Acceleration of wound healing can be achieved with the use of wound dressings. Through the electrospinning technique, a polymeric scaffold composed of two layers was processed: a gelatin and polyvinylpyrrolidone layer with gentamicin, and a second layer of cellulose acetate. The conditions for the electrospinning process were standardized for voltage parameters, feed flow and the distance from the injector to the collector. Once the values of the main variables for the electrospinning were optimized, a three-hour processing time was established to allow the separation of the material from the collector. The obtained material was characterized by observations on scanning electron microscopy, Fourier transform infrared spectroscopy and thermal analysis; contact angle measurement was performed to evaluate wettability properties, and antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus were evaluated using the Kirby–Bauer test. The obtained fibers that form the bi-layer scaffold present diameters from 100 to 300 nm. The scaffold presents chemical composition, thermal stability, wettability characteristics and antibacterial activity that fulfill the proposal from this study, based on obtaining a scaffold that could be used as a drug delivery vehicle and a wound dressing material.
1 April 2021 in International Journal of Biological Macromolecules
Contamination caused by heavy metals in wastewater has a high potential of risk because they easily penetrate in to the trofic chain accumulating as organometallic compounds. In this work, the expression of mice metallothionein in E. coli (pMt-Thio) was examined as a strategy to enhance metal biosorption efficiency of bacterial biosorbents for Pb(II) and Cd(II) ions. The results showed that pMt-Thio led to significant increase in overall biosorption capacity, especially for biosorption of Pb. Isotherms and kinetic of biosorption were evaluated in this designed system. The influence of metal concentration in solution is discussed in terms of Langmuir and Freundlich isotherm and constants. The Langmuir model was found to correlate better with the experiment data. The biomass showed maximum capacities according to Langmuir adsorption model of 28.14 mgPb/gpMt-Thio and 24.27 mgCd/gpMt-Thio. The study proved that pMt-Thio is a suitable material for the removal of the heavy metal ions studied from aqueous solutions, achieving removal efficiencies higher than 90% for Pb(II) and higher than 40% for Cd(II), and could be considered as a potential material for treating effluent polluted with Cd(II) and Pb(II) ions.