Não-tecido bicamada produzido por fiação por sopro em solução utilizando borracha natural, poli(ácido lático) e nanopartículas bactericidas para aplicações em curativos de pele

Abstract

The treatment of skin wounds and a fast and effective healing process results in savings on medical costs and also reduces the incidence of functional and aestethical complications. Bilayer membranes are promising materials for usage as wound dressings because its different porous layers simultaneously allow the protection against infections, air and humidity flow, and also promote a favorable environment for cellular adhesion and growth. The natural rubber (NR) is a polymer extensively used in the manufacturing of biomaterials, but very little explored in the production of micro-nanofibers which could compose bilayer nonwovens. This research project proposed the development of a bilayer nonwoven, using NR as one of the components, through the solution blow spinning technique. The produced material is composed of: an inferior layer, destined to the direct contact with the wounded area, made out of a blend of NR, poly(lactic acid) (PLA) and polyethyleneglicol (PEG) at the respective ratio of 2:1:3 w/w; and a superior layer, for external coating of the wound dressing and protection against infections, composed of PLA with incorporated ZnO nanoparticles (NPs), at the tested concentrations of 1%, 2.5% and 5% w/w relative to the PLA, and later aspersion of Ag NPs suspension. It was observed that, although the usage of PEG modifies the inferior layer’s morphology, it presents moderate hydrophobicity, adequate to cellular adhesion (contact angle ranging from 51,95 ± 0,64 to 83,99 ± 2,26 for the samples containing Ag). The usage of PEG combined with ZnO mechanically weakens the material, although the resistance is recovered by increasing the ZnO load, and the Ag NPs provide antimicrobial properties to the material through direct contact. The presence and distribution of Ag and ZnO NPs was confirmed through X-ray energy dispersion spectroscopy, and the absence of chemical reactions between the components was verified through Fourier Transformed infrared spectroscopy. Thus, the nonwoven bilayer could be successfully obtained by a simple and low-cost production process, without the need for chemical modifications of the components, aiming at potential application in wound dressings for skin lesions.