While carbon nanotubes have been used for a variety of purposes, it was not known whether they can improve tribological properties of polymers. Polyamide 6 (PA6) has been reinforced with 0.2, 0.5 and 1.0 wt% of multiwall carbon nanotubes (MWCNTs) by melt mixing process and characterized by scanning electron microscopy (SEM), transmission electron microscopy, thermogravimetric analysis (TGA), scratching, sliding wear and tensile testing. TGA results for the air atmosphere show that MWCNTs shift the onset of thermal degradation to higher temperatures. Sliding wear tests show that the penetration depth decreases as the concentration of carbon nanotubes increases. However, the viscoelastic healing is hampered by the MWCNTs presence and the residual depths increase at the same time. Narrower scratch groove widths are seen in SEM for composites with MWCNTs, and scratch hardness increases. Tensile tests show an increase of 27% in the Young modulus value upon addition of 1.0% of MWCNTs. The stress at yield is also higher for the nanocomposites.

Amphotericin B (AmB) is a broad spectrum of antifungal drug used to treat antifungal diseases. However, due to the high toxicity of AmB, treated patients may suffer the risk of side effects, such as renal failure. Nanoencapsulation strategies have been reported to elicit low toxicity, albeit most of them possess low encapsulation efficiency. The aim of this research is to develop micellar delivery systems for AmB with reduced toxicity while maintaining its affectivity by employing retinol (RET)-conjugated amphiphilic block copolymers (ABCs) as precursors. Copolymers composed of poly(ε-caprolactone) (A) and polyethylenglycol (B) of types AB and ABA were synthesized by ring opening polymerization and subsequently conjugated with RET by Steglich esterification. ¹H-NMR spectroscopy was used to corroborate the structure of copolymers and their conjugates and determine their molecular weights. Analysis by gel permeation chromatography also found that the materials have narrow distributions. The resulting copolymers were used as precursors for delivery systems of AmB, thus reducing its aggregation and consequently causing a low haemolytic effect. Upon conjugation with RET, the encapsulation capacity was enhanced from approximately 2 wt % for AB and ABA copolymers to 10 wt %. AmB encapsulated in polymer micelles presented improved antifungal efficiency against Candida albicans and Candida auris strains compared with Fungizone^®, as deduced from the low minimum inhibitory concentration.