## 4 Discussion  
Four IR absorption features characteristic of polyvinylpyrrolidone macromolecule were selected as spectral markers for polyvinylpyrrolidone in the thin films (Figure 1). These selected IR absorption features were as follows: 2957 cm\({}^{-1}\) (characteristic C-H stretching vibrations) visible in Figure 1 a\({}_{1}\)-a\({}_{6}\); 1672 cm\({}^{-1}\) (the vibration band of the C=O group) evidenced in Figure 1 b\({}_{1}\)-b\({}_{6}\); 1461 cm\({}^{-1}\) (bending vibration of the CH\({}_{2}\) group) shown in Figure 1 c\({}_{1}\)-c\({}_{6}\), and 1291 cm\({}^{-1}\) (the C-N stretching vibration of N-vinyl pyrrolidone) presented in Figure 1 d\({}_{1}\)-d\({}_{6}\). Two absorption bands known as being characteristic of amphoteric in B were selected as spectral markers: 1620 cm\({}^{-1}\) (symmetric stretching vibrations of the hydrogen-bonded C=O group in the non-ionized carboxyl group) exhibited in Figure 1 e\({}_{1}\) and e\({}_{3}\), and 3310 cm\({}^{-1}\) (assigned to the C-N stretching vibrations in the NH\({}_{2}\) group) revealed in Figure 1 f\({}_{1}\) and f\({}_{3}\). The absorption band noted in quercetin dihydrate was selected as a spectral marker--1100 cm\({}^{-1}\) (C-OH stretching vibration)--while the characteristic absorption band of resveratrol was selected as a spectral marker--3400 cm\({}^{-1}\) (OH group) [26]. Two absorption bands known as being characteristic of voriconazole were selected as a spectral marker--1270 cm\({}^{-1}\) (C-F vibration) displayed in Figure 1 e\({}_{2}\), e\({}_{4}\), e\({}_{5}\), and e\({}_{6}\), and 1644 cm\({}^{-1}\) (C=N) as exposed in Figure 1 f\({}_{2}\), f\({}_{4}\), f\({}_{5}\), and f\({}_{6}\).The observed differences in the FTIR spectra are due to different absorption bands specific to each composite configuration: polyvinylpyrrolidone-quercetin dihydrate-ambbtericin B (Figure 2a), polyvinylpyrrolidone-resveratrol-amphotericin B (Figure 2b), polyvinylpyrrolidone-quercetin dihydrate-voriconazole (Figure 2c), and polyvinylpyrrolidone-resveratrol-voriconazole (Figure 2d). FTIR spectra revealed that MAPLE is suitable for preparing polyvinylpyrrolidone-flavonoid-antibiotic composite thin films with chemical structures close to those of the starting materials. Important information was also acquired by AFM analyses. No grain boundaries and a lack of large material agglomerates were observed in the scanned samples. The scans of polyvinylpyrrolidone with quercetin dehydrate, as well as polyvinylpyrrolidone, only showed the highest roughness values (\(>\) 100 nm) and z-ranges (\(>\) 1.4 \(\upmu\)m) among the scanned materials. The thin films that contained resveratrol or amphotericin B showed surface roughness values at the lower end among the scanned  
Figure 6: Graphic representation of fungal growth inhibition diameters obtained in the presence of different thin films. Positive controls—amphotericin B (AmphB), voriconazole (Vor), polyvinylpyrrolidone–voriconazole (PVP-Vor), polyvinylpyrrolidone–ambphotericin B (PVP-AmphB), polyvinylpyrrolidone–quercetin dehydrate (PVP-Q), polyvinylpyrrolidone–resveratrol-voriconazole (PVP-Q-Vor), polyvinylpyrrolidone–quercetin dihydrate-amphotericin B (PVP-R-Vor), polyvinylpyrrolidone–quercetin dihydrate- and polyvinylpyrrolidone–resveratrol-amphotericin B (PVP-R-AmphB), and polyvinylpyrrolidone–resveratrol-amphotericin B (PVP-R-AmphB); Negative control—sterile microscopic slides. samples (Figure 3). The polyvinylpyrrolidone-quercetin dehydrate-amphotericin B sample had the lowest surface roughness and z-range values among all of the scanned samples (Table 1). In the current study, the ability of our biomimetic coatings to inhibit the development of biofilms formed by _C. parapsilosis_ and _C. albicans_, two organisms which are frequently medical device-associated infections, was determined under _in vitro_ conditions. The obtained results were significantly different for the two strains (_p_! 0.001). For _C.