Phage Therapy and Photodynamic Therapy: Low Environmental Impact Approaches to Inactivate Microorganisms in Fish Farming Plants

Owing to the increasing importance of aquaculture to compensate for the progressive worldwide reduction of natural fish and to the fact that several fish farming plants often suffer from heavy financial losses due to the development of infections caused by microbial pathogens, including multidrug resistant bacteria, more environmentally-friendly strategies to control fish infections are urgently needed to make the aquaculture industry more sustainable. The aim of this review is to briefly present the typical fish farming diseases and their threats and discuss the present state of chemotherapy to inactivate microorganisms in fish farming plants as well as to examine the new environmentally friendly approaches to control fish infection namely phage therapy and photodynamic antimicrobial therapy

Les benzodiazépines (du bon usage à l'abus. Rôle du pharmacien dans le suivi et l'accompagnement)

LIMOGES-BU Médecine pharmacie (870852108) / SudocSudocFranceF

Cellulose surface grafting with polycaprolactone by heterogeneous click-chemistry

International audienc

Photobactericidal plastic films based on cellulose esterified by chloroacetate and a cationic porphyrin.

International audienceThe synthesis and characterisation of pyridinium porphyrinic chloroacetyl cellulose ester chlorides, where photosensitizing agents are covalently bounded to the polymeric chain, is presented in this paper. First, cellulose was homogenously converted into chloroacetatecellulose ester in DMAc/LiCl solvent by using chloroacetyl chloride. The complete substitution of cellulose was achieved using 7 equiv of chloroacetyl chloride for a 2 h reaction at room temperature. The absence of base did not prove detrimental to reaction. The grafting of monopyridyltritolylporphyrin onto chloroacetatecellulose ester was then realised by alkylation of the photosensitizer in DMF. These new plasticfilms were found to be thermostable up to 55 °C; higher temperatures led to progressive deacetylation. First results of their photobactericidal activity against Staphylococcus aureus and Escherichia coli strains are very encouraging. Such materials could find applications in medical environments as an alternative to overcome the rampant bacterial multiresistance to classical antibiotics

Photobactericidal films from porphyrins grafted to alkylated cellulose - synthesis and bactericidal properties

International audienceTwo series of porphyrinic cellulose laurate esters plastic films, where the photosensitizers are covalently linked to the cellulosic polymer have been synthesised by using a "one-pot, two-step" esterification reaction. The photosensitizers were first covalently bounded to the cellulosic polymer using either 4- or 11-carbon spacer arms. The porphyrinic plastic films were then obtained by a second esterification with lauric acid. The reaction was studied according to reaction time, temperature, lauric acid amount, pyridine playing the role proton trapping base. Para-toluenesulfonylchloride has been proved to be a powerful activating agent for this reaction. The drawback of the steric hindrance of the porphyrinic macrocycle towards cellulosic hydroxyl groups has been overcome by increasing the number of carbon of spacer arms from 4- to 11-carbons. The photobactericidal activity of these materials was evaluated against Gram positive and Gram negative strains bacteria. First results show that these new plastic films display photobactericidal activity for porphyrin grafting percentage higher than 0.16, whereas the non-porphyrinic control allowed full growth of bacteria. These materials could be an alternative in order to overcome the growing bacterial multiresistance to classical antibiotics

Vers de nouveaux films photobactéricides élaborés à partir de cellulose et de porphyrines

Des travaux menés dans notre laboratoire ont montré que l on peut obtenir des matériaux plastiques en estérifiant la cellulose par des acides gras. Nous avons utilisé cette propriété dans le cadre de la photothérapie antimicrobienne, pour élaborer de nouveaux films plastiques photobactéricides à partir de cellulose, de porphyrines et d acides gras. Dans un premier temps, la synthèse et la caractérisation de tritolylporphyrines para-substituées par un bras espaceur comprenant quatre ou onze atomes de carbones portant une fonction acide est présentée. Les laurates de cellulose meso-arylporphyriniques sont alors obtenus en estérifiant successivement le polysaccharide par une porphyrine puis par l acide laurique, en présence du système activant TsCl/pyridine. Dans un second temps, des laurates de cellulose protoporphyriniques ont été préparés en utilisant la même méthodologie. Ces polymères ont également été obtenus par acylation de la cellulose sous activation micro-onde. La présence de deux bras carboxyéthyles sur la protoporphyrine IX a permis d améliorer la fixation de ce macrocycle sur la chaîne cellulosique. Enfin, nous présentons également la synthèse de chloroacétates de cellulose pyridylporphyriniques cationiques, obtenus par alkylation de chloroacétates de cellulose par la pyridyltritolylporphyrine. Tous ces composés ont été caractérisés par diverses méthodes spectrales (UV-Visible, RMN 1H, SM MALDI). Une étude préliminaire d activité biologique a également été réalisée sur les souches bactériennes Staphylococcus aureus (Gram+) et Escherichia coli (Gram-) afin d'évaluer leur activité photobactéricide.LIMOGES-BU Sciences (870852109) / SudocSudocFranceF