during ageing and their relationship to meat quality. The results presented an increase of myofibril proteins and collagen solubility promoted by the enhanced proteases activities during storage. Ultramicroscopically, the PSE meat samples revealed intracellularly a sarcomere super contraction and lacunas within the A and I bands while Z-lines appeared very dense and fragmented in comparison to normal samples. This observation was noticed already at 4h storage while extracellularly collagen fibrils decreased visually within the endomysium only after 24h of conditioning. These results influenced the quality as the PSE meat presented better functional properties at the first hours of conditioning before further proteins degradation by proteases. Thereafter, at the later ageing stage a further disintegration of the abnormal meat structure would affect the meat functional properties.

Morphological observation of bone marrow mesenchymal stem cells under matrigel three dimensional culture conditions / Observación morfológica de células madre mesenquimales de médula ósea en condiciones de cultivo tridimensional con matrigel

SUMMARY: Matrigel is a basement membrane matrix extracted from the EHS mouse tumor containing extracellular matrix protein, its main components are laminin, type IV collagen, nestin, heparin sulfate, growth factor and matrix metalloproteinase.At room temperature, Matrigel polymerized to form a three dimensional matrix with biological activity. It can simulate the structure, composition, physical properties and functions of the cell basement membrane in vivo, which is beneficial to the culture and differentiation of the cells in vitro, and can be used for the study of cell morphology, biochemical function, migration, infection and gene expression. In this study, Matrigel three-dimensional culture model of bone marrow mesenchymal stem cells(BMSCs) was established, and its morphology, proliferation and survival were observed. BMSCs were isolated and cultured with whole bone marrow adherence method. The Second generation BMSCs with good growth condition were selected and mixed with Matrigel to form cell gel complexes. The morphology and proliferation of mesenchymal stem cells were observed by phase contrast microscope and HE staining,Live/Dead staining was used to evaluate the cell activity.Phase contrast microscopy showed that BMSCs were reticulated in Matrigel and proliferated well, After 7 days, the matrix gel gradually became soft and collapsed, a few cell reticular crosslinking growth was seen at 14 days; HE staining showed that the cytoplasm of the cells was larger on the fourth day and the cells were elongated and cross-linked on the seventh day; Live/dead staining showed that most cells showed green fluorescence with the prolongation of culture time, on the first, 4 and 7 days, the activity of bone marrow mesenchymal stem cells in Matrigel gradually increased, and the percentages were 92.57 %, 95.54 % and 97.37 %, respectively. Matrigel three-dimensional culture system can maintain the morphology, function and proliferation ability of bone marrow mesenchymal stem cells.

RESUMEN: Matrigel es una matriz de membrana basal extraída del tumor de ratón EHS que contiene proteína de matriz extracelular. Los componentes principales son laminina, el colágeno tipo IV, nestina, sulfato de heparina, factor de crecimiento y metaloproteinasa de matriz. A temperatura ambiente, Matrigel se polimerizó para formar una matriz tridimensional. Es posible simular la estructura, la composición, las propiedades físicas y las funciones de la membrana basal celular in vivo, lo que es beneficioso para el cultivo y la diferenciación de las células in vitro, y se puede utilizar para el estudio de la morfología celular, la función bioquímica, la migración, infección y expresión génica. En este estudio, se estableció el modelo de cultivo tridimensional Matrigel de células madre mesenquimales de médula ósea (BMSC), y se observó su morfología, proliferación y supervivencia. Las BMSC fueron aisladas y cultivadas con el método de adherencia de la médula ósea completa. Se seleccionaron las BMSC de segunda generación con buenas condiciones de crecimiento y se mezclaron con Matrigel para formar complejos de gel de células. La morfología y la proliferación de las células madre mesenquimales se observaron con microscopio de contraste de fase y se tiñó con Hematoxilina-Eosina (HE); para evaluar la actividad celular se usó la tinción Live/Dead. La microscopía de contraste mostró que las BMSC se reticularon en Matrigel y proliferaron bien. Después de 7 días, se observó que el gel de matriz gradualmente se volvió blando y colapsó, y se visualizó un cruce transversal de algunas células reticulares a los 14 días. La tinción mostró que la mayoría de las células mostraron una fluorescencia verde con la prolongación del tiempo de cultivo; en los primeros 4 y 7 días, la actividad de las células madre mesenquimales de la médula ósea en Matrigel aumentó gradualmente y los porcentajes fueron de 92,57 %, 95,54 % y 97,37 %, respectivamente. El sistema de cultivo tridimensional de Matrigel puede mantener la morfología, la función y la capacidad de proliferación de las células madre mesenquimales de la médula ósea.

