Assessing Label Stability in Oligopeptide-Modified Polymer Filament for Advanced Materials: Ultraviolet Exposure and Biodegradation Study

This study explores the integration of triglycine, an oligopeptide, as a green molecular marker in 3D-printed poly-(1,4-butylene adipate-<i>co</i>-1,4-butylene terephthalate)/polylactide (PBAT/PLA)-based specimens with different printing temperatures to enhance the traceability of (bio)-degradable polymers. This approach supports the advancement of sustainable materials by enabling the identification of the material origin and degradation processes. The research assesses the behavior of the labeled polymer under UV exposure, evaluating the stability of the oligopeptide marker to ensure that the information remains retrievable even after exposure to environmental stressors. In addition, their behavior during aerobic composting, as well as anaerobic digestion, is investigated to promote environmentally friendly practices. This study employed an extraction procedure to isolate and retrieve encoded information, which was then analyzed using a mass spectrometry method, ESI/TIMS-Q-TOF. This makes it possible to determine the sequence of the oligopeptide and compare it with the previously used MALDI-TOF/TOF mass spectrometry procedure. Cytotoxicity studies were also conducted to assess the potential hazards associated with PBAT/PLA-based specimens, considering their potential biomedical applications. The PBAT/PLA-based specimens demonstrated good oligopeptide stability, enabling effective retrieval of recorded information from the green polymer/oligopeptide system even after UV exposure. UV irradiation affected cold crystallization temperature and melting temperature and caused self-chain/cross-linking of the PBAT/PLA-based specimens. In general, the analyses show that specimens printed at a higher temperature (190 °C) have a higher degradation rate than those printed at a lower temperature (155 °C). This phenomenon was attributed to the higher porosity and increased water permeability of the specimens printed at 190 °C, compared to those printed at 155 °C, which is likely due to the greater phase separation and reduced miscibility in the former.