Osteoblast Behavior on Novel Porous Polymeric Scaffolds

Current efforts in bone tissue engineering have as one focus the search for a scaffold material that supports osteoblast proliferation, matrix mineralization, and, ultimately, bone formation. Electrospraying of polymer solutions has enabled the engineering of porous materials to meet current challenges in bone replacement therapies. Porous scaffolds of poly( -caprolactone)/poly(diisopropyl fumarate) compatibilized blend for bone tissue engineering were obtained by electrospraying technique in order to create a better osteophilic environment for the growth and differentiation of osteoblasts. Non-porous films having smooth surface were obtained by casting and used for comparison purposes. Studies on cell-scaffold interaction were carried out by culturing two osteoblastlike cell lines, MC3T3E1 and UMR106, on three-dimensional scaffolds and two-dimensional films. Growth, proliferation, and differentiation (alkaline phosphatase activity) of osteoblasts, were assessed. Scaffolds displayed a highly porous structure with interconnected pores formed by polymer microparticles, and higher hydrophobicity than the observed in non-porous films. The adhesion, proliferation and alkaline phosphatase activity of cells grown on the porous scaffolds increased significantly in comparison to those observed on flat films. The rough surface morphology of this novel scaffold enhances osteoblast response. These results suggest that electrosprayed porous scaffolds may be potentially used as tissue engineering scaffolds with high bone regenerative efficacy.Facultad de Ciencias Exacta

Osteoblast Behavior on Novel Porous Polymeric Scaffolds

Current efforts in bone tissue engineering have as one focus the search for a scaffold material that supports osteoblast proliferation, matrix mineralization, and, ultimately, bone formation. Electrospraying of polymer solutions has enabled the engineering of porous materials to meet current challenges in bone replacement therapies. Porous scaffolds of poly( -caprolactone)/poly(diisopropyl fumarate) compatibilized blend for bone tissue engineering were obtained by electrospraying technique in order to create a better osteophilic environment for the growth and differentiation of osteoblasts. Non-porous films having smooth surface were obtained by casting and used for comparison purposes. Studies on cell-scaffold interaction were carried out by culturing two osteoblastlike cell lines, MC3T3E1 and UMR106, on three-dimensional scaffolds and two-dimensional films. Growth, proliferation, and differentiation (alkaline phosphatase activity) of osteoblasts, were assessed. Scaffolds displayed a highly porous structure with interconnected pores formed by polymer microparticles, and higher hydrophobicity than the observed in non-porous films. The adhesion, proliferation and alkaline phosphatase activity of cells grown on the porous scaffolds increased significantly in comparison to those observed on flat films. The rough surface morphology of this novel scaffold enhances osteoblast response. These results suggest that electrosprayed porous scaffolds may be potentially used as tissue engineering scaffolds with high bone regenerative efficacy.Facultad de Ciencias Exacta

Fabrication of gelatin methacrylate (GelMA) scaffolds with nano- and micro-topographical and morphological features

The design of biomimetic biomaterials for cell culture has become a great tool to study and understand cell behavior, tissue degradation, and lesion. Topographical and morphological features play an important role in modulating cell behavior. In this study, a dual methodology was evaluated to generate novel gelatin methacrylate (GelMA)-based scaffolds with nano and micro topographical and morphological features. First, electrospinning parameters and crosslinking processes were optimized to obtain electrospun nanofibrous scaffolds. GelMA mats were characterized by SEM, FTIR, DSC, TGA, contact angle, and water uptake. Various nanofibrous GelMA mats with defect-free fibers and stability in aqueous media were obtained. Then, micropatterned molds produced by photolithography were used as collectors in the electrospinning process. Thus, biocompatible GelMA nanofibrous scaffolds with micro-patterns that mimic extracellular matrix were obtained successfully by combining two micro/nanofabrication techniques, electrospinning, and micromolding. Taking into account the cell viability results, the methodology used in this study could be considered a valuable tool to develop patterned GelMA based nanofibrous scaffolds for cell culture and tissue engineering.Fil: Aldana, Ana Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Malatto, Laura. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Rehman, M. A. U.. Universitat Erlangen-Nuremberg; AlemaniaFil: Boccaccini, A. R.. Universitat Erlangen-Nuremberg; AlemaniaFil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

An Exogenous Pre-Storage Melatonin Alleviates Chilling Injury in Some Mango Fruit Cultivars, by Acting on the Enzymatic and Non-Enzymatic Antioxidant System

