Antifungal susceptibility of Candida species to copper oxide nanoparticles on polycaprolactone fibers (PCL-CuONPs).

The integration of metallic or ceramic nanoparticles in polymer matrices has improved the antimicrobial and antifungal behavior, resulting in the search for composites with increased bactericidal and antimycotic properties. A polycaprolactone fibers with copper oxide nanoparticles was prepared. Polycaprolactone-copper fibers (PCL- CuONPs) were prepared into two major steps in situ method: (a) Synthesis of CuO particles, then (b) incorporation of polycaprolactone to electrospun process. The first step is the reduction of Cu+2 ions by gallic acid in N,N-dimethylformamide and tetrahydrofuran solution with the simple addition of polycaprolactone in the solution for the second electrospun step. Raman spectra provide information about the nature of the copper oxide synthesized. There are three Raman peaks in the sample, at 294 and 581 cm-1 and a very broad band from 400 to 600 cm-1 which are characteristics bands for CuO. Scanning electron microscopy (TEM) revealed copper oxide nanoparticles with semispherical shapes with diameter 35 ±11 nm. Dynamic light scattering (DLS) analysis showed uniform CuONPs in a range of 88±11 nm. Scanning electron microscopy (SEM) of PCL-CuONps reveled fibers with diameters ranging from 925 to 1080 nm were successfully obtained by electrospinning technique. Orientation, morphology and diameter were influenced by the increment on CuONPs concentration, with the smaller diameter present in samples prepared from low concentrated solutions. The antimycotic applicability of the composite was evaluated to determine the antifungal activity in three species of the genus Candida (Candida albicans, Candida glabrata and Candida tropicalis). PCL-CuONPs exhibit a considerable antifungal effect on all species tested. The preparation of PCL-CuONPs was simple, fast and low-cost for practical application as an antifungal dressing.

Novel Route of Synthesis of PCL-CuONPs Composites With Antimicrobial Properties.

Nanoparticles of metals can be toxic to bacteria, showing biocidal activities at low concentrations. Metal, oxide, or compounds based on copper are applied like antimicrobial agents. The capacity of integration of metallic nanoparticles in polymer matrices has improved the antimicrobial behavior, resulting in the search for composites with increased bactericidal properties. A polycaprolactone (PCL) film polymer with copper oxide nanoparticles (CuONPs) was prepared. Dynamic light scattering analysis showed the sizes from 88 to 97 nm of CuONPs. Scanning electron microscopy (SEM) revealed CuONPs with semispherical shapes with diameter 35 nm. The prepared PCL-CuONPs exhibited a nanoporous structure by SEM. The antibacterial applicability of the composite was evaluated to determine the minimum inhibitory concentration in 6 different bacteria and the experimental tests were carried by disk diffusion and spectrophotometric methods. The PCL-CuONPs exhibit a considerable antibacterial effect in gram-positive bacteria in contrast to gram-negative bacteria. The preparation of PCL-CuONPs was simple, fast, and low cost for practical application as wound dressings.