# Biological and Physicochemical Characterization of Biodegradable Aliphatic Polyesters with Copper Deposited by Magnetron Sputtering

## TL;DR

This paper explores biodegradable polymers with copper coatings for antimicrobial and UV protection properties, suitable for medical and packaging applications.

## Contribution

The study introduces copper-deposited biodegradable polymers as a cost-effective alternative with antimicrobial and UV protection capabilities.

## Key findings

- Copper-coated polymers provided excellent UV protection with UPF > 50.
- Aging processes altered surface properties due to copper oxidation.
- Materials showed antimicrobial activity against Staphylococcus aureus and Escherichia coli.

## Abstract

Biodegradable polymer materials, which reduce the problem of waste and are often produced from renewable raw materials, contribute to sustainable development. The imparting of antimicrobial properties to biodegradable materials represents a significant advantage in a variety of potential applications, including the domain of packaging materials and medical applications. In this study, biodegradable polymer compositions, including polylactide (PLA) and polycaprolactone (PCL), were prepared with copper, which was applied to the polymers using a magnetron sputtering technique. PLA and PCL were selected as representatives of biodegradable polymers of natural and synthetic origin. Copper was used as an alternative to other more expensive metals with antimicrobial properties. The microbiological properties of the samples were examined, the ultraviolet protection factor (UPF) was determined, and the influence of controlled thermo-oxidative and weathering aging on the surface properties of the materials (color, wettability, surface energy, UV-Vis spectra) was analyzed. The UPF values for the PLA and PCL samples containing copper were UPF > 50, so the materials provided excellent UV protection. Thermo-oxidative aging of PCL and weathering aging of PLA influenced the change in color and surface properties (wettability and surface energy) of the composition, resulting from the oxidation of the copper layer deposited on the polymers. Biological evaluation included measurements of prothrombin time (PT) and activated partial thromboplastin time (aPTT) to assess how the synthesized materials influence the intrinsic and extrinsic pathways of blood coagulation, reflecting their potential biomedical relevance. Furthermore, the antimicrobial performance of the obtained samples was examined against representative bacterial strains—Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative)—to verify their ability to inhibit microbial growth and ensure their suitability for use in infection-prone environments.