Melatonin (MT) treatment (100 M, 2 h) was applied to four mango fruit cultivars (‘Langra’, ‘Chaunsa’, ‘Dashehari’, and ‘Gulab Jamun’), before being stored at 5 1 C for 28 d, in order to alleviate chilling injury (CI). Maximum CI reduction was observed in ‘Langra’ mangoes, and minimum in ‘Gulab Jamun’ mangoes. This positive effect on quality preservation was associated with an increased concentration of endogenous MT, which prevented the accumulation of reactive oxygen species (H2O2 and O2 ) and stimulated non-enzymatic antioxidants (total phenolic compounds and total flavonoids), possibly due to higher activity of phenylalanine ammonia lyase and tyrosine ammonia lyase. Increased antioxidant activity was also documented in MT-treated ‘Langra’ mangoes, according to four different assays (DPPH, TEAC, FRAP, and CUPRAC) and higher activity of six antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase). In contrast, ‘Gulab Jamun’ mangoes showed minimal or no positive effects on the aforementioned variables in response to the exogenous MT application. ‘Chaunsa’ and ‘Dashehari’ mangoes had some intermediate effects on their antioxidant system (enzymatic and non-enzymatic) and alleviation of CI, when treated with exogenous MT.We conclude that exogenous MT exerts a cultivar-dependent stimulating effect on the antioxidant system of mangoes, which results in an increase in the fruits’ resistance to low temperature

Longitudinal development of extensive air showers: hybrid code SENECA and full Monte Carlo

New experiments, exploring the ultra-high energy tail of the cosmic ray spectrum with unprecedented detail, are exerting a severe pressure on extensive air hower modeling. Detailed fast codes are in need in order to extract and understand the richness of information now available. Some hybrid simulation codes have been proposed recently to this effect (e.g., the combination of the traditional Monte Carlo scheme and system of cascade equations or pre-simulated air showers). In this context, we explore the potential of SENECA, an efficient hybrid tridimensional simulation code, as a valid practical alternative to full Monte Carlo simulations of extensive air showers generated by ultra-high energy cosmic rays. We extensively compare hybrid method with the traditional, but time consuming, full Monte Carlo code CORSIKA which is the de facto standard in the field. The hybrid scheme of the SENECA code is based on the simulation of each particle with the traditional Monte Carlo method at two steps of the shower development: the first step predicts the large fluctuations in the very first particle interactions at high energies while the second step provides a well detailed lateral distribution simulation of the final stages of the air shower. Both Monte Carlo simulation steps are connected by a cascade equation system which reproduces correctly the hadronic and electromagnetic longitudinal profile. We study the influence of this approach on the main longitudinal characteristics of proton-induced air showers and compare the predictions of the well known CORSIKA code using the QGSJET hadronic interaction model.Comment: 11 pages (LaTeX), 15 postscript figures, 3 table

Osteoblast Behavior on Novel Porous Polymeric Scaffolds

Current efforts in bone tissue engineering have as one focus the search for a scaffold material that supports osteoblast proliferation, matrix mineralization, and, ultimately, bone formation. Electrospraying of polymer solutions has enabled the engineering of porous materials to meet current challenges in bone replacement therapies. Porous scaffolds of poly( -caprolactone)/poly(diisopropyl fumarate) compatibilized blend for bone tissue engineering were obtained by electrospraying technique in order to create a better osteophilic environment for the growth and differentiation of osteoblasts. Non-porous films having smooth surface were obtained by casting and used for comparison purposes. Studies on cell-scaffold interaction were carried out by culturing two osteoblastlike cell lines, MC3T3E1 and UMR106, on three-dimensional scaffolds and two-dimensional films. Growth, proliferation, and differentiation (alkaline phosphatase activity) of osteoblasts, were assessed. Scaffolds displayed a highly porous structure with interconnected pores formed by polymer microparticles, and higher hydrophobicity than the observed in non-porous films. The adhesion, proliferation and alkaline phosphatase activity of cells grown on the porous scaffolds increased significantly in comparison to those observed on flat films. The rough surface morphology of this novel scaffold enhances osteoblast response. These results suggest that electrosprayed porous scaffolds may be potentially used as tissue engineering scaffolds with high bone regenerative efficacy.Facultad de Ciencias Exacta

Antioxidant activity and prevention of pork meat lipid oxidation using traditional Mexican condiments (pasilla dry pepper, achiote, and mole sauce)

Antioxidant activity and prevention of pork meat lipid oxidation using traditional Mexican condiments (pasilla dry pepper, achiote, and mole sauce

