Desenvolvimento de membranas de poli (εcaprolactona) incorporadas com nano partículas de prata com rota de síntese verde

Abstract

The development of nanofibers through the electrospinning process has a prominent field of study in nanotechnology, due to their unique physicochemical properties and versatile manufacturing capabilities. Electrospinning is a method that uses electrostatic forces to control the dimensions, morphologies, and nano-scale composition of fibers from solutions and polymer blends, which is crucial for optimizing surface properties and functionality. In pharmaceutical applications, nanofibers produced by electrospinning have shown great potential in controlled drug release, a key technique for enhancing therapeutic efficacy and minimizing side effects. Nanofibers can be ingeniously designed to have specific degradation rates, porosity, and functional surfaces. Moreover, the ability to incorporate multiple therapeutic agents within the same fibers opens paths to combined and personalized therapies, marking a significant evolution in the area of drug delivery systems. This dissertation aims to provide a deeper understanding of the underlying technology and its utility, highlighting the control over the properties of fibers with and without therapeutic agents, such as pure PCL fibers, PCL and Sodium Alginate (NaAlg), and PCL and AgNPs synthesized through green synthesis using NaAlg as a stabilizing precursor. The objective of this study is to develop Poly(ε-Caprolactone) (PCL) membranes containing sodium alginate (NaAlg) and silver nanoparticles (AgNPs) as a model drug. The AgNPs were synthesized through sonochemistry (green synthesis route) and the membranes were obtained by electrospinning. Ultraviolet visible (UV-Vis) spectroscopy and Fourier-transform infrared spectroscopy (FTIR) techniques were used to detect the presence of AgNPs in the aqueous solution, and transmission electron microscopy (TEM) was employed to determine the average particle size. To evaluate the morphology of the membranes and visualize the fiber diameter, scanning electron microscopy (SEM) was used. The nanoparticles and membranes were successfully produced, visually showing fine-tuning levels in the applied parameters. In UV-Vis characterization, the characteristic peak of AgNPs was recorded at approximately 420 nm. In FTIR, the chemical characterizations showed no apparent changes with increasing concentrations of NaAlg and AgNP in the membrane. Through TEM, the morphology of the NPs was observed, showing clusters of NPs of different sizes. The electrospun membranes showed morphological differences among them, with PCL + NaAlg and PCL + AgNP fibers showing greater size variation than PCL fibers. Finally, in antibacterial activity, inhibition halos only appeared in liquid AgNP samples at concentrations C1=0.1 M and C2=0.01 M, with diameters of 13 to 15 mm, while the membranes showed no activity.