doctoralThesis
Nanoestrutura plasmônica de ouro e sua aplicação em nanobiotecnologia têxtil: avaliação antimicrobiana e de citotoxicidade
Fecha
2017-03-17Registro en:
SILVA, Iris Oliveira da. Nanoestrutura plasmônica de ouro e sua aplicação em nanobiotecnologia têxtil: avaliação antimicrobiana e de citotoxicidade. 2017. 159f. Tese (Doutorado em Engenharia Mecânica) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2017.
Autor
Silva, Iris Oliveira da
Resumen
Several studies reported on the development of functional textile materials using metallic
nanoparticles. These particles exhibit high reactivity and characteristic properties of
nanometer-scale materials. The main characteristic of gold nanoparticles (NPAu) is the effect
of plasmon resonance, which is a phenomenon that occurs as a consequence of the size
and morphology of nanomaterials. In this work, a functional textile material of biodegradable
fibers of soybean and bamboo was developed, modified with chitosan and functionalized with
NPAu in different concentrations. The objective was to give the substrates bioactive
properties, such as antimicrobial action, and to verify the degree of cytotoxicity in fibroblasts
in vitro. Initially, the soybean and bamboo knitted fabrics were targeted and later modified
with chitosan at varied concentrations in order to obtain the best NPAu depletion result in the
substrates, by K/S result (Kubelka-Munk). Afterwords, the NPAu were incorporated in the
samples through an experimental design 23, aiming to obtain the highest concentration of
nanomaterials in the fibres. The synthesized NPAu were characterized by UV/Vis
spectroscopy, zeta potential, DLS, MET and AFM, techniques that demonstrated
characteristic peaks of absorbance, mean size, morphology and surface charge of gold
nanoparticles. The bioactive samples were evaluated using SEM/EDS, TG and XRF
techniques, which determine the incorporation of NPAu on the surface of the fabrics in study.
In addition, the NPAu adsorption isotherm was studied in the substrates, as well as the
influence of wash fastness and colorimetric values (L * a * b *) in order to verify the color and
chroma variations (ΔE) of the samples before and after successive washes. In addition, the
bioactive properties of the fabrics were verified by quantitative and qualitative antimicrobial
analysis for gram-positive (Staphylococcus aureus) and gram-negative (Klebsiella
pneumoniae), bacterias measuring the immediate quantitative inhibition and/or contact (0
hour) of 89.38% and inhibition over time (24 hours) of 98.22% for S. aureus and 74.14%
inhibition (0 hour) and 96.45% inhibition (24 hours) for K. pneumoniae. Finally, the cellular
viability was studied through NPAu cytotoxicity analysis at 115 μg/ml, where there was a
non-significant reduction in fibroblasts viability (12.55%). According to established analysis, it
can be demonstrated that the functional tissues developed, have a greater potential for
technological and biomedical applications.