A new approach for the development of antimicrobial coatings based on functionalized polysulfone

Introduction

Polysulfone is a high-performance polymer used in the biomedical field due to its thermal, mechanical, and chemical stability and biocompatibility [1]. Its performance is significantly enhanced through quaternization, which imparts antimicrobial activity, hemocompatibility, and hydrophilicity [2]. The present study aims to obtain and characterize coatings based on quaternized polysulfone (QPSF) for medical instruments with broad-spectrum antimicrobial activity by incorporating an antifungal agent, amphotericin B (AmB), and/or an antibiotic, norfloxacin (NFX), into the material’s structure.

Methods

Drug-containing coatings were prepared by mixing QPSF, AmB, and/or NFX in different mass ratios, casting the polymer–drug solutions, and drying at 70 °C for 48 h. The obtained materials were characterized from a structural, supramolecular, and morphological point of view and their surface properties, as well as antioxidant and antimicrobial activities, were also investigated.

Results

¹H-NMR and FTIR spectra of the coatings highlighted the successful incorporation of the drugs into the QPSF matrix, as well as strong physical interactions between the components.

The absence of a specific drug’s reflection in the formulations’ XRD diffractograms suggested their uniform dispersion within the material’s structure, and the polarized optical microscopy images revealed an interface-coupled ordering, attributed to the electrostatic interactions between the positively charged amino groups of the polymer and the electron-rich groups of the drugs.

The surface of the coatings presented a smooth morphology and moderate wettability, with contact angle values ​​ranging from 72 to 93º.

The incorporation of the two drugs into the material structure had a beneficial effect on antioxidant activity, increasing the capacity to inhibit free radicals up to 67 %, improving antibacterial activity, and conferring antifungal activity to the materials.

Conclusion

All these data indicate the application potential of these materials as antimicrobial coatings for surgical instruments.

[1] E.R. Radu, S.I. Voicu, Polymers, 1130, 2022.

[2] O. Dumbrava, A. Filimon, L. Marin, Eur. Polym. J., 112316, 2023.