Influence of ethanol-wet dentin, adhesive mode of application, and aging on bond strength of universal adhesive

Abstract The aim of this study was to evaluate the effect of ethanol on the bond longevity of a universal adhesive system to bovine dentin, under different modes of adhesive application and artificial aging. Bovine dentin was exposed, and the smear layer was standardized by sandpaper polishing. Specimens were randomly divided into 2 groups: ethanol (E) and non-ethanol (N). Groups were subdivided according to adhesive mode of application into etch-and-rinse (Er) and self-etching (S). Resin blocks were built onto the treated surface, and the specimens were stored in deionized water at 37°C for 48 h. Half of the specimens (n = 10) were subjected to thermomechanical aging (A for aged and Na for non-aged). Resin/dentin beams were obtained and subjected to microtensile test in a universal testing machine. Data were analyzed using a three-way ANOVA and Tukey's tests (α = 5%). There was interaction among the three factors (p=0.0003). The use of ethanol resulted in higher values, except for the Er and Na groups (E_Er_Na = N_Er_Na). The mode of application was similar, except for the N and A groups (N_S_A > N_Er_A). For the A groups, the values were lower, except in the cases using ethanol, in which the results were not affected. The study concluded that the use of ethanol resulted in higher microtensile bond strength values, even after aging. The mode of adhesive application did not influence the results.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

Abstract Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Resumo Biomateriais inovadores podem fornecer uma promissora nova direção para o tratamento de defeitos ósseos, estimulando um processo de reparo adequado, sem danos aos tecidos adjacentes. O objetivo deste estudo in vivo foi avaliar a biocompatibilidade e a capacidade osteoindutora de uma biomembrana e um scaffold compostos por colágeno e quitosana, contendo cimento de aluminato de cálcio. Dezoito coelhos (New Zealand White, Oryctolagus cuniculus) foram distribuídos de acordo com os períodos experimentais de análise (7, 15 e 30 dias). Quatro defeitos foram criados na calvaria dos coelhos, que foram individualmente preenchidos com a biomembrana, scaffold, coágulo (controle negativo) e osso autólogo (controle positivo). A avaliação histopatológica foi realizada em microscópio óptico em aumentos de 32´, 64´, 125´ e 320´. A resposta celular à inflamação e à formação de novo tecido ósseo foi quantificada utilizando um sistema de escore. O grupo da biomembrana apresentou maior resposta inflamatória no período de 15 dias, com diferença significativa para o grupo do osso autólogo (p<0,05). Não houve diferença estatística significante para a reação do tipo corpo estranho entre os grupos (p>0,05). Em relação à neoformação óssea, observou-se fechamento linear da área do defeito, que foi mais evidente no grupo em que se utilizou o osso autólogo. O grupo scaffold apresentou resultados semelhantes ao grupo do osso autólogo no período de 30 dias (p>0,05). Ambos os biomateriais testados apresentaram biocompatibilidade similar em comparação com os grupos controle. Além disso, a biomembrana e o scaffold apresentaram capacidade osteoindutora similar, estimulando o reparo ósseo ao longo dos intervalos de tempo experimentais.

Collagenolytic enzymes produced by fungi: a systematic review

Abstract Specific proteases capable of degrading native triple helical or denatured collagen have been required for many years and have a large spectrum of applications. There are few complete reports that fully uncover production, characterization and purification of fungi collagenases. In this review, authors searched through four scientific on line data bases using the following keywords (collagenolytic OR collagenase) AND (fungi OR fungus OR fungal) AND (production OR synthesis OR synthesize) AND (characterization). Scientific criteria were adopted in this review to classify found articles by score (from 0 to 10). After exclusion criteria, 21 articles were selected. None obtained the maximum of 10 points defined by the methodology, which indicates a deficiency in studies dealing simultaneously with production, characterization and purification of collagenase by fungi. Among microorganisms studied the non-pathogenic fungi Penicillium aurantiogriseum and Rhizoctonia solani stood out in volumetric and specific collagenase activity. The only article found that made sequencing of a true collagenase showed 100% homology with several metalloproteinases fungi. A clear gap in literature about collagenase production by fungi was verified, which prevents further development in the area and increases the need for further studies, particularly full characterization of fungal collagenases with high specificity to collagen.

