Matrices nanocompuestas de alcohol de polivinilo (PVA)/celulosa bacteriana (CB) para el crecimiento celular y la regeneración de tejidos

RESUMEN: En esta investigación se desarrollaron biomateriales de PVA, CB y nanocompuestos PVA/CB mediante fermentación in situ utilizando una bacteria productora de celulosa Gluconacetobacter medellinensis. Los biomateriales fueron caracterizados mediante microscopía electrónica de barrido (SEM), pruebas de hinchamiento y proliferación celular in-vitro utilizando células de piel humana (Fibroblastos). No se observaron cambios en la morfología celular por el uso de los biomateriales y su microestructura estuvo estrechamente ligada a la proliferación celular. Las células mostraron una mayor afinidad por la CB, resultado relacionado con su similitud en morfología y estructura química con el colágeno. La respuesta obtenida sumada a la capacidad de la CB de imitar la forma de la interfaz gas-líquido durante su síntesis, permitió la construcción de una prenda apósito de CB en forma de guante que podría tener aplicaciones en el tratamiento de quemaduras y úlceras cutáneas.ABSTRACT: In this research, biomaterials of PVA, CB and in situ fermented PVA/CB nanocomposites were developed, using a cellulose producer bacterium, Gluconacetobacter medellinensis. The biomaterials were characterized through scanning electron microscopy (SEM), swelling and in vitro cell proliferation assay with skin cells (Fibroblast). Changes in the cell morphology were not found by the use of the biomaterials and the cell proliferation is associated with the microstructure of them. Cells showed a higher affinity to CB, outcome related to the morphological and chemical similitudes with collagen. Joining this response with the CB capacity of mimic the gas-liquid interface, was developed a glove shaped wound dressing that will have applications in burn and skin ulcer treatment

Celulosa : un polímero de siempre con mucho futuro

RESUMEN: Dentro de la gran cantidad de sustancias naturales que han sido de un valor significativo a lo largo de todo el desarrollo científico – tecnológico de la humanidad se destaca sin lugar a dudas la celulosa, considerada como uno de los polímeros naturales de mayor abundancia en la naturaleza, y que puede ser obtenida desde las más variadas fuentes entre las que se encuentran: todo tipo de cuerpos vegetales, en diferentes tipos de algas, de la actividad extracelular de múltiples tipos de microorganismos y en el caparazón o estructura de algunos animales marinos (Zuluaga, 2014)

Development of a fortified drink from the mixture of small colombian native fruits

Strawberry (Fragaria ananassa), blackberry (Rubus glaucus), Peruvian cherry (Physalis peruviana L.) and purple passion fruit (Passiflora edulis Sims) are important fruit crops in Colombia, due to their organoleptic properties and nutritional qualities, making them attractive for international markets. This study was undertaken to characterize the physicochemical properties of these four fruits and to present an alternative for their use. To achieve this goal, the moisture, pH, soluble solids, acidity, color, iron and vitamin C concentration were determined, and a fortified mixed fruit drink was developed. All of the fruits can be classified as high acidity products due to the acidity results. Purple passion fruit and Peruvian cherry presented the highest content of soluble solids, while blackberry, purple passion fruit and Peruvian cherry did not exhibit statistically significant differences in their iron contents, and strawberry exhibited the highest contribution of vitamin C.La fresa (Fragaria ananassa), la mora (Rubus glaucus), la uchuva (Physalis peruviana L.) y la gulupa (Passiflora edulis Sims) son cultivos frutales importantes en Colombia por sus propiedades organolépticas y nutritivas. Este estudio se realizó para caracterizar las propiedades fisicoquímicas de estos cuatro frutos y presentar una alternativa para su uso. Para lograr este objetivo, se caracterizaron las cuatro frutas determinando humedad, pH, sólidos solubles, acidez, color, contenido de hierro y la concentración de vitamina C. Posteriormente se desarrolló una bebida fortificada de frutas. De acuerdo a los resultados de acidez, todos los frutos se pueden clasificar como productos de alta acidez. La gulupa y la uchuva, presentaron el mayor contenido de sólidos solubles, mientras que la mora, la gulupa y la uchuva, no presentaron diferencias estadísticamente significativas en su contenido de hierro. La fresa presentó la mayor contribución de la vitamina C

Development of a fortified drink from the mixture of small colombian native fruits

Strawberry (Fragaria ananassa), blackberry (Rubus glaucus), Peruvian cherry (Physalis peruviana L.) and purple passion fruit (Passiflora edulis Sims) are important fruit crops in Colombia, due to their organoleptic properties and nutritional qualities, making them attractive for international markets. This study was undertaken to characterize the physicochemical properties of these four fruits and to present an alternative for their use. To achieve this goal, the moisture, pH, soluble solids, acidity, color, iron and vitamin C concentration were determined, and a fortified mixed fruit drink was developed. All of the fruits can be classified as high acidity products due to the acidity results. Purple passion fruit and Peruvian cherry presented the highest content of soluble solids, while blackberry, purple passion fruit and Peruvian cherry did not exhibit statistically significant differences in their iron contents, and strawberry exhibited the highest contribution of vitamin C

Aplicaciones biomédicas de biomateriales poliméricos

Los materiales poliméricos han tenido una imagen desfavorable, ya que son asociados con contaminación. Sin embargo, estos son de gran importancia para la biomedicina. Los polímeros son materiales muy versátiles, se pueden obtener de múltiples configuraciones químicas y mezclas para generar materiales compuestos con propiedades sinérgicas. En esta investigación se realizó un análisis científico y tecnológico de las aplicaciones biomédicas de biomateriales poliméricos y se recopila algunas de sus aplicaciones, propiedades mecánicas y características importantes para la industria biomédica. Los biomateriales poliméricos son una temática de punta como se refleja en el número de artículos científicios y de patentes. En la actualidad, estos biomateriales pueden llegar a reemplazar, reforzar o cumplir una función específica en el cuerpo humano. No obstante, debido a la complejidad de los sistemas biológicos aún se siguen presentando reacciones inmunes, que evitan el desarrollo de tejidos u órganos funcionales a escala de laboratorio.Polymer biomaterials have had an unfavourable image due to their association with pollution. However, they are important in biomedicine. Polymers are versatile materials, they can be obtained in several chemical configurations and mixtures to generate composite materials with synergistic properties. In this research, a scientific and technological analysis of the biomedical application of polymeric biomaterials was performed, along with the compilation of their applications, production, mechanical properties and important features for the biomedical industry. Polymeric biomaterials are a cutting-edge topic, as reflected in the number of scientific articles and patents. Nowadays, these biomaterials can replace, reinforce or fulfil a specific function in the human body. However, due to the complexity of biological systems, immune reactions are still present, preventing the development of tissues and functional organs in laboratory scale

Use of Fourier Series in X-ray Diffraction (XRD) Analysis and Fourier-Transform Infrared Spectroscopy (FTIR) for Estimation of Crystallinity in Cellulose from Different Sources

Cellulose crystallinity can be described according to the crystal size and the crystallinity index (CI). In this research, using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods, we studied the crystallinity of three different types of cellulose: banana rachis (BR), commercial cellulose (CS), and bacterial cellulose (BC). For each type of cellulose, we analyzed three different crystallization grades. These variations were obtained using three milling conditions: 6.5 h, 10 min, and unmilled (films). We developed a code in MATLAB software to perform deconvolution of the XRD data to estimate CI and full width at half-maximum (FWHM). For deconvolution, crystalline peaks were represented with Voigt functions, and a Fourier series fitted to the amorphous profile was used as the amorphous contribution, which allowed the contribution of the amorphous profile to be more effectively modeled. Comparisons based on the FTIR spectra and XRD results showed there were no compositional differences between the amorphous samples. However, changes associated with crystallinity were observed when the milling time was 10 min. The obtained CI (%) values show agreement with values reported in the literature and confirm the effectiveness of the method used in this work in predicting the crystallization aspects of cellulose samples