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Detection of Food, Agricultural and Aquatic Contaminants
Published in Richard O’Kennedy, Caroline Murphy, Immunoassays, 2017
Marie Le Berre, Caroline Viguier, Caroline Murphy, Niamh Gilmartinb
Due to the small size of these drugs and their residues most immunoassays used for their detection are competitive in format. For example, Cooper et al. [35] used a novel carboxyphenyl semicarbazide (SEM) derivative to raise a polyclonal antibody to SEM, the marker residue for the banned nitrofuran veterinary antibiotic nitrofurazone (NFZ). This antibody was incorporated into a direct competitive ELISA format for the detection of SEM in chicken muscle with a detection capability of 0.25 g kg−1, thus satisfying the EU minimum required performance limit of 1 g kg−1 for nitrofurans. Samples containing SEM at 0.5–5.0 g kg−1 by LC–MS/MS, all screened positive by this ELISA, indicating the utility of this assay in screening samples for the presence of drug residues. A recombinant antibody developed against halofuginone (an antiprotozoal drug used in poultry) was also used in a competitive assay format and showed a limit of detection of 80 pg mL−1 well below the MRL of 1 ng mL−1 [36].
Clindamycin releasing bionanocomposite hydrogels as potential wound dressings for the treatment of infected wounds
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Saba Delir, Mohammad Sirousazar, Farshad Kheiri
In the past researches, PVA-based hydrogels have been successfully prepared via different techniques and their performances evaluated as novel wound dressings in the wound and burn management. Nesovic et al. [30] prepared PVA/chitosan hydrogel wound dressings via the freezing-thawing cyclic technique for the treatment of infected wounds. The prepared hydrogel wound dressings were served as excellent carriers for the controlled release of silver nanoparticles, as antibacterial agents. The prepared PVA-based hydrogel wound dressings were nontoxic and their excellent antibacterial activity against Staphylococcus aureus and Escherichia coli strains were proved. Silver nanoparticles release profiles indicated burst release behavior, which is beneficial for wound dressing applications. Feiz and Navarchian [31] prepared PVA hydrogel films containing chitosan and modified MMT through the phase separation method for wound dressing applications. They studied the microstructural properties of the prepared hydrogel wound dressings and also investigated the effects of MMT content on their gel fraction, water vapor permeability, water uptake and tensile/rheological properties. The prepared wound dressings were also loaded with nitrofurazone and their drug release behavior was studied at the simulated wound conditions. The nitrofurazone loading and release rate showed a dependency on the quantity of MMT incorporated into the wound dressing. In addition, a Fickian diffusion mechanism was found for the nitrofurazone release from the wound dressings. Baron et al. [32] fabricated hydrogel wound dressings on the basis of PVA and oxidized polysaccharides (cellulose and pullulan). The resulted hydrogel wound dressings were investigated using spectral and microscopic techniques and their rheological and swelling properties analyzed. The prepared hydrogel wound dressings were also loaded with L-arginine as an amino acid involved in the synthesis of collagen, re-epithelialization and tissue reorganization. They concluded that the PVA-based L-arginine loaded hydrogel wound dressings can be used as sponges to treat heavily scarred wounds, burns or other skin conditions. Another PVA-based hydrogel wound dressing was prepared by Tao et al. [33] by blending the silk sericin with PVA through the repetitive freezing-thawing process. The prepared hydrogel wound dressing exhibited the ability to load and release antibiotics, such as gentamicin for the treatment of infected wounds. Cytotoxicity and immuno-toxicity assays suggested the gentamicin loaded hydrogel wound dressing had an excellent cytocompatibility on mammalian cells. Bacterial inhibition assay and wound infection model demonstrated the gentamicin loaded hydrogel wound dressing could effectively inhibit the bacterial growth and maintain cells viability.