High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

ABSTRACT Objective To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats. Method Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification. Results No significant difference was observed among the groups regarding collagen realignment (types I or III collagen) or quantity of blood vessels. Conclusion High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats.

Chitosan-collagen biomembrane embedded with calcium-aluminate enhances dentinogenic potential of pulp cells

Abstract The development of biomaterials capable of driving dental pulp stem cell differentiation into odontoblast-like cells able to secrete reparative dentin is the goal of current conservative dentistry. In the present investigation, a biomembrane (BM) composed of a chitosan/collagen matrix embedded with calcium-aluminate microparticles was tested. The BM was produced by mixing collagen gel with a chitosan solution (2:1), and then adding bioactive calcium-aluminate cement as the mineral phase. An inert material (polystyrene) was used as the negative control. Human dental pulp cells were seeded onto the surface of certain materials, and the cytocompatibility was evaluated by cell proliferation and cell morphology, assessed after 1, 7, 14 and 28 days in culture. The odontoblastic differentiation was evaluated by measuring alkaline phosphatase (ALP) activity, total protein production, gene expression of DMP-1/DSPP and mineralized nodule deposition. The pulp cells were able to attach onto the BM surface and spread, displaying a faster proliferative rate at initial periods than that of the control cells. The BM also acted on the cells to induce more intense ALP activity, protein production at 14 days, and higher gene expression of DSPP and DMP-1 at 28 days, leading to the deposition of about five times more mineralized matrix than the cells in the control group. Therefore, the experimental biomembrane induced the differentiation of pulp cells into odontoblast-like cells featuring a highly secretory phenotype. This innovative bioactive material can drive other protocols for dental pulp exposure treatment by inducing the regeneration of dentin tissue mediated by resident cells.

Estimation of the use of fibrin and collagen membranes as carriers for platelet-derived growth factor-BB (PDGF-BB) in the presence of amoxicillin.

The effect of homogeneous fibrin (Fb), collagen (Coll) and composite fibrin-heparin (Fb-Hp), fibrin-collagen (Fb-Coll) membranes on in vitro release of platelet-derived growth factor (PDGF-BB) was evaluated in the presence or absence of amoxicillin using of the ELISA immunoassay test. Amoxicillin concentration was determined spectrophotometrically at 272 nm. The process of the PDGF-BB growth factor and amoxicillin release from the studied membranes was of a two-phase nature in the majority of the systems analysed. The PDGF-BB was released in the highest amount from the Coll membrane (M7) without the presence of amoxicillin – 546.2 ±7.47 pg, t0.5 = 0.88 h and 202.5 ± 6.83 pg, t0.5 = 26.65 h during the first phase and second phase, respectively. The lowest PDGF-BB release was observed from composite M4 (Fb-Hp) membrane – 5.88 ± 0.81 pg, t0.5 = 1.69 h; and 110.2 ± 6.48 pg, t0.5 = 855.6 h during first and second phase respectively. An optimal release of amoxicillin was observed in the case of the composite M6 (Fb-Coll) membrane – only in the second phase: 64.2 ± 7.8 mg, t0.5 = 83.5 h. The lowest and delayed amoxicillin release was achieved for M4 membrane (approx. 17.1 ± 1.12 mg, t0.5 = 46.5 h). The results of the PDGF-BB release and amoxicillin from membranes indicated a correlation between the level of release and composition of the film. Our results suggested that fibrin and collagen membranes may be beneficial to enhance periodontal bone regeneration.

Efeito do cranberry e seus componentes sobre a dentina submetida à erosão / Effect of cranberry on dentin erosion challenge

Existem indícios de que o Cranberry e a Proantocianidina (polifenol desta fruta) tenham potencial para inibir as metaloproteinases da matriz (MMPs) que degradam o colágeno dentinário, porém estes agentes não foram adequadamente avaliados em estudos sobre erosão dentária. Assim, o objetivo desta tese será avaliar o papel do extrato de Cranberry e do seu principal agente ativo isolado (proantocianidina) aplicados na forma de gel tópico na inibição da degradação da matriz orgânica da dentina desmineralizada e consequentemente na minimização do desgaste da dentina submetida à erosão. Para isso, foram realizados 3 trabalhos buscando avaliar os seguintes objetivos específicos: Artigo 1- Verificar se diferentes concentrações de géis a base de extrato de Cranberry e de Proantocianidina apresentam papel inibitório do desgaste de espécimes dentinários submetidos à erosão in vitro, tendo como controles um grupo placebo e a clorexidina; Artigo 2- Avaliar o possível efeito protetor in situ de um gel de Cranberry aplicado à dentina submetida a ciclagem erosiva, quando comparados a grupos placebo e clorexidina; Artigo 3- Avaliar o efeito de diferentes concentrações de géis de Proantocianidina, aplicados por diferentes tempos de aplicação na minimização do desgaste da dentina exposta a desafios erosivos in vitro. Os resultados desta tese mostraram que os géis experimentais testados tiveram efeitos superiores aos grupos placebos e semelhantes ao controle positivo (clorexidina) na minimização do desgaste da dentina submetida à erosão. Além disso, nas concentrações avaliadas, não foi possível encontrar uma relação dose e tempo de aplicação/ resposta na prevenção da erosão. Assim, considerando os resultados apresentados na presente tese pôde- se concluir de forma geral que os géis de Cranberry e Proantocianidina foram efetivos na diminuição do desgaste dentário quando a dentina é exposta a desafio erosivo.(AU)

There are indications that the Cranberry and Proanthocyanidin (this fruit's polyphenol) have the potential to inhibit matrix metalloproteinases (MMPs) that degrade collagen from dentin, however these agents have not been adequately evaluated in studies of dental erosion. Thus, the aim of this thesis was to evaluate the role of Cranberry extract and its isolated main active agent (proanthocyanidin) applied as topical gel in the inhibition of organic matrix degradation and thus minimizing wear of dentin subjected to erosion. For that, three studies were conducted to assess the following specific objectives: Paper 1- Evaluate different gel concentrations of Cranberry extract and Proanthocyanidin on diminishing dentin erosion progression in vitro, having as control a placebo group and chlorhexidine; Paper 2- Evaluate the possible protective in situ effect of a Cranberry gel applied to dentin subjected to erosive cycling, when compared to placebo groups and chlorhexidine, Paper 3- Evaluate the effect of different concentrations of proanthocyanidin gels, applied by different application times in minimizing the wear of dentin exposed to erosive challenge in vitro. The results of this thesis showed that the tested experimental gels had greater effect than placebos groups and similar to the positive control (chlorhexidine) in minimizing the wear of dentin subjected to erosion. Furthermore, in the concentrations evaluated, it was not possible to find a dose and time of application / response in the prevention of erosion. Thus, considering the results presented in this thesis, it could be concluded that in general the gels of Cranberry and Proanthocyanidin were effective in decreasing the tooth wear when the dentin was exposed to erosive challenge.(AU)

Bioassay-guided evaluation of wound healing effect of fatty acids-incorporated collagen-based films

PURPOSE: To evaluate the effects of fatty acids-incorporated collagen-based dressing films on wound healing in rodents. METHODS: Therefore, surgical wounds were performed in the back of 80 Wistar rats, and dressed with collgane-based films (COL), and collagen-based films containing fatty acids (AGEF50 and AGEF100). Undressed wounds were regarded as controls (CTR). The animals were euthanized after three, seven, 14 and 21 days, and the macroscopic wound contraction rates (WRC) were assessed. The wounded area was also analyzed by conventional and polarized light microscope. RESULTS: No sign of abscess or hypertrophic scar formation was observed in none of the groups. At seven days, the WRR of AGEF50 was significantly higher than CTR (p<0.01), whereas at 14 days, both AGE 50 and AGE100 showed a significant increase of the WRR compared to CTR (p<0.001) and COL (p<0.01). Both films promoted increased influx of neutrophils at three days (p<0.01), but reduced significantly the mononuclear infiltrate at 14 days (p<0.05). It was also observed earlier maturation of the granulation tissue, full epithelization and cutaneous appendages development, as well as better collagenization, in AGEF50 and AGEF100. CONCLUSION: The application of AGEF50/100 as wound dressing improved wound healing in rodents.

Topical estradiol does not interfere with the expression of the metalloproteinase-1 enzyme in photo exposed skin cells / Estradiol tópico não interfere na expressão da enzima metaloproteinase-1 em células da pele fotoexposta

BACKGROUND: In postmenopausal women there is a rapid destruction of dermal collagen, resulting in accelerated skin ageing, which is manifested by cutaneous atrophy, increased number and depth of wrinkles and sagging. This accelerated catabolism of the collagen is due to estrogen deficiency and increased synthesis of the metalloproteinase-1 enzyme, which degrades the dermal collagen. OBJECTIVES: To assess whether the use of topical estradiol 0.05% cream on photo exposed skin can inhibit the expression of the metalloproteinase-1 enzyme on the dermis and subsequently the rapid loss of collagen in women after menopause. METHODS: We included 40 postmenopausal women without hormone replacement therapy. Information about lifestyle, lipid profile, blood glucose level, thyroid hormones, mammography, Pap smear and transvaginal ultrasound were obtained to rule out associated diseases. Skin biopsy of the right preauricular region was performed before and after treatment with topical estradiol 0.05% for 30 days. The biopsy specimens were subjected to immunohistochemistry to identify the expression of the metalloproteinase-1 enzyme. RESULTS: There was no statistically significant difference on the expression of the metalloproteinase-1 enzyme in keratinocytes, fibroblasts and endothelial cells before and after treatment with topical estradiol for 30 days. CONCLUSION: Treatment with estradiol 0.05% cream, in photo exposed skin for 30 days, does not inhibit the production of metalloproteinase-1.

FUNDAMENTOS: Na pós-menopausa, ocorre rápida destruição do colágeno dérmico, com consequente envelhecimento acelerado da pele, que se expressa com atrofia cutânea, aumento do número e da profundidade das rugas e flacidez. Esse catabolismo acelerado do colágeno ocorre por deficiência estrogênica e aumento na síntese da enzima metaloproteinase-1, que degrada o colágeno dérmico. OBJETIVOS: Avaliar se o uso de estradiol tópico a 0,05% em creme na pele fotoexposta pode inibir a expressão da enzima metaloproteinase-1 na derme e, consequentemente, a perda acelerada do colágeno em mulheres na pósmenopausa. MÉTODOS: Foram incluídas 40 mulheres na pós-menopausa sem terapia de reposição hormonal. Informações sobre hábitos de vida, perfil lipídico, níveis glicêmicos, hormônios tireoidianos, mamografia, colpocitologia oncótica e ultrassom transvaginal foram obtidas para excluir doenças associadas. Biópsia de pele da região pré-auricular direita foi realizada antes e após tratamento com estradiol tópico a 0,05% por 30 dias. Os espécimes de biópsia foram submetidos à reação imunoistoquímica para identificar a expressão da enzima metaloproteinase-1. RESULTADOS: Não foi observada diferença estatisticamente significativa na expressão da enzima metaloproteinase-1 em queratinócitos, células endoteliais e fibroblastos da pele antes e após tratamento com estradiol tópico por 30 dias. CONCLUSÃO: O tratamento com creme contendo estradiol a 0,05% em pele fotoexposta por 30 dias não inibe a produção da enzima metaloproteinase-1.

Avaliação do direcionamento e angulação das fibras de colágeno ao redor de implantes do tipo cone morse e hexágono externo sob luz polarizada em cães / Histological evaluation of collagen fibers orientation and angulation around external hexagon and cone morse implants under a polarized light

Foram avaliados o direcionamento e as características das fibras colágenas ao redor de dois diferentes tipos de implantes, cone Morse e hexágono externo. Este estudo foi aprovado pelo comitê de ética no ensino e pesquisa em animais da Faculdade de Odontologia de Bauru, recebendo o protocolo de número 03/2008. Foram instalados 42 implantes em sete cães, sendo 14 do tipo hexágono externo (Osseotite - 3i, USA ) e 28 do tipo Cone Morse ( Titamax EX CM Neodent, Brazil ), todos receberam componentes protéticos, seguindo o protocolo de carga imediata, após 4 meses, todos os animais foram sacrificados e as amostras coletadas e processadas pelo sistema Exakt. Para a avaliação do direcionamento das fibras colágenas foram avaliadas 18 amostras, que foram observadas em um microscópio óptico, sobre a influência de luz polarizada. No grupo hexágono externo foram encontradas fibras colágenas oriundas do epitélio alveolar correndo paralelamente a superfície do implante e seu componente protético, em algumas amostras se uniam a outros grupos de fibras e se direcionavam a região das roscas do implante. Foram encontradas fibras que poderiam ser classificadas como perpendiculares em apenas 3 amostras, localizadas abaixo da plataforma protética, não foram observados sinais de inserção das fibras nas regiões do cilindro de proteção ou componente rotético, apenas abaixo da plataforma do implante. Ao redor das amostras do grupo cone morse, foram encontrados grupos de fibras que corriam paralelamente a superfície do componente protético, em direção a plataforma do implante. Em 6 amostras deste grupo, foram observadas fibras que foram classificadas como obliquas ou perpendiculares, distribuídas lateralmente a região mais profunda do componente protético, apresentando sinais de inserção, não foram observadas fibras se inserindo diretamente ao implante. Quando observamos os valores correspondentes aos dois grupos avaliados, podemos observar a maior predominância de...

This study aims to evaluate the presence and orientation of the collagen fibers around two different implant types. 42 implants were installed in seven dogs, 14 external hexagon (Osseotite - 3i, USA) and 28 cone morse (CM Titamax EX - Neodent, Brazil), all received prosthetic components, following the immediate loading protocol. After 4 months of healing, the animals were sacrificed and samples were collected and processed for histological evaluation by means of Exakt processing system. To assess the direction of collagen fibers, 10 samples from each group were evaluated in an optical microscope, under the incidence of polarized light. In the external hexagon group were found collagen fibers derived from alveolar epithelium running parallel to the implant and his prosthetic component, in some samples these fibers joined with other groups and drove to the implant threads. Were found Fibers that could be classified as perpendicular in only three samples, located below the implant platform, no insertion signals were observed on cylinder of protection or prosthetic component, just below the implant platform. Around the morse taper group samples were found groups of fibers that ran parallel to the surface of the prosthetic component toward the implant platform. In six samples of this group, were observed fibers that were classified as oblique or perpendicular, laterally distributed to the deepest region of the prosthetic component, showing signs of insertion, were no observed fibers inserting directly to the implant surface. When we look at the values corresponding to both groups, we can observe the predominance of fibers classified as parallel-oblique on group I, with 16 samples, two other samples of this group could be classified as oblique. On group III, the highest prevalence of the samples are classified as oblique, with 11 samples, five other samples of this group can be classified as oblique-perpendicular, the morse taper group...

Avaliação do direcionamento e angulação das fibras de colágeno ao redor de implantes do tipo cone morse e hexágono externo sob luz polarizada em cães / Histological evaluation of collagen fibers orientation and angulation around external hexagon and cone morse implants under a polarized light

Foram avaliados o direcionamento e as características das fibras colágenas ao redor de dois diferentes tipos de implantes, cone Morse e hexágono externo. Este estudo foi aprovado pelo comitê de ética no ensino e pesquisa em animais da Faculdade de Odontologia de Bauru, recebendo o protocolo de número 03/2008. Foram instalados 42 implantes em sete cães, sendo 14 do tipo hexágono externo (Osseotite - 3i, USA ) e 28 do tipo Cone Morse ( Titamax EX CM Neodent, Brazil ), todos receberam componentes protéticos, seguindo o protocolo de carga imediata, após 4 meses, todos os animais foram sacrificados e as amostras coletadas e processadas pelo sistema Exakt. Para a avaliação do direcionamento das fibras colágenas foram avaliadas 18 amostras, que foram observadas em um microscópio óptico, sobre a influência de luz polarizada. No grupo hexágono externo foram encontradas fibras colágenas oriundas do epitélio alveolar correndo paralelamente a superfície do implante e seu componente protético, em algumas amostras se uniam a outros grupos de fibras e se direcionavam a região das roscas do implante. Foram encontradas fibras que poderiam ser classificadas como perpendiculares em apenas 3 amostras, localizadas abaixo da plataforma protética, não foram observados sinais de inserção das fibras nas regiões do cilindro de proteção ou componente rotético, apenas abaixo da plataforma do implante. Ao redor das amostras do grupo cone morse, foram encontrados grupos de fibras que corriam paralelamente a superfície do componente protético, em direção a plataforma do implante. Em 6 amostras deste grupo, foram observadas fibras que foram classificadas como obliquas ou perpendiculares, distribuídas lateralmente a região mais profunda do componente protético, apresentando sinais de inserção, não foram observadas fibras se inserindo diretamente ao implante. Quando observamos os valores correspondentes aos dois grupos avaliados, podemos observar a maior predominância de...

This study aims to evaluate the presence and orientation of the collagen fibers around two different implant types. 42 implants were installed in seven dogs, 14 external hexagon (Osseotite - 3i, USA) and 28 cone morse (CM Titamax EX - Neodent, Brazil), all received prosthetic components, following the immediate loading protocol. After 4 months of healing, the animals were sacrificed and samples were collected and processed for histological evaluation by means of Exakt processing system. To assess the direction of collagen fibers, 10 samples from each group were evaluated in an optical microscope, under the incidence of polarized light. In the external hexagon group were found collagen fibers derived from alveolar epithelium running parallel to the implant and his prosthetic component, in some samples these fibers joined with other groups and drove to the implant threads. Were found Fibers that could be classified as perpendicular in only three samples, located below the implant platform, no insertion signals were observed on cylinder of protection or prosthetic component, just below the implant platform. Around the morse taper group samples were found groups of fibers that ran parallel to the surface of the prosthetic component toward the implant platform. In six samples of this group, were observed fibers that were classified as oblique or perpendicular, laterally distributed to the deepest region of the prosthetic component, showing signs of insertion, were no observed fibers inserting directly to the implant surface. When we look at the values corresponding to both groups, we can observe the predominance of fibers classified as parallel-oblique on group I, with 16 samples, two other samples of this group could be classified as oblique. On group III, the highest prevalence of the samples are classified as oblique, with 11 samples, five other samples of this group can be classified as oblique-perpendicular, the morse taper group...

Caracterização químico-nutricional de um isolado protéico de soro de leite, um hidrolisado de colágeno bovino e misturas dos dois produtos / Chemical-nutritional characterization of a whey protein isolate, a bovine collagen hydrolysate and mixtures of the two products

OBJETIVO:Estudar química e nutricionalmente um isolado protéico de soro de leite bovino, um hidrolisado de colágeno bovino e misturas dos dois produtos visando elevado valor nutritivo e funcional. MÉTODOS: Realizaram-se análises da composição centesimal e do perfil de aminoácidos dos dois materiais protéicos, para cálculo da melhor adequação dos aminoácidos essenciais, com base no perfil recomendado pela Organização Mundial de Saúde. Os índices de valor nutritivo para o isolado de soro de leite, o hidrolisado de colágeno e as misturas foram determinados em ratos, a partir de ensaios de crescimento e de balanço de nitrogênio. Os resultados dos parâmetros nutricionais foram submetidos à análise de variância e ao teste de Tukey para a verificação de diferenças entre médias (p<0,05). RESULTADOS: O isolado protéico de soro de leite mostrou-se completo quanto aos aminoácidos essenciais pelo padrão de referência da Organização Mundial de Saúde enquanto que o hidrolisado de colágeno bovino mostrou-se deficiente em todos os aminoácidos essenciais, com agravante de completa ausência de triptofano. A caseína mostrou-se mais eficaz que o isolado de soro e as misturas quanto ao poder de promover crescimento em ratos. Não houve diferença estatística no crescimento dos ratos entre o isolado protéico de soro e a mistura 60 por cento isolado de soro e 40 por cento hidrolisado de colágeno. Nos demais índices de valor protéico a mistura 60 por cento isolado de soro: 40 por cento hidrolisado de colágeno mostrou-se igual ou superior à caseína e ao isolado (100 por cento). CONCLUSÃO: A mistura 60 por cento isolado de soro mais 40 por cento hidrolisado de colágeno bovino apresentou elevado valor nutritivo e alto índice de solubilidade em água, mostrando-se promissora como ingrediente na formulação de alimentos dietéticos para idosos, inclusive pelas propriedades funcionais já descritas para essas proteínas.