Optimization of total anthocyanin content and antioxidant activity of a Hibiscus sabdariffa infusion using response surface methodology

Hibiscus sabdariffa L. calyces are underutilized sources of health-promoting anthocyanins. Infusions are the most common way to consume them, but because anthocyanins are thermosensitive, prolonged extraction times at high temperatures may reduce their bioactivities, suggesting the need to identify optimal preparation conditions. Response surface methodology was used to establish calyces-to-water ratio (X1: 1–20 g/100 mL), temperature (X2: 70–100 °C), and time (X3: 1–30 min) that would produce an infusion with optimized total anthocyanin content (TAC) and antioxidant activity. Under optimum conditions (X1=10 g/100 mL, X2=88.7 °C, and X3=15.5 min) TAC was 132.7±7.8 mg cyanidin-3-glucoside equivalents (C3G)/100 mL, and antioxidant activity was 800.6±69.9 (DPPH assay), and 1792.0±153.5 (ABTS assay) μmol Trolox equivalents (TE)/100 mL. Predicted and experimental results were statistically similar. Identifying ideal processing conditions can promote consumption of an H. sabdariffa-based functional beverage with high anthocyanin content and antioxidant activity that exert health-promoting bioactivities on the consumer

Detección de unidades discretas de tipificación de Trypanosoma cruzi en triatominos recolectados en diferentes regiones naturales de Perú

Introduction: Trypanosoma cruzi has been divided by international consensus into six discrete typing units (DTU): TcI, TcII, TcIII, TcIV, TcV y TcVI. The factors determining the dynamics of T. cruzi genotypes vector transmission of Chagas’ disease in the different geographical regions of Perú are still unknown.Objective: To detect and type T. cruzi DTUs from the faeces of seven species of triatomines (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni and T. infestans) captured in eight departments from different natural regions of Perú.Materials and methods: We examined 197 insects for detecting trypanosomes. DNA was extracted from each insect intestinal contents and PCR amplification of kDNA, SL-IR, 24Sα rRNA and 18Sα RNA was performed for detecting T. cruzi DTUs.Results: Five T. rangeli and 113 T. cruzi infections were detected; 95 of the latter were identified as TcI (two in P. chinai, one in P. geniculatus, 68 in P. herreri, four in R. pictipes, seven in R. robustus, one in T. carrioni, 12 in T. infestans), five as TcII (four in P. herreri, one in T. infestans), four as TcIII (three in P. herreri, one in R. robustus) and four TcIV infections in P. herreri.Conclusions: This is the first study which has attempted a large-scale characterization of T. cruzi found in the intestine of epidemiologically important vectors in Perú, thus providing basic information that will facilitate a better understanding of the dynamics of T. cruzi vector transmission in Perú.Introducción. Trypanosoma cruzi se ha dividido en seis unidades taxonómicas discretas (Discreet Typing Units, DTU) denominadas TcI, TcII, TcIII, TcIV, TcV y TcVI. Aún se desconocen los factores determinantes de la dinámica de la transmisión vectorial de los genotipos de T. cruzi en las diferentes regiones geográficas de distribución de la enfermedad de Chagas en Perú.Objetivo. Detectar y tipificar las unidades taxonómicas discretas de T. cruzi en las heces de siete especies de triatominos (Panstrongylus chinai, P. geniculatus, P. herreri, Rhodnius robustus, R. pictipes, Triatoma carrioni y T. infestans), capturados en ocho departamentos de diferentes regiones naturales de Perú.Materiales y métodos. Se examinaron 197 insectos para la detección de tripanosomas. Se extrajo el ADN del contenido intestinal de cada insecto y se amplificó mediante reacción en cadena de la polimerasa (PCR) de los genes kDNA, SL-IR, 24Sα rRNA y 18Sα RNA para detectar las DTU de T. cruzi. Resultados. Se detectaron cinco infecciones con T. rangeli y 113 con T. cruzi. De estas últimas, fue posible identificar 95 de TcI (dos en P. chinai, una en P. geniculatus, 68 en P. herreri, cuatro en R. pictipes, siete en R. robustus, una en T. carrioni, y 12 en T. infestans); cinco de TcII (cuatro en P. herreri, una en T. infestans); cuatro de TcIII (tres en P. herreri, una en R. robustus) y cuatro infecciones de TcIV en P. herreri.Conclusión. Este es el primer trabajo de caracterización a gran escala de T. cruzi en el intestino de vectores de importancia epidemiológica en Perú, orientado a generar información básica que permita entender la dinámica de la transmisión vectorial de T. cruzi en esta región del continente