Cultural heritage (CH) relics are irreplaceable records of human civilization, encompassing diverse historical, technological, and artistic achievements. Extracting their structural and compositional information without affecting their physical integrity is a critical challenge. This review summarizes recent advances in non-destructive techniques (NDTs) for CH analysis and emphasizes the balance between the depth of analysis and conservation ethics. Techniques are broadly categorized into spectrum-based, X-ray-based, and digital-based methods. Spectroscopic techniques such as Fourier transform infrared (FTIR), Raman, and nuclear magnetic resonance (NMR) spectroscopy provide molecular-level insights into organic and inorganic components, often requiring minimal or no sampling. X-ray-based techniques, including conventional and spatially resolved XRD/XRF and total reflection XRF (TRXRF), provide powerful means for crystal and elemental analysis, including in situ pigment identification and trace material analysis. Digital-based methods include high-resolution imaging, three-dimensional modeling, data fusion, and AI-driven diagnosis to achieve the non-invasive visualization, monitoring, and virtual restoration of CH assets. This review highlights a methodology shift from traditional molecular-level detection to data-centric and AI-assisted diagnosis, reflecting the paradigm shift in heritage science.

A comprehensive evaluation of collagen-based historical artifacts is crucial for the preservation and inheritance of cultural relics, necessitating interdisciplinary approaches that integrate scientific knowledge with practical expertise to develop effective conservation strategies. The present work was focused on a piece of historical leather armor housed in Turpan Museum, Xinjiang, China. SEM–EDS, XRD, ATR-FTIR, and NMR were carried out on this historical leather armor from macro and micro perspectives, mainly including morphology observation, composition analysis, structural assessment, which could provide both quantitative and qualitative insights into the deterioration of the historical leather armor. Additionally, the non-destructive sampling methods and the third-generation sequencing technology (TGS) were employed to identify a total of 13 bacterial species and 8 fungal species, and their metabolic pathways were predicted, providing guidance for preventive conservation and restoration strategies. By the present work, necessary fundamental knowledge might be provided for the effective preservation and inheritance of collagen-based historical artifacts. Graphical Abstract

Tanneries are increasingly focusing on environmentally friendly processes, emphasizing the concept of clean production to minimize the environmental impact. This study investigated the eco-friendly application of an α-amylase/neutral protease system (ANS) in a single-step process for unhairing, fiber opening, and bating, providing an effective alternative to the conventional complex chemical-based lime-sulfide system (LSS). A mathematical model was established using response surface methodology (RSM) to optimize the operational conditions, yielding a 0.3 wt% α-amylase/0.5 wt% neutral protease solution at 28.4 °C for 16.6 h. The effects on unhairing and fiber opening were evaluated using scanning electron microscopy (SEM), while the effect on bating was accessed by the removal of carbohydrates and proteoglycans. The obtained leathers had comparable physical properties to their conventional counterparts, with enhanced hydrothermal shrinkage temperature and softness. In terms of environmental benefits, the optimized ANS could significantly decrease more than 90% of the chemical oxygen demand (COD), NH₃–N, and Cl⁻, respectively, along with a 73.91% reduction in total solids (TS). Cost analysis indicated direct savings with a significant cost reduction of 30.98% of the ANS compared to that of the LSS, as well as additional indirect cost reduction through improved production efficiency and streamlined wastewater treatment processes. The use of electricity and water was reduced by 44.6% and 93.9%, respectively, which could reduce greenhouse gas emissions by 44.6%. This study highlighted the potential of α-amylase/neutral protease as a sustainable and cost-effective alternative in leather manufacturing that aligns with environmentally friendly practices.