OBJECTIVE:The objective was the chemical and nutritional study of a bovine whey protein isolate, a bovine collagen hydrolysate and mixtures of the two products aiming at high nutritional and functional value. METHODS: Centesimal composition and amino acid analyses were performed on both proteinaceous materials for the calculation of an adequate amino acid profile based on the Food and Agriculture Organization/World Health Organization recommendation. The nutritive value indexes for the whey protein isolate, the collagen hydrolysate and mixtures of both proteins were determined in rats through growth assay and nitrogen balance. The experimental parameters from nutritional assays were submitted to analysis of variance and the Tukey test applied for differences among means (p<0.05). RESULTS: The whey protein isolate met all the requirements of the Food and Agriculture Organization/World Health Organization reference for essential amino acids while the collagen hydrolysate showed deficiency in all essential amino acids and complete absence of tryptophan. The casein showed higher efficiency than the whey isolate and mixtures of both proteins in promoting growth in the rat. There was no statistical difference in growth between the whey protein isolate and the mixture of 60 percent whey protein isolate and 40 percent collagen hydrolysate. In all other indexes of protein nutritive value the mixture 60 percent whey protein isolate and 40 percent collagen hydrolysate revealed itself equal or superior to casein and the 100 percent whey isolate. CONCLUSION: The protein mixture 60 percent whey protein isolate and 40 percent collagen hydrolysate showed high nutritive value and water solubility indexes, considered favorable properties as an ingredient for the formulation of dietetic products for elderly people.

Fibroblasts in three dimensional matrices: cell migration and matrix remodeling

Fibroblast-collagen matrix culture has facilitated the analysis of cell physiology under conditions that more closely resemble an in vivo-like environment compared to conventional 2-dimensional (2D) cell culture. Furthermore, it has led to significant progress in understanding reciprocal and adaptive interactions between fibroblasts and the collagen matrix, which occur in tissue. Recent studies on fibroblasts in 3-dimensional (3D) collagen matrices have revealed the importance of biomechanical conditions in addition to biochemical cues for cell signaling and migration. Depending on the surrounding mechanical conditions, cells utilize specific cytoskeletal proteins to adapt to their environment. More specifically, cells utilize microtubule dependent dendritic extensions to provide mechanical structure for matrix contraction under a low cell-matrix tension state, whereas cells in a high cell-matrix tension state utilize conventional acto-myosin activity for matrix remodeling. Results of collagen matrix contraction and cell migration in a 3D collagen matrix revealed that the use of appropriate growth factors led to promigratory and procontractile activity for cultured fibroblasts. Finally, the relationship between cell migration and tractional force for matrix remodeling was discussed.

Tissue Engineering of Injectable Soft tissue Filler: Using Adipose Stem Cells and Micronized Acellular Dermal Matrix

In this study of a developed soft tissue filler, adipose tissue equivalents were constructed using adipose stem cells (ASCs) and micronized acellular dermal matrix (Alloderm). After labeling cultured human ASCs with fluorescent green protein and attaching them to micronized Alloderm (5X10(5) cells/1 mg), ASC-Alloderm complexes were cultured in adipogenic differentiation media for 14 days and then injected into the dorsal cranial region of nude male mice. The viabilities of ASCs in micronized Alloderm were determined at 1, 4, 7, and 14 days, and complexes, which had been cultured for 14 days and implanted in vivo for 2 months, were histologically evaluated by light, confocal, and scanning electron microscopy. The viabilities represented that ASCs in micronized Alloderm were alive during the culture period. ASC-Alloderm complexes cultured for 14 days contained round cells with large lipid vesicles by light microscopy and many spherical cells by SEM. ASCs in implanted ASCAlloderm complexes harvested from mice at 2 months postinjection were histologically found to have differentiated into adipocytes which had green fluorescence dye. Micronized Alloderm may be found useful as scaffold for human ASCs when constructing fat tissue for three-dimensional soft tissue filling. The present study suggests that ASC-Alloderm complexes can be used as injectable three-dimensional soft tissue fillers.