Composite films are an alternative in the replacement of synthetic polymers. These films can be prepared from polysaccharides and used to store various drugs to be applied in different areas. In addition, aminoethoxyvinylglycine (AVG) is an ethylene inhibitor that prolongs shelf life of food. For this reason, this research aimed to take advantage of the brown algae Macrocystis pyrifera and Lessonia trabeculata to extract sodium alginate and produce films composed of sodium alginate/kappa-carrageenan/iota-carrageenan, which were plasticized with glycerol and polyethylene glycol 400 and loaded with aminoethoxyvinylglycine. The extracted sodium alginate was characterized by 1H and 13C nuclear magnetic resonance (NMR), size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS), thermogravimetry (TG/DTG), Fourier transform infrared (FTIR), and X-ray diffraction (XRD); and the composite films were characterized by FTIR, XRD, TG/DTG, and scanning electron microscopy (SEM). Then, the drug release kinetics were investigated using Higuchi and Korsmeyer-Peppas kinetic models. The extracted alginates obtained were of low molecular weight, and the films showed desirable properties for AVG release. Furthermore, drug release profiles revealed that AVG release is governed by Fick’s Law, and this is favored at low temperatures. In summary, sodium alginate allows the preparation of composite films, which can replace synthetic polymers to be used in the loading and releasing of drugs.

El desarrollo de organismos incrustantes o biofouling en ambientes marinos, afectan numerosas estructuras metálicas sumergidas fijas (boyas) o móviles (cascos de embarcaciones), e inducen procesos de corrosión del metal, reducen la velocidad de desplazamiento, incrementan el consumo de combustible y aumentan la frecuencia de entradas en dique seco para mantenimiento, con diversas consecuencias económicas. Las pinturas antiincrustantes se han desarrollado con el propósito de mitigar estos impactos, teniendo la capacidad de excluir los organismos marinos que se ponen en contacto con la superficie pintada, por medio de la liberación de un biocida. La evaluación del comportamiento de las pinturas antiincrustantes comprende la inmersión de paneles pintados sujetos en estructuras flotantes estáticas y el seguimiento periódico de su desempeño. Como paso previo, es indispensable realizar una caracterización fisicoquímica y biológica del medio marino en la zona de interés. Con este propósito, se realizó un completo estudio en la zona de Mamonal (bahía de Cartagena), incluyendo valoraciones de: radiación solar, disponibilidad de la luz, oxígeno disuelto, temperatura, pH, potencial redox, alcalinidad y salinidad, además de la determinación y conteo de los principales grupos de organismos recolectados.

The incrustation of marine organisms (biofouling) affect several submerged metallic structures, like ship hulls. Biofouling frequently induces metal corrosion, reduces the speed of displacement, increases fuel consumption, and increases the frequency of dry-dock operations. Antifouling paints which have the capacity to prevent the marine organisms from contacting the painted surface (by means of biocide release), have been developed in order to mitigate these deleterious effects. Static tests of antifouling paints include immersing painted panels (attached to floating structures), and periodically evaluating its performance. Before conducting these static tests, it is important to characterize the local maritime environment by determining the range of values of the most significant physical, chemical and biological variables. A complete characterization of the sea water in the zone of Mamonal (Cartagena Bay) was conducted; variables such as solar irradiation, light availability, dissolved oxygen, temperature, pH, redox potential, alkalinity, and salinity were measured. In addition, the determination and quantification of the main biological entities present in the samples was also carried out.

La protección de superficies sumergidas en agua de mar tiene además de los aspectos de corrosividad un aspecto importante que debe considerarse y es evitar la colonización por especies marinas. La colonización de superficies sumergidas, además de deteriorar todo el sistema de protección, genera inconvenientes en cuanto a la operatividad de naves y estructuras, debido al aumento en rugosidad y peso de estas. Como medida preventiva se emplean recubrimientos de pintura denominados antiincrustantes, los cuales evitan la adhesión de organismos a las superficies. Para la formulación y posterior evaluación de una nueva pintura es necesario tener conocimiento del medio ambiente y disponer montajes tanto de laboratorio como de campo, para lograr resultados representativos y de inmediata aplicación. En el presente trabajo se describen los pasos recomendados a seguir en un estudio de este tipo, metodología que se ha desarrollado y aplicado recientemente con resultados muy halagadores.

Biofouling is an important aspect to consider in the protection of a structure submerged in sea water. In fact, besides causing deterioration of the entire protective system (e. g., corrosion protection), biofouling increases roughness and weight in ships and other structures therefore affecting their operation. Antifouling paints, having the capacity to exclude the marine organisms that tend to adhere to the surface, have been developed in order to mitigate these adverse effects. In order to formulate and evaluate a potential paint it is necessary to have knowledge of the marine environment, and to be able to conduct both laboratory and field tests so representative and applicable results are obtained. The recommended steps to follow in such a study are described in this paper. The methodology proposed has been recently developed and applied with